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R/WAR italian deep seismic data
The following is a selected references list (1) with short abstracts, sorted by year.
Operators: A. Gassi (2002) and M. Maistrello (2004-'05)
Reference Type: Journal Article
Record Number: 226
Author: Cassinis, R.
Year: 1958
Title: La
sismica di
rifrazione nella ricerca delle strutture profonde.
Journal:
Quaderni di geofisica
applicata
Volume: XVIII-XIX
Issue: 18-19
Pages: 20-70
Abstract: The limiting factors to the application of
refraction are discussed particularly in case of the exploration for
deep
structures, where long range shots and very low frequancy are involved.
Errors
coming either from ahallow or deep effects are analyzed. Different
field
techniques are described and compared, as well as interpretation
procedures. A
particular attention is given to the problems involved in the
determination of
horizontal displacement and depth when the velocity in the overburden
is a
function of depth or when it is subjected to lateral changes. The
possible
velocity distributions in the overburden are examined according to the
different geological pictures. Comparisons are made between depth
sections
computed assuming straigth or curved paths. Discussion is made about
the
possibility of determining faults through diffraction; an experiment on
a
seismic model is presented. An analytical method of taking into account
the
effect of dip in the determination of the shape of structures is
suggested.
Reference Type: Journal Article
Record Number: 227
Author: Linsser, H.
Year: 1961
Title: The generation of seismic Waves by Explosions.
Journal: Geophysical Prospecting
Issue: special issue 10 years E.A.E.G.
Pages: 54-64
Abstract: In the mathematical treatment of the
propagation of
seismic waves, the process in the medium surrounding the point of
explosion is
introduced as initial condition in to the differential equations. It is
the
purpose of this paper to contribute to the knowledge of this process.
The treatment of
the process of explosion is a difficult one because the elastic limit
is
exceeded in the surroundings of the point of explosion. To gain a
better view
on the acting forces the space concerned is replaced by a simplifying
model. It
is shown that a permanent deformation is caused by the explosion. This
deformation will be especially intensive if the rock does not offer any
resistance to tensile forces.
To determine the
extent of such a permanent deformation a sudden release of pressure -
the
opposite of an explosion - was recorded by seismographs. It has been
proved
that any seismic waves of measurable magnitude are not
produced. This leads to the conclusion that
permanent deformation plays an essential part in the generation of
seismic
waves.
[ top ]
Reference Type: Journal Article
Record Number: 100
Author: Behnke, Claus; Giese, Peter; Prodehl, Claus;
G, De
Visintini
Year: 1962
Title: Seismic refraction investigations in the
Dolomites
for the exploration of the Earth's Crust in the Eastern Alpine Area
1961.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: IV
Issue: 14
Pages: 110-132
Abstract: In September 1961, seismic refraction
investigations
were caried out in the Eastern Alps, under participation of several
Institutes
and organisation of the Osservatorio Geofisico Sperimentale - Trieste.
The
isntruments used and their magnification chracteristics are there
described. The
shotpoit was fixed in the South Dolomitic area; profiles of 130-160 km
legth
proceeded towards West, North and East.
For the
interpretation, the seismograms have been reduced and 'normalized'. To
determine the surfaces of discontinuity, the wave front method had been
used. Details
on the relief of the crystalline basement and of the Moho discontinuity
are
given. Owing to the relatively small charges of explosive, no reliable
data on
other horizons of the Earth's crust could be obtained with sufficient
certainty.
Reference Type: Journal Article
Record Number: 101
Author: Closs, Hans; Morelli, Carlo
Year: 1962
Title: Seismic experiments in the Dolomites (lago
Lagorai)
to investigate the Earth's Crust in the Eastern alpine area.
Journal:
Bollettino di
Geofisica teorica ed Applicata (BGTA)
Volume: IV
Issue: 14
Pages: 99-109
Abstract: The "Sous-Commission des Explosions
Alpines" carried out a series of explosions; the aim of experiments is
described, the choice of a lake as shotpoint is discussed, operational
details
are illustrated, data on seismic parties and instrumentations are
tabulated.
Reference Type: Journal Article
Record Number: 225
Author: Cassinis, R.
Year: 1963
Title:
L'uso dei fenomeni di
diffrazione per l'interpretazione delle faglie nelle prospezioni
sismiche a riflessione.
Journal:
Quaderni di Geofisica
applicata
Volume:
XXIV
Pages:
1-26
Abstract: The importance of diffraction in faults
interpretation was recognized long time ago (1936) but only with the
new
technique of processing records through corrected cross sections a
clear
picture of the phenomena was obtainable. Though attenaution mesurements
are not
possible, because the AGC action of the amplifiers, geometric
interpretation
can be made in the case of good reflected and diffracted events. Both
static
and dynamic corrections are applied and observed diffraction hiperbolae
are
compared to the theoretical patterns.
Common fault types
are examined and the pattern of diffraction predicted when the seismic
line
runs normally to the fault edge. Three seismic bidimensional models are
presented in which the effect of a step simulating a fault is observed.
On the
models, the mesure of the attenuation is possible and the effect of the
different shapes of the faults are clearly visible. An explanation is
given for
avery case.
The more
complicated behaviour of diffracted events is considered when the
seismic
profile is not perpendicular to the fault; the possibility to determine
the
angle between the line and the fault from the shape of the diffraction
hyperbolae is evaluated. Several field examples are shown.
Notes:
Editi dalla Fondazione
Ing. C.M.Lerici e dall'Istituto di Geofisica applicata del Politecnico
di
Milano
Reference Type: Journal Article
Record Number: 99
Author: O'Brien, P.N.S.
Year: 1965
Title: Seismic observations 20 km from explosions in
a
lake.
Journal:
Bollettino di
Geofisica Teorica ed Applicata
Volume: VII
Issue: 26
Pages: 144-164
Abstract: Records of ground motion about 20 km from
explosions
in a lake in the Eastern Italian Alps were made for charges in the
range 5 kg
to 320 kg.
Measurements on both
the shock wave and bubble pulse arrivals agreed well with theoretical
predictions. In particular, body wave amplitudes were proportional to
about W 2/3
and surface wave arrivals were proportional to about W 1/2,
with the
consequence that larger shots produced a smaller proportion of surface
waves. Bottom
shots produced more shear wave and surface wave energy than did a
suspended
shot.
Using the times of
arrival of P and S waves to define the transmission path, and knowing
the
chemical energy in the explosive, their absolute amplitudes were
calculated. In
order to match the recorded amplitudes it was necessary to postulate a
velocity
gradient in the refractor, the amount required is quite consistent with
laboratory measurements on rock samples. The first P-wave
arrival was significantly polarised and this was probably due to a near
surface
velocity gradient.
Reference Type: Report
Record Number: 112
Author: Giese, Peter
Year: 1965
Title:
Versuch einer Gliederung der Erdkruste im nördlichen
Alpenvorland, in den Ostalpen und in Teilen der Westalpen mit Hilfe
charakteristicher Refraktions-Laufzeit-Kurven sowie eine geologische
Deutung.
Institution:
Institut für Meteorologie und Geophysik
Date: 1968
Type of Work: Geophysikalische Abhandlungen
Report Number: Reihe B / Band 2
Abstract: During the last years the crustal structures
of
Central Europe has been investigated by several European geophysical
Institutes. Especially the region of the Alps was studied intensively
by
refraction seismic in cooperation of geophysicists from the countires
adjoining
the Alps.
In this paper a
part of the seismic records of the Institut für Angewandte
Geophysik der
Universität München are interpreted. In order to
complete the results other
measurements already published have been used, too.
many questions
concerning the crustal structure are still unswered. So, for instance,
the
existance of the Conrad-discontinuity is doubtful in many cases and the
sharpness of the Moho-discontinuity is also open to question.
These difficulties
are caused partly by a fixed conception of the crustal structure as a
sequence
of layers separated by discontinuities. Certain velocities are regarded
as
typical for the layers of the crust. In this paper an attempt is made
showing
the existance of a "typical structure" of the time-distance graph. A
typical arrangement of the time-distance curves is more important than
the
values of velocity. First arrivals are of the same importance as later
arrivals. The type of time-distance pgaph published here is very
similar to
those of deep seismic sounding in the UdSSR. Generally the curves in
the
time-distance graph are separated. The use of the commonly applied
equations of
reflection and refraction work for depth determination presumes a
discontinuous
increase of velocity. But the existance of possible transition zones
has to be
investigated. So the method of Herglotz-Wiechert should be used, but as
the
curves are separated this method is not applicable. Therefore an
approximation
method is described valid for reflected waves as well as for
penetrating ones.
In chapter G
refraction profiles of the northern foreland of the Alps, of the
Eastern,
Southern and Western Alps are discussed. The typical arrangement of the
curves
can be found in all the time-distance graphs with small variations
only. In the
range of velocity from 5,0 to 6,6 km/s the increase is countinuous in
average. But
small discontinuities (0,1 km/s) may exist. The discontinuity 6,6/8,2
km/s does
not exist, a continuous transition was found (6-20 km).
.................
omissis ..........................
[ top ]
Reference Type: Report
Record Number: 102
Author: Behnke, Claus; Giese, Peter
Year:
1969
Title:
Bericht über refraktionsseismiche Untersuchungen
1956-1969 zur Erforschung der Erdcruste in den Alpen.
Institution:
Institut für Meteorologie und Geophysik der Freien
Universität Berlin
Abstract:
Der vorlegende Bericht ist Bestandteil des Berichtes
der Arbeitsgruppe "Seismiche Feldmessung und Auswertung" (ASFA) des
Forschungskollegiums Physik des Erdkörpers e.V. (FKPE)
für das Jahr 1968. Er
wird dort unter der lfd. Nummer 4 geführt. Der hier vorgelegte
Bericht umfaßt
die refraktionsseismiche Untersuchungstätigkeit der Jahre 1956
bis 1969 in den
Alpen und enthält ausgewählte Meßdaten,
Bemerkungen zur Krustenstruktur der
Alpen und den Versuch einer geophysikalisch-geologischen Synthese.
Hinsichtlich
der Meßdaten konnte in diesem Rahmen noch keine
Vollständigkeit erreicht
werden.
::::::::::::::::::::::::::
Notes:
FU Berlin Report
Reference Type: Report
Record Number: 160
Author:
Cassinis, Roberto;
Finetti, Icilio; Giese, Peter; Morelli, Carlo; Steinmetz, L.; Vecchia,
O.
Year: 1969
Title: Deep seismic refraction research in Sicily
for
Earth's Crust investigation.
Institution: European Seismological Commission (ESC)
Abstract: From October 2nd to 5th, 1968, a Deep Seismic
Refraction profile was recorded in Northern Sicily, under the
sponsorship of
the European Seismological Commission.
During more tha 10
years of Earth Crust exploration by exploion seismology in the Alpine
Chain an
effective type of international cooperation among the European
Institutes has
grown up and strengthened. This has resulted in training much personnel
and
gathering an efficient but costly common equipment to be employed in
further
explorations on land.
After the success
reached in the Alps, in spite of the complexities and difficulties of
the
Alpine horogenesys in comparison with the extra-alpine cratonic
territories,
the new "Sub-Commission for the explosions in South and West Europe"
decided to extend his activity to the apenninic and mediterranean
territories,
although there exist much more severe problems both in regard of the
technical
organization side, and in respect of the quality of the results and
interpretation.
Only to mention
some of those difficulties, we shall remember that in the Italian
peninsula and
in its major islands, qualified shotpoints cannot be established other
than in
the sea and that, owing to the narrowness of the land, it is not
possible to
find out more than one or two land profiles radiating from a shotpoint.
Moreover, the
geologic conditions limit even more the really possible lines. The
terrains,
generally of recent geologic age, are as a rule sedimentary and soft;
they have
been accumulated in basin of the alpine cycle reaching very large but
much
varied thickness.
......................
omissis .................
Reference Type: Journal Article
Record Number: 229
Author: Berckhemer, H.
Year: 1969
Title: Direct evidence for the composition of the
Lower
Crust and the Moho.
Journal:
Tectonophysics
Volume:
8
Pages:
97-105
Reference
Type:
Journal Article
Record
Number: 161
Author:
Cassinis, Roberto;
Finetti, Icilio; Giese, Peter; Morelli, Carlo; Steinmetz, L.; Vecchia,
O.
Year: 1969
Title: Deep seismic refraction research on Sicily.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XI
Issue: 43-44
Pages: 140-160
Abstract: In 1968 DSS investigation was performed on
Sicily by
a cooperation of French, German and Italian geophysical research
institutions. The
main refraction line was recorded on Northern Sicily using offshore
shots near
Trapani and Catania. A second more widespread line was recorded along
the
Southern coast.
An interpretation
is presented firstly which is founded only on first arrivals. From a
two-layer-model (6.000 m/s vs. 8.000 m/s) results a depth of 38 km for
the
8.000 m/s velocity. Follows a detailed
interpretation based on record sections, which yelds a very complex
crustal
structure. The western part is characterized by a thin sialic Crust
(about 15
km) and a wide zone forming the transition to the Upper mantle. In the
eastern
part of Sicily the sialic Crust has a thickness of 25 km including a
distinct
low velocity layer. A transition layer (7,2 km/s) exists between 25 and
35 km
depth.
Reference Type: Report
Record Number: 13
Author:
Scarascia, Salvatore;
Colombi, Bruno
Year: 1971
Title:
Interpretazione
preliminare del profilo sismico a rifrazione profonda in Calabria.
Institution:
Laboratorio per la
Geofisica della Litosfera (LGL) - CNR
Date: Dicembre 1971
Type of Work: LGL Report
Report Number: LGL-CNR 3
Abstract:
Viene presentata una
interpretazione preliminare del profilo sismico crostale eseguito in
Calabria
nell'Ottobre 1970. Sono esposti i criteri adottati per
l'interpretazione e
vengono forniti i risultati tramite due diagrammi delle
velocità e una sezione
profondità. Gli strati superiori del mantello appaiono
nettamente distinti da
quelli inferiori della crosta; la profondità della
discontinuità di Mohorovicic
risulta compresa tra 39 e 40 km e si riconosce l'esistenza di strati
lenti
intermedi che raggiungono spessori ragguardevoli nelle vicinanze dello
stretto
di Messina. Vengono onfine suggeriti alcuni criteri da seguire per
un'interpretazione più completa.
Reference Type: Journal Article
Record Number: 17
Author:
Giese, Peter; Morelli,
Carlo; Steinmetz, L.
Year: 1971
Title: Main features of crustal structure in western
and
southern Europe based on data of explosion seismology.
Journal:
Tectonophysics
Volume:
20
Issue: 1-4
Pages: 367-379
Abstract: During the past two decades deep seismic
sounding
measurements have been carried out in western and southern Europe,
mainly using
refractiuon method. These investigations were performed partly on a
national
basis but as well within international cooperative programs under the
sponsorship of the European Seismological Commission. ... (omissis...) Very intensive refraction
work has been
carried out in the Alpine area. The maximum crustal thickness found
near the
axis of the negative gravity anomaly is about 55-60 km. Furthermore, a
clear
low velocity layer at a depth between 10 and 30 km has been detected. A
key
position with regard to the geotectonic structure of the Alps is held
by the
zone of Ivrea characterized by a pronunced gravity high. From the
refraction
work it may be concluded that there material of the lower crust and
upper
mantle (7.2-7.5 km/sec) is overlying a layer of extremely low velocity
(5.0
km/sec) which is interpreted as sialic crust.....
Notes: copyryght 1973 by Elsevier; doi:
10.1016/0040-1951(73)90124-8
Reference Type: Journal Article
Record Number: 57
Author: Choudhury, M.; Giese, Peter; Visintini, G. de
Year: 1971
Title: Crustal structure of the Alps: some general
features
from Explosion Seismology.
Journal:
Bollettino di
Geofisica teorica ed Applicata (BGTA)
Volume: XIII
Issue: 51-52
Pages: 211-240
Abstract: A systematic study of the structure of the
Alps by
expolosion Seismology has started since about 15 years. From 15
shotpoints
about 60 profiles have been layed out and the total number of recording
points
is now approximately 1900. In order to elaborate a model of homogeneous
interpretation all material displayed in record sections has been
re-interpreted. To avoid the complexity of correlation only the most
important
phases which could be identified more or less clearly - namely the Pg,
PM (or PMP) and Pn
branch - were used.
A qualitative
picture of the main features of the crustal structure in the Alps is
given in
the contour maps showing the critical distance Dc
of PM,
the corresponding reduced traveltime tc, the crossover distance Dd
between
Pn
and V=6 km/s, and the Pn velocity. Dc,
tc
and Dd
reproduce approximately the general contours of the
Alps.
The
methods applied for depth
calculation include the possible existance of velocity gradients as
well as low
velocity layers. Transition zones are indicated by a stronger curvature
of the
reversed segment, whereas a low velocity zone can be detected by
parallel
traveltime curves. The velocity distribution is displayed in the form
of cross
sections with lines of equal velocity.
The
main results are the
following ones:
1)
the Crust in the Alps has
a maximum thickness of about 50-60 km under their axis;
2)
the lower Crust and/or the
transition from Crust to Mantle is thicker than in the foreland;
3)
in general there exists an
extensive velocity inversion under the Alps;
4)
in the Western Alps the
low-velocity zone extends eastwards under the high-velocity material
(7.2 km/s)
of the Ivrea zone which is characterized by a strong gravity high. But
on the
eastern side the high velocity material of the Ivrea body has a direct
link to
the transition zone between Crust and Mantle under the Po Plain.
Reference Type: Journal Article
Record Number: 228
Author: Giese, P.
Year: 1972
Title: The special structure of the PmP traveltime
curve.
Journal:
Zeitschrift für Geophysik
Volume:
38
Pages:
395-405
Reference
Type:
Journal Article
Record
Number: 98
Author:
Finetti, Icilio;
Morelli, Carlo
Year: 1972
Title: Deep seismic refraction exploration on
Eastern Alps.
Journal:
Bollettino di
Geofisica teorica ed Applicata
Volume: XIV
Issue: 53-54
Pages: 59-66
Abstract: On June 1966 it has been recorded a deep
seismic
refraction profile along the line Trieste-Eschenlohe (Germany), with
shots in
Trieste Gulf and Doberdò Lake. The position of the profile
was suggested by the
future possibility to reverse it by recording of big explosions that
sometime
are produced by mining activity at Eschenlohe.
The missing
opportunity to operate the reversing of the profile suggested to the
AA. to
present now the yet acquired results.
Among the various
obtained seismograms, it was selected that (28) having better energy
and more
reliable correlations. The interpretation of these seismograms brought
to the
identification of two direct waves (transversal and longitudinal) on
the
outcropping or shallow limestone sequence (Vs=3.10 km/s; Vp=5.85 km/s),
and
three refractors having respectively the speed of 6.20, 7.00 and 8.00
km/s, and
the depth of about 12, 28 and 45 km. The last one correspond to the
Moho
discontiuity, while the other two have more uncertain attribution.
Reference Type: Report
Record Number: 158
Author:
Colombi, Bruno;
Scarascia, Salvatore
Year: 1973
Title:
Particolari criteri
interpretativi dei profili di sismica crostale - Calcolo diretto
Institution:
L.G.L. - CNR
Date: April 26-27, 1973
Type of Work: IGL Report
Abstract: Gli
eventi sismici che
sono più facilmente correlabili negli esperimenti di sismica
a rifrazione
profonda per lo studio della crosta terrestre, sono quelli che si
riferiscono
alle cosiddette "onde di penetrazione": il percorso di tali onde
coincide con quello del raggio rifratto in corrispondenza del "punto
critico" ed è caratterizzato pertanto da una maggiore
energia.
Gli
impulsi relativi alle onde di penetrazione si
allineano, nel diagramma tempo-distanza, secondo tratti curvi; il
valore della
tangente in un punto di dette linee corrisponde alla
velocità dello strato
situato alla profondità di massima penetrazione del raggio
che emerge in quello
stesso punto.
I
tratti di dromocrone possono presentare velocità
crescenti con le distanze (tratti "diretti") oppure velocità
decrescenti con l'aumentare della distanza (tratti "inversi").
L'interpretazione conduce alla determinazione della
velocità, funzione della
profondità, nell'ipotesi di stratificazioni isotrope nel
senso orizzontale.
I
diagrammi tipici della crosta terrestre
presentano un primo tratto di solito del tipo "diretto", ed uno o
più
tratti successivi del tipo solitamente "inverso. Tra i vari tratti
esistono poi dei ritardi di tempo, che si interpretano come strati
"lenti", cioè come strati con velocità minori di
quelli sovrastanti.
L'esistenza
di tali strati lenti comporta un certo
grado di indeterminazione nell'interpretazione degli strati sottostanti.
........................ omissis
.............
Notes:
Riassunto della
comunicazione presentata al Congresso AGI, CNR (RM), 26-27/4/1973
Reference Type: Journal Article
Record Number: 41
Author:
Colombi, Bruno; Giese,
Peter; Luongo, Giuseppe; Morelli, Carlo; Riuscetti, Marcello;
Scarascia,
Salvatore; Shutte, K.G.; Strowald, J.; Visintini, G. de
Year: 1973
Title: Preliminary report on the seismic refraction
profile
Gargano - Salerno - Palermo - Pantelleria (1971).
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XV
Issue: 59
Pages: 225-254
Abstract: In 1971, a deep seismic sounding refraction
profile
was carried out in Southern Italy in order to investigate the
transition
between the continental and the oceanic crustal structure. The
recording
stations were located in Southern Italy - between the Gargano
promontory and
the Gulf of Salerno - in Sicily - between Palermo and Menfi at the
southern
cosat - and on the island of Pantelleria. The shots were fired in the
Tyrrhenian Sea and in the Channel of Sicily. By aid of some refraction
buoys,
laid out in the Tyrrhenian Sea, attempts were made to get near surface
information on the oceanic crust. This research program was carried out
in
close cooperation of Italian and German Geophysical Instituions, under
participation of a French group.
Between Pantelleria
and southern coast of Sicily, a typical continental crust is existing,
indicated by a strong velocity increase from 6.3 to 8,0 km/s in a depth
range
between 20-21 km. A moderate crustal low velocity layer showing a
maximum
decrease of about 1.0
km/s could be
detected. The maximum crustal thickness is reached under Sicily with
about 35
km.
At the transition
to the deep sea region of the Tyrrhenian Sea, velocity values of 7-8
km/s
(crust/mantle boundary) were measured in 20-25 km depth.
The cross section
between the shelf edge and the coast near the Gulf of Salerno shows a
crustal
thickness of about 20 km. Because of the existance of a crustal low
velocity
layer and an upper mantle velocity of about 8.0 km/s, this part of the
crust
may be classified as a continental one.
When moving in the
NE-direction, the typical oreviously observed crust/mantle reflections
become
less clear, but a later distinct phase in greater distance appears,
indicating
a deeper interface at about 45 km depth. These two high velocity layers
(30 km
an 45 km) are separated by an intensive low velocity zone.
The internal
crustal structure under the depression of NE-Puglia near Foggia,
situated
between the Apennine and the Gargano promontory, remains unknown due to
the unfavourable
distances between shotpoints and receivers.The total crustal thickness
is about
35-40 km. Under the Gargano promontory, a velocity distribution is
assumed
similar to that in the platform of Puglia where a typical continental
crust of
32 km thickness has been found.
Reference Type: Journal Article
Record Number: 3
Author: Hirn, Alfred; Steinmetz, L.; Kind, Reiner;
Fuchs,
Karl
Year: 1973
Title: Long Ragne Profiles in Western Europe: II.
Fine
structure of the Lower Lithosphere in France (Southern Bretagne).
Journal:
Zeitschrift fur Geophysik
Volume: 39
Pages: 363-384
Abstract: This is an account of the inversion of P-wave
observations from the lower lithosphere obtained on a long-range
profile
through France in 1971. A brief description is given of technical
essentials of
the field operation: 60 mobile stations have been employed as a mobile
array
with close detector spacing. In the second part, the P-wave
observations are
described and discussed with the help of record sections (foldout). The
close
station separation of only 5 km allowed the correlation of two phases
following
Pn in a distance range from 300 to 600 km with phase velocities of
8.1-8.3 and
of 8.3-8.6 km/sec. In the third part the joint inversion of traveltime,
phase
velocity and amplitude data with the help of synthetic seismograms is
described
in detail....
Notes:
Institut de Physique du Globe, Paris, Contribution No.
72;
University of
Karlsruhe, Geophys. Inst., Contribution No. 162.
Reference Type: Journal Article
Record Number: 153
Author:
Colombi, B.;
Scarascia, S.
Year: 1973
Title:
Sulla interpretazione
dei profili sismici crostali. calcolo diretto della funzione
Velocità-Profondità.
Journal:
Rivista Italiana di
Geofisica (cont. di Geofisica e Meteorologia)
Volume: XXII
Issue: 3-4
Pages: 213-226
Abstract: The deep seismic sounding experiments lead to
the
velocity-depth function determination. The interpretation is based on
the
seismic events generated by penetrating waves and makes use of a crust
schematization which foresees the subdivision of the crust itself into
a number
of horizontal layers within each one of them a linear velocity
variation is
assumed. The general relationships which connect the horizontal shifts
of the
seismic rays and their travel-times to the layers' characteristics
(i.e. depth,
thickness and velocity gradient), are firstly resumed. They allow to
calculate,
from a known velocity-depth function, the corresponding travel-time
curves; for
interpretation an iterative best fitting process, starting from a first
approximation model of the crust, is employed. Afterwards the paper
illustrates
a mothodology for calculating directly from the observed data the
velocity-depth function, by the aid of a computer. The concept is to
solve each
layer starting from the uppermost one and going on in an orderly way to
the
lower layers, by means of the same above-mentioned formulas, expressed
in depth
terms.
The direct calculus
can be carried out as far as the travel-time curves are continuous. In
the
presence of a discontinuity (time-delays between two correlation-lines
probably
due to velocity inversion), it is necessary to solve the low-velocity
layers
before proceeding to the lower layers calculation. The solution of
layers with
velocity inversion is indetermined; an appropriate methodology for the
direct
calculation of thickness and minimum velocity value for any assumed
velocity
distribution is given. Some possible solutions are examined and the
conclusion
results that the low-velocity layers indetermination involves a limited
influence on the lower layers calculation. The indeterminations due to
some
incomplete correlation-lines are examined too, with the same conclusion
of a
good approximation of the results.
Reference Type: Journal Article
Record Number: 146
Author:
Scarascia, Salvatore
Year: 1974
Title:
Evoluzione e ruolo
della Sismica crostale in Italia
Journal:
Memorie della Società
Geologica Italiana
Volume: XIII
Issue: 2 (suppl.)
Pages: 97-112
Abstract: In the frame of the European Seismological
Commission's programme, several deep refraction profiles (D.S.S.) have
already
been carried out in Italy.
At this point some
considerations can be made regarding the importance of this geophysical
method
in studying the Earth's Crust in the Italian Region.
The level expertise
achieved in our country is illustrated in relation to operative
procedures and
interpretation techniques. For this purpose, a number of velocity-depth
functions concerning particular geological situations in Southern Italy
are
shown; by means of up-to-date interpretation criteria used one can
observe how
the models of Earth's Crust are richer in details, and, in some regards
at
least, different from the classical ones. One depth-section taken in
the area
which crosses the zone from the Apennines to the Tyrrhenian basin
offers a
clear example of how research on the Earth's Crust can contribute to
the study
of large geological structures and their evolution.
Lastly, some
forecasts about possible developments in the method, both in the
operative
field and in data interpretation, are advanced. The latter could be
improved
considering, for example, the dynamic features of seismic ecents and
other
types of waves. Moreover, the utility of a possible integration of the
seismic
data with those coming from other geophysical method is proposed.
In conclusion, one
can affirm that, while on one hand the obtained results confirm the
validity of
the method, on the other hand they are, at this point, not complete
enough to
permit a systematic study of a Region, such as the Italian one, at the
center
of large geological events. It is for this reason that the continuation
of
seismic experiments is recommended and the necessity for grater
collaboration
between geophysical and geological components of research is pointed
out.
Reference Type: Report
Record Number: 52
Author: Cassinis, Roberto
Year: 1974
Title: Crustal investigations in Italy: the
contribution of
active seismology.
Institution: Geophysical institute
Abstract: 1) Active seismology or explosion seismology
has
been since 20 years the main tool for crustal investigations.
Outstanding
results were reached through International Cooperation programmes (IGY,
CUMP);
ultimately, the research has received a new strong impact by the
Geodynamic
Project.
It is well known
the importance of the results achieved all over the world in defining
both the
continental and oceanic crust, detailing the properties of the crustal
materials as well as those of the upper mantle.
The isostatic
theory was proved and a new dimension has been given to tectonophysics.
The investigations
in the Mediterranean area started later than those in Continental U.S.,
in
Oceans, on the Siberian Plateau and even in Northern Europe. This is
due,
partly to the lack of equipment and funds, partly to the difficulty of
the
problems involved. In 1954 the General Assembly of the IUGG adopted a
resolution requesting the Governements of the Countries surroundings
the Alps
to contribute to the study of the deep alpine structure. From that time
the
investigations have been continously intensified over the whole
area.....
Notes: Summary of a lecture held by the Author at
Aarhus
University, Laboratoriet for Andvendt Geophysik.
Reference Type: Journal Article
Record Number: 163
Author:
Colombi, Bruno; Giese,
Peter; Luongo, Giuseppe; Morelli, Carlo; Scarascia, Salvatore; Schutte,
K.G.;
Strowald, J.; Visintini, G. de
Year: 1974
Title: Preliminary report
on the sesmic refraction profile Gargano - Salerno -
Palermo -
Pantelleria (1971).
Journal: Bulletin of the Geological Society of Greece
Volume:
X
Pages:
39-42
Abstract: In 1971, a deep seismic sounding refraction
profile
was carried out in Southern Italy in order to investigate the
transition
between the continental and the oceanic crustal structure. The
recording
stations were located in Central Italy - between the Gargano promontory
and the
Gulf of Salerno - on Sicily - between Palermo and Menfi at the Southern
Coast -
and on the island of Pantelleria.
The shots were
fired in the Tyrrhenian Sea and in the Channel of Sicily, being spaced
5 km on
an average. By aid of some refraction buoys, laid out in the Tyrrhenian
Sea,
attempts were made to get near surface information of the oceanic
crust. This
research program was carried out in close cooperation of Italian and
German
geophysical institutions under participation of a French group.
Reference Type: Report
Record Number: 149
Author:
Scarascia, Salvatore
Year: 1975
Title:
Indagini crostali in
Italia e programma orientativo pluriennale.
Institution: IGL-CNR
Date: October 23, 1975
Report Number: 30
Abstract: Le
indagini crostali
in Italia, mediante la tecnica dei profili a rifrazione profonda, si
inquadrano
perfettamente nel programma finalizzato della 'Geodinamica', laddove si
ravvisa
l'opportunità che l'Italia partecipi attivamente al
programma Internazionale
del "Geodynamics Project" e la necessità di questo tipo di
ricerca di
base, indispensabile per un corretto inquadramento scientifico delle
ricerche
maggiormente applicative. In particolare queste indagini hanno
l'obiettivo
della ricostruzione delle strutture crostali e della loro dinamica,
anche in
rapporto con le strutture dei terreni di copertura. La
necessità di un
programma pluriennale, anche se redatta nelle sue linee generali,
risulta poi
ovvia quando si vogliano coordinare i mezzi a disposizione ed evitare
la
dispersione degli sforzi.
Questi
appunti preliminari sono un riassunto dello
stato delle indagini crostali in Italia e indicano un possibile
programma di
sviluppo. Essi non considerano le esplorazioni sulle Alpi, che sono
state
condotte secondo il programma internazionale della Commissione
Sismologica
Europea, ma si riferiscono solamente a quelle nell'Italia peninsulare
(appennini) che possono essere inquadrate in un programma nazionale. In
effetti
gli Istituti italiani che si interessano a questo tipo di ricerca
raggruppano
ormai un numero sufficiente di mezzi ed hanno acquisito un'adeguata
esperienza
per operare indipendentemente dai programmi internazionali.
La
fig. 1 mostra i profili sismici eseguiti a
tutt'oggi nell'Italia peninsulare. Essi sono concentrati in Italia
meridionale
(Sicilia, Calabria, Puglia) e sull'arco dell'Appennino settentrionale,
tra le
direttrici Elba-Ancona e Chiavari-Piacenza.
......................omissis
Notes:
Rapporto IGL-CNR n. 30
Reference
Type:
Journal Article
Record
Number: 171
Author:
Morelli, Carlo; Giese,
Peter; Cassinis, Roberto; Colombi, Bruno; Guerra, Ignazio; Luongo,
Giuseppe;
Scarascia, Salvatore; K.G.Schutte
Year: 1975
Title: Crustal structure of Southern Italy. A
seismic refraction profile between Puglia - Calabria - Sicily.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XVII
Issue: 67
Pages: 183-210
Abstract: In continuation of the investigations of the
Earth's
Crust in southern Italy a refraction seismic program was carried
through
between the southern part of the Adriatic Sea and Sicily. The recording
station
were located in Southern Puglia, Calabria, on the Eolian islands and in
the
eastern part of Sicily. The shots were fired in the Adriatic Sea, the
Gulf of
Taranto and in the Tyrrhenian Sea. This research program was carried in
1972
through in close cooperation of Italian and German Geophysical
Institutions.
The platform of
Puglia, being the foreland of the Apennines system has a typical
continental
crust, indicated by a crustal thickness of 28-30 km and a moderate low
velocity
layer in a depth of about 8 km.
Under the Gulf of
Taranto, the foredeep of the Orogene, the Crust/Mantle boundary lies at
a depth
of about 30 km and dips in the direction of the Calabria Massif. Here
the total
crustal thickness amounts to 40-45 km. In the Sila region at a depth of
about
20 km, high-velocity material is detected, which is underlain by a
strong low
velocity layer: an inversed sequence of layering of intermediate and
basic
rocks, lying over sialic material, seems to be present; taht is, the
Calabrian
Massif is formed by a crystalline nappe of a thickness of about 20 km.
An abrupt decrease
in crustal thickness is detected just W of Cosenza with values of about
30 km. The
Crust/Mantle boundary rises in SW direction up to 20 km under the
Tyrrhenian
shelf edge. A low-velocity layer, which is found in the coastal region,
diminuishes in SW direction.
In the region of
the Eolian Islands the crustal thickness reaches no more than 16 to 18
km. Because
of the existance of a crustal low velocity layer and a quite normal
upper
Mantle velocity of 8.0-8.2 km/s, this part of the Crust may be
classified as a
continental one.
A further detailed
interpretation of the records on the line Eolian Islando to Sicily will
reveal
wheter there esists a similar structure as under Calabria.
Reference Type: Journal Article
Record Number: 140
Author:
Aric, Karl; Giese,
Peter; Miller, Hans; Morelli, Carlo; Nicolich, Rinaldo
Year: 1976
Title: Crustal structure and seismicity of Northern
Italy.
Journal:
Bollettino di
Geofisica teorica ed Applicata (BGTA)
Volume: XIX
Issue: 72
Pages: 273-278
Abstract: The Friuli area is situated in a region where
the
Dinarides split off from the Eastern Alps. Besides, this region is not
far from
the eastern end of the Alps and the transition to the Carpathians and
the
Pannonian basin. Each of these tectonic units has its own typical
crustal and
upper mantle structure, and the structure at the joining point has to
be seen
within the pattern of the surrounding mountain system.
In the eastern part
of the Southern Alps, this unit chenges its tectonic behaviour. In
respect to
the Alps it acts as hinterland, with regard to the Dinarides it begins
to
behave as foreland.
..........................
omissis .............
Notes: Proceedings of the Intern. Meeting on the
Friuli
Earthquake, Udine, Decembre 4-5, 1976; section I: Seismology -
Geophysics -
Geology
Reference Type: Book Section
Record Number: 159
Author: Giese, P.; Prodehl, C.
Year: 1976
Title: 4. Problems of evaluation of
seismic-refraction data
for Crustal and Upper-Mantle studies.
Book Title: Explosion Seismology in Central Europe. Data
and
Results
Editor: P. Giese, C.Prodehl and A.Stein
Publisher: Springer-Verlag
City: Berlin (D)
Volume: 1
Number of Volumes: 1
Pages: 129-145
Abstract: This chapter deals with methods of evaluation
of
deep-seismic sounding data. The procedure of data interpretation starts
with
the presentation of the data observed and ends with the display of a
cross
section which can reversely generate the primary observations. This
procedure
passes through several stages and it is quite evidente that the final
stage can
be reached only in a more or less satisfactory approximation. This
chapter
contains contributions to some problems of evaluation of deep-seismic
sounding
data.
The first basic
task should be the presentation of the observed data. This topic has
already
been discussed in Chapter 3. The next step of evaluation concerns the
correlation of wave groups in the record sections. Just this task is
the most
critical step of the whole procedure, and some basic problems are
discussed in
4.1.
As an intermediate
step in the interpretation process, methods may be useful that allow
the
presentation of traveltime in a form which already reflects
qualitatively the
main features of crustal structure including their lateral variations.
4.2
shows some possibilities for this task.
............................
omissis ..................
Reference Type: Journal Article
Record Number: 2
Author: Bandford, D.; Faber, S.; Jacob, Brian;
Kaminski,
Werner; Nunn, K.; Prodehl, Claus; Fuchs, Karl; King, Reiner; Willmore,
P.
Year: 1976
Title: A Lithospheric seismic profile in Britain - I
-
Preliminary results.
Journal: Geophys. Journal of the R.A.S.
Volume: 44
Pages: 145-160
Abstract: The planning, execution and preliminary
results of a
major Anglo-German explosion seismic project are presented in this,
paper I of
a series. The Lithospheric Seismic Profile in Britain (LISPB) was
planned as a
reversed 1000 km line between two major sea-shot points off Cape Wrath
in
Scotland and one in the English Channel; additional sea-shots and
intermediate
land-shots were fired to give reversed and overlapping crustal coverage
(to
180-400 km distance) along the line. In all, 29 shots were fired and 60
mobile
mag. tape stations recorded three-components of ground motion. The
resulting 14
crustal and 3 long-range profiles have observations at intervals of
typically
2-4 km. Recordings have been digitized and 4 examples of filtered,
computer-plotted record sections are presented to illustrate data
quality....
Notes: Deutsche Forshungsgemeinshaft (German
Research
Association): contribution No. 182.
University of
Karlsruhe, Geophys. Institute; contribution No. 121.
Reference Type: Journal Article
Record Number: 168
Author: Miller, H.; Group, and Alpine Explosion
seismology
Year: 1976
Title: A Lithospheric seismic profile along the Axis
of the
Alps, 1975. I: first results.
Journal:
Pageoph.
Volume:
114
Pages: 1109-1130
Abstract: From 8 to 20 September 1975 refraction
seismic
measurement were carried out in close European cooperation on a long
range
profile along the strike of the Alps between France and Hungary.
The execution and
first results of the Alpine Longitudinal Profile (ALP) 1975 are
presented in
this paper, which is the first of a series, 20 shots from 9 different
shotpoints were recorded by 193 mobile stations along a main line of a
length
of 850 km as well as on a number of fans and additional shorter
profiles.
The recordings were
subsequently digitized and a number of computer generated record
sections are
presented to illustrate the quality of the data. First results are
given in the
form of a simple crustal cross section along the main profile and of
two
velocity depth functions, which indicate a substantial difference in
type
between the westernmost part and the eastern part of the profile.
Reference Type: Conference Proceedings
Record
Number: 4
Author:
Morelli, Carlo; Giese,
Peter; Hirn, Alfred; Colombi, Bruno; Eva, Claudio; Guerra, Ignazio;
Letz, H.;
Nicolich, Rinaldo; Reichert, C.; Scarascia, Salvatore; Wigger, Peter
Year: 1976
Title: Seismic investigations of Crustal and Upper
Mantle
structure of the Northern Apennines and Corsica
Conference Name: International
Symposium on the
structural History of the Mediterranean Basins
Editor: Eds., B. Buu-Duval & L. Montadert
Publisher: Technips Editions, Paris, 1977
Conference Location: Split
(Yugoslavia)
Number of Volumes: 1
Pages: 281-286
Abstract: In 1974, the crustal structure between
Corsica and
the Northern Apennines was investigated by seismic refraction
measurements
within a French, german and Italian cooperation. Corsica shows a
typically
continental Crust, 30 km thick. Elba and the NE Ligurian Sea are
characterized
by two discontinuities, both having the properties of a crust/mantle
boundary. The
deeper boundary (40-50 km) belongs to the Corsica-Sardinia block
whereas the
shallow one (15-25 km) must be associated with the Adriatic microplate.
Reference Type: Conference Proceedings
Record Number: 32
Author: Scarascia, Salvatore; Group), (Italian
Explosion
seismology
Year: 1976
Title: A deep seismic sounding across the Eastern
Alps
(from Vicenza to Innsbruck)
Conference Name: 15th General
Assembly of E.S.C.
Editor: ESC
Conference Location: Krakow
Abstract: This presentation deals with the first
results of
the seismic profile n.6 ('H-D') explored in September 1975, in the
frame of the
'ALP' Project.
The ends of the
profile H-D are the shot point 'H', located in the 'Colli Euganei'
region nera
Vicenza (N.E.Italy) and shot point 'D', located in Thorsee lake, near
Innsbruck
(Austria).
Its length is about
230 km and it was explored employing about 30 mobile recording
stations. Moving
these stations about 60 recordings were obtained for each shot point.
The mean
distance between recordings resulted about 4 km.....
Reference Type: Journal Article
Record Number: 12
Author: Morelli, C.; Cassinis, R.; Giese, P.; Rower,
P.
Year: 1977
Title: Structure of the Lithosphere of the Italian
Peninsula.
Journal: Publication of the Geophys. Institute of Pol.
Acad.
of Sciences
Volume: A-4
Issue: 115
Pages: 451-456
Abstract: In 1973 a long-range seismic refraction
profile was
carried out along the Italian Peninsula between Puglia and Tuscany.
Four large
shots were fired offshore Puglia which were observed up to a distance
of about
600 km. The Pn-group is split into three separated branches. The first
dies out
at about 250 km distance. The second curve, between 325 and 425 km,
reveals a
reflector depth of 82 km (8.25 to 8.45 km/s). The third branch,
observed
between 450 and 600 km, gives a depth of 110 km (8.46 to 8.60 km/s). A
strong
low-velocity zone could be detected between the M-discontinuity (30 km)
and the
83-km discontinuity. A weak inversion zone exists, too, between 82 and
110 km
depth.
Reference Type: Journal Article
Record Number: 169
Author:
Morelli, Carlo; Giese,
Peter; Carrozzo, Maria T.; Colombi, Bruno; Guerra, Ignazio; Hirn,
Alfred; Letz,
H.; Nicolich, Rinaldo; Prodehl, Claus; Reichert, C.; Rower, P.; Sapin,
M.;
Scarascia, Salvatore; Wigger, Peter
Year: 1977
Title: Crustal and Upper Mantle structure of the
Northern
Apennines, the Ligurian Sea and Corsica, derived from seismic and
gravimetric
data.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Issue: 75-76
Pages: 199-260
Abstract: In 1964, the crustal structure between
Corsica and
the Northern Apennines was investigated by seismic refraction
measurements
within a French, German and Italian cooperation. This offers the
possibility to
discuss the structure of this area involving also other geophysical
methods.
The first paper (Morelli
and Giese) outlines the general aim of this project and prevents some
technical
data. The second report, given by Nicolich, deals with seismic
reflection data
of the area under study which completes the picture in the uppermost
part of
the crust. Some time-contour (base of the Plio-Quaternary, base of the
upper
Miocene, top of the crystalline basement) delineate the structure of
the
sedimentary cover under the Ligurian Sea. The next three papers,
presented by
Colombi et al., Letz et al., Hirn et al., describe the results obtained
by the
seismic refraction project 1974.
The main facts are
the following: Corsica
shows a
typically continental crust, 30 km thick. Elba and the NE Ligurian Sea
are
characterized by two discontinuities, both having the properties of a
crust/mantle boundary. The deeper boundary (40-50 km) belongs to the
Corsica-Sardinia block whereas the shallow one (15-25 km) must be
associated
with the Adria microplate.
Carrozzo and
Nicolich checked the cross-section, derived from the seismic data, by
gravimetric calculations. In general, the seismic results could be
confirmed. In
some cases, minor modifications must be applied. E.g. under Corsica
channel a
small updoming of the crust/mantle boundary must be claimed in order to
compensate the thick sedimentary fill of this graben.
A short
contribution by Rower et al., deals with the results of a seismic
refraction
profile observed in 1966, running from the Massif Mercantour along the
Ligurian
coast. A crustal overlapping for the transition between the Northern
Apennines
and the Western Alps W of Genova could be evidenced.
The last paper by
Giese et al. summarizes the results and contains some geological
remarks.
.......................................... omissis
.............
Reference
Type:
Journal Article
Record
Number:
166
Author:
Miller, Heinz; Gebrande, Helmut; Schmedes, Eberhard
Year:
1977
Title:
Ein verbessertes Strukturmodell für die Ostalpen,
abgeleitet aus refraktions-seismichen Daten unter
Berücksichtigung des Alpen-Längsprofils.
Journal:
Sonderdruck aus der Geologischen Rundschau
Volume: 66
Issue: 2
Pages: 289-308
Abstract: Refraction seismic measurements along the
Alpine
Longitudinal Profile 1975 (ALP-75) yeled among other things data for a
reliable
determination of the velocity-depth distribution beneath the crest of
the Alps.
This velocity-dapth distribution is characterized by a rather thick
inversion
zone in the depth range between 20 and 30 km - which is deeper than
with
earlier models - as well as another less pronounced one in the lower
crust.
A reinterpretation
of the Eschenloe-Southeast profile consistent with these new data
allowed the
development of a two-dimensional crustal model along the line
Eschenloe-Trieste. This model is in excellent agreement with results
from
refraction profiles Eschenloe-East and Lago Lagorai-East. It
furthermore
satisfies travel time observations from aftershocks of the Friulian
earthquake.
Reference Type: Thesis
Record Number: 110
Author: Wigger, Peter J.
Year:
1977
Title:
Ergebnisse refraktionsseismicher messungen in der
Toskana 1974
Academic
Dept.:
Fachbereich Geowissenshaften
University:
Freien Universität
City:
Berlin (D)
Pages:
70 (+ figures)
Thesis
Type:
Diplomarbeit
Abstract:
Im Oktober 1974 wurden in enger Zusammenarbeit zwischen
deutschen, italienischen und französichen geophysikalischen
Instituten
refraktionsseismiche Messungen im Bereich des Nordapennins, auf Elba
und auf
Korsika, im Seegebiet um Korsika und im Ligurischen Meer mit den Ziel
durchgefürt, die Struktur der Erdkruste und des oberen
Erdmantels zu
erforschen.
Die
deutsche
Beteiligung fand im Rahmen des von der Deutschen Forschungssemeinshaft
(DFG)
geförderten Schwerpunktprogrammes "Geodynamik des Mediterranen
Raumes" statt. Weitere Unterstützung für die
Untersuchungen wurde von
italienischen Consiglio Nazionale delle Ricerche (CNR) gewährt.
Gemessen
wurde auf
vier Profilen, die quer zum Apennin verlaufen. Profil 1 und 3 sind
über Korsika
hinhaus verlängert. Die vorliegende Arbeit befaßt
sich mit der Aufbereitung und
Auswertung der Registrierdaten des Profils 3, das durch Korsika, Elba
und
dieToskana verläuft.
Reference Type: Thesis
Record Number: 126
Author:
Carabelli, Claudio
Year: 1978
Title:
Interpretazione
geofisico-strutturale della linea sismica crostale effettuata lungo le
Alpi
meridionali 'SUDALP-77'.
Academic Dept.: Geology
University: Università degli studi
City: Milan (I)
Pages: 100
Thesis Type: Diploma
Abstract: In
ogni campo della
scienza sono rare le nuove teorie che razionalizzino globalmente un
gran numero
di osservazioni e che spieghino tutti i principali aspetti del mondo
fisico.
Una
sintesi di questo genere sembra attualmente a
portata di mano in Geofisica.
Basata
sull'osservazione della distribuzione dei
sedimenti, le faglie, i terremoti, la morfologia dei fondali oceanici,
il campo
magnetico terrestre, è stata formulata una Teoria che
è riuscita a spiegare
molte strutture della superficie terrestre e a chiarire la natura dei
processi
che si svolgono all'interno della Terra. In questo quadro sintetico si
inseriscono gli sforzi della sismica (D.S.S.) quali contributi basilari
per
studiare in dettaglio la struttura della Crista.
In
Europa una delle zone più studiate dal punto di
vista geofisico è rappresentata dall'Orogene Alpino. Alla
luce della moderna
Tettonica a Zolle, la compressione cui è legata la nascita
delle Alpi ha
interessato zolle litosferiche relativamente rigide per uno spessore di
circa
100 km. Solo la porzione pellicolare più esterna
è stata incorporata nel
sistema di coltri che costituisce l'edificio Alpino; il resto della
Litosfera è
finito nell'interno della Terra a profondità di diverse
centinaia di km. Questo
dimostra che il processo di formazione degli Orogeni non può
venire ricostruito
in modo chiaro, basandosi pertanto sulle strutture vicine alla
superficie.
In
questa situazione sono necessari dati più
precisi sulla struttura degli strati più profondi che
rendano possibile una
scelta del più appropriato fra i vari modelli interpretativi
geodinamici
proposti.
In
particolar modo ci si aspetta che questi dati
vengano forniti dalla sismica. La sismica a rifrazione può
soddisfare queste
richieste; però è necessaria una maggior
profondità di penetrazione rispetto
alle ricerche finora effettuate nelle Alpi (fa eccezione il profilo
ALP-'74.
.................. omissis
.........................
Notes:
A.A. 1977-1978;
Relatore: Prof. R.cassinis; Correlatore: Ing. S.Scarascia
Reference Type: Journal Article
Record Number: 30
Author:
Scarascia, Salvatore;
Profili, e Gruppo Italiano Grandi
Year: 1978
Title: Preliminary interpretation of the profile H-D
across
the Eastern Alps.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XX
Issue: 79
Pages: 287-302
Abstract: In the first part, the preliminary
interpretation of
the ALP-1975 DSS experiments along the profile H (Orgiano, VI) - D
(Innsbruck)
has been performed by means of horizontally layered models.
In the second part
a crustal model has been derived by ray tracing techniques and the
trend of the
main discontinuities was further confirmed by a gravimetric model and
the fit
between observed and computed Bouguer anomalies.
Along the
investigated profile the crust is continental-like, but:
I°: North to the
Insubric Line exists a typical Alpine crust, consisting of a thick
upper
crust (~
35 km) with
well-defined velocity inversion; a normal lower crust (~15 km); a
well-defined
crust mantle boundary.
II°: South of
Thiene (VI), the crust consists of a thinner (~25 km) upper crust with
no
velocity inversion, and a thick lower crust (~30 km), in which very
high
velocities (7,6 km/s, 30 km depth, and 8.2 at 53 km depth) could be
found. One
possible explanation calls for a typical crust of the platform type,
with a
soft mantle; another one for a double crust, one with the Moho at 30 km
and the
other one with the Moho at 50 km. In this second case the lower crust
of the
Adriatic microplate would overthrust the lower crust of the European
plate.
III°: Between
Thiene (VI) and the Insubric Line, the crust shows a transitional
structure
between the two types above described.
Reference Type: Book Section
Record
Number: 69
Author:
Giese, Peter; Morelli,
Carlo; Nicolich, Rinaldo
Year: 1978
Title: Review of the crustal structure of the
Northern
Apennines, the Ligurian Sea and Corsica.
Book Title: Alps, Apennines, Hellenides
Editor: Closs H., Roeder D., Schmidt K.
Publisher:
Schweizerbart'sche Verlagsbuchhandlung
City:
Stuttgart
Pages: 221-225
Abstract: In this contribution the results obtained by
seismic
reflection and refraction measurements as well as by gravimetric
studies have
been compiled in order to obtain an overall picture of crustal and
upper mantle
structure of the Northern Apennines and their adjacent areas. The
elaborated
model may serve as a basis for further geotectonic considerations.
Geological
development and crustal structure suggest the subdivision into the
following
regions:
- the Balearic Sea
and the deep-sea part of teh Ligurian Sea;
- the
Corsica-Sardinia block;
- the border region
between the European continental fragment Corsica and the Adria
microplate;
- the
Adria microplate;
the border region
between the Apennines and the western Alps, W of Genoa.
Notes: Inter-Union Commission on Geodynamics -
Scientific
Report No. 38
Reference Type: Thesis
Record Number: 125
Author: Badessi, Oscar Ogliar
Year: 1978
Title:
Interpretazione
geologico-strutturale della Linea sismica crostale effettuate lungo le
Alpi
Centrali (progetto 'A.L.P.').
Academic Dept.: Geology
University: Università degli studi
City: Milan (I)
Pages: 96
Thesis Type: Diploma
Abstract: Lo
studio della Crosta
terrestre con l'impiego delle tecniche di sismica a rifrazione profonda
ha
avuto grande sviluppo in Europa, negli ultimi 20 anni.
Tutte
le esperienze si sono svolte nell'ambito
della 'Commissione Sismologica Europea'.
Per
quanto riguarda l'Italia, gli esperimenti
cominciarono nel 1956, con l'esplorazione dell'area alpina.
Nella
regione delle Alpi il numero complessivo dei
profili esplorati arriva ad una quarantina, di cui una decina sono
stati
registrati utilizzando due punti di scoppio, localizzati alle due
estremità di
ognuno di essi (profili 'reciproci').
Nel
1975 sono stati eseguiti due profili sulle
Alpi: uno parallelo all'asse strutturale della catena, con punti di
scoppio in
Francia (A), Svizzera (B, C), Austria (D, E) e in Ungheria (F); e
l'altro
orientato perpendicolarmente ad essa, dal punto di scoppio (H) in
prossimità di
Vicenza, al punto di scoppio (D) vicino ad Innsbruck.
Lo
scopo di questo lavoro è lo studio e
l'interpretazione del primo profilo lungo il tratto B-E.
Si
auspica che i risultati siano un importante
contributo per la comprensione dei processi geodinamici che hanno
portato alla
formazione delle Alpi.
Il
processo di formazione delle catene montuose,
infatti, non può benire ricostruito in modo chiaro tenendo
conto soltanto delle
strutture superficiali, ma è necessario ottenere dati sulla
ubicazione e natura
degli strati profondi, perchè sia possibile una scelta
ragionata fra i vari
modelli geodinamici proposti.
A
questo scopo i metodi geofisici possono essere
di valido aiuto, specie la gravimetria e la sismica.
Dalla
sismica a rufrazione profonda, in
particolare, ci si aspettano buone probabilità di successo
per la
determinazione della distribuzione in profondità delle onde
acustiche, da cui
si possono trarre utili considerazioni sulla natura delle varie
unità
litologiche.
Notes:
A.A. 1977-1978;
Relatore: Prof. R.cassinis; Correlatore: Ing. S.Scarascia
Reference Type: Journal Article
Record Number: 167
Author: IESG; Group, Italian Explosion Seismology
Year: 1978
Title: Preliminary interpretation of the profile
'H-D'
across the Eastern Alps.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XX
Issue: 79
Pages: 287-302
Abstract: In the first part, the preliminary
interpretation of
the ALP-1975 DSS experiments along the profile H-D (Orgiano, Vicenza -
Innsbruck) has been performed by means of horizontally layered models.
In the second part
a crustal model has been derived by ray tracing techniques and the
trend of the
main discontinuities was further confirmed by a gravimetric model and
the fit
between observed and computed Bouguer anomalies.
Along the
investigated profile the crust is continental-like, but:
1) North to the
Insubric Line exists a typical Alpine crust consisting of a thick upper
crust
(ca 35 km) with well-defined velocity inversions; a normal lower crust
(ca 15
km); a well-defined crust/mantle boundary;
2) South of Thiene,
the crust consists of a thinner (ca 25 km) upper crust with no velocity
inversions, and a thick lower crust (ca 30 km), in which very high
velocities
(7,6 km/s at ...km depth and 8,2 km/s vel. at 53 km depth) could be
found. One
possible explanation calls for a typical crust of the platform type,
with a
soft mantle; another one for a double crust, one with the Moho at 30 km
and the
other one with the Moho at 50 km. In this second case, the lower crust
of the
Adriatic microplate would overthrust the lower crust of the European
plate.
3) Between Thiene
and the Insubric Line, the crust shows a transitional structure between
the two
tyoes above described.
Reference Type: Journal Article
Record Number: 73
Author:
Panza, Giuliano
Year: 1978
Title: The Crust and Upper Mantle in Southern Italy
from
Geophysical data.
Journal:
Rivista Italiana di
Geofisica e Scienze affini
Volume:
V°
Pages:
17-22
Abstract: The area covered by the Tyrrhenian sea, the
Calabrian Arc, the southern Apennines and the Apulian plate is one of
the
tectonically most interesting regions in the Mediterranean, being the
result of
the collision between the African and European plates and the
subsequent
opening of an oceanic basin. In this area a strong seismic activity is
recorded, and shallow earthquakes are rather frequent in the Calabrian
arc and
in the Apennines, while the Tyrrhenian sea is characterized by
intermediate and
deep focus earthquakes. The Apulian plate, excluding the Gargano
promontory, is
rather stable. From a practical point of view the importance of
studying the
geophysical properties of this area arises from the seismic activity
which
affects the Calabrian arc and the Apennines. In fact, for a correct
determination of the seismic risk, are necessary structural models,
which can
explain the dynamical processes driving the Lithosphere.
In the last twenty
years a considerable amount of geological and geophysical data have
been
produced. These data, even if not yet conclusive, are very useful to
focus the
most significant problems and allow the formulation of working
hypothesis to be
tested in the future.
The purpouse of
this paper is to give an unitary picture of the most significant
geophysical
features as an introduction to the study of the origin and the
evolution of the
Calabrian arc, Tyrrhenian and Ionian Sea, in the frame of tectonical
models
suitable for continent-continent collision areas.
Reference Type: Book Section
Record Number: 29
Author: Stein, A.; Vecchia, G.; Froelich, R.
Year: 1978
Title: A seismic model of a refraction profile
across the
western Po Valley
Book Title: Alps, Apennines, Hellenides
Editor: Closs H., Roeder D., Schmidt K.
Publisher:
Schweizerbart'sche E. Verlagsbuchhandlung
City: Stuttgart 1978
Volume: 1
Number of Volumes: 1
Pages: 181-189
Series Title: Inter-Union Commission on Geodynamics
Abstract: Seismic recordings were made along a NE
profile
across the Po Valley in 1966 by 15 groups from West Germany and Italy
following
nine large explosions set off in a high mountain lake in the Mercantour
Massif
(Stein et al. 1967). This profile connects the Western Alps with the
Southern
and Central Alps across the Po Valley. Recordings were made on an arc
at a
shotpoint distance of 120 km connecting the profile with the Ivrea Zone
in the
Western Alps. This was done to facilitate the identification of the
seismic
phases along the profile.
Reference Type: Report
Record Number: 174
Author:
Scarascia, Salvatore;
Colombi, Bruno; Eva, Claudio; Guerra, Ignazio; Morelli, Carlo;
Nicolich,
Rinaldo; Riuscetti, Marcello; Scotti, Adriano; Ansorge, Jorge; Mueller,
Stefen
Year: 1978
Title: A seismic profile in the Southern Alps 1977 -
Description of the experiment and first results.
Institution: CNR-IGL
Date: September 4, 1978
Report Number: 253
Abstract: In July 1977 a seismic refraction profile was
carried out in the Southern Alps covering a distance range of about 400
km,
from the 'Lago Maggiore' to the 'Piani di Resia' (Friuli; NE-Italy).
The experiment was
a common project of Italian and Swiss Geophisical Institutes within the
International Geodynamics Project. 60 mobile recording stations
observed the
explosions at the four shot-poins: Lentate (Lago maggiore), Albiano
(Trento),
Tambre (Belluno) and Piani di Resia (UD).
This system of
profiles is the first one which is entirely situated in the Southern
Alps and
thus complements the measurements along the long-range Alpine profile
of 1975
(ALP-'75) parallel to the strike of the Central Alps.
The crustal
thickness ranges from 35 km near the western shotpoint to 45 km in the
eastern
section of the profile.
The average crustal
velocities are higher than what is found under the Central Alps.
Notes: presented at 16th ASC-EGS Meeting, Starsbourg
1978
Reference Type: Conference Proceedings
Record Number: 147
Author: Cassinis, Roberto
Year: 1979
Title:
Seminario sulla
integrazione dei dati di sismologia attiva e passiva.
Conference Name:
Seminario
sulla integrazione dei dati
Editor: CNR
Publisher: CNR - P.F.Geodinamica
Conference Location: Milan (I)
Volume: 1
Number of Volumes: 1
Pages: 42
Abstract: Nel
Progetto per la
Geodinamica, il ruolo della Sismologia è particolarmente
importante sia per la
ricostruzione del modello strutturale che per lo studio della
sismicità, del
resto strettamente legati l'un l'altro.
La
prospezione sismica (sismologia
"attiva") è uno strumento particolarmente efficace per
delineare le
strutture e, in genere, le disomogeneità della Crosta; in
misura minore anche
per mettere in evidenza quelle del mantello superiore.
Questo
tipo d'indagine fornisce, tra l'altro,
elementi utili ai sismologi per la corretta determinazione dei
parametri
cinematici e dinamici dei terremoti.
D'altra
parte la Sismologia "passiva" è
anch'essa un mezzo per la definizione delle grandi strutture,
naturalmente con
potere risolvente diverso, sia attraverso lo studio della propagazione
dei vari
tipi di onde provocate dagli eventi sismici che mediante l'analisi
dell'attività tettonica rivelata dai terremoti.
In
tre anni di intensa attività svolta nel quadro
del Progetto, è stata raccolta una importante massa di dati
con entrambi i
metodi di indagine. Si tratta di un patrimonio prezioso la cui
elaborazione è
stata effettuata solo in parte. L'esplorazione del territorio mediante
la
prospezione sismica profonda, inoltre, non è ancora
completa; i
"vuoti" che si spera di colmare prima della fine del progetto, si
trovano soprattutto nell'Italia centrale.
..................... omissis
.......................
Notes: CNR
- P.F.G.
Pubblicazione N. 315
Reference Type: Report
Record Number: 89
Author:
Panza, Giuliano;
Calcagnile, G
Year: 1979
Title: The Crust and upper Mantle beneath the
Central,
Eastern and Southern Alps.
Institution:
CNR
Date:
1979?
Type of Work: Progetto Finalizzato 'Geodinamica'
Report Number: ??
Abstract: We have combined the available surface wave
dispersion results with the DSS carried out in the Alpine region. In
some cases
using Rayleigh wave dispersion data it has been possible to estimate
the
average S-wave velocity in the crustal low-velocity layers, outlined by
DSS
data interpretation. The S-wave velocity distribution in the upper
mantle has
been determined in correspondence of the DSS profiles. relevant lateral
variations in the lid and underlying low-velocity layer have been
detected. A
thinning of the lid in the Eastmost portion of the area considered
seems to
indicate that the tensional force field which produced the Pannonian
basin
extends under the Alpine system.
Reference Type: Thesis
Record Number: 120
Author: Bonmassar, Sergio
Year: 1979
Title:
Contributo dei profili
di sismologia passiva alla conoscenza delle strutture profonde nella
regione
Friulana.
Academic Dept.: Geology
University: Università degli studi
City: Milan (I)
Pages: 104
Thesis Type: Diploma
Abstract:
Allo scopo di
effettuare uno studio dettagliato delle strutture della Crosta
terrestre si
utilizzano i sondaggi sismici a rifrazione profonda (D.S.S. = Deep
Seismic
Sounding). Tali esperienze si sono sempre svolte nell'ambito della
Commissione
Sismologica Europea e hanno avuto inizio in Italia nel 1956 con
l'esplorazione
dell'area alpina e successivamente nel 1966 sono state estese
all'Italia
meridionale. Nel a974 tali ricerche hanno riguardato l'Appennino
settentrionale,
mentre il tronco centrale è stato studiato nel 1978.
Sempre
lungo l'arco alpino, con andamento
all'incirca E-W, sono stati realizzati due profili sismici crostali:
l'uno
riguardante le Alpi settentrionali (1975), l'altro le Alpi Calcaree
meridionali
(1977).
Nel
1976 e precisamente durante il periodo 21-26
Ottobre, è stato effettuato un profilo sismico passivo nella
regione friulana
tra Gemona e Trieste utilizzando alcuni aftershocks registrati per
mezzo di 13
stazioni intermedie lavoranti in registrazione continua.
Infine,
nel Luglio 1978, sempre in Friuli, è stato
eseguito il profilo sismico attivo Trieste-Gemona-Obersee per
completare e
verificare le conoscenze acquisite con il profilo passivo
Gemona-Trieste.
Il
presente lavoro si rivolgerà specificatamente a
questi ultimi due profili, proponendosi di apportare un contributo alle
conoscenze delle strutture profonde nella Regione Friulana.
.................... omissis
........................
Notes:
A.A. 1978-1979;
Relatore: Prof. Ing. R.Cassinis; Correlatore: Ing. S.Scarascia
Reference Type: Journal Article
Record Number: 175
Author:
Ansorge, Jorge;
Mueller, Stephan; E.Kissling; Guerra, Ignazio; Morelli, Carlo;
Scarascia,
Salvatore
Year: 1979
Title: Crustal section across the zone of
IVREA-VERBANO
from the Valais to the lago Maggiore.
Journal:
Bollettino di
Geofisica teorica ed Applicata (BGTA)
Volume: XXI
Issue: 83
Pages: 149-157
Abstract: In a977 a detailed seismic refraction
experiment was
carried out in the Southern Alps through the cooperative effort of a
number of
Italian, Swiss, French and German Institutes. The four shotpoints and
six
profile segments are all located in the Southern Alps between the lago
Maggiore
in the west and Gemona near the Italian-Yugoslavian border in the east.
The aim
of this project was to obtain a detailed set of crustal seismic data in
the
area where only very few data were available.
In this
investigation a preliminary interpretation of the westernmost segment
between
the Lago Maggiore and Trento is presented. A rather uniform type of
crust has
been found in this area of the Southern Alps indicating a total crustal
thickness of 35 km. This crustal structure contrasts very much with the
zone of
Ivrea and the Central Alps immediately west and north of the Southern
Alps. A
crustal cross-section has been constructed along a NW-SE trending
profile which
extends from the Rhine-Rhone Line near Brig (Switzerland) to the east
of the
lago Maggiore near Varese. In this section also older data from the
Zone of
Ivrea and west of it have been incorporated. The crustal models for the
different areas indicate rather strong lateral variations of the
velocity-depth
distributions of P-waves.
Reference Type: Report
Record Number: 173
Author:
Colombi, Bruno;
Guerra, Ignazio; Luongo, Giuseppe; Scarascia, Salvatore
Year: 1979
Title:
Profilo sismico a
rifrazione "Acireale-Termini Imerese" (1977)
Institution: CNR-IGL
Type of Work: P.F.Geodinamica
Report Number: 235
Abstract: This paper reports an evaluation of the data
recorded along the DSS profile "Acireale-Termini Imerese", 1977. A
first inversion leads to a three-layered model of the crust: the first
refracting horizon corresponds to the so-called top of the crystalline
basement. The interpretation of the later arrivals requires the
occurrence of
two low velocity layers, but the velocity decrease is very low. Mt.
Etna seems
to exert only a small influence on the regional pattern of crustal
structure.
Notes:
Pubbl. No. 235 del
P.F."Geodinamica" del CNR, Sottoprogetto "Sorveglianza dei
Vulcani e Rischio vulcanico"; pp. 155-170.
Reference Type: Report
Record Number: 182
Author:
Nicolich, Rinaldo;
Dordolo, Giuliano; Marino, Bruno; Scotti, Adriano
Year: 1979
Title:
Grandi scoppi nel
Medio-Basso Tirreno, Mar di Sardegna, Mar Ionio - 1979.
Institution: OGS
Date: October 1, 1979
Report Number: 79546
Abstract:
L'Osservatorio
Geofisico Sperimentale di Trieste ha eseguito una campagna di sismica a
rifrazione profonda per il C.N.R. - P.F. "Geodinamica" - Modello
strutturale (titolo della ricerca: "Sismica crostale: preparazione ed
effettuazione degli scoppi del profilo Jonio Val d'Aosta e Mar di
Sardegna -
Mar Adriatico. Registrazione a riflessione dei punti di scoppio,
partecipazione
all'elaborazione dei dati"). e per il C.N.R. - P.F. "Energetica"
- Energia Geotermica (titolo della ricerca: "Studi di dettaglio sulla
struttura crostale nell'area delle isole Eolie e dell'Etna").
Le
operazioni di campagna si sono svolte nel
periodo 9/7 - 14/871979 e sono state eseguite dalla squadra sismica
MD-180
imbarcata a bordo della N/O "L.F.Marsili".
Il
posizionamento è stato controllato mediante
sistema Loran-C.
Il
sistema di energizzazione era costituito da
cariche di dinamite fino a 250 kg più 7 scoppi con cariche
di 400 kg.
La
registrazione dell'istante di scoppio è stata
eseguita mediante registratore magnetico P.I.6200 e camera
galvanometrica SIE
VRO-6.
Sono
stati lanciati in mare n. 8 OBS (Ocean Bottom
Seismometers) per un totale di 23 stazioni. Degli OBS, 6 erano quelli
dell'IPG
di Parigi (resp.: Steinmetz) e 2 dell'Istituto di Geofisica
dell'Università di
Amburgo (resp.: Herber).
Sono
stati eseguiti in totale n° 141 scoppi.
......................
omissis ......................
Reference Type: Journal Article
Record Number: 94
Author: Cassinis, Roberto; R., Franciosi; Scarascia,
Salvatore
Year: 1979
Title: The structure of the Earth's Crust in Italy -
A
preliminary typology based on seismic data.
Journal:
Bollettino di
Geofisica Teorica e Applicata (BGTA)
Volume: XXI
Issue: 82
Pages: 105-126
Abstract: About 100 velocity-depth functions computed
from the
deep seismic soundings recorded up to 1977 in the Italian region have
been
normalized and evaluated.
Typical functions
for the Crust have been derived; 5 fundamental types have been defined
ranging
from the "suboceanic" to the "thickened continental" Crust
and to the type where a double Crust-mantle transition appears. A
"Crustal
typology" map gas been drawn as well as interval average velocity maps
for
several depth intervals. This last type of presentationseems very
effective to
point out the most anomalous areas as well as the relative importance
of
velocity inversion zones.
The interpretation
for the complex areas where a double transition occurs has been
particularly
discussed and the different possible hypotheses evaluated.
This paper
represents only a preliminary attempt to produce a synthetic map of
crustal
structures, also owing to the lack of data in Central Italy. However,
some
general considerations can already be made and a future line of
investigation
can be better planned in order to give a increasing contribution to an
updated
structural model of the Italian region.
Reference Type: Report
Record Number: 97
Author: Nicolich, Rinaldo
Year: 1979
Title:
Ipotesi di un modello
strutturale del Friuli dagli studi di sismologia sperimentale.
Institution:
Università degli studi
- Ist. di Miniere e Geofisica Applicata
Report Number: 41
Abstract: This work aims to sum up the results obtained
from
the DSS experiences in the Eastern Alps, with particular reference to
the
Friuli-Venetia Julia region, where a strucural model is of greta
interest to
understand the geodynamics and the seismicity of the area affected by
the 1976
earthquake.
In its northern
part the model seems to be well defined expecially after the results
published
by the German researches, on the countrary towards South it has to be
adapted
to take into account the results obtained by the recent experiences. In
fact
there is evidence of a wedging towards North and North-East of
high-velocity
roks, which might belong to the Adria Plate.
Reference Type: Report
Record Number: 176
Author:
Scarascia, Salvatore
Year: 1979
Title:
D.S.S. 1978 - Rapporto
annuale
Institution: CNR-IGL
Date: Jan. 15, 1979
Type of Work: IGL Report
Abstract: Il
lavoro svolto nel
1978 dal Gruppo "Grandi Profili sismici" comprende l'esplorazione di
alcuni profili nell'Italia Centrale (Toscana-Umbria-Marche) e di un
profilo nel
Friuli, secondo il programma operativo concordato all'inizio del
progetto.
Per
quello che riguarda l'Italia Centrale, la fig.
1 riporta l'ubicazione dei profili, dei punti di scoppio e delle
stazioni di
registrazione. In questa zona sono stati effettuati un totale di 8
scoppi,
utilizzando per ognuno di essi una serie di pozzetti e impiegando una
carica
totale variabile da 1 a 1,5 ton di esplosivo. Sono stati effettuati 2
scoppi
nella posizine 'C' (Roccastrada-GR), 2 nella posizione 'B'
(Umbertide-PG) e 2
nella posizione 'A' (Filottrano-AN). Uno scoppio singolo è
stato effettuato
nella posizione 'N' (Nugola-PI) ed 'S' (Canino-VT).
.......................... omissis
..........................
Notes:
Rapporto presentato al
Congresso annuale del PFG, Sub. 5 - Modello strutturale, Gruppo profili
sismici"
Reference Type: Conference Proceedings
Record Number: 42
Author: Scarascia, Salvatore; Group, and Italian
Explosione
Seismology
Year: 1980
Title: Calabrian Arc Project: first results on the
1979
seismic experiments.
Conference Name: 7th annual Meeting
of EGS-ESC
Editor: ESC
Publisher: ESC
Conference Location: Budapest
Label: 6 pp. + 16 figs.
Abstract: In Summer 1979 some DSS experiments were
carried out
in Southern Italy. About 90 shots (charge of 200 kg) were fired in the
Tyrrhenian and Ionian Sea along a profile running in the NW-SE
direction and
crossing the Calabrian Arc. Moreover several mayor shots (charge of 400
kg)
were fired in some selected points in the two seas. On land about 35
Mars-66
mobile seismic stations were employed, as well as 3 local seismic
networks in
Calabria and on the Eolian Islands, while other regional stations were
installed
at the borders of the investigated area. All these supplementary
stations
operated during some months in order to get more detailed information
on the
seismic activity of the region and its structure.
In this paper the
preliminary results of the joint interpretation of data collected both
from
explosions and earthquake are discussed.
Reference Type: Report
Record Number: 66
Author:
Giese, Peter; Wigger,
P.; Morelli, Carlo; Nicolich, Rinaldo
Year: 1980
Title: Seismic studies for the determination of the
crustal
structure in the area of the geothermal anomaly in Tuscany.
Institution: UNI
(Ist. di Miniere e
Geofisica applicata)
Report Number: 47
Abstract: Refraction seismic measurements were carried
out in
July 1978 and 1979 in Tuscany and Latium with the goal to receive the
crustal
and upper mantle structure and the velocity distribution in the
geothermal
anomaly of Tuscany.
The main results
are: the Crust of Tuscany is thin. On reason of the relative high
velocity and
the missing of distinct velocity inversions it must be excluded that a
greater
extent of molten material in the upper crust could be found. However,
the
transition zone to the upper mantle shows layers of extreme low
velocity, at
least temperatures of 600-700° C have to be expected in this
region.
Besides, in the
transition zone under the area of Larderello, a jump of 6-7 km to the
upper
mantle was found possibly corresponding to the jump in the basement of
that
region.
Model calculations
which were made for the temperature distribution in this area are
discussed.
Notes:
UNI-TS (Ist. Min.
e Geof. applicata);
Contributo n. 47
Reference Type: Thesis
Record Number: 123
Author:
Gaudiosi, Germana;
Ossella, A.
Year: 1980
Title:
Evoluzione geodinamica
del mediterraneo occidentale e strutture profonde dell'area Italiana.
Academic Dept.: Earth's sciences; Geology
University:
Università degli studi
City: Naples (I)
Pages: 298
Thesis
Type:
Diploma
Abstract: In
questi ultimi anni
il principale obiettivo della ricerca geologica in Italia è
stao quello di
comprendere tutti i processi geodinamici che hanno caratterizzato
l'evoluzione
della penisola italiana ed hanno portato alla sua attuale struttura.
Questa
conoscenza è indispensabile per programmare
in modo corretto ogni intervento da attuare sul territorio, sia per
quanto
riguarda la ricerca e l'utilizzazione delle risorse naturali
(minerarie,
geotermiche, ecc.), sia per la prevenzione e difesa contro le
"calamità
naturali" (eruzioni, terremoti, alluvioni, frane).
La
ricerca geologica perde così il suo aspetto
puramente accademico, per assumere un importante ruolo nella
realtà sociale e
politica del Paese.
Per
la conoscenza dei processi geodinamici è necessario
il riferimento ad un modello globale che permetta la ricostruzione
degli eventi
succedutisi, nel tempo, in una certa zona.
Nel
nostro studio sull'evoluzione dell'area del
Mediterraneo occidentale, ci siamo attenuti al modello della Tettonica
a Zolle.
Questa Teoria, negli ultimi 60 anni, ha rivoluzionato i concetti
fondamentali
sull'evoluzione geologica della Terra. Si è passati da un
modello che
considerava i processi geologici legati esclusivamente a movimenti
verticali,
ad un modello che giustifica i processi geologici come conseguenza di
movimenti
orizzontali di grosse zolle rigide, con notevoli dimensioni areali e
spessori
di circa 160 km. Il motore di questi movimenti sarebbe localizzato nel
Mantello, ove celle convettive trasferiscono parte del loro movimento
alla
Litosfera sovrastante.
Il
vecchio modello è chiaramente deterministico,
in quanto prevede una successione di causa ed effetto relativamente
semplici.
Al contrario, quello dinamico della Tettonica a Zolle è di
tipo
indeterministico, in quanto alla definizione dei processi tettonici
concorrono
un numero infinito di variabili che dipendono dal tipo di interazione
tra le
zolle in continua evoluzione (geometria del contatto, caratteristiche
meccaniche e termiche delle zolle in contatto, velocità
relativa delle zolle,
caratteristiche fisico-dinamiche del Mantello).
Dai
vari tentativi effettuati fino ad ora, sono
state riscontrate molte difficoltà ad applicare il modello
classico della
Tettonica a Zolle nell'area del Mediterraneo. In pratica, in quest'area
esistono una serie di strutture, quali catene con opposta vergenza,
archi
metamorfici, archi vulcanici, bacini, a volte sovrapposte fra loro. E'
difficile correlare, secondo il modello classico della Tettonica a
zolle,
queste strutture con i meccanismi che le hanno generate, sia
perchè mancano
delle relazioni spaziali e temporali, sia perchè il modello
è privo di
"consistenza fisica".
Lo
scopo del nostro lavoro è la comprensione dei
principali processi geodinamici in atto nella penisola italiana e nel
Mediterraneo Occidentale, dall'analisi di dati geologici e geofisici.
In
particolare per la comprensione delle strutture dell'Italia
Centro-Settentrionale sono stati analizzati i dati di sismica a
rifrazione
profonda ottenuti dalle campagne sismiche del 1974 e 1978.
Inizieremo
il nostro lavoro con un esame dei dati
geologici a disposizione sul Mediterraneo occidentale, dal Triassico
fino
all'attuale.
Notes:
A.A. 1979-1980;
Relatore: Prof. G.Luongo, Correlatore: Dr. R.Scarpa
Reference Type: Report
Record Number: 180
Author:
Scarascia, Salvatore
Year: 1980
Title:
Struttura crostale
della Sardegna dagli esperimenti di sismica attiva condotti nel 1979.
Institution: CNR-IGL
Type of Work: IGL Report
Abstract: Nel
quadro del
Progetto Finalizzato "Geodinamica" del C.N.R., durante l'estate 1979
sono stati eseguiti una serie di profili sismici a rifrazione profonda
(DSS) in
Sardegna, nel Tirreno, in Calabria e Sicilia. Per quello che riguarda
la
Sardegna, è stato esplorato un profilo con direzione SW-NE.
dall'isola di
S.Antioco ad Arbatax, impiegando un gruppo di 13 stazioni, tutte del
tipo
MARS-66, e registrando i segnali di una serie di scoppi ubicati nei
mari
adiacenti Mediterraneo e Tirreno.
.....................
omissis ................
L'obiettivo
che ci si proponeva di raggiungere con
questi esperimenti era lo studio della struttura crostale sia
all'interno del
blocco sardo, sia nella zona di transizione tra detto blocco e il
Tirreno.
Questi dati, uniti a quelli ottenuti in esperimenti analoghi condotti a
Nord
della Corsica nel 1974 e 1978, dovevano poi servire per ottenere un
quadro più
completo dell'evoluzione geodinamica della regione, dovuta agli effetti
combinati della rotazione antioraria del blocco Sardo-Corso e
dell'apertura del
bacino Tirrenico.
Reference Type: Report
Record Number: 96
Author:
Giese, Peter; Morelli,
Carlo; Nicolich, Rinaldo; Scarascia, Salvatore
Year: 1980
Title: Crustal structure of the Italian Pensinsula.
Institution: CNR-IGL
Report Number: 319
Abstract: Extensive seismic crustal studies have been
carried
out on the italian Peninsula, organized by the Italian Geophysical
Institutes
in cooperation with German and French geophysicists. The main features
of
crustal structure could be revealed which are in agreement with the
Bouguer
gravity. From the tectonic point of view the Italian pensinsula,
including
Sicily and adjacent sea areas, can be subdivided into the following
zones (each
of them has a typical crustal thickness (CT)
1a) Foreland with
stable platform, SE-Sicily and Apulia (CT: 25-30 km)
1b) Foreland with
recent folding: Po-Plain, Bradanic Basin (CT: 35 km)
2) Central
zone with compressional tectonics:
Ligurian Apennines, Umbria-Marches, Romagna, Campania, Basilicata,
calabria,
Northern Sicily (CT: 40-45 km)
Reference Type: Report
Record Number: 59
Author:
Nicolich, Rinaldo;
Pellis, Giulio
Year: 1980
Title: Il
contributo dei dati
geofisici per lo studio delle strutture crostali della provincia
geotermica
Tosco-laziale.
Institution: OGS
/ Uni (Ist. di
Geofisica applicata e Miniere)
Report Number: 38
Abstract: A discussion of the record obtained from DSS
experiences in the Tuscan-Latial geothermal region is presented.
P-waves and for
some profiles S-waves as well, have been analyzed. Aiming to elaborate
an
interpretative model also the results obtained from other geophysical
surveys
(shallow seismic, geothermal and gravimetric data, etc...) have been
taken into
account.
Further
development of
interpretation methods
and collection of new data may confirm the hypotheses which point out
the trend
of the Moho belonging to the Adria microplate and the anomalous
structure of
the Lower Crust in the Tuscan-Latial region.
Notes:
UNi-TS (IGAM, contributo N.38; 53 pp).
Reference Type: Journal Article
Record Number: 151
Author: Giese, P.; Morelli, C.
Year: 1981
Title: The method of reduced traveltime curve.
Journal:
Bollettino di
Geofisica teorica ed Applicata (BGTA)
Volume: XXIII
Issue: 90-91
Pages: 243-260
Abstract: The procedure proposed by Pavlenkova is
applicable
to lateral inhomogeneous media. The first aim is to determine the
nature of the
waves and to correlate them to velocity levels. The procedure is as
follows:
all traveltime curves are transformed into a X/2, T-X/Vr display, using
different reduction velocities Vr. From each travel-time branch results
a
family of curves, eachhaving a maximum or minimum if the reduction
velocity is
within the interval of slope values of the curve under discussion.
Progressive
curves show a minimum, whereas retrograde branches give a maximum.
Linear
travel-time curves do not change their
form, only the slope varies. It is now possible to find out from the
pattern of
the reduced traveltime curves those branches belonging to the same
velocity
level Vi. Progressive (normal) travel-time curves are always associated
with
layer velocities. The case is different for reversed segments. Because
reversed
branches can be generated by sharp discontinuities and/or strong
gradient
zones, the nature of the quantity dx/dt is open. It is also possible to
transform reversed branches completely and to construct the envelopes.
The
second aim is to obtain a qualitative picture of the main features of
vertical
as well as of horizontal velocity distribution by means of the velocity
isolines in the distance-intercept-time section. Reduced travel-time
curves
also enable the detection of low-velocity zones and the determination
of their
laterla variations. An intercept-time section with isolines of velocity
can be
used as base for the next step to invert intercept-time values into
depth
values. The construction of velocity isolines or seismic boundaries by
aid of
the reduced travel-time curve method is possible only in smoothed form.
If the
dimensions of quasi-homogeneous blocks or structures at the given level
are
less than the length of the travel-time curves of the waves penetrating
to this
depth, the lateral inhomogeneities are smoothed in respect to their
relief.
In conclusion it
can be said that the intercept-time method is a powerful tool for
evaluation
deep seismic-sounding data obtained by quite different field techniques.
Reference Type: Conference Proceedings
Record
Number: 34
Author:
Luzio, Dario; sismici,
e Gruppo Italiano Grandi Profili
Year: 1981
Title:
Profilo longitudinale
sulle Alpi centrali (1975)
Conference Name: 1st
GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: II
Number of Volumes: 2
Pages: 653-664
Abstract: We are presenting here a new interpretation
of the
data along the longitudinal seismic profile, surveyed with
international
cooperation in the Central Alps in 1975, with reference to the line
between
Grenoble and Innsbruck (shotpoints: A, B, C and D). We applied the
classical
methods of inversion to this data and we checked the results with the
ray-tracing method.
Later, we built up
a crustal model in terms of the mean density of the most important
geological
structures in agreement with the seismic model, that gives a calculated
gravitational effect that fits the Bouguer anomaly along the profile.
Fibally we are
presenting some features of the crustal structure of the Central Alps
along the
above-mentioned line, pointing out some divergences from the previously
constructed models.
Reference Type: Conference Proceedings
Record
Number: 179
Author:
Guerra, Ignazio;
sismici, e Gruppo Italiano dei grandi profili
Year: 1981
Title:
Struttura crostale
della Sardegna sulla base di dati sismici e gravimetrici.
Conference Name: 1st GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 2
Number of Volumes: 2
Pages: 639-652
Abstract: This paper describes the interpretation of
the DSS
profile S.Antioco-C.Bellavista, which crosses Sardinia in a SW-NE
direction. The
crustal thickness is maximum (about 31 km) beneath the center of the
profile
and decreases towards the ends, amounting to 20 and 23 km beneath the
SW and NE
coastlines respectively. The structure of the crust is rather simple
and the
transition to the adjacent seas does not show any evidence of
overthrusting or
interbedding.
The Bouguer anomaly
field was also inverted to outline the bathymetry of the Moho beneath
Sardinia.
Reference Type: Report
Record Number: 43
Author: Linari, R.
Year: 1981
Title: DSS
1979:
Interpretazione preliminare del profilo Calabria-M.Ionio
Institution:
UNI-TS (Ist. di
Miniere e Geofisica applicata)
Date: Marzo 1981
Report Number: 52
Abstract: A preliminary interpretation of the DSS 1979
experiments (Calabria-Ionia Sea profile) is presented.
The investigated
area occupies a key position from the geodynamic point of view to
understand
the relations between the Tyrrhenian and Adriatic plates and the
relative
still-going on orogenetic processes.
The methods adopted
for the interpretation are discussed and a model checked by raytracing
computation is presented.
Reference Type: Report
Record Number: 39
Author:
Giese, Peter; Wigger,
P.; Morelli, Carlo; Nicolich, Rinaldo
Year:
1981
Title:
Seismiche Studien zur Bestimmung der Krunstenstruktur
im Bereich der geothermischen Anomalie der Toskana.
Institution: Freie Universitat
Report Number: EG contract N. 486-78-1 EG D
Abstract: Within this project the crustal and upper
mantle
structure in the region of the strongest continental European
geothermal
anomaly - the western parts of Tuscany and adjacent areas - have been
investigated by seismic and magnetotelluric methods. From geothermal
point of
view the following questions were studies.......
Reference Type: Conference Proceedings
Record Number: 11
Author: Nicolich, Rinaldo
Year: 1981
Title:
Esplorazione sismica
multicanale nei mari italiani.
Conference Name:
Convegno
P.F. Oceanografia e fondi marini
Editor: CNR
Publisher: CNR
Conference Location:
Roma
(15-17/12/1981)
Pages:
165-176
Abstract:
Esplorazioni sismiche
sono state effettuate con successo nel Mar Mediterraneo su ampia scala:
i
bacini sedimentari in corrispondenza delle scarpate continentali e
coperti da
diritti minerari sono stati esplorati in modo intensivo dalle compagnie
petrolifere, tenendo conto ovviamente degli interessi economici. Nello
stesso
tempo rilievi di ricognizione regionali sono stati condotti da altre
istituzioni
con finanziamenti provenienti dai Consigli Nazionali delle Ricerche e
dalle
stesse Compagnie petrolifere. L'OGS di Trieste ha condotto esplorazioni
geofisiche (batimetriche, gravimetriche e magnetiche) in quest'area sin
dal
1953, iniziando nel 1969 l'esplorazione sismica a riflessione. Sono
stati
eseguiti profili per un totale di 37.833 km per lo più in
copertura 1200%...
Notes:
Uni-Trieste - Ist.
Miniere e Geof. applicata; pubbl. N. 70
Reference Type: Conference Proceedings
Record
Number: 95
Author:
Scarascia, Salvatore;
sismici, e Gruppo italiano dei grandi profili
Year: 1981
Title:
Profili sismici
profondi: alcuni risultati e rielaborazioni dei profili esplorati.
Conference Name: 1st
GNGTS meeting
Editor: CNR
Conference Location: Roma (CNR)
Volume: 2
Number of Volumes: 2
Pages: 615-620
Abstract: A general picture of the Deep Seismic
Sounding
experiments carried out in Italy and the programme for the next future
is
presented. In the last 5 years the seismic experiments have been
carried out nearly
completely in the frame of the Italian 'geodynamics' Project,
Structural Model
of Italy sub-project. The programme in the next future is, at least
partly, a
completion of the Programme of the 'Geodynamics' Project, and will be
performed
in the frame of the international Project 'Dynamics and evolution of
the
Litorsphere'. The obtained results have been partly published and
partly
presented in national and international meetings in provisional form.
At
present some results will be shown on the profiles carried out in 1980
and some
elaborations of data concerning previously explored profiles.
Reference Type: Journal Article
Record Number: 172
Author:
Carrozzo, Maria T.;
Luzio, Dario; Eva, Claudio; Merlanti, M.; Calcagnile, G.; Panza,
Giuliano;
Carli, Vittorio; Cassinis, Roberto; Colombi, Bruno; Scarascia,
Salvatore;
Morelli, Carlo; Pellis, Giulio; Cosentino, Mario; Riuscetti, Marcello;
Nicolich, Rinaldo; Scotti, Adriano; Guerra, Ignazio; Luongo, Giuseppe;
Scarpa,
Roberto; Ansorge, Jorge; Mueller, Stephen
Year: 1981
Title: Crust and upper mantle structures in the
southern
Alps from deep seismic sounding profiles (1977, 1978) and surface wave
dispersion analysis.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XIII
Issue: 92
Pages: 297-330
Abstract: During Summer 1977, within the frame of the
Italian
Geodynamics Project, a seismic profile was carried out in the southern
Alps. It
was intended as the necessary complement to the Alpine Long-range
profile
executed in 1975 in the Central Alps.
The data collected
in this experiment are presented together with those of a 1978 profile
in the
Eastern alps. The interpretation, carried out initially under the
hypothesis of
horizontal layering, was afterwards improved by ray-tracing methods and
gravity
modeling. Moreover data of previously explored profiles in the Alpine
region
have been reexamined and the interpretation of the crustal structure
complemented with detailed lithospheric data obtained from surface wave
dispersion analysis is presented.
The main results
concerning the crustal structure are:
- the Moho
discontinuity of the European plate, at a depth of about 30-35 km in
the
molasse basin, reaches the maximum depth of 55 km along the axis of the
Alps. Southwards,
up to the Varese-Udine line, the discontinuity is detected at depths of
35 to
45 km.
- A shallower
discontinuity, with P-wave velocity values of 7,0-7,5 km/s, has been
detected
at a depth of 20-30 km in a wide region covering approximately all the
Eastern
Alps.
- At the margin of
the Po Plain (Adriatic plate) and in the Pannonian basin, the depth of
the
crust/mantle boundary is about 30-35 km.
Questions
concerning the intaraction between the African and European plates are
discussed, suggesting the possibility of remarkable overthrusting
movements at
crustal levels in the Alpine region. The available results on surface
wave
dispersion have been analyzed and an attempt has been made to estimate
the
average S-wave velocity in the crustal low-velocity layers, outlined by
DSS
data interpretation. The S-wave velocity distribution in the upper
mantle has
been determined in areas close to the DSS profiles. Considerable
lateral
variations in the lid and an underlying low-velocity layer have been
detected. A
thinning of the lid in the easternmost portion of the considered area
seems to
indicate the extension of the tensional field of the Pannonian basin
under the
Alpine system.
Reference Type: Conference Proceedings
Record Number: 181
Author: Nicolich, Rinaldo
Year: 1981
Title: Il
profilo
Latina-Pescara e le registrazioni mediante OBS nel mar Tirreno
Conference Name: 1st GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 2'
Number of Volumes: 2
Pages: 621-637
Abstract: Two deep seismic profiles running from
Sardinia to
Pescara and from the Tyrrhenian bathyal plain to the Campanian coast
are
presented. The data have been obtained by the employment of OBS
offshore and
mobile recording stations on land. The former profile reveals well
diversified
crustal structures: crustal thinning in correspondence of the central
Tyrrhenian Sea, a peculiar lower crust configuration toward the Latial
coasts
that can be correlated to the crustal models of the geothermal region
of
Tuscany, and a continental crust characteristic of the Adriatic margin
from
Anzio to Pescara.
The latter profile,
explored by higher resolution techniques, evidentiates a very thin
crust in
correspondence of the Tyrrhenian bathyal plain and points out the fine
structure
of the crust-mantle boundary towards the Campania coasts.
Reference Type: Conference Proceedings
Record Number: 135
Author: Cassinis, Roberto
Year: 1981
Title:
Prime correlazioni tra
struttura crostale e sismicità della regione Italiana.
Conference Name: 1st CNR-GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 2
Number of Volumes: 2
Pages: 507-532
Abstract: During the last years, chiefly owing to the
activity
of the national programme on Geodynamics, a large amount of data has
been
collected on the seismicity of the Italian area and several new surveys
have
been carried out on crustal structure using geophysical methods and
especially
deep seismic soundings.
The aim of this
investigation is threefold:
a) to prepare a
versatile data base both for the historical and for the new
instrumental
seismic data in order to extract the statistical information in every
form
suitable for the analysis
b) to test the
effectiveness of the seismographic networks and to predict its future
contribution to the seismotectonic and to the earthquake origin zones
evaluation
c) to start the
comparison between the seismicity and the structural features of the
region as
outlined by geological and geophysical surveys.
Notes:
Progetto finalizzato
'Geodinamica', CNR, pubbl. n. 468
Reference Type: Conference Proceedings
Record Number: 150
Author: Morelli, Carlo
Year: 1981
Title: La
geofisica della
Terra solida ed il Gruppo Nazionale.
Conference Name: 1st GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 1
Number of Volumes: 2
Pages:
23-42
Abstract: 1.
L'importanza della
Geofisica della Terra solida.
Essendo
questa la prima volta che la Geofisica
della terra solida appare, grazie al CNR, in una assise nazionale ad
essa
specifica, mi sia consentito anzitutto presentarla. La Geofisica
è lo studio
dell'interno della Terra con metodi fisici, applicati alla sua
superficie. La
più parte di questi metodi consentono sia lo studio globale
della Terra, fino
alle massime profondità, a scopi esclusivamente scientifici,
sia - con un
cambio di scala - ricerche di dettaglio nei primi km più
prossimi alla
superficie, con finalità sia scientifiche che applicative.
La
Geofisica della terra solida è quindi
determinante ed essenziale:
a)
per la ricerca e lo sfruttamento delle risorse
del sottosuolo cui essa offre metodi insostituibili;
b)
per la difesa dell'ambiente, in particolare
delle calamità nazionali;
c)
per le Scienze naturali in genere, Oceanografia
inclusa;
d)
per le Scienze Geologiche in particolare, le
cui osservazioni alla superficie della Terra possono essere integrate
ed
estrapolate con le risultanze geofisiche in profondità.
.............................. omissis
.....................
Reference
Type:
Journal Article
Record
Number: 19
Author:
Alfano, Luigi;
Decandia, Francesco; Lavecchia, Giusi; Pialli, Gianpaolo; Biella,
Giancarlo;
Lozey, Alfredo; Scarascia, Salvatore
Year: 1982
Title:
Profilo
Piombino-Ancona: dati geofisici ed interpretazione geologica.
Journal: Boll. Soc. Geol. Italiana
Issue: 101
Pages:
247-258
Keywords:
Geofisica applicata;
Geotraversa; Tettonica regionale; Geodinamica
Abstract: Results of geophysical researches performed
along
the transect Piombino-Ancona (Central Italy) by means of seismic
refraction
profiles, electrical soundings and a gravimetric profile are given in
this
paper.
By seismic profiles
it's possible to distinguish three sectors in the Crust: the Tyrrhenian
or
Western, about 25 km thick, the Umbrian-Marchean or Central, 35 km
thick and
the Eastern or Adriatic whose thickness is intermediate. Shot points A
and C
located in the tyrrhenian and adriatic sides of the transect show a 6
km/s
refraction horizon, dipping westward and eastward respectively, which,
on the
basis of surface geology data, refers to the granit in western Tuscany
and to
massif limestone in eastern Marches. The shot point B (Etruscan side of
the
Tiber Valley) shows a low velocity interval between two lines of 6
km/s. This
result in the frame of stratigraphy of Perugia-2 well, is in agreement
with a
thrustting of regional interest of the metamorphic basement over its
sedimentary cover.
Electrical methods
gave good results in the thickness evaluation of Pliocene and
flysh-type cover
(including the allochtonous ligurids). No reliability they have in
distinguishing Mesozoic limestones from Triassic evaporites or
Verrucano-basement group.
Notes:
CNR-P.F.G.,
pubblicazione N. 508
Reference Type: Conference Proceedings
Record
Number: 186
Author:
Scarascia, Salvatore;
Maistrello, Mariano; Demartin, Martina; Biella, Giancarlo; Scotti,
Adriano;
Morelli, Carlo; Nicolich, Rinaldo; Pellis, Giulio; Scarpa, Roberto;
Guerra,
Ignazio; Luongo, Giuseppe; Carrozzo, Maria T.; Luzio, Dario
Year: 1982
Title: Crustal structures in the Central-Southern
Apennines
from DSS data (1980 experiments).
Conference Name: XVIII ESC General
Assembly
Editor: ESC
Conference Location: Leeds (UK)
Pages: 239-246
Abstract: In summer 1980 large scale experiments were
carried
out in Central and Southern Apennines, in the frame of the Italian
Geodynamic
Project, structural Model sub-project. In this paper the preliminary
results
are given, completing the partial results on some profiles already
published,
and considering also the results of previously explored profiles, in
order to
get a more complete picture of crustal structure in the explored region.
...........................
omissis ................
Reference Type: Thesis
Record Number: 121
Author: Ruspa, Dario
Year: 1982
Title:
Primi elementi per la
valutazione dei rapporti tra struttura crostale e sismicità
nella regione
italiana: zonazione in base ai dati geofisici.
Academic Dept.: Earth's Sciences; Geology
University:
Università degli studi
City: Milan (I)
Pages: 120
Thesis
Type:
Diploma
Abstract: Lo
scopo principale di
questo lavoro è lo studio della Crosta della regione
Italiana attraverso i
D.S.S. (Deep Seismic Soundings) e il confronto dei risultati di altri
metodi
geofisici.
Ho
proceduto innanzitutto alla raccolta di tutti i
dati, editi ed inediti, relativi alla sismica crostale e ad un loro
controllo.
Terminato
l'esame critico delle varie sezioni
interpretate sono passato alla stesura di queste sezioni con metodi
diversi,
usando in altro modo i dati, per cercare di dare una rappresentazione
più
sintetica delle strutture.
Un
passo ulteriore è stato la stesura della carta
della profondità della discontinuità di
Mohorovicic utilizzando tutti i dati
che permettono di avere un quadro abbastanza completo, in quasi tutta
Italia,
dell'andamento della transizione "Crosta-mantello".
sono
stati fatti anche vari tentativi di
interpretazione e di rappresentazione delle zone di possibile
"sovrapposizione" crostale (doppia transizione Crosta-mantello)
utilizzando tutti i dati a disposizione.
Mi
è parso più significativo rappresentare tale
situazione anomala che ha dato origine a diverse interpretazioni e il
cui
significato non è completamente chiaro, in modo
più generalizzabile.
Ho
presentato anche una classificazione di tipi
crostali in base all'andamento delle funzioni
Velocità/profondità che vanno a
completare l'analisi delle unità crostali e
l'interpretazione dell'andamento
della transizione Crosta-Mantello sulle varie sezioni.
Sono
passato quindi ad esaminare la possibilità di
completare le osservazioni sfruttando altri metodi geofisici. La
Gravimetria,
in special modo le anomalie di 'Bouguer', mi hanno dato un valido
contributo,
pur tenendo conto dei limiti del metodo, sottolineando in modo
abbastanza
evidente ed uniforme le strutture evidenziate con la sismica crostale.
Infine
la Sismica passiva (sismologia) mi ha
permesso di collegare le unità strutturali con la
sismicità e la magnitudo di
tali eventi.
In
altra parte di questo lavoro presenterò
dettagliatamente i metodi e i dati usati.
Notes:
A.A. 1981-1982;
Relatore: Prof. R.Cassinis; Correlatore: Ing. S.Scarascia
Reference Type: Conference Proceedings
Record Number: 143
Author: GNGTS, CS
Year: 1982
Title:
Progetto italiano
"Dinamica ed evoluzione della Litosfera: programma-quadro per la
Geofisica
della Terra solida".
Conference Name:
Consiglio
Scientifico GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Rome
(I)
Abstract:
..... omissis...
TEMA
1. Ricerche sulla struttura profonda
dell'Italia e delle aree circostanti.
Obiettivi:
conoscenza della struttura della crosta
terrestre in Italia e mari circostanti, con particolare riferimento
alle
possibilità di sfruttamento di risorse minerali ed
energetiche, di riduzione
del rischio sismico e geologico, alla protezione dell'ambiente.
SOTTOTEMA
1.1:
Modello strutturale d'Italia.
Questo
sotto-tema, già iniziato dal P.F.
'Geodinamica', sarà continuato attraverso le seguenti linee
di ricerca:
1.1.1:
Carta Gravimetrica d'Italia
...................
omissis
1.1.2:
Anomalie del potenziale di gravità
...................
omissis
1.1.3:
Profili sismici profondi
Costituiscono
il mezzo più potente e sistematico
per l'esplorazione diretta della Crosta terrestre e del Mantello
superiore, e
come tali sono la base su cui costruire il modello strutturale d'Italia.
Il
P.F. 'Geodinamica' aveva elaborato un programma
da realizzare dal 1975 al 1980 e costituito un "Sotto-Gruppo Grandi
Profili Sismici". Esso ha potuto realizzare nel 1975-1980 i profili di
cui
alla fig. 1. E' stato così possibile ricavare i primi
elementi sulla struttura
della Crosta Terrestre nelle Alpi, in Toscana, nell'Italia meridionale,
in
Sicilia, oltre che nel mare Tirreno e Canale di Sicilia. Questi
elementi sono
di fondamentale importanza scientifica, per i problemi di sfruttamento
delle
risorse del sottosuolo e per la difesa dell'ambiente, aprendo nuovi
orizzonti
di ricerca e lasciando però scoperte molte aree. A partire
dal 1982, il
programma sarà continuato fino al raggiungimento
dell'obiettivo principale prefissato,
che è quello di arrivare, utilizzando anche i dati di
gravità e aeromagnetismo,
ad un modello 3D della struttura della Crosta Profonda in Italia e mari
circostanti.
...................
omissis
Notes:
Verbale della seduta
del CS del GNGTS del 5/7/1982; Allegato n. 2 (22 pp.)
Reference Type: Conference Proceedings
Record
Number: 187
Author:
Biella, Giancarlo;
Gaudiosi, Germana; Guerra, Ignazio; Luongo, Giuseppe; Maistrello,
Mariano;
Scarascia, Salvatore
Year: 1983
Title:
Profili sismici profondi
in sardegna - 1982
Conference Name: 2nd GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (CNR)
Volume: 1
Number of Volumes: 1
Pages: 127-139
Abstract: As preparation for the seismic experiments
planned
in 1983 in the frame of the "European Geotraverse", three deep
seismic soundings were carried out in Sardinia during 1982.
Preliminary results
of the WNW-ESE profile (Funtanazza-C.Ferrato) and of the N-S profile
(C.Ferro-C.Ferrato) are presented here.
1)
Funtanazza-C.Ferrato profile.
Crustal thickness
reaches the maxima values of 31-32 km in the middle of Sardinia and its
western
margin, while it grows thinner in the direction of the tyrrhenian
coast, where
a thickness not greater than 25-26 km has been interpreted. A reduction
of the
crustal thickness is also present under the Campidano graben. Moreover
a
shallower discontinuity (from 6.5 to 7.0 km/s) appears along the whole
profile,
that seems to break off near the eastern margin of the island..
2)
C.Ferro-C.Ferrato profile.
The crustal
thickness is 28 km in the southern sector of the profile and 32 km in
the
northern sector. The presence of a "soft mantle" is evidenced.
The crustal
structure along the explored profiles may be related to the opening of
the
Tyrrhenian abyssal plain.
Reference Type: Conference Proceedings
Record
Number: 64
Author:
Bottari, A.; Caccamo,
D.; Carapezza, E.; Cosentino, Mario; Cosentino, Pietro; Federico, B.;
Fradella,
P.; Giudice, Emanuele Lo; Lombardo, G.; Neri, G.; Patanè,
G.; Trong, P. Hoang
Year: 1983
Title: Crustal regional travel times of P and S
waves in
Sicily
Conference Name: 2nd Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location: Roma (CNR)
Volume: 1
Number of Volumes: 1
Pages: 605-614
Abstract: The characterization of short period seismic
phases
for the Sicilian area is presented in this study. This aim is of
primary
importance for the standardisation of criteria used by local seismic
network
operating in Sicily, in the location of regional seismic events.
Travel times of
both longitudinal and transversal seismic phases, observed in the range
0.05 £ D° £6.00 were analyzed for about fifty earthquakes
which
took place during past decade in the area of Sicily. Hypocentral
parameters
were selected according to standards of I.S.C. and the detection of
each onset
of different phases was operated on local records, using suitable and
standardized criteria.
Such analysis made
possible to characterize equations of travel times of Pg, Pn, Sg, Sn
phases, as
well as a refracted phase which can be referred to the propagation of
longitudinal waves in lower crust.
Values of
velocities obtained are compared with those derived from the
interpretation of
several deep seismic refraction profiles, and they are interpreted in
the frame
of the geo-structural setting of the region.
Reference Type: Thesis
Record Number: 114
Author: Stangl, Reimund
Year: 1983
Title:
Geschwindigkeits-tiefen-verteilungen von P-wellen im
oberen mantle Süddeutschlands, die mit laufzeit und
amplitudenbeobachtungen auf
zwei gegen-geschossenen langsprofilen verträglich sind.
Academic
Dept.:
Geophysikaliches Institut
University:
Universität Karlsruhe
City:
Karlsruhe (D)
Pages:
172
Thesis
Type:
Diplomarbeit
Abstract:
1.1: Die Erforschung des obersten Erdmantels mit
sprengseismichen Methoden, ein kurzer Überblick
............
omissis..............
1.2:
Die Inversion
bzw. Interpretation von refraktionsseismichen Beobachtungen
............
omissis
..............
1.3:
Die Problematik
der Interpretation von Laufzeiten
............
omissis
..............
1.4:
Untersuchung der
geschwindigkeitsstruktur des oberen Erdmantels in
Süddeutschland, Einführung in
die Fragestellung.
Reference Type: Journal Article
Record Number: 44
Author:
Steinmetz, L.;
Ferrucci, Fabrizio; Hirn, Alfred; Morelli, Carlo; Nicolich, Rinaldo
Year: 1983
Title: A 550 km long Moho traverse in the Tyrrhenian
Sea
from O.B.S. recorded Pn waves.
Journal: Geophysical Research Letters
Volume: 10
Issue: 6
Pages: 428-431
Abstract: Six OBS deployed on a 550 km line in the
Tyrrhenian
Sea furnish reversed and overlapping profiles from 43 shots at 12 km
intervals.
Head waves recorded from a 8 km/s refractor, the Moho, permitted the
computation of the crustal thickness, which shows this basin to be
underlain by
an oceanic type of crust, at least in two 100 km wide regions.
Variations of Pn
arrival times mirror strong topographycal changes of the Moho.
Differences in dips
at the extremities towards Corsica and Calabria are documented.
Reference Type: Journal Article
Record Number: 139
Author: Cassinis, Roberto
Year: 1983
Title: Seismicity and crustal structure in the
Italian
region: a preliminary zoning.
Journal:
Bolletttino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XXV
Issue: 97
Pages: 3-26
Abstract: The relationship between seismicity and
crustal
structure along the Italian mobile belt is complicated by the collision
between
Eurasian and African plates.
Therefore, the
active or potential sources of earthquakes are positioned at various
levels,
both in the lower and the upper crust, including the shallow
sedimentary layers.
Very seldom the activity is found in the upper mantle, except along the
"Aeolian arc".
The paper
illustrates the first phase of an investigation on the elements of
unstability
in the crust. A preliminary zoning has been made, based mainly on
historical
seismic data. The relevant seismological parameters as well as other
geophysical data (deep seismic soundings results, gravity-anomalies)
are used
to characterize each zone.
In spite of the
insufficiency of some type of foundamental information, such as a
reliable
knowledge of the focal depth and of the focal mechanism, some results
have been
obtained that suggest priority objectives for a new phase of
geophysical
exploration.
One of the
conclusive remarks is that the earthquake sources of high Magnitude (M ³ 5.5) are all related to the main lateral
crustal
discontinuities outlined by seismic exploration. Other remarks concern
the
existance of boundaries where a sudden change of character of the
seismic
activity occurs, not always corresponding to the known boundaries
netween
surface geological units.
Reference Type: Report
Record Number: 209
Author:
Morelli, C.; Nicolich,
R.; Scotti, A.
Year: 1983
Title: EGT - DSS of the Lithosphere along the
Southern
Segment (Po Plain, Northern Apennines and Western Alps, Ligurian Sea,
Corsica,
Sardinia, Algeria). Report N. 1: Field data acquisition.
Institution:
OGS
Date:
10/'83
Type of Work: OGS Report
Report Number: 1
Abstract: The experiments for the Deep Seismic Sounding
of the
Lithosphere along the Southern Segment of the EGT (European
Geotraverse)
consist of a system of refraction seismic profiles from the Southern
Alps to
the Northern Africa with marine shots in Sardinia Channel, Bonifacio
Strait,
Ligurian Sea and land shots in Northern Apennines.
The marine program
has been carried out from September 7 to Sept. 19, with the italian CNR
research vessel "L.F.Marsili" and "Minerva". All the large
explosions (from 300 to 1125 kg) and all the small shots (75 or 100 kg)
between
Genova and Corsica, have been handled by the R.V. Marsili; the Ocian
Bottom
Seismographs (OBS) operations in the Ligurian Sea by the R.V. Minerva.
A newly developed
air gun equipment (UNI Hamburg), as an alternative energy source on
board of
the R.V.Minerva for the OBS experiment, has not been put into
operations
because of an interruption to the pipes carrying the pressured air
during the
handling in rough sea.
Both vessels were
equipped with positioning systems and with the instruments for the
recording of
the time-break and of the absolute times.
The communications
between the shooting crew on the ship and land stations were not
completely
satisfactory because of troubles with the 150 W radio transmitters
R.V.Marsili
and land communication Center of Mount Limbara (Sardinia).
..............................
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Reference Type: Conference Proceedings
Record
Number: 45
Author:
Baticci, G.; Vedova,
Bruno Della; Pellis, Giulio; Torelli, L.
Year: 1983
Title:
Lineamenti
geologico-strutturali del canale di Sardegna e aree limitroge.
Conference Name: 2' Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: 1'
Number of Volumes: 1
Pages: 725-735
Abstract: The Mediterranean Sea area between
North-Algerian
Basin and West Sicily is considered relating seismics, heat flow and
dredges.
Initial findings
point out some different geostructural trends in the explored area.
A division in
geologic domains is consequently proposed.
In details,
southern limit of Sardinia margin and the zone of possible first
opening of
Tyrrhenian Sea are defined.
Applying a new
mathematical model to the heat flow field we made time predictions on
some
important tensile thermotectonic events.
Reference Type: Conference Proceedings
Record Number: 111
Author: Finlayson, D.M.; Ansorge, Jorge
Year: 1983
Title: Workshop proceedings: Interpretation of
seismic wave
propagation in laterally heterogeneous structures.
Conference Name: 5th Workshop CCSS
(IASPEI)
Editor: Australian Government Publishing Service,
Canberra
1984
Publisher: Bureau of Mineral resources, Geology
&
Geopgysics
Conference Location: Einsiedeln (CH)
Volume: 1
Number of Volumes: 1
Pages: 207
Series Editor: BMR
Abstract: The IASPEI Commission on Controlled Source
Seismology (CCSS) held its 5th Workshop in Einsiedeln near Zurich (CH),
from 7
to 12 August 1983. The primary aim of this fourth "hard" workshop was
again a critical assessment and comparison of the various
interpretation
methods used by different groups.
The previous
workshop in Park City (USA, 1980) was to a large extent focused on
seismic
studies in laterally heterogeneous structures. For that purpose a set
of real
data from Saudi Arabia was distributed to the participants prior to the
workshop.
The discussions very quickly showed that most participants reached a
common
basis for their interpretation of the data covering the more
homogeneous area
of the Arabian shield, But when entering the transition region to the
Red Sea
the interpretations diverged considerably. This was partly caused by
the lack
of a sufficient amount of data to resolve this complicated structure
and partly
by the limited inversion techniques available at that time.
There is an
increasing number of seismologists applying new methods to determine
two-dimensional velocity distributions in the lithosphere from a
rapidly
growing amount of experimental data. A principal objective of having a
group of
people apply independently different concepts and methods to a common
data set
is to obtain an indication of the constraints and limitations which
various
methods of analysis can place on the resolution of such structures. A
synthetic
set of data may serve as the most suitable basis to reveal the power of
the
presently available analysis methods.
Realizing these
trends, it was proposed to concentrate once more on laterally
heterogeneous
structures as the major topic for the next workshop in Einsiedeln.
Again common
data sets were distributed and all participants were asked to apply
whatever
technique they find appropriate for the interpretation. Three specific
sets of
data were chosen for this purpose.
DATA SET I
consisted of 16 synthetic record sections whith true and normalized
amplitudes
provided by V.Cerveny
and I.Psencik (Praha).
The sections covered a realistically varying crustal structure over a
distance
range of 520 km. The aim was to find the initial laterally
heterogeneous model
from the synthetic sections.
The
inverse problem was
addressed with DATA SET II. From a two-dimensional seismic model with a
reasonable crustal structure proposed by W.Mooney (Menlo Park)
synthetic record
sections had to be calculated by whatever suitable method. During the
workshop
the tehniques and capabilities of the various procedures used to
synthesize
record sections for laterally heterogeneous structures were discussed.
A
3rd topic was to combine
interpretation of real seismic refraction and reflection data. The
geophysical
Institute of the University in Kiel (Germany) provided DATA SET III
covering a
distance range of up to 80 km from a geothermally anomalous area near
Urach in
Southern Germany.
This
Report contains a
collection of contributions to the topics one and three.
................
omissis............
Reference Type: Report
Record Number: 208
Author: Morelli, C.; Nicolich, R.; Scotti, A.
Year: 1984
Title: EGT - Souther Segment 1984: DSS in Sicily;
Field
data acquisition.
Institution: OGS
Date: October, 1984
Type of Work: OGS Report
Report Number: 1/'84
Abstract: The 1984 experiments of the DSS along the
Southern
segment of the EGT (European Geotraverse) consist of a system of
refraction
seismic profiles recorded on land in Sicily, with marine shots in the
Sicily
Channel, Southern Tyrrhenian Sea, Ionian Sea.
The program was
carried out from August 10th to 29th, by the italian research vessel
"Minerva". The vessel was equipped with positioning system and with
instruments for the recording of the time break and of the absolute
times. The
communications between the shooting crew on ship and the land stations
were
kept by a radio link (transmitters from FU-Berlin) which connected the
M/V
Minerva with the land communication Center of Mount Cammarata (Sicily).
The
weather conditions were satisfactory. Only a few changes in the
scheduled
program were requested for land stations.
...............................
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Reference Type: Thesis
Record Number: 118
Author: Deichmann, Nicholas
Year: 1984
Title: Combined travel-time and amplitude
interpretation of
two seismic refraction studies in Europe.
Academic Dept.: Geophysical Inst.
University: Swiss Federal Institute of Technology (ETH)
City: Zurich (CH)
Pages: 143
Thesis Type: PhD
Abstract: Refraction seismology is one of the most
effective
methods to obtain information about the structure of the Earth's crust.
However,
interpretations based on travel-time data alone suffer from a certain
degree of
non-uniqueness. Synthetic seismogram calculations for a number of
theoretical
models and the combined travel-time and amplitude evaluation of
digitized
refraction profiles in southwestern Germany and in the Southern Alps
illustrate
how information about the amplitude-distance behaviour of the recorded
waves
can contribute significantly to constraining the range of possible
interpretation.
The theoretical
model calculations were performed, mainly using the reflectivity
method, to
examine the effect of various physical parameters on the
amplitude-distance
behaviour of the wave refracted in the upper crustal basement (Pg) and
of the
reflected from the crust-mantle boundary (PmP).
This gave a
quantitative picture of how the peak in the amplitude-distance curve of
the
Pg-phase, caused by a positive velocity-depth gradient, is enhanced for
higher
frequency source signals, and how the end of the gradient zone or the
existance
of a velocity inversion below it accellerates the amplitude fall-off
with
distance. While the amplitude-distance behaviour of the PmP-phase can
be used
as a measure of the abruptness of the crust-mantle boundary itself, it
is not
sensitive to the structure of the transition zone just above it.
However, under
favourable circumstances, the signal character of the reflected waves,
in
particular the amplitude of possible precursors to the PmP, can help
distinguish between transitioons cinsisting of a smooth velocity
gradient, of a
stepwise increase in velocity or of a series of velocity inversions.
...........................
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Notes: published in Journal of Geophysics, 51,
153-164 and
52, 109-118.
Reference Type: Conference Proceedings
Record
Number: 184
Author:
Biella, Giancarlo;
Lozej, Alfredo; Scarascia, Salvatore; Tabacco, Ignazio
Year: 1984
Title:
Profili sismici in
Appennino settentrionale per l'esplorazione della Crosta superiore.
Conference Name: 3th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (CNR)
Volume: 1
Number of Volumes: 2
Pages: 117-128
Abstract: Four seismic refraction profiles, two of
which
reversed, were carried out in 1984 in order to increase the knowledge
of the
upper Crust structure. Four shots were fired (two of which quarry
blasts),
recorded by 45 land stations.
In the
record-sections three main phases are evident:
- P-wave correlated
in a first branch propagating mainly through the flysh cover;
- supewr-critical
reflections from an intermediate boundary, recorded at
distance more than 15 km. This phase has
been related to the top oo better to a discontinuity inside the
carbonatic
sequence;
- super-critical
reflections from a deeper boundary recorded at distance more than 25 km
and
related to the metamorphic crystalline basement;
Seismic models were
constructed by the ray-tracing method with a 'trial-and-error'
procedure; the
models show the following features:
- in the Northern
part of the studied area strong lateral velocity variations are
evident,
related to the 'Bobbio window'; the carbonatic sequence is 5-7 km
depth, while
the depth of the metamorphic basement varies from 10 to 12 km;
- in the Southern
part, the Flysh thickness is lower (2-3 km) than exected; the reflected
branches disappear; no reflections have been recorded from the
carbonatic
sequence and the crystalline basement.
The boundary
between Northern and Southern part corresponds to the
'Levanto-Ottone-Varzi'
line, which has been interpreted by some Authors as the boundary of the
Miocene
overthrust of the Alps on the Apennines.
Reference Type: Journal Article
Record Number: 133
Author:
Cassinis, Roberto;
Scarascia, Salvatore; Zini, E.
Year: 1984
Title: Shallow seismicity and seismic velocity
distribution
as determined by DSS in the Italian region.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: XXVI
Issue: 103
Pages: 49-59
Abstract: The available hypocenters of the earthquakes
with M ³ 3.5 have been compared with the functions of Vp
obtained
using the wide angle reflection seismic profiles (DSS). The comparison
is made
considering the hypocenters contained in a vertical cylinder with a
radius of
40 km around the average position of the calculated velocity function.
In spite of the low
homogeneity of the data on hypocenters (areal and temporal) as well as
of the
uncertainties of the velocity functions (especially concerning the
velocity
inversion) some interesting correlations can be seen also in the
general scale.
In the upper crust,
the highest magnitude and the strongest seismic activity seems
concentrated
near the top of the first low velocity zone where the velocity gradient
decreases.
This seems to
happen in the south eastern Alps as well as along the northern and
central
Apennines, while, in some areas like the Calabrian arc and north
Sicily, the
most active seismic layer seems to be located near the "M" transition.
Notes: Silver Anniversary Volume
Reference Type: Journal Article
Record Number: 77
Author: Menard, G.; Thouvenot, Francois
Year:
1984
Title:
Écaillage de la lithospère européenne
sous les Alpes
Occidentales: arguments gravimétriques et sismiques
liés à l'anomalie d'Ivrea.
Journal:
Bull. Soc. géol. France
Volume:
XXVI
Issue:
5
Pages:
875-884
Keywords:
Structure profonde; anomalie d'Ivrea; ècaillage
lithospherique; orogenèse alpine
Abstract: The Ivrea anomaly is the main geopgysical
feature in
the Western Alps. This paper presents a structural model built on
lithospheric
flaking. It takes account of the different facets of the anomaly
(mainly
gravitational and seismic). In this model, the "Ivrea body" is split
up into several upper mantle units, each unit being connected to a more
external and shallower thrust: a lower unit, at a depth of about 30 km,
is
connected to the thrust of the "massifs cristallins externes" upon
the Subalpine basement; the main unit, at a depth of about 10 km, is in
the prolongation
at depth of the frontal Penninic overthrust; a surface unit, straight
under the
Insubric line, is directly linked to the outcroping peridotites. If a
crustal
flaking can probably be put forward wherever a chain is built by
collision
processes, the share of the upper mantle in such a mechanism seems to
be an
original feature of the Western Alps. This character could be explained
by a
lenticular structure of the upper mantle which was produced during the
Liassic
rifting.
Reference Type: Conference Proceedings
Record
Number: 26
Author:
Ferrucci, Fabrizio;
Gaudiosi, Germana; Hirn, Alfred; Luongo, Giuseppe; L.Mirabile; Zullo,
Aldo
Year: 1985
Title:
Primi risultati di
indagini DSS nell'area vulcanica campana.
Conference Name: 5th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1'
Number of Volumes: 2
Pages: 639-646
Abstract: Linear and constant-offset profiles, carried
out in
1985-'86, put into evidence a very rough topography of the crust-mantle
interface across the neapolitan area of quaternary volcanism.
A least crustal
thickness of about 16 km is obtained under Campi Flegrei, marking the
top of a
sharp Moho uprise in the S-N direction.
First-order
structural heteorogeneity variations are also found at the immediate
West and
East of this zone, as well as along the Sorrento Peninsula at South.
Reference Type: Report
Record Number: 211
Author:
Morelli, C.; Nicolich,
R.; Vedova, B. Della; Scotti, A.
Year: 1985
Title: EGT - Southern Segment 1985: onshore Tunisia,
Sardinia and Sicily Channel experiments.
Institution: OGS
Date: September 1985
Type of Work: OGS Report
Abstract: The European Geotraverse (EGT) is an
international
project investigating the nature of the Lithosphere along a 4000 km
long line,
running from Scandinavia throughout Europe to Tunisia.
This profile
consists of three interlinking segments (Northern, Central and
Southern)
designed to investigate the three-dimensional structure, composition
and state
of the continental Lithosphere to be used as a basis for the
understanding of
its evolution and dynamics.
A series of seismic
experiments (termed EGT-S) have been performed across the Southern
segment in
1982, 1983 and 1985.
The 1985 programme
was carried out in Sardinia, Sardinia Channel, Tunisia and in the
western part
of the Sicily Channel.
The structure of
this region were to be investigated using a wide angle seismic
experiment. Shots
were to be fired at sea North (Sardinia Channel) and East (Sicily
Channel) of
Tunisia and onshore Tunisia. There were scheduled to be 120 seismic
stations on
land in Tunisia, 23 Ocean Bottom Hydrophones (OBHs) in the Sardinia
Channel, 15
OBHs in the Sicily Channel, 19 land stations in Sardinia and two ships.
The
experiments aimed at providing a detailed network (7 profiles and 5
land shots)
in Tunisia, a N-S oriented profile across the Sardinia Channel and a
NE-SW
profile in the Sicily Channel from the Pantelleria Graben to Mahedia
(Tunisia).
The results of this
study promise to provide a detailed picture of the following:
1) collisional
features in the Sardinia Channel between the European and Kabylian
structures;
2) transition from
the Sardinian block to the thinner crust of the Sardinia Channel;
3) transition from
the Sardinian block to the folded and thrusted Tellian amd Numidian
units of
northern Tunisia;
4) atlasic folds
and N-S axis in the center of Tunisia
5) transition from
the stable cratonic region of the Sahara to the Sahel-Pelagian block
area and
to the Pantelleria-Malta system.
......................................... omissis
........................
Reference Type: Conference Proceedings
Record Number: 207
Author: Galson, D.A.; Müller, St.
Year: 1985
Title: Second EGT Workshop - The Southern Segment.
Conference Name: EGT: the Southern
Segment
Editor: E.S.F.
Publisher: European Science Foundation - Strasbourgh
Conference Location: Venice (I)
Volume: 1
Number of Volumes: 1
Pages: 268
Series Title: European Geotraverse
Abstract: .......
omissis......
The Scientific Coordinating
Committee (SCC) for the EGT Project has arranged a series of EGT
Workshops in
order to facilitate the integration of these dtata and to offer a forum
for
early presentation and discussion of the preliminary results of the
Joint
Programme, as well as to provide a basis for the planning of further
experiments which are within the scope of the Joint Programme. In the
first
years of the Project, a great deal of attention has been given to the
Northern
segment,.....
omissis ......
The second EGT
Workshop, held in Venice, Italy, in February 1985, was concerned with
the
Southern Segment. This choice indicates the attention being directed to
this
Segment, where a series of seismic experiments (termed EGT-S) was
executed in
1983, and a southwards extension of which has been planned for July
1985. It
was essential at this time to draw together scientists who had worked
on the
1983 data set, along with a group of experts in the geology and
geophysics of
the area, to review the results of the 1983 experiments, as well as
those of
earlier years and, on the basis of this and the other, non-seismic data
presented, decide what should and could be done in the 1985 phase of
experiments.
.........................
omissis ....................
Notes: published with the aid of the UE Commission.
Reference Type: Conference Proceedings
Record Number: 144
Author: Morelli, Carlo
Year: 1985
Title: La
Geotraversa Europea
- settore sud: Risultati e prospettive.
Conference Name: 4th GNGTS meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 2
Number of Volumes: 2
Pages:
899-910
Reference
Type:
Journal Article
Record Number: 138
Author: Cassinis, Roberto; Mazzoni, P.; Ranzoni, A.
Year: 1985
Title: Active seismic layers and crustal structure
in some
Italian regions.
Journal: Journal of Geophysics
Issue: 56
Pages: 153-159
Keywords: Seismogenesis; Brittle-plastic transition;
Velocity
functions; Inversion zones
Abstract: Following a general comparison between the
hypocenters and crustal structure derived mainly from deep seismic
soundings, a
more detailed analysis is attempted in some areas of the Italian
region. This
study is undertaken by defining a region as homogeneous when the same
type of
velocity-depth functions has been obtained. All available earthquake
hypocenters within the area are used for the correlation with the Vp
distribution in order to obtain a sufficiently large number of data.
Where
available, low magnitude events and aftershock sequences have also been
used. The
conclusions already derived are more clearly confirmed.
In the
south-eastern Alps (Friuli) the main earthquake sources are in the
upper crust,
between 5 and 15 km, at the top of the first velocity inversion zone.
In
tuscany (thin continental, transitional crust) the seismicity is weak
and very
shallow. In the Calabrian arc, the main seismicity seems to originate
in the
lower crust or at the top of the lithospheric "lid" which appears to
be decoupled from the overlying, highly mobilized formations of the
crust.
Tentative
explanations of these different regimes are given with regard to the
influence
of factors that can determine the transition from brittle to
quasi-plastic
behaviour.
Reference Type: Book Section
Record Number: 141
Author: Morelli, Carlo
Year: 1985
Title: Seismicity and crustal structure in Italy.
Book Title: Seismic Activity in Western Europe
Editor: P., Melchior
Publisher: Reidel D. Publishing Company
City: Trieste
Volume: 1
Number of Volumes: 1
Pages: 145-155
Abstract: The extensive geophysical surveys in Italy,
especially ithe extended DSS profiles program (from 1956), have
permitted a
first knowledge of the main crustal conditions, which are very varied
and cover
most of the normaql and extreme features. Of particular importance for
the
understanding of the actual seismicity and of the chracter of the
seismogenetic
zones are:
- a long strip of
Moho vertical discontinuities, faults and subductions along the axis of
the
Apennines, from the Po Plain to Calabria, to which correspond the
maxima of
seismicity;
- the presence of
infra-crustal and crustal doublings all around the Adriatic microplate,
the
borders of which are also characterised by a strong seismicity.
Notes: Trieste University, IMGA, Contribution n. 99
Reference Type: Thesis
Record Number: 109
Author: Egger, Adrian
Year:
1985
Title:
Struktur der Lithosphere unter Korsika und Sardinien
abgeleitet aus refraktionsseismichen messungen.
Academic
Dept.:
Abteilung für Naturwissenschaften
University: ETH
City: Zürich (CH)
Pages:
109 (+ 9 anhangs)
Thesis
Type:
Diplomarbeit
Abstract:
Die europäischen geowissenschaftlichen Institutionen
haben 1982 ein Forschungsprojekt ausgearbeitet, das zum besseren
Verständnis
des Aufbaus der europäischen Lithosphäre und deren
Entwicklung vom Archaikum
bis zur Gewenwart beitragen soll. Dieses Projekt der
"Europäischen
Geotraverse (EGT)" verläuft von Nordskandinavien bis nach
Tunesien in
Nordafrika und ist in verschiedene Teilprojekte unterteilt.
Ein
Teil des
Südsegmentes der EGT kam im September 1983 zur
Ausführung. Die
refraktionsseismichen Messungen als Teilprojekt überdecken den
Westteil des
alpin-mediterranen Raumes von den Südalpen über die
Poebene und die nördlichen
Apenninen, das Ligusche Meer, sowie die Inseln Korsika und Sardinien.
Zudem ist
ein Teil der südlichen Westalpen, der Poebene und der
nördlichen Apenninen mit
Querprofilen abgedeckt.
.................
omissis...............
Notes: EGT 1983 seismic data processing (profile
N-S: from
Ligurian Sea to Sardinia Channel)
Reference Type: Thesis
Record Number: 128
Author:
Maistrello, Mariano
Year: 1985
Title:
Acquisizione ed
elaborazione digitale dei dati sismici a rifrazione profonda (DSS) per
lo
studio di strutture crostali.
Academic Dept.: Physics
University: Università degli studi
City: Milan (I)
Pages:
Vol.I: 112 pp. + 37 annexed; Vol. II: software package listings
Thesis
Type:
Diploma
Abstract: Le
registrazioni
sismiche di tutte le campagne di acquisizione (o se vogliamo tutti i
'dati' dei
profili sismici esplorati) sono state finora restituite, conservate ed
elaborate in maniera analogica.
L'attuale
rivoluzione post-industriale, con la
possibilità di usare massicciamente l'elaboratore numerico
('computer') a costi
ormai contenuti ed accessibili, unita agli indiscutibili vantaggi sulla
facilità della gestione-dati, ha fatto sì che
l'aspetto digitale entrasse
finalmente anche in questo relativamente 'povero' settore (che non
è legato
alla ricerca petrolifera!), contribuendo non poco ad affinare anche le
tecniche
interpretative: dalla restituzione della sezione-film digitale al
calcolo
diretto della funzione Velocità/Profondità, dalle
metodologie di 'ray-tracing'
alla costruzione dei 'sismogrammi sintetici', per l'approfondimento
teorico-pratico delle problematiche connesse con la modellistica
impiegata.
Scopo
del presente lavoro è illustrare in
dettaglio la metodologia impiegata per questa conversione al digitale,
realizzata nel nostro Istituto di ricerca: dalla conversione A/D dei
sismogrammi, alla restituzione degli stessi nella sezione-film digitale
attraverso una particolare tecnica di elaborazione; effettuare i
necessari
confronti con la versione analogica di partenza, evidenziare le diverse
possibilità di filtraggio numerico e, nella parte finale,
illustrare un intero
'percorso' interpretativo, impiegando anche l'altra parte di software
(qui non
presentato) relativa al grande ed appassionante settore della
eleborazione
numerica.
Notes:
A.A. 1984-1985;
Relatore: Ing. S.Scarascia; Correlatori: Dr. P.Cortellessa, Prof. G.
Degli
Antoni
Reference Type: Conference Proceedings
Record Number: 145
Author: Morelli, Carlo
Year: 1985
Title: Il
progetto strategico
"Crosta Profonda"
Conference Name: 4th GNGTS Meeting
Editor: CNR
Publisher: CNR
Conference Location: Rome (I)
Volume: 2
Number of Volumes: 2
Pages: 929-945
Abstract: From 10 years, the USA project COCORP for the
study
of the Earth's Crust and of the Upper Mantle by means of the deep
reflection
seismics (convenientely adapted in the recording technologies) is
giving
results of paramount importance for Science. Equally important are the
results
of similar more recent projects (BIRPS in U.K., ECORS in France, etc.).
Also to
answer to an analog request from EEC and of bordering Countries
(France,
Switzerland), the GNGTS has promoted, in agreement with the National
Committee
for Geological Sciences of CNR, an italian national program, which has
been
included in the Strategic Projects of the same CNR. A synthesis of the
Program
is presented, together with its social and economic finalities and to
the
organisatory and technological lines identified.
Reference Type: Thesis
Record Number: 115
Author: Cattaneo, Umberto
Year: 1986
Title:
Ricostruzione ed
applicazione di sismogrammi sintetici in modelli a due dimensioni nelle
prospezioni geofisiche di sismica crostale.
Academic Dept.: Physics
University: Università degli studi
City: Milan (I)
Pages: 149
Abstract: Si
è sviluppata
abbastanza recentemente una parte della Fisica terrestre (o Geofisica)
che si
occupa dello studio della Crosta terrestre, fino al Mantello, con
metodi
sismici. La finalità di tali studi è quella di
arrivare a costruire dei modelli
di strutture crostali, fino a profondità che possono andare
a circa 70 km, ove
è situata la transizione tra Crosta e Mantello
(discontinuità di Mohorovicic),
che possano fornire indicazioni per meglio comprendere la dinamica
terrestre.
Tutto ciò, oltre a contribuire a uno sviluppo di base nel
campo delle Scienze
della Terra, riveste anche rilevanti aspetti di interesse pratico.
In
particolare all'asssetto geologico di un territorio
è legato direttamente il problema dei terremoti e del
rischio sismico che,
specialmente in Italia, è di notevole importanza.
Per
svolgere queste indagini si utilizza il metodo
della "sismica attiva", in cui si fanno brillare, in pozzi profondi
alcune
decine di metri, delle cariche esplosive (fino a qualche tonnellata) e
si
registrano, lungo particolari profili, gli impulsi provenienti dalla
Crosta
terrestre. In seguito, interpretando i tempi d'arrivo e la forma degli
impulsi,
si arriverà a ricostruire un possibile modello della crosta
nella zona
investigata.
Il
presente lavoro si propone di studiare
l'aspetto dinamico degli impulsi: ampiezze, forma del segnale, ecc...
Dopo
un inquadramento del problema, si studierà da
un punto di vista fisico quali sono le leggi che descrivono la
propagazione
delle onde nei mezzi elastici, si illustrerà un metodo di
ricostruzione del
segnale sismico a partire da modelli matematici (approssimazione
dell'ottica
geometrica) e si applicherà ad un caso reale la tecnica dei
"sismogrammi
sintetici" per l'interpretazione dei dati sperimentali.
Le
ricerche in questa direzione non sono state
sinora affrontate in modo organico dagli Istituti scientifici italiani
e si
sono utilizzati principalmente programmi costruiti all'estero. Risluta
quindi
importante che anche in Italia ci sia un contributo allo sviluppo di
questa
tecnica, per una interpretazione più accurata dei dati.
Ciò
è necessario specialmente nella nostra regione
dove la situazione geologica è generalmente complessa e dove
occorrono, quindi,
strumenti di calcolo più raffinati.
Notes:
A.A. 1985-1986
Relatore:
Dr. Ing. S.Scarascia; Correlatore: Prof.
L.Galgani
Reference Type: Journal Article
Record Number: 37
Author:
Deichmann, Nicholas; Ansorge, Jorge; Mueller, Stephan
Year: 1986
Title: Crustal structure of the southern Alps
beneath the
intersection with the European Geotraverse.
Journal:
Tectonophysics
Issue:
126
Pages:
57-83
Abstract: Newly digitized and amplitude controlled
record sections
from the 1977 Southern Alps refraction compaign permitted a
reinterpretation of
the crustal structure in the area between western Lombardy and the
Giudicaria
fault. The resulting model exhibits considerable lateral heterogeneity:
in the
west, below 7.5 km of sediments of the Lombardy basin, the crust
reaches a
depth of only 31 km, whereas it thickness towards the more mountainous
area in
the east, reaching a depth of 46 km below the Adamello Massif.
Although the signal
character of the corresponding reflections is somewhat erratic, the
data are
satisfied best by models with a low-velocity zone in the upper crust.
An
additional small velocity discontinuity from 6.2 to 6.4 km/s was found
in the
middle crust at around 20 km. Earlier interpretations, based on
travel-times
alone, included a layer with a velocity of about 7 km/s at this depth.
This
high-velocity layer was then interpreted as lower-crustal material of
the
Adriatic-African plate, which had been overthrust onto the European
plate
during the Alpine orogeny, thus expalining the uplift of the Southern
Alps. However,
this model of crustal doubling is questionable, because such a
mid-crustal
high-velocity layer is not in agreement with the amplitude data. The
relatively
thin crystalline part of the crust under the Lombardy Basin is interpreted, in
accordance with
geological evidence, as e relic of a Late Hercynian rifting event.
Reference Type: Thesis
Record Number: 122
Author: Zappone, Alba
Year: 1986
Title:
Metodologia di
interpretazione mediante il metodo di costruzione dei sismogrammi
sintetici.
Academic Dept.: Eath's Science; Geology
University:
Università degli studi
City: Milan (I)
Pages: 41
Thesis
Type: PhD
Abstract:
L'insieme delle
procedure che permettono di passare dallo spazio dei dati sperimentali
allo
spazio dei modelli è detta 'inversione' dei dati.
Nell'insieme dei dati
sperimentali si può accedere per via strumentale ad un
sottoinsieme finito di
misure che sono caratterizzate dall'essere affette da errori ed
incomplete.
L'incompletezza
e gli errori impediscono di
definire univocamente un modello, ma una classe di modelli.
Il
sottoinsieme dei modelli geofisici in questione
è costituito dalla distribuzione dei parametri fisici che
caratterizzano la
propagazione dei mezzi attraversati dalle onde sismiche dalla sorgente
al sito
di registrazione:
-
geometrie del mezzo
-
velocità delle onde (P, S, superficiali)
-
coefficienti di anisotropia
-
fattori di attenuazione delle onde.
Da un
punto di vista fisico il mezzo può essere
definito in termini di distribuzione nello spazio del parametro:
-
omogeneo: il parametro è costante nel mezzo
-
disomogeneo: il parametro varia nel mezzo
-
isotropo: il parametro è costante in ogni
direzione
-
anisotropo: il parametro varia con la direzione
Oppure
il mezzo si può definire in termini di tipo
di onde sismiche che si propagano in esso:
-
acustico: onde di pressione (fluidi)
-
elastico: onde sismiche di compressione o di
taglio o di superficie (cristalli)
-
anelastico: onde sismiche attenuate (rocce).
.......................... omissis
....................
Notes: V
ciclo di Dottorato
(1986); Relatore: Dr. G.Biella
Reference Type: Conference Proceedings
Record
Number: 155
Author:
Cattaneo, Umberto;
Franco, Roberto de; Scarascia, Salvatore
Year: 1986
Title:
Sismogrammi sintetici
per strutture con variazioni laterali: un'applicazione su un profilo
sismico
crostale.
Conference Name: 5th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 1
Number of Volumes: 2
Pages: 733-750
Abstract: In this paper an example of synthetic
seismograms
for laterally varying structures in crustal seismic explorations is
given.
The examined
profile is the one explored in Sicily in 1984, in the frame of the
"European Geotraverse".
After a short
description of the employed method for synthetic seismograms based on
the
asymptotic ray theory (A.R.T.), of its performances and restrictions,
the
procedures followed in order to obtain the best fitting between
sperimental and
theoretical data are described. Particularly it is pointed out that
taking into
account both cinematic and dynamic data, remarkable restrictions to the
construction of the final model are introduced, thus obtaining a
probable
representation of the geologic-structural features in the explored
region.
Reference Type: Thesis
Record Number: 130
Author: Zuaboni, P.
Year: 1986
Title:
Interpretazione del
profilo sismico Perugia-Umbertide e confronto con i dati relativi ad un
pozzo
perforato nella zona del profilo
Academic
Dept.:
Geology
University:
Università degli studi
City:
Milan (I)
Pages: 36
Thesis
Type:
Sottotesi
Abstract: Nel
corso di una
campagna di ricerca lungo il profilo Perugia-Frontone, organizzato nel
1984
dall'IGL (CNR) e dall'Università di Perugia, fu evidenziato,
nell'area compresa
tra la media Valle Tiberina ed il lago Trasimeno, un possibile
raddoppio di
serie del basamento della zona umbra.
Per
verificare questi risultati e per ottenere
allo stesso tempo informazioni più precise sullo stile di
deformazione
interessante la copertura sedimentaria dell'Appennino
Umbro-Marchigiano, furono
effettuate altre campagne sismiche in zona. La scelta delle linee da
seguire fu
condizionata anche dalla presenza, nell'area in esame, di pozzi di
perforazione.
Il
lavoro di questa sottotesi è consistito dunque
nell'interpretare un profilo sismico ricavato durante tali operazioni
di
ricerca lungo il tratto Perugia-Umbertide.
................... omissis
....................
Notes:
A.A. 1985-1986;
Relatore: Ing. S.Scarascia
Reference Type: Thesis
Record Number: 131
Author: Azzali, Andrea
Year: 1986
Title:
Progetto e
realizzazione di un sistema automatico di registrazione dei segnali
sismici.
Academic Dept.: Physics
University: Università degli studi
City: Milan (I)
Pages: 111
+ 44 annexed tables
Thesis
Type:
Diploma
Abstract:
Punto cardine della
speculazione attiva nella Fisica terrestre e fonte preziosa di
significativi
dati che copiosamente arricchiscono una ormai radicata base di
conoscenza, la
prospezione sismica nelle sue più svariate tecniche
costituisce il punto di
forza che stimola l'avvio del presente lavoro.
Infatti
tra i numerosi metodi di indagine
geofisica che l'Uomo ha successivamente sviluppato (gravimetrici,
elettrici,
magnetici, radioattivi, ecc...) quello che fornisce le più
complete e
dettagliate informazioni è noto con la denominazione di
'sismica attiva',
attiva in quanto la tecnica in questione fa uso di esplosioni
controllate ed
energeticamente definite da programma. Questo metodo d'indagine
permette di
affrontare lo studio delle strutture crostali in base alle loro
specifiche
caratteristiche elastiche. Appare dunque chiaro che, a seguito di una
perturbazione del sottosuolo terrestre mediante una predeterminata
serie di
esplosioni controllate, vengono prodotte in detto mezzo delle onde
elastiche
che possono essere di due tipi differenti: onde longitudinali (il
vettore di
propagazione K è parallelo allo spostamento ondoso) e onde
trasversali (il
vettore di propagazione è perpendicolare allo spostamento).
Perciò in base alla
differente velocità di propagazione Vp delle suddette onde
nei successivi
strati componenti la crosta continentale
..................... omissis ...............
Lo
scopo del presente lavoro di tesi è quello di
progettare e realizzare uno strumento, in seguito chiamato 'timer'
programmabile, per l'automatizzazione della stazione di registrazione
dei
segnali sismici. L'introduzione di un tale strumento per
l'automatizzazione
della 'stazione' agevola notevolmente la successione delle operazioni,
in gran
parte ripetitive, svolte dall'operatore cui è affidata la
stazione durante le
operazioni in campagna per la raccolta dei dati sperimentali.
Gli
elementi componenti la stazione di
registrazione, contenuti in un'apposita custodia antiurto al fine dle
trasporto, comportano già un certo ingombro (ca 70x50x24 cm)
e una discreta
massa (ca 18 kg); pertando il timer programmabile deve avere delle
caratteristiche fisiche tali da inserirsi in questa situazione.
Inoltre, dato
il tempo limitato che l'operatore ha a disposizione per
l'allocazione-predisposizione della stazione automatica (infatti ad un
operatore sono date da gestire più stazioni), si tratta di
adottare una
soluzione non troppo complessa relativamente al problema della
programmazione
della stazione automatica.
Infine
si vuole implentare, sulla stessa scheda
hardware relativa al timer programmabile, un circuito dedicato alla
'scansione'
del tempo (generazione di un segnale di clock) il quale consenta di
'ricostruire' il talvolta evanescente segnale orario di tempo campione
ad alta
precisione (dell'ordine di 10-12) indispensabile
per
l'interpretazione del segnale sismico. Infatti l'assenza di un
qualsiasi
riferimento temporale di notevole precisione contemporaneamente alle
registrazioni dei segnali sismici, implica un'onerosa perdita di dati
sperimentali.
Notes:
A.A. 1985-1986;
Relatore: Ing. S.Scarascia; Correlatori: Prof. P.Guazzoni, P.I.
P.Secomandi
Reference Type: Conference Proceedings
Record
Number: 46
Author:
Ferrucci, Fabrizio;
Gaudiosi, Germana; Hirn, Alfred; Luongo, Giuseppe; Morelli, Carlo;
Nicolich,
Rinaldo; Steinmetz, L.
Year: 1986
Title:
Recenti risultati DSS
nell'area della Calabria meridionale e dello Ionio nord-occidentale.
Conference Name: 5th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: 1'
Number of Volumes: 2
Pages: 721-731
Abstract: Within the frame of a 850 km long traverse of
the
Tyrrhenian and North-Western Ionian basins (1979) a profile-fan
recording DSS
experiment was performed across the southern Calabria in 1984.
OBS and land data
allow to reconstruct the Calabria-Ionian transition, characterized by
strong
horizontal variations of the crustal structure and dramatical changes
in the
Moho topography.
Reference Type: Journal Article
Record Number: 49
Author: Ginzburg, A.; Makris, Jan; Nicolich, Rinaldo
Year: 1986
Title: European Geotraverse: a seismic refraction
profile
across the Ligurian Sea.
Journal:
Tectonophysics
Issue:
126
Pages:
85-97
Abstract: A seismic refraction profile was shot in the
Ligurian Sea between Italy and Corsica in September 1983. The profile,
which is
part of the southern portion of the European Geotraverse (EGT), was
shot using
small dynamite charges, and the seismograms were recorded by ocean
bottom
seismometers and land stations, resulting in a number of partially
overlapping
reversed profiles.
The refraction data
were interpreted by means of the velocity-intercept and ray-tracing
methods,
using seismic reflection derived velocity-depth information for the
sedimentary
section. Refraction velocities of 4.8, 6.0 and 6.6 km/s were calculated
for the
base of the sedimentary section, crystalline basement and lower crust,
respectively. An upper mantle velocity of 7.4 km/s was inferred using
the
refraction profiles recorded on Corsica.
The interpretation
of the data indicates a prominent high in the crystalline basement in
the
northern part of the profile, while the sedimentary section increases
in
thickness from about 1.5 km over the basement high to over 6 km between
the
basement high and Corsica, and includes a considerable thickness of
pre-Miocene
sediments.
The crust-mantle
boundary shows shoaling towards the centre of the profile, where a
minimum
crustal thickness of 16 km is reached. The model, therefore, is that of
a
stretched and thinned continental crust which was rifted in
Oligo-Miocene
times. The presence of a low-velocity upper mantle may be indicative of
the
present renewal of subcrustal activity under the Ligurian Sea.
Reference Type: Journal Article
Record Number: 47
Author: Makris, Jan; Nicolich, Rinaldo; Weigel, W.
Year: 1986
Title: A seismic study in the western Ionian Sea.
Journal:
Annales Geophysicae
Volume:
4
Issue: B, 6
Pages: 665-678
Keywords: seismic soundings; seismic reflection; crust;
Ionian
Sea.
Abstract: By combining reflection seismic data with
deep
seismic soundings along two profiles offfshore Calabria and Sicily, we
obtained
the following results.
The continental
crust of the Ragusa-Sicily plateau thins from appr. 30 km below the
plateau to
nearly 17 km at the Malta escarpment. For almost 150 km to the
south-east offshore
Sicily the crust is 15 to 17 km thick, of which 6 to 7 km are
sediments. Further
to the south-east the crust thins to 11 km, but the sediments retain
their
previous thickness (nearly 7 km); thus, the crystalline or igneous part
of the
crust is reduced in thickness from more than 7 km to approximately 5
km, and
could be of oceanic origin, or severely stretched continental intruded
by upper
mantle material.
The geometry and
thickness of the sediments show clearly that the escarpment was formed
for the
greater part in post-Tortonian times. The tectonic activity and
tendency to
further subsidence are well evidenced in the deformation of even the
most
recent sediments, and in the continuing seismicity.
The results
obtained permit the following evolutionary model for the IOnian Sea. An
early
Mesozoic oceanic crust floors most of the deep part of the basin. A
passive
continental margin extending for nearly 150 km between Sicily and the
deep part
of the basin was exposed during Mesozoic times to moderate subsidence
creating
not more than 2 to 3 km of sediments. A very active phase of
tectonization and
subsidence formed the escarpment, and produced nearly 2 to 3 km of
sediments
during the Miocene. This faulting and folding activity at the Calabrian
arc is
still very intensive.
Reference Type: Report
Record Number: 210
Author:
Morelli, C.; Nicolich,
R.; Scotti, A.
Year: 1986
Title: EGT - Central Segment 1986: onshore Po-Plain
and
offshore Ligurian Sea experiments.
Institution: OGS
Date: October 1986
Type of Work: OGS Report
Abstract: The European Geotraverse (EGT) is an
international
project investigating the nature of the Lithosphere along a 4000 km
long line,
running from Scandinavia throughout Europe to Tunisia.
This profile
consists of three interlinking segments (Northern, Central and
Southern)
designed to investigate the three-dimensional structure, composition
and state
of the continental Lithosphere to be used as a basis for the
understanding of
its evolution and dynamics.
A series of seismic
experiments (termed EGT-S) have been performed across the Southern
segment in
1982, 1983 and 1985.
The 1985 programme
was carried out in Sardinia, Sardinia Channel, Tunisia and in the
western part
of the Sicily Channel.
In 1986 the
Programme was performed across the Central Segment (EGT-C) concerning
in Italy
the Ligurian Sea and the Po Plain, and towards the Northern
Switzerland,
Germany as far as the German/Danish border.
In Italy a shot was
fired in the Gulf of Genoa (SP.A) and 4 on land, plus 2 test shots.
I.M.G.A. (UNI
Trieste) was charged with the shooting operation of shots A, B01
(test-shot),
B1, B02 (test-shot) and B2.
In Italy the
experiments aimed at providing a detailed picture of the following:
a) interaction
Ligurian Sea - Maritime Alps - Northern Apennines and Po Plain;
b) investigation of
Po Plain's deep structure;
c) Alpine
collisional zone and interaction with the Po Plain's structures.
The operations at
sea were performed on Sept. 25th aboard the italian research vessel
"Minerva".
........................................ omissis
.....................
Reference Type: Book Section
Record Number: 92
Author: Morelli, Carlo
Year: 1986
Title: Deep crustal knowledge in Italy.
Book Title: Reflection Seismology: a global Perspective
Editor: Barazangi M., Brown L.
Publisher: A.G.U.
City: Washington D.C.
Volume:
13 (Geodynamics Series)
Pages:
161-164
Series Title: Geodynamics
Abstract: From 1956 to 1982 extended deep seismic
surveys have
been performed in Italy under the auspices of the Consiglio Nazionale
delle
Ricerche (CNR) and the European Seismological Commission (ESC, an
IASPEI
Commission).The surveys were carried out on a number of different
tectonic
domains, both on land and on sea (orogens: Alps and Apennines; island
arc:
Calabria; thick sedimentary Basins: Po Plain and peri-Apenninic basins;
rifts:
Sicily Channel; paleo-rifts: Ligurian Sea, Sardinia; oceanic crust:
Tyrrhenian
Sea). In particular, the Apennines domain is the area where in the
1930's
geologists discovered that overthrusts are the dominant feature.
The main results
are: (1) on both the continental and the oceanic domains different
types of
crustal structure have been revealed; (2) a double crust probably
exists all
around the Adriatic microplate; (3) extended Moho faulting along the
axis of
the Apennines, from the Po Plain to Calabria, was delineated and found
to be
correlated with the strongest seismicity in Italy; (4) a deep certical
Moho
fault with -10 km throw was found in the Larderello geothermal area.
Notes: Publication No. 0112 of the I.L.P.
Reference Type: Conference Proceedings
Record Number: 137
Author: Mele, Francesca; Valensise, Gianluca
Year: 1987
Title: Un
modello crostale
per la localizzazione di eventi sismici regionali rilevati dalla rete
sismica
nazionale centralizzata dell'I.N.G.
Conference Name: 6th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 3
Number of Volumes: 3
Pages: 1377-1395
Abstract: The centralized National Seismic Network of
the National
Institute of Geophysics was established in 1982 with the aim of
real-time
monitoring of the seismicity in the Italian region and of collecting
data for
seismological studies concerning the OItalian Peninsula and surrounding
Countries. For both the monitoring and the scientific processing
purposes an
accurate location of the events occurring within the area covered by
the
network is needed. However, it is well known that the accuracy of
hypocentral
locations is strongly affected by the assumptions made about the
velocity
structure. This paper reports recents achievements of the I.N.G.
concerning the
knowledge of the crustal structure in the Italian area; the new
acquisitions
are mostly geared towards a more precise extimation of the hypocentral
parameters. The method we use implies subdivision of the country and
surrounding areas in 36 crustal blocks, each one composed by two
crustal layers
and an half-space. All the blocks are assumed to be laterally
homogeneous. By
inverting 6321 Pg-Pn observations, we simultaneously relocated more
than 100
crustal earthquakes occurred between 1984 and 1987, computed thickness
and Pn
velocity for each block, and evaluated static corrections for more than
200
stations located in the investigated area. Subsequent checks have shown
that
the proposed crustal model allows significant improvement in the
accuracy of
the hypocentral locations, not only for today's earthquakes but also
for those
recorded since the network has been established.
Reference Type: Thesis
Record Number: 124
Author: Viel, Lotar
Year: 1987
Title:
Untersuchung der Lithosphärenwurzel unter den Alpen mit
hilfe teleseismicher laufzeitresiduen.
Academic
Dept.:
Institut für Meteorologie und Geophysik
University: J.W.Goethe Universität
City:
Frankfurt am main (D)
Pages:
104 (+ 28 fig.)
Thesis
Type:
Diplomarbeit
Abstract:
Die Erforschung der Tiefenstruktur der Alpen ist ein
Problem, das die Geophysiker seit drei Jahrzehnten intensiv
beschäftigt. Zur
Untersuchung der Erdkruste und des Erdmantels kommen neben
sprengseismischen
und gravimetrischen vor allem die seismologischen Verfahren in
Betracht. Aber
auch hier gibt es mehrere Möglichkeiten, die
bezüglich ihrer Anwendbarkeit und
Aussagekraft - je nach Problemstellung - unterschiedliche Vor - und
Nachteile
besitzen. es ist deshalb oftmals nötig, die Ergebnisse
mehrerer - methodisch
unterschiedlicher - Untersuchungen in einem Gebiet gemeinsam zu
betrachten, um
zu einer schlüssigen Interpretation zu gelangen.
........................
omissis ................
Reference Type: Report
Record
Number: 188
Author:
Scarascia, Salvatore;
Franco, Roberto de; Biella, Giancarlo
Year: 1987
Title:
Rilievi sismici
nell'area vulcanica campana: Pozzuoli-'85.
Institution: CNR-IGL
Date: July 1987
Type of Work: IGL Report
Abstract: Nel
Maggio 1985 sono
stati eseguiti numerosi esperimenti di sismica nell'area vulcanica
della
Campania, comprendenti il Vesuvio, i Campi Flegrei e Roccamonfina. Tali
esperimenti sono stati finanziati dalla Regione Campania e sono stati
organizzati dall'Istituto di Oceanografia dell'Università di
Napoli. Vi hanno
partecipato numerosi Istituti geofisici italiani (Napoli, Milano,
Genova,
Trieste, Lecce) e l'I.P.G. di Parigi. Essi avevano lo scopo della
ricostruzione
del modello strutturale nell'area esplorata e soprattutto nell'area dei
Campi
Flegrei dove si erano ripetuti recentemente movimenti bradisismici.
La
massima parte dei rielievi effettuati è
riportata in fig.1. Essi cionsistono in una serie di 5 profili
esplorati da 3
punti di scoppio localizzati a mare, e 2 profili 'ad arco' (o 'fan').
L'ubicazione dei profili e dei punti di scoppio, come pure quella degli
archi,
è stata programmata al fine di avere il massimo delle
informazioni sulla
struttura crostale in una fascia di territorio approssimativamente a
cavallo
della linea di costa compresa tra la Penisola Sorrentina e Gaeta,
attraverso il
Vesuvio e i Campi Flegrei. La posizione degli specchi riflettenti dei
ventagli
'C' e 'B' indica approssimativamente la fascia di territorio esplorata.
In
particolare l'area di Pozzuoli è interessata
contemporaneamente dai profili DD,
DP, e dagli archi Fan-C e Fan-B.
................................ omissis
................
Notes: Una
versione in
inglese è stata presentata al XIX IUGG General Assembly
(Vancouver, CA;
9-22/8/1987).
Reference Type: Conference Proceedings
Record
Number: 83
Author:
Bottari, A.;
Cannatelli, D.; Federico, B.; A., A. Teramo
Year: 1987
Title: A crustal model with spherical symmetry for
Sicily. Travel
time equations and stripping techniques.
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 3
Number of Volumes: 3
Pages: 1125-1136
Abstract: Pointed out that a crustal model for the
structures
that cgaracterize Sicily is needed, a method to draw up a better model
for P
and S waves, more refined than a previous one, is proposed.
Our study starts
from an analysis of a great number of travel times observed, for the
most part,
by the stations of the Messina Strait seismic network and by the
portable
stations of the Insititut de Physique du Globe of Strasbourg seismic
network on
the occasion of a sequence of explosions for exploration of Sicily
crust
(1984).
To outline the
model a technique called "stripping", already tested un previous
studies, is used, This approach allows to determine crustal models for
P and S
waves, taking into account earth curvature. Particularly the travel
time
equations coefficients for direct phase and refracted one on the four
crustal
layers found, have been computed.
Besides, an
analysis of medium and per cent errors in computation of travel time
equations
coefficients allows a valuation of reliability of the model proposed,
in
comparison to other models derived by similar techniques.
Reference Type: Conference Proceedings
Record Number: 54
Author: Ferri, Mario; Guerra, Ignazio; Kovachev,
S.A.;
Kuzin, I.P.; Luongo, Giuseppe; Soloviev, S.L.
Year: 1987
Title:
Osservazioni sismografiche
nel Tirreno meridionale mediante OBS e stazioni temporanee a terra.
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1'
Number of Volumes: 2
Pages: 235-246
Abstract: In May 1987 a seismic reconnaissance survey
was
carried out in the southern Tyrrhenian Sea. Five OBS were deployed
between the
coast-line and the sub-marine volcano 'Palinuro', while nine temporary
digital
seismographic stations were operated along the Tyrrhenian coast of
Calabria.
Preliminary
analysis of the records shows that the data from OBS are very helpful
in
overcoming the difficulties arising from the geographical configuration
of the
area. Algorithms that can take into account the strong lateral
variations of
the geological structures improve at a significant degree the quality
of the
hypocentral locations.
The OBS recorded
numerous low energy events, very similar in shape to
ultramicroearthquakes
observed in the volcanic tremor preceeding the 1983 eruption of Mt.
Etna.
Reference Type: Journal Article
Record Number: 193
Author: Bayer, Roger; Cazes, Michel; Piaz, Giorgio
Dal;
Damotte, Bernard; Elter, Giulio; Grosso, guido; Hirn, Alfred; Lanza,
Roberto;
Lombardo, Bruno; Mugnier, Jean-Louis; Nicolas, Adolphe; Nicolich,
Rinaldo;
Polino, Riccardo; Roure, Francois; Sacchi, Rosalino; Scarascia,
Salvatore;
Tabacco, Ignazio; Tapponnier, Paul; Tardy, Marc; Taylor, Matthew;
Thouvenot,
Francois; Torreilles, Gérard; Villien, Alain
Year:
1987
Title:
Premiers résultats de la traversée des Alpes
occidentales par sismique reflexion verticale (Programme ECORS-CROP).
Journal:
C.R. Académie des Sciences - Paris
Volume:
305
Issue:
Série II
Pages: 1461-1470
Abstract: A line-drawing summarisez the first results
of a
deep seismic profile through the western Alps. <the main
reflectors display
an apparent 20° East dip, underlying major lithospheric thrusts
produced by the
recent collision and typical of a crustal accretion prism. The internal
suture
zones and the Sesia and Ivrea Units are transparent to 10-14 km,
suggesting the
presence of steep structures to that depth.
Reference Type: Conference Proceedings
Record
Number: 79
Author:
Carrozzo, Maria
Teresa; Colella, Pietro; Luzio, Dario; Margiotta, C.; Quarta, Teresa
Year: 1987
Title:
Interpretazione
comparata sismica e gravimetrica lungo i profili C.Tindari-Gela e
Marsala-C.Passero.
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 3
Number of Volumes: 3
Pages: 1075-1094
Abstract: A comparative interpretation of seismic and
gravimetric data is carried out. Data were obtained in 1984 in Sicily
along the
profiles C.Tindari-Gela and Marsala-C.Passero.
We think that the
results do not deny the hypothesis of a crust doubling in north-eastern
Sicily
(Calabrian-Peloritan arch) and show a typically continental crust along
the
profile Marsala-C.Passero.
Reference Type: Conference Proceedings
Record Number: 80
Author: IESG; Project, Italian Explosion Seismology
Group -
Sicily
Year: 1987
Title:
Profili sismici
profondi in Sicilia Nord-Orientale (1986)
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 3°
Number of Volumes: 3
Pages: 1063-1074
Abstract: In this paper a first field work executed by
the
D.S.S. Group of the "Progetto Sicilia" in order to acquire
experimental data in North-Eastern Sicily is described.
Three offshore shot
points executed by the Osservatorio Vesuviano of Naples in order to
study the
geological structures of the Eolian Island have been recorded by twenty
seismic
stations in order to investigate the structure of the crust along an
ENE-WSW
profile (135 km in lenht) going from Capo Milazzo to Geraci Siculo.
Three other
shot points, located along the offshore prolongation of the line
Tindari-Letojanni have been used to record a triple fan (60 km in
lenght) along
the Northern coast of Sicily from Rocca di Caprileone to Spadafora.
Finally some
digitized seismic film sections are presented.
Reference Type: Conference Proceedings
Record
Number: 85
Author:
Carrozzo, Maria
Teresa; Colella, Pietro; Luzio, Dario; Margiotta, C.; Quarta, T.
Year: 1987
Title:
Interpretazione
gravimetrica e sismica lungo i profili Cefalù-Sciacca e
Cefalù-Gela e possibile
modello cristale tridimensionale.
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 3
Number of Volumes: 3
Pages: 1095-1114
Abstract: A comparative interpretation of seismic and
gravimetric data has been carried out. Data were obtained in 1984 in
Sicily
along the profiles Cefalù-Sciacca (II) and
Cefalù-Gela (III). The results,
together with those concerning the profiles Marsala-C.Passero (I) and
C.Tindari-Gela (IV), have been syntetized into a schematic 3-D crustal
model.
Reference Type: Conference Proceedings
Record
Number: 185
Author:
Cosentino, Mario;
Cosentino, Pietro; Domenico, R. De; Candela, E. Gagliano; Luzio, Dario
Year: 1987
Title:
Tentativo di
integrazione di dati geofisici e geologici per problemi strutturali
nell'area
di Caltabellotta (Sicilia Sud-occidentale).
Conference Name: 6th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (CNR)
Volume: 3°
Number of Volumes: 3
Pages:
1137-1143
Abstract:
Questo rapporto,
presentato in forma sintetica, rappresenta una relazione sullo stato di
avanzamento del ben più ampio lavoro di reinterpretazione
dei dati geofisici
crostali nell'area della Sicilia occidentale.
La
ricerca viene condotta con metodologie
integrate per poter giungere ad un'interpretazione in tre dimensioni
delle
strutture tettoniche e geodinamiche che interessano l'area in studio.
Ci si
è serviti della maggior parte dei dati
geofisici e geologici disponibili, che possono essere schematicamente
raggruppati in:
-
dati di sondaggi (geofisici e geognostici);
-
dati areali (metodi di potenziale o assimilati).
La
reinterpretazione è partita da un'area più
ristretta (zona di Caltabellotta) dove il numero di dati di ambedue i
tipi è
più copioso e la loro raccolta già fatta.
L'indagine si va estendendo
gradualmente alle aree limitrofe utilizzando i dati che meglio si
prestano ad
individuare gli andamenti laterali delle strutture (gravimetria,
magnetismo,
profili sismici ed elettrici). La disponibilità di ulteriori
dati idonei a
ricostruire l'andamento delle strutture lungo la direzione verticale
nelle aree
più esterne (soprattutto i risultati della campagna sismica
a riflessione
profonda prevista nell'ambito delle ricerche del programma CNR-Regione
Sicilia)
permetterà di giungere ad un modello tridimensionale
dell'intera area che sia
compatibile con tutti i dati sperimentali.
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[ top ]
Reference Type: Conference Proceedings
Record
Number: 84
Author:
Carapezza, E.;
Carrozzo, Maria Teresa; Colella, Pietro; Cosentino, Pietro; Domenico,
R. De;
Fradella, P.; Gagliano-Candela, E.; Luzio, Dario; Margiotta, C.;
Quarta, T.
Year: 1987
Title:
Interpretazione
comparata sismica e gravimetrica lungo il profilo crostale
C.Milazzo-Geraci
(Sicilia).
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 3
Number of Volumes: 3
Pages: 1115-1124
Abstract: In this paper an interpretation of the
seismic
refraction crustal profile recorded in the 1986 by D.S.S. Group of the
'Sicilia' Project is presented. The profile was recorded using three
shot
points executed in the Tyrrhenian Sea by the Osservatorio Vesuviano in
order to
study the buried structures of the Eolian islands.
The profile, about
135 km in length, was preliminarly interpretated using only two shot
points
located offshore, in the N-E part of the profile. For this
interpretation
gravity data, other interpreted seismic refraction profiles as well as
geo-structural information referred to the investigated area have been
taken
into account.
Reference Type: Conference Proceedings
Record Number: 189
Author: Nicolich, Rinaldo; Group, e CROP-ECORS Working
Year: 1987
Title: CROP-ECORS activity in the western Alps: a
summary.
Conference Name: 6th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (CNR)
Volume: 2
Number of Volumes: 3
Pages:
883-886
Abstract: Nel
1985 è stato
promosso il programma italo-francese CROP-ECORS per lo studio con i
metodi
sismici di una traversa nelle Alpi Occidentali. Esso è
iniziato con
l'applicazione di tecniche a grande angolo con obiettivo la
discontinuità
crosta/mantello e preliminari alla sismica a riflessione eseguita nel
1986 e
completata nel 1987. Risultati ancora preliminari confermano
l'esistenza nelle
Alpi occidentali di un prisma di accrezione e di un sistema di
sovrascorrimenti
interessanti tutta la litosfera.
Reference Type: Conference Proceedings
Record
Number: 36
Author:
Pino, N. A.; Ferrucci,
Fabrizio; Godano, C.
Year: 1987
Title:
Applicazione del
metodo del rey-tracing dinamico con fasci gaussiani ad alcuni dati DSS
ottenuti
nell'area vulcanica napoletana: nota preliminare.
Conference Name: 6th GNGTS meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 2
Number of Volumes: 3
Pages: 887-893
Abstract: A DSS profile crossing the Phlegrean Fields
(Naples)
along a roughly S-N direction is analized by the use of the gaussian
beam
method. Synthetic seismograms in good agreement with the experimental
data are
obtained.
A 2-Dimensional
modeling of the crustal structure beneath the volcanic area has been
also
performed, fitting a first-order travel-time discontinuity revealed at
the
immediate East of the Phlegrean Fields by a fan-recorded shot at sea.
The results show a
Moho deepening towards East as well as the possible presence of a thin
but
strong velocity inversion in the intermediate crust, moving towards
South along
the fan.
Reference Type: Journal Article
Record Number: 75
Author:
Biella, Giancarlo;
Gelati, Romeo; Maistrello, Mariano; Mancuso, M.; Massiotta, P.;
Scarascia,
Salvatore
Year: 1987
Title: The structure of the upper Crust in the
Alps-Apennines boundary region deduced from refraction seismic data.
Journal:
Tectonophysics
Issue:
142
Pages:
71-85
Abstract: Analysis of data gathered during the 1983
European
Geotraverse southern segment (EGT-S '83) experiments in the region
extending
from the Emilia-Liguria Apennines to the western Alpine Arc together
with data
from seismic profiles in the northwestern Apennines accumulated within
the
framework of the Alps-Apennines Orogene Study Group indicate new
details on the
structure of the upper crust east and west of the Alps-Apennines
boundary.
The main results of
this analysis centre on two areas. In the Piedmont tertiary Basin we
could
determine the depocenter configurations of the 6-7 km thick terrigenous
sequence and differentiate the tectonic units in the Piedmont (Alpine)
and the
Ligurian (Apennines) domains within the basement. In the other area,
the
Insubric domain underneath the Ligurian nappes of the northern
Apennines, we
found indications of tectonic doubling within the terrigenous-carbonate
sequence in which thrusting attenuates towards the underlying basement,
detected at a depth of 12-15 km. In addition, we found that, on a line
from the
Emilia Apennines to the Monferrato Hills, displecement of the Ligurian
nappes
over the Insubric domain diminuishes to nearly one-third its original
extend.
Reference Type: Conference Proceedings
Record
Number: 27
Author:
Biella, Giancarlo;
Franco, Roberto de; Lozej, Alfredo
Year: 1987
Title:
Risultati di una
prospezione sismica con archi e profili per l'individuazione di
rifrattori
profondi nell'area dei Monti Vulsini.
Conference Name: 6th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: 2
Number of Volumes: 3
Pages: 867-879
Abstract: Analysis of seismic data gathered in the
Monti
Vulsini area during 1986 in the framework of PFE, subproject Geothermal
Energy,
indicates more details on the structure of the upper crust around the
Bolsena
Lake. The travel-time durves show similar trends for three reversed
profiles.The upper velocities, corresponding to the volcanic cover and
theq
flysh formation, vary from 4.1 to 4.3 km/s and are greater on the west
side of
the Bolsena lake. A second layer, with velocities of 5.4-5.6 km/s, has
been
interpreted as the carbonatic sequence. The deep discontinuity is found
at 5-6
km depth with velocity of 7.0 km/s should correspond to the sienitic
body,
similar to that found by ENEL wells in the Latera caldera at depth of
2-2,5 km.
Finally the fans
interpretation show a deepening of the deepest refractor in the central
zone of
the investigated area.
Reference Type: Thesis
Record Number: 129
Author:
Calcagni, Dario
Year: 1988
Title:
Interpretazione di un
profilo sismico a rifrazione sui ricoprimenti alloctoni dell'Appennino
settentrionale e relativo modello geologico strutturale.
Academic Dept.: Earth's Sciences; Geology
University:
Università degli studi
City: Milan (I)
Pages: 95
Thesis
Type:
Sottotesi
Abstract: Il
presente lavoro di
sottotesi è consistito nella elaborazione e successiva
interpretazione
geologica, di un profilo sismico ottenuto con la tecnica della sismica
a
rifrazione profonda.
Il
profilo è situato nel settore Nord-occidentale
della catena Appenninica ed è esteso fra l'alta Val d'Aveto
e il Passo Cento
Croci, per una lunghezza di 30 km ed una profondità massima
di penetrazione
degli impulsi di 15 km.
L'orientamento
risulta essere WNW-ESE.
Il
lavoro si è svolto, dapprima, approfondendo le
tecniche utilizzate per la raccolta dei dati e la loro successiva
elaborazione
al fine di ottenere una sezione-film.
Si
è quindi passsati all'interpretazione sismica
dei dati ricavati in campagna; per tale studio ci si è
avvalsi dell'uso di
computers tramite i quali si sono realizzati una serie di modelli
geofisici di
volta in volta affinati tramite la generazione di sismogrammi sintetici
e di
diagrammi di ray-tracing, fino ad ottenere un modello con un
più che soddisfacente
grado di approssimazione alla realtà.
Il
modello crostale ottenuto è rappresentato da 4
interfacce principali con variazioni di impedenza acustica e quindi di
velocità
non molto marcate (al massimo 0,3 km/s) che permettono di individuare
una
struttura crostale a corpi tabulari di spessore variabile e immergenti
verso
Ovest con debole inclinazione.
La
successiva interpretazione geologica ottenuta
tramite la commistione di dati sismici e di dati derivati dalla
geologia
superficiale (a causa della mancanza di un pozzo perforato nell'area)
ha
portato a ritenere sufficientemente comprovato un raddoppiamento delle
Unità
Toscane nella zona del Passo cento Croci e, nel contempo, un
coinvolgimento
delle Unità Liguri in posizione interna nelle dislocazioni
profonde della
catena.
Inoltre
si è cercato di spiegare la posizione
alloctona delle Unità collegate con la Ruga del Bracco e in
questa sede
denominate "Melange Ofiolitico" come un lembo sovrascorso verso Est
al di sopra delle Unità Toscane.
Notes:
A.A. 1987-1988;
Relatore: Ing. S.Scarascia
Reference Type: Journal Article
Record Number: 74
Author: Egger, Adrian; Demartin, Martina; Ansorge,
Jorge;
Banda, Enrique; Maistrello, Mariano
Year: 1988
Title: The gross structure of the Crust under
Corsica and
Sardinia.
Journal:
Tectonophyscs
Issue:
150
Pages:
363-389
Abstract: As part of the European Geotraverse Project
(EGT) a
number of international cooperative seismic refraction surveys were
carried out
along the N-S segment from the Ligurian Sea, across the islands of
Corsica and
Sardinia, to the Sardinian Channel between Sardinia and North Africa,
from 1982
to 1985. For all the experiments offshore explosions served as energu
sources
ranging from 200 to 1125 kg. The main result is that the crust in the
Ligurian
Sea is of transitional type with a thickness of only 18 km. The two
continental
blocks of Corsica and Sardinia have a maximum crustal thickness of 33
and 34 km
with average crustal velocities of 6.4 and 6.3 km/s respectively. Other
results
are that the internal crustal structure as derived from the available
data in
both islands is rather undifferentiated with only local evidence for a
more
steplike interface in the lower crust (Corsica 6.3 to 6.6 Km/s;
Sardinia 6.5 to
6.8 km/s). There are also indications of a slight velocity inversion
under the
southwestern part of Sardinia. Further south in the Sardinian Channel
the
crustal thickness decreases again to 20 km.
A significant
feature is the observed Pn velocity. This parameter increases from the
relatively low value of 7.5 km/s in the North (Ligurian Sea) to 7.7-7.9
km/s
for Corsica and Sardinia and finally to 8.0 km/s under the Sardinian
Channel. These
values reflect the tectonic evolution of that part of the Mediterranean
Sea.
Reference Type: Thesis
Record Number: 119
Author: Pedone, Roberto
Year: 1988
Title:
Analisi ed
interpretazione di alcuni profili sismici DSS della campagna EGT-'86
(Southern
Segment).
Academic Dept.: Earth's Science - Geophysics
University:
Università degli studi
City: Genoa (I)
Pages: 154
Thesis
Type: PhD
Abstract: La
presente tesi di
dottorato si occupa di sismica a rifrazione profonda (DSS) e in
particolare
consiste in un lavoro di acquisizione, restituzione, digitalizzazione
ed
interpretazione dei dati sismici del profilo principale del progetto
'EGT-1986'
che dal Mar Ligure raggiunge, seguendo il meridiano n.9 da Greenwich,
il
confine italo-svizzero presso Chiavenna e lo Spluga, e dei profili e
fans del
sotto-progetto 'Appennino' sempre incluso nella campagna del progetto
EGT-1986.
Il
progetto 'Geotraversa Europea' (E.G.T.) del
1986 costituisce un progetto multidisciplinare internazionale basato su
un
profilo litosferico lungo circa 4.000 km dal Capo Nord (Norvegia) sino
alla
Tunisia meridionale.
Lo
scopo dell'EGT è di fornire una
rappresentazione tridimensionale della Litosfera continentale, in
termini di
struttura, composizione e stato attuale, permettendo quindi una
migliore
comprensione dei suoi meccanismi evolutivi.
Il
prpgetto vede l'interazione di metodi geofisici
(sismica, aeromagnetismo, magnetotellurica, gravimetria, geotermia,...)
con
studi di tettonica e di geologia strutturale.
................................. omissis
......................
Notes: II
ciclo di Dottorato
(1988); Relatore: Prof. C.Eva
Reference Type: Conference Proceedings
Record
Number: 195
Author:
Milano, Giuseppe;
Gaudiosi, Germana; Guerra, Ignazio; Ferrucci, Fabrizio
Year: 1988
Title: La
transizione
Tirreno-Isole Eolie-Sicilia mediante modellizzazione diretta ai fasci
gaussiani
di dati sismici.
Conference Name: 7th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 3
Number of Volumes: 3
Pages: 1565-1576
Abstract: A DSS experiment, carried out in 1986 in the
Southern Eolian Islands, focused on the crustal transition Tyrrhenian
Basin -
Eolian Arc - Northern Sicily.
Two linear NW-SE
profiles (s.p. HN, HS) across Salina, Lipari and Vulcano, modeled by
gaussian-beam dynamic raytrecing, and a fan profile recorded in
north-eastern
Sicily illustrate a short-wavelength upheaval of deep and
intermediate-crust
interfaces.
The constant-offset
profile 'C', recorded at a very dense array (x=200 m), and a
P-traveltimes
inversion performed on natural seismicity data, allow to constrain the
shallower part of the crustal model, not directly resolvable by DSS
profiling.
Reference Type: Conference Proceedings
Record
Number: 56
Author:
Zitellini, N.;
Torelli, L.; Brancolini, G.; Tricart, P.; Argnani, A.; Nieto, D.; Peis,
D.;
Persoglia, S.; Ramella, R.; Rekhiss, F.
Year: 1989
Title:
Ricerche di sismica a
riflessione profonda nel Canale di Sicilia e nel Tirreno meridionale:
primi
rislutati.
Conference Name: 8th GNGTS meeting
Editor: CNR
Publisher: CNR
Conference Location:
Roma
(CNR)
Volume: 2
Number of Volumes: 2
Pages: 823-827
Abstract: The first deep seismic reflection survey
carried out
in the area embracing the Southern Tyrrhenian Sea, the Sardinia Channel
and the
Western Pelagian Sea, is presented (date of survey: July '89). Of
remarkable
interest is a single profile that runs from an extensional basin
(Tyrrhenian
Sea) to relatively undeformed area. This line crosses a fold-thrust
belt
(Maghrebian Chain), and an area of extensional deformation within the
foreland
(Strait of Sicily Rift zone). The seismic data are interpreted in the
framework
of the regional geodynamic evolution.
Reference Type: Journal Article
Record Number: 190
Author: Hirn, Alfred; Nadir, Sohie; Thouvenot,
François;
Nicolich, Rinaldo; Pellis, Giulio; Scarascia, Salvatore; Tabacco,
Ignazio;
F.Castellano; Merlanti, Fulvio
Year: 1989
Title: A new picture of the Moho under the western
Alps.
Journal:
Nature
Volume:
337
Issue: 6204
Pages: 249-251
Abstract: The Moho - the boundary between crust and
mantle
first discovered by A.Mohorovicic in 1909 - is the main seismic marker
in the
continental Litosphere. The seismic nature of this interface, in terms
of its
position, topography, smoothness and continuity, may preserve imprints
of the
regional geodynamic evolution of the lithosphere.
Here we report the
results of a wide-angle seismic profiling experiment across the Western
Alps,
which allows us to draw a cross-section of the Moho across this
mountain belt. A
tight sampling of this deep reflector shows abrupt changes in its depth
and
dip. The root zone of the chain (the zone of maximum crustal thickness)
is well
defined, with a 55-km-deep crust-mantle boundary. The Moho under the
western Po
plain is also clearly seen, and a shallow reflective structure is
mapped under
the Briançonnais zone in the 25-30 km depth range. This
structure, if
interpreted as lower-crustal or upper-mantle material, would support
the
hypothesis of a flaking of the lithosphere under the western Alps.
Reference Type: Journal Article
Record Number: 33
Author: Yan, Q. Z.; Mechie, James
Year: 1989
Title: A fine structural section through the Crust
and
lower Lithosphere along the axial region of the Alps.
Journal:
Geophys. Journal International
Volume:
98
Pages:
465-488
Abstract: By making new phase correlations and using
ray-tracing and ray-theoretical seismogram calculations in laterally
inhomogeneous media a unified two-dimensional lithospheric model has
been
derived for the P-wave velocity structure beneath the Alpine
Longitudinal
Profile (ALP-'75) main line. Due essentially to an increase in
thickness of the
lower crust, the total crustal thickness increases quite abruptly from
30-40 km
in the peripheral regions to about 50 km in the central region of the
Alps. In
both the upper and lower crusts rather thick low velocity layers occur.
In the
upper crust the velocity decreases from 5.8-6.2 km/s to as low as 5.6
km/s
while in the lower crust the velocity decreases from 6.5-6.7 km/s to as
low as
6.0-6.2 km/s. The upper mantle structure consists of alternating high
and low
velocity layers down to about 100 km depth where a velocity of about
8.8 km/s
occurs. Calculation of the mass of litospheric columns down to 56 km
depth
shows that the topography of the Alps is essentially compensated for by
the
increase in crustal thickness.
Reference Type: Conference Proceedings
Record
Number: 154
Author:
Biella, Giancarlo;
Franco, Roberto de; Lentini, Eugenia; Masotti, Roberta
Year: 1989
Title:
Analisi delle onde 'S'
nella sismica a rifrazione profonda.
Conference Name: 8th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (I)
Volume: 1
Number of Volumes: 2
Pages: 565-578
Abstract: Seismic signals of deep refraction seismic
surveys
from 1981 - 1987, have been examined in detail. The analysis inquired
into a
correlation between shot configuration, source site lithology and
S-waves
identified along the corresponding seismic profile.
SV and SH phases
have been observed in the Analysed seismic lines: these phases are
probably
generated at the free surface or at an interface in close proximity of
the source.
Reference Type: Report
Record Number: 213
Author: Gajewski, D.; Prodehl, C.; Zeis, St.
Year: 1989
Title: A compilation of data from the
Wildflecken-1982
seismic refraction experiment in Southern Germany.
Institution: Geoph. Institute of UNI-Karlsruhe
Date: January 1989
Report Number: Open file Report 8901
Abstract: In October 1982 the armed forces of the FGR
carried
out a series of explosions on a troop training area near Wildflecken
(Rhön
Mountains). In coordination with two of the authors (DG and CP) charges
and
shot times were arranged that these explosions could be used for a
detailed
seismic-refraction experiment in Southern Germany. The
seismic-refraction
survey comprises 6 profiles which run fan-like from shot point WF
Wildflecken
in southern directions. The survey was supported by the special
research
program of the German Research Society "Stress and Stress Release in
the
Lithosphere" (SFB 108) at the University of Karlsruhe.
Previous
investigations have covered only parts of the South German Triangle.
Consequently,
the deep structure of wide areas of the South German Triangle is still
quite
unknown. The main purpose of the survey was to get a more areal
coverage of the
Southern Germany by deep seismic profiling. Interpretations of the
data,
carried out so far, are listed in the references (Zeis, 1988; Zeis et
al.,
1989).
Reference Type: Conference Proceedings
Record Number: 91
Author: Egger, Adrian; Ansorge, Jorge
Year: 1989
Title: Compilation of refraction seismic data on the
Southern Segment of the European Geotraverse (EGT) between Liguria and
Sardinia
Channel.
Conference Name: 6° Workshop
on the EGT Project - Data
compilation and Synoptic interpretation
Editor: Mueller, R.Freeman and St.
Publisher: E.S.F.
Conference Location: Einsiedeln (CH)
Volume: 1
Number of Volumes: 1
Pages: 189-196
Abstract: In this report we give a short overview about
the
refraction seismic experiments, the characteristics of profiles, and
the data,
which are used for the determination of the crustal structure under the
Southern Segment of the EGT between Liguria and the Sardinia Channel.
Reference Type: Thesis
Record Number: 106
Author:
Dahnken, L.
Year:
1989
Title:
Auswertung Refraktionsseismicher Messungen auf Sizilien
(1968).
Academic
Dept.:
Institut für Geophysik
University: Freien Univesität
City: Berlin (D)
Pages: 83
Label: TH
Abstract: In 1968 seismic refraction measurements were
performed in Sicily. The main profile was situated parallel to the
northern
coast, a smaller profile was recorded parallel to the southern coast.
The interpretation
of the record sections results in two strong gradients of the velocity
in the
crust under the eastern part of Sicily in 25 and 38 km depth, however
there is
only one strong gradient under the western part of the island between
25 and 29
km depth.
The earth's crust
is becomming thinner towards north-western direction.
Notes: Copy of original thesis written in deutsch.
Reference Type: Journal Article
Record Number: 191
Author:
Hirn, Alfred; Nadir,
Sophie; Thouvenot, Francois; Nicolich, Rinaldo; Pellis, Giulio;
Scarascia,
Salvatore; Tabacco, Ignazio; Castellano, Mario; Merlanti, Fulvio
Year: 1989
Title: Mapping the Moho of the Western Alps by
wide-angle
reflection seismics.
Journal:
Tectonophysics
Volume:
162
Pages: 193-202
Abstract: A new picture of the Moho beneath the Western
Alps
could be obtained using wide-angle reflection seismic data.
This picture, in
addition to its increased sharpness, clearly shows how the Moho deepens
down to
the root zone of the chain (55 km). A 25-30 km deep reflector with
upper mantle
characteristics is discovered under the Briançonnais zone
where it overlies the
autochthonous Moho. This unit does not seem to connect the so-called
"Ivrea body", situated much shallower and farther into the chain. It
supports a hypothetical flaking of the European litosphere beneath the
Western
Alps. Farther east, the Moho beneath the po Plain is clearly mapped
too, with a
crustal thickness increasing in steps from 25 to 35 km. This P-wave
Moho
picture is compared with an S-wave picture, and major differences
appearing in
the middle crust are discussed. Finally, the seismic response of the
Moho is
investigated, and is shown to be shifted towards low frequencies in the
inner
zones of the chain. This could partly explain why the ECORS-CROP
vertical
seismic line, equipped with high-frequency geophones, faltered over the
identification of the deep Alpine Moho.
Reference Type: Report
Record Number: 55
Author:
Nieto, D.; Persoglia,
S.
Year: 1989
Title:
Programma 'Canale
Sardo: area studio di una catena sommersa'.
Institution:
OGS
Date:
10/09/1989
Report Number: REL/89-43/SIS-GA-1
Abstract: Il
presente rapporto
illustra la campagna sismica in mare che l'OGS di Trieste ha effettuato
nel
periodo 10-27/7/1989, nei settori di mare situati nel Tirreno
meridionale, nel
Canale di Sardegna e nel mar Pelagiano intorno a Lampedusa, utilizzando
la
propria nave OGS-EXPLORA.
Tale
ricerca è stata effettuata nell'ambito di una
collaborazione tra:
1)
l'Osservatorio Geofisico Sperimentale - TS
2)
l'Università degli Studi di PR, Istituto di
Geologia
3)
l'Istituto di geologia Marina del CNR, BO
4) il
Dipartimento di Geologia ENIS-SFAX.
Il
rilievo è stato effettuato con il metodo della
sismica a riflessione e, nella prima linea, sono stati raccolti anche
dati
magnetici.
Reference Type: Conference Proceedings
Record
Number: 71
Author:
Carrozzo, Mraia
Teresa; Colella, Pietro; Luzio, Dario; Margiotta, C.; Quarta, T.
Year: 1989
Title:
Struttura crostale
dell'area Siciliana: un possibile modello tridimensionale.
Conference Name: 8th convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: I
Number of Volumes: 2
Pages: 487-500
Abstract: A method for the interpretation of the
Bouguer
anomalies by means of tridimensional models is related; it, founded on
trial
and error procedure, provides for the use of preliminary knowledges.
This
method is applied to the Bouguer anomalies of the Sicilian area.
The tridimensional
Crust model is choosen according to the values of some statistical
structures. Some
of the most important structural bounds seem to be also in the lower
crust.
Reference Type: Thesis
Record Number: 117
Author: Canclini, G. W.
Year: 1989
Title:
Sviluppo di tecniche
interattive per l'interpretazione di dati di sismica attiva e passiva.
Academic
Dept.:
Information
Science
University:
Università degli studi
City:
Milan (I)
Pages: 148
Abstract:
Negli ultimi anni, con
lo sviluppo dell'acquisizione digitale dei dati sismologici,
è cresciuta sempre
più l'esigenza di disporre di strumenti software che
migliorino, in termini di
qualità e di tempo, il lavoro di trattamento ed
interpretazione dei dati.
Per
elaborazione e trattamento di dati sismologici
si intende l'utilizzazione di diverse procedure che consentono
l'analisi delle
caratteristiche del dato, il miglioramento dello stesso e l'estrazione
di informazioni
utilizzabili in fase interpretativa.
Questa
tesi, sviluppata presso l'Istituto per le
Geofisica della Litosfera del C.N.R. di Milano, ha avuto come oggetto
la
progettazione e la realizzazione di un pacchetto software integrato per
il
trattamento di sismogrammi acquisiti in campagne di prospezione o da
reti
locali di rilevamento.
Una
delle caratteristiche peculiari del sistema
realizzato, denominato 'Seis-Tool', è quella di permettere
una evoluzione nel
lavoro di interpretazione passando dall'utilizzo di moduli, con
caratteristiche
software diverse, che permettono la risoluzione di singoli problemi ad
un
sistema integrato che controlli e concateni logicamente l'insieme dei
programmi. Il sistema è stato sviluppato su macchine IBM e
compatibili, in ambiente
PC e sotto il sistema operativo MS-DOS.
La
necessità di rendere disponibile il pacchetto
ad un gruppo eterogeneo di utenti, con una conoscenza limitata
sull'utilizzo
degli strumenti di elaborazione e sul trattamento dei dati, ha portato
alla
definizione e alla realizzazione di un'interfaccia uomo-macchna che ne
consenta
un uso immediato e di facile apprendimento.
Nella
nostra applicazione lo stile più appropriato
di dialogo per l'interfaccia è la "selezione a menu" mentre
il
ricorso al "form filling" permette di introdurre un criterio di
uniformità per la specifica dei parametri operativi ai
diversi programmi
applicativi.
........................
omissis
.......................
Notes:
A.A. 1988-1989;
Relatore:
Dr. R. de Franco; Correlatore:
Prof. M. Italiani
Reference Type: Conference Proceedings
Record
Number: 63
Author:
Milano, Giuseppe;
Ferrucci, Fabrizio; Guerra, Ignazio
Year: 1989
Title:
Interpretazione
preliminare di profili DSS nel Tirreno meridionale.
Conference Name: 8th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR, I)
Volume: 1
Number of Volumes: 2
Pages: 525-533
Abstract: We report the results obtained by
gaussian-beam
direct modelling of a DSS profile carried out in 1986, between Northern
Sicily
and the Southern Tyrrhenian Sea. The data are jointly discussed with
the
results of a former survey, carried out in 1979 in the same area. A
crustal
deepening is observed both along the ENE-WSW direction, beneath the
Gulf of
Patti, in correspondence of the southeastern edge of the Tyrrhenian
basin.
Reference Type: Thesis
Record Number: 127
Author: Todeschini, Luisa
Year: 1989
Title:
Prospezione sismica
nell'area geotermica del lago di Bolsena: zona di Montefiascone.
Academic Dept.: Geology
University: Università degli studi
City: Milan (I)
Pages: 152
Thesis Type: Diploma
Abstract:
Oggetto di questo
lavoro di tesi, svolto in collaborazione con i colleghi R.Nardiello e
P.Trognacara, è la definizione strutturale della zona dei
Monti Vulsini (Lazio
sett.) mediante la prospezione a rifrazione integrata con altri dati
geofisici
e geologici disponibili in letteratura.
Si
tratta di una regione vulcanica situata sul
margine tirrenico dell'Italia centrale, appartenente
all'estremità
settentrionale del Lazio (provincia di Viterbo), che si estende
all'interno
della provincia di Grosseto a NW e di Terni a SE.
Elemento
fondamentale della sua configurazione è
la cintura vulcanica quaternaria che si allunga da Siena verso sud,
dando luogo
ad una topografia collinare entro cui spiccano grandi depressioni
morfologiche
di natura calderica tra le quali una più estesa occupata
dalle acqua del lago di
Bolsena ed unaminore, asciutta, data dalla caldera di Latera.
Lo
studio di tale zona si inquadra in un programma
di ricerche interdisciplinari coordinate, all'interno del Progetto
Finalizzato
'Energetica', sotto-progetto 'Energia geotermica' del C.N.R. Scopo del
progetto
è l'individuazione delle risorse di natura geotermica
dell'Italia Centrale e la
definizione della loro economicità in previsione di un
successivo sfruttamento
dell'energia geotermica dell'area quale fonte energetica alternativa.
Notes:
A.A. 1988-1989;
Relatore: Dr. Lozej A.; Correlatori: Prof. Tabacco
I., Dr. Biella G.
Reference Type: Report
Record Number: 220
Author:
Maistrello, M.;
Scarascia, S.; Corsi, A.; Egger, A.; Thouvenot, F.
Year: 1990
Title: EGT 1985 Southern Segment
- Compilation of data from the seismic refraction
experiments in
Tunisia and Pelagian Sea.
Institution: CNR-IGL
Date: November 1990
Report Number: Open file Report
Abstract: In the frame of the European Geotraverse
(EGT)
southern segment, from June 24th to July 16th 1985 a large seismic
refraction
experiment was carried out in Tunisia and both the Sardinia and Sicily
Channels, for a reconnaissance of the deep structures of Tunisia and
surrounding Seas.
In these surveys
120 mobile analog MARS-66 stations (1 or 3 components) weere deployed
on land,
23 Ocean Bottom Seismometers (OBS) in the Sardinia Channel, 15 OBS in
the
Sicily Channel and 21 land stations onshore Sardinia.
Two italian vessels
were involved in these experiments: the M/S "Bannock" and
"Minerva". All details on the various operations of shooting teams on
land and sea can be found in the Report of Morelli et al., 1985.
The earlier
publications of seismic refraction data from this area were made by
Makris et
al., 1987 and Scarascia et al., 1988. Other partial results have been
published
also in the 6th EGT Workshop proceedings (research Group for
Lithospheric
structure in Tunisia, 1990).
In this compilation
we present all data recorded in Tunisia and Pelagian Sea.
Reference Type: Journal Article
Record Number: 23
Author:
Cassinis, Roberto;
Lozej, Alfredo; Tabacco, Ignazio; Gelati, R.; Biella, Giancarlo;
Scarascia,
Salvatore; Mazzotti, A.
Year: 1990
Title: Reflection and refraction seismics in areas
of
complex geology. An example in the Northern Apennines.
Journal:
Terra Nova
Volume: 2
Pages: 351-362
Abstract: An experimental survey, employing refraction
wide-angle reflection seismic techniques (DSS: deep seismic soundings)
was
carried out in the Northern Apennines (North Italy).
The main objective
of the experiment was the application of DSS to better-define the
structure of
the upper crust, down to about 15 km depth, in the crucial
Alps-Apennins
boundary zone. A second objective was to understand the potential of
DSS as a
complementary tool in areas of complex ceology, where the results of
near
vertical reflection (NVR) are generally poor.
The results of the
experiment show that DSS, if properly planned, can continuously follow
deep
markers, and therefore impart a greater significance to faint and
discontinuous
NVR, as well as data on the P-wave velocity of the seismic units.
Reference Type: Report
Record Number: 219
Author: Aichroth, B.; Ye, S.; Feddersen, J.;
Maistrello, M.;
Pedone, R.
Year: 1990
Title: A compilation of data from the 1986 European
Geotraverse experiment (main line) from Genova to Kiel.
Institution: UNI Karlsruhe
Date: February 1990
Report Number: Open file Report 90-1
Abstract: As part of the European Geotraverse (EGT) a
seismic
refraction experiment was carrioed out in September 1986 with shots
along a
1200 km line between Genova (Italy) and Kiel (F.R.Germany) and with fan
profiles for the Pg and
PmP phases in the Po Plain and the Northern
Apennines.
This compilation
includes only the data along the main line between the Gulf of Genova
and the
Baltic Sea. Altogether, the experiment involved about 200 persons from
10
Countries (Denmark, Finland, France, F.R.Germany, Ireland, Italy,
Spain,
Sweden, Switzerland and the United Kingdom), 288 recording units and 30
shots
fired at 14 locations. This survey achieves a continuous coverage with
modern
seismic refraction data along the 1200 km line. The profile traverses
the
Caledonides and the Variscides of Germany as well as the young Alpine
Orogene
of Switzerland and North Italy. A first interpretation of the observed
data is
published in a special EGT issue in Tectonophysics (EUGEMI Working
Group,
1990). A more detailed manuscript is in preparation by Aichroth and
Prodehl for
the last EGT issue of Tectonophysics, to be published by 1991.
Reference Type: Journal Article
Record Number: 48
Author:
Boccaletti, M.;
Nicolich, Rinaldo; Tortorici, L.
Year: 1990
Title: New data and hypothesis on the development of
the
Tyrrhenian basin.
Journal: Palaeogeography, Palaeoclimatology,
Palaeoecology
Issue: 77
Pages: 15-40
Abstract: Among those basins which developed during the
Neogene and Quaternary at the rear of the perimediterranean mountain
chains,
the Tyrrhenian basin is the most recently formed. Comparing the
available
geological and geophysical data, the Tyrrhenian domain and its
neighbourhoods
can be divided into more or less homogeneous sectors: namely Northern
and
Southern Tyrrhenian Apenninic chain, Maghrebides chain, Apulian and
Iblean-African foreland, Ionian foreland. For each sector the different
phenomena involved and the crustal characteristics are discussed. The
evolution
of the domain has been explained by the application of a crustal
stretching
model developed for continental margins. This approach predicts the
formation
of a basinal areas as a result of the Europe/Africa collisional
movements
within a plastic-rigid deformation model. Taking into account the mass
redistribution after collision, the model explains both the distension
developed within the collisional system and the penecontemporaneous
development
of compressive and distensive phases. As a consequence of the
intraplate
stresses, horizontal shearings afftecting the whole lithosphere at
different
levels, occur, with delaminations, asthenosphere uprising and gradual
collapse
in the upper crust. E-W trending and strike-slip dextral faults played
a
primary role in the evolution of the Tyrrhenian basin inducing the
largest
tearings at the end of the major transcurrent systems. Such an
evolution is
complicated by the migrating motion of the shear zone from N to S and
by the
penecontemporaneous stop in the extension from the northern towards the
southern domains. Of outstanding importance is the shear zone which
borders the
Southern Tyrrhenian enabling the opening of the basin and allowing the
development of the major group of en-echelon sub-basin with a NW-SE
trend.
Reference Type: Book
Record Number: 216
Author:
Meissner, R.; Bortfeld, R. K.
Year:
1990
Title:
DEKORP-Atlas Results of Deutsches Kontinentales
Reflexionsseismiches Programm
Series
Editor:
Meissner, R.; Bortfeld, R. K.
Publisher:
Springer-Verlag
City:
Berlin
Volume: 1
Number of Volumes: 1
Number of Pages: 19 pp (+ 80 plates)
Abstract: This Atlas is the product of more than 5
years of
field work, processing and interpretation of the DEKORP Research Group
(DEKORP=Deutsches Kontinentales Reflexionsseismisches Programm). Since
field
work started in the summer of 1984, about 1700 km of deep reflection
lines have
been observed in the Federal Republic of Germany. Except for the very
first
line DEKORP 2-S all other profiles were observed by the Vibroseis
method.
Although DEKORP
activities started rather late compared to their big forerunners, e.g.
COCORP
in the USA and BIRPS in GB, they are neverthless rooted in many
pre-DEKORP
activities. Ample refraction work started in the late 1940s, wide-angle
observations and the very first (statistical) near-vertical reflection
studies
began in the late 1950s. They were already followed in 1964 by the
first
specific reflection experiments near Augsburg which proved the reality
of deep
crustal reflections. In the following years between 1964 and 1979 a
number of
short reflection lines across specific geological boundaries were
observed,
e.g. those across the Ries astrobleme, various Variscan collisions or
the Urach
geothermal anomaly.
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......................
Reference Type: Journal Article
Record Number: 157
Author: Kohler, William M.; Fuis, Gary S.
Year: 1990
Title: Empirical dependence of seismic ground
velocity on
the weight of explosives, shotpoint site condition and recording
distance for
seismic-refraction data.
Journal: Bulletin of the Seismological Society of
America
(BSSA)
Volume: 82
Issue: 5
Pages: 2032-2044
Abstract: In this study, we have constructed an
empirical
least-squares model for maximum seismic ground velocity (vertical
component),
as a function of source size and distance, from explosions in
drillholes and
bodies of water.This model is intended, in part, for use in designing
explosion-seismic experiments in order to produce acceptable
signal-to-noise
ratios at larger distances (> 10 km) and to avoid damaging human
structures
at smaller distances (< 1 km).
Data consist of
velocities recorded by 120 portable seismographs from 159 shots fired
by the
U.S. geological Survey in Alaska and Arizona. results show that maximum
ground-velocity amplitude (not necessarily first-arrival amplitude)
decreases
with distance, and the functional dependence changes with distance; for
example, at 3 km amplitudes decrease as 1/r2,
but at 73 km they
decrease as 1/r .
Results
also show a strong dependence on dsite conditions at the shotpoint; for example
a drillhole shot in wet alluvium produces amplitudes that are four
times larger
than a drillhole shot in dry alluvium. Ground velocities are
proportional to
the square root of the weight of explosives.
Reference Type: Report
Record Number: 217
Author: Egger, A.
Year: 1990
Title: A comprehensive compilation of seismic
refraction
data along the Southern segment of the EGT, from the northern Apennines
to the
Sardinia Channel (1979-1985).
Institution: ETH Zürich
Date: November 1990
Report Number: Open file Report
Abstract: This Report comprises a compilation of
seismic
refraction data collected on the European Geotraverse (EGT) Southern
Segment
from the Northern Apennines extending across the Ligurian Sea, Corsica,
Sardinia to the Sardinia Channel. The experiment was completed in three
phases:
a reconnaissance experiment in Corsica and Sardinia in 1982; the main
experiment from the Northern Apennines to sardinia in 1983; and a final
experiment in the Sardinia Channel in 1985 (part of the EGT Project in
Tunisia).
An additional
profile shot in Sardinia in 1979 is also included since this crosses
three of
the EGT profiles.
The analysis of the
data from these experiments is the subject of the Author's dissertation
to be
finished in 1991.
Further
compilations of data for the Sothern Segment of the EGT (Southern and
Western
Alps, po Plain, Northern Apennines, Tunisia) were prepared by Buness,
Berlin
(1990) and Maistrello, Milano (1990a, 1990b).
Earlier
publications of seismic refraction data from this area are: Biella et
al.,
1983, 1987; Buness, 1985; Cassinis et al., 1990; Egger et al., 1988;
Ginzburg
et al., 1986; Lozej et al., 1990; Morelli et al., 1977; Nicolich, 1981;
Scarascia, 1980; Wigger, 1984.
Reference Type: Report
Record Number: 221
Author: Buness, H.
Year: 1990
Title: A compilation of data from the 1983 EGT
experiment,
from the Ligurian Sea to the Southern Alps.
Institution: FU Berlin
Report Number: Open file report
Abstract: This report comprises a compilation of data
of the
EGT-South 1983 experiment recorded in the Northern Apennines, the Po
Plain and
the Southern and Western Alps. It is one in a series of reports which
present
the refraction seismic data related to the EGT project.
Further compilation
referring to the southern and central segment were prepared by A.Egger,
Zurich
(EGT-South, Ligurian Sea to Sardinia Channel), M.Maistrello, Milan
(EGT-South
1986, Ligurian Sea to Southern Alps) and B.Aichroth et al., Karlsruhe
(EGT-Southern and Central part, Genoa to Kiel). First results of the
EGT-S 1983
data are published in: D.A.Galson and St. Mueller (1985): 'Proceedings
of the
2nd workshop on the European Geotraverse Project', ESF, Strasbourg.
Reference Type: Conference Proceedings
Record Number: 206
Author: Freeman, Roy; Müller, Stephen
Year: 1990
Title: Sixth EGT Workshop: data compilations and
synoptic
interpretation.
Conference Name: 6th EGT Workshop
Editor: Strasbourg, ESF -
Publisher: ESF
Conference Location: Einsiedeln (CH)
Volume: 1
Number of Volumes: 1
Pages: 457
Series Title: European Geotraverse (EGT)
Abstract: These proceedings contain short papers and
extended
abstracts of lectures given at the Sixth Workshop of the European
geotraverse
(EGT). The Workshop took place at the Swiss Youth and Education Centre
in
Einsiedeln, Switzerland, from November 29 to December 5, 1989. Sixty scientists
participated and 80% of the
contributions are presented in these Proceedings.
The purpose of the
Workshop was to efficiently prepare for the final phase of analysis and
interpretation of the large amount of data acquired and compiled along
the
4.600 x 250 km EGT swat, from the North capa to the Sahara. The
emphasis was
therefore not on results and interpretation, but on acquainting those
involved
with each other, to familiarize them with the character and quality of
the
available data, and to discuss the methods and programmes for
integrative
inperpretation.
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omissis
....................
Notes: Published with the aid of the EU Commission.
Reference Type: Report
Record Number: 218
Author:
Hauser, F.; Prodehl, C.; Schimmel, M.
Year: 1990
Title: A compilation of data from the 'FENNOLORA'
seismic
refraction experiment 1979.
Institution: UNI Karlsruhe
Date: February 1990
Report Number: Open file Report 90-2
Abstract: In August 1979 a seismic refraction survey
was
carried out along a 1900 km long line through Scandinavia in order to
investigate the structure of the Lithosphere and Asthenosphere beneath
the
Baltic Schield. Large explosions at the shotpoints near Karlskrona in
the south
(B) and near the North Cape in the north (H and I), were recorded along
the
whole line which served to penetrate the Earth's mantle to depths of
approximately 400 km (Fuchs et al., 1982, 1987; Guggisberg and
Berthelsen,
1987; Lund, 1979). In order to be able to control the data for lateral
inhomogeneities in the lower Lithosphere and in the Crust, a series of
intermediate shotpoints was arranged with an average spacing of about
300 km
(C, D, E, F and G). Recording stations were positioned at about 3 km
interval
for distances up to 1000 km and 10 km interval for the large shots
being
recorded at distances beyond 1000 km.
The field work was
carried out from August 13 to 25, 1979. In addition to the main line
through
Scandinavia from B to H, the shots at G were recorded along additional
lines in
Finland and the major shots at B and I were recorded along two lines
south of
the Baltic Sea, one running towards SE through Poland into the Ukraine
and one
running along the East-German-Polish Border into Czechoslovakia. The
additional
shotpoints W and BW in East Germany were also successfully recorded in
the
southern part of Sweden, starting at recording distances of 140 km
resp. 420
km. In total 56 explosions were fired at 15 locations.
Along the main line
through Scandinavia 96 recording stations of type MARS-66 were used and
28
explosions ranging in size between 1.8 and 8 tons TNT were fired at 8
shotpoints.
From the shotpoints W and BW in the GDR 8 explosions were recorded
along the
Scandinavian Peninsula. By this scheme a morefold coverage of the main
line
between W and I was obtained as far as the structure of the Crust and
lower
Lithosphere is concerned.
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...................
Reference Type: Conference Proceedings
Record
Number: 9
Author:
Scandone, Paolo;
Patacca, E.; Meletti, Carlo; Bellatalla, M.; Perilli, N.; Santini, U.
Year: 1990
Title:
Struttura geologica,
evoluzione cinematica e schema sismotettonico della penisola italiana.
Conference Name: GNDT meeting -1990
Publisher:
CNR
Conference
Location: Pisa
Volume:
1
Pages:
119-135
Abstract:
Viene presentato uno
schema sismotettonico della penisola italiana e della Sicilia nel quale
sono
individuate zone sismogenetiche con differenti caratteristiche alla
sorgente:
zone in estensione, zone in compressione e fasce di trasferimento
sorgente-sorgente,
sorgente-accumulo e accumulo-accumulo. Gli elementi utilizzati per
l'analisi
sismotettonica sono un modello strutturale dell'area italiana, un
modello
cinematico della regione circumtirrenica riferito agli ultimi 8 milioni
d'anni
e le informazioni sulla storia sismica d'Italia contenute nel catalogo
dei
terremoti ENEL-CNR P.F.geodinamica e nell'archivio dei dati
macrosismici
disponibili. .....
Reference Type: Journal Article
Record Number: 22
Author:
Amato, Alessandro;
Biella, Giancarlo; Franco, Roberto de
Year: 1991
Title: Velocity structure of the Vulsinian volcanic
complex
(Latium, Italy) from seismic refraction data and three-dimensional
inversion of
travel times.
Journal: Journal of Geophys. Research
Volume: 96
Issue: B1
Pages: 517-535
Abstract: We have interpreted three reversed seismic
refraction profiles and three related fans in the Monti Vulsini
volcanic
complex, modelling travel times and amplitudes calculated using the
asymptotic
ray theory. The interpretation of the refraction lines revealed complex
structure in the shallow crust (0-7 km), characterized by strong
lateral
heterogeneities. The three-layer seismic model of the volcanic area is
characterized by relatively high P wave velocities, generally ranging
from
4.0-4.5 km/s in the uppermost layer to 6.7-7.1 km/s at a depth of about
7 km. Yhe
upper layer (0.5-2.7 km thick) corresponds to the volcanic cover and
the upper
part of the flysch sequence. The depth to the top of the middle layer,
corresponding to the lower part of the flysch unit and to the
Meso-Cenozoic
carbonate sequence, is very irregular and is strongly controlled by the
tectonic evolution of the area. The thickness of this layer ranges
between 2.2
and 5.0 km. The third layer extends beneath the whole Vulsinian region
and is
characterized by high P velocity (6.7-7.1 km/s) at relatively shallow
depth
(5-7 km). We interpret the high velocity observed in the third layer as
being
caused by mafic intrusive rocks, such as gabbros, or by high-grade
metamorphic
rocks, such as shists, granulites or metatuffs. The results of the
refraction
modelling have been compared with a three-dimensional (3-D) P velocity
model
calculated by inverting travel
time
residuals from explosions and local earthquakes. Generally, close
agreement is
observed between refraction and inversion models. The fan-profiles, as
well as
three unreversed refraction profiles and 3-D inversion, showed a
velocity
decrease, as low as 5%, within the deepest layer in the central part of
the
volcanic complex. The low-velocity zone in the central region could be
related
either to high temperatures and/or partial melt in the intrusive (or
metamorphic) body, or to the deepening of the top of the third layer.
Reference Type: Book Section
Record Number: 72
Author: Buness, Hermann
Year: 1991
Title: A seismic refraction line between the
Ligurian Sea
and the Southern Alps - Evidences for crustal doubling.
Book Title: Joint interpretation of Geophysical and
Geological
data applied to Lithospheric studies.
Editor:
al., P.Giese et
Publisher: Kluwer Academic Pub.
City: Berlin
Volume: 338
Pages: 193-215
Series Editor: NATO
Series Title: NATO ASI series 'C' (Mathematical and
Physical
sciences)
Abstract: Within the European Geotraverse Project (EGT)
extensive seismic refraction studies were carried out along the
northern part
of the southern segment, comprising the Ligurian Sea, the Northern
Apennines,
the Po Plain and the Southern Alps. A very complicated and anomalous
crustal
structure could be detected beneath the Southern Alps as well as
beneath the
Northern Apennines.
If going southwards
from the Central Alps, the European Moho discontinuity dips down the
upper
mantle of the Southern Alps, forming
a
crustal doubling beneath the Northern border of the Adriatic plate. A
further
crustal doubling could be evidenced beneath the Northern Apennines.
Here a thin
northern Apennine crust with mantle material at its base overlies a
southwards
downdipping Po Plain crust, ahich extends almost beneath the Ligurian
coast. Very
low crustal velocities in the upper and middle crust were found et the
northern
margin of the Apennines.
Reference Type: Report
Record Number: 215
Author:
Maistrello, M.;
Scarascia, S.; Ye, S.; Hirn, A.
Year: 1991
Title: EGT 1986 Central Segment - Compilation of
seismic
data (additional profiles and fans) in Northern Apennines, Po Plain,
Western
and Southern Alps.
Institution: CNR-IGL
Date: February 1991
Report Number: Open file Report
Abstract: In the frame of the European Geotraverse -
Central
Segment - a large seismic refraction experiment was carried out in
Central
Europe, from the Gulf of Genova (Italy) to Kiel (Gernmany), in
September 1986.
The compilation of
the seismic data along the main north-south profile has been performed
by the
Geophysical Institute of Karlsruhe University (Aichroth et al., 1990).
This
compilation concerns only the supplementary data obtained from in-line
and fan
profiles explored in Northern Italy, in the Northern apennines, Po
Plain,
Western and Southern Alps. The aim was to obtain additional information
on the
crustal structure in regions of particular geodynamic interest, where
the
transition from the Ligurian Crust to the Po Plain one under the
Apennines, and
from the Po Plain crust to the European one under the Alps are
expected, and
where the boundary between Alps and Apennines is located.
.....................
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Other information
on EGT-1986 experiments and first results are reported by EUGEMI
Working Group,
1990; Buness et al., 1990a, 1990b; IMGA-Uni TS, 1986; Lozej et al.,
1990;
Nadir, 1988; Scarascia et al., 1990; Ye et al., 1990a, 1990b.
Additional
information about other crustal seismic surveys in the same area
carried out
before this last EGT experiment, are in the reference list. Most of the
observers and equipments involved in the experiment along the main
north-south
profile participated also in this additional survey.
Reference Type: Journal Article
Record Number: 35
Author:
DeFranco, Roberto;
Biella, Giancarlo; Corsi, Adelmo; Ponziani, Francesco
Year: 1991
Title:
Digitalizzazione del
profilo Corsica-Ancona e profili adiacenti: primi risultati.
Journal:
Studi Geologici
Camerti
Volume: 1 (1991)
Pages: 65-70
Keywords: seismic refraction; deep structures
Abstract: We present the analogic/digital conversion of
the
DSS profiles acquired during the 'Toscana'78' seismic experiment. Some
interpretative results in the area that will be explored with deep
seismic
reflection profile CROP-03 are shown.
In the Tuscany
region the Moho has a depth of about 24-25 km and presents anomalous
velocity
values of 7.6-7.8 km/s. Eastward of Tiber valley the Moho is located at
about
35 km depth with velocity value of 8.0 km/s.
Reference Type: Thesis
Record Number: 105
Author: Buness, Hermann
Year: 1992
Title:
Krustale Kollisionsstrukturen an den Rändern der
nordwestlichen Adriaplatte
Academic
Dept.:
Institut für Geologie, Geopkysik und Geoinformatik
University: Freien Universiät
City: Berlin (D)
Pages: 221
Thesis Type: PhD
Label:
Reihe B - Band 18
Abstract: The mountain chains of the Alps and the
Northern Apennines,
which developed from the collision of the Adriatic and the European
plate,
border each other in the area of the western Po-plain with opposite
vergences. In
order to investigate these different orogenes extensive seismic
refraction
measurements were carried out in the siuthern segment of the European
Geotraverse (EGT) in the years 1983 and 1986. Combined with older
refraction
profiles they served as a basis for this thesis, which investigates the
structures of the mountain ranges that encircle the northwestern
Adriatic
plate, the Southern Alps and the Northern Apennines.
Together with the
results of seismic reflection studies the seismic refraction
measurements
confirmed that the northern and western margin of the northwestern part
of the
Adriatic plate is lying onto the European plate. Along the EGT-mainline
a
continuation of crustal material of the European plate at a depth range
of
45-65 km beneath the Southern Alps can be concluded. The resulting
crustal
overlapping with its flakelike and strongly asymmetric structures shows
similarities to the tectonic situation in the western part of the Alps
as well
as to the Pyrenees. A crustal balancing in the European part of the
Alps under
consideration of geological constraints shows that the deep Alpine root
contains European crustal material and that this deep root developed in
Neogene
times.
The Adriatic plate
shows a very distinct fragmentation with a stacking of lithospheric
units.The
fragments can be subdivided according to their geographical position
and to
their stacking sequence in the Ligurian, the Po-plain and the Southern
Alps
unit, the last one lying on the European plate. Beneath the northern
rim of the
Northern Apennines the geophysical results suggest a intracontinental
subduction. The corresponding decoupling horizon cuts through the whole
crust
and a part of the uppermost mantle. Movement along this system must
result in
an upwards motion of the fragmented rim of the Adriatic plate,
including parts
of the upper mantle. As a consequence, the extensional tectonic, which
can be
observed in the upper crustal layers in Tuscany, may develop. The
late-miocene
and pliocene thrusting of the lithospheric wedge seems to be the final
stage of
the orogenic development in the Northern Apennines after the paleogene
oceanic
subduction and the development of a wedge of continental crust in early
to
middle miocene. A crustal balancing along the EGT-mainline results in a
minimum
shortening of 90 km since tortonian times.
The geophysical
results in particular are:
- below the
northern part of the Po-plain the crustal thickness reaches 29-30 km;
- about 20 km north
of the river Po the Moho starts to dip southwards with an angle of
10-14°. At
the southernmost provable position 20 km north of the coastline the
depth of
the Moho reaches 55 km;
- beneath the
Ligurian coast the Moho lies at a depth of 20-22 km. It is documented
till 25
km north of the coastline at a depth of 22-24 km. Together with the
previous
point it follows a crustal doubling beneath the crest of the Northern
Apennines;
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Reference Type: Thesis
Record Number: 108
Author: Egger, Adrian
Year: 1992
Title: Lithospheric structure along a transect from
the
Northern Apennines to Tunisia derived from seismic refraction data.
Academic Dept.: Inst. of Geophisics
University: Swiss Federal Institute of Technology (ETH)
City: Zurich (CH)
Pages: 207
Thesis Type: PhD
Abstract: The region of the Mediterranean Sea has gone
through
a complicated history of evolution and it has been tectonically active
until
the present. Continental collisions zones with the evolution of
orogenies,
isolated continental fragments, young marine basins partly overlying
oceanic
crust, and subduction zones are found close together. The general
stress
distribution of the whole region is controlled by the relative motion
between
Africa and Eurasia. However, movements of small blocks can be locally
more
significant.
The whole region of
the Mediterranea Sea has been the subject of many geological and
geophysical
studies. Nevertheless, there are still many open questions to answer
which are
important for a better understanding of its tectonic evolution. A
series of
seismic wide-angle reflection and refraction experiments was carried
out
between the Northern Apennines in northern Italy and Tunisia as part of
the
Southern Segment of the international European Geotraverse project
(EGT). Several
of these experiments were designed for a high resolution survey of the
crustal
structure in the marine areas. The method of two-dimensional
ray-tracing was
used for the interpretation of these mostly N-S oriented profiles and
several
other profiles in Sardinia and the Tyrrhenian Sea. Limited information
was
obtained also about the lower lithosphere beneath Corsica and Sardinia
from
data at recording distances of up to 580 km.
The crustal
structure of the Corsica-Sardinia block in the center of the segment is
laterally
rather homogeneous and has at a depth of 16 to 19 km a clear boundary
to the
lower crust except for southern Sardinia. In general the seismic
velocities
increase at this boundary from 6.1 to 6.3 km/s to 6.6 to 6.8 km/s.
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Reference Type: Conference Proceedings
Record
Number: 70
Author:
Caielli, Grazia;
Delfrati, Luca; Biella, Giancarlo; Franco, Roberto de
Year: 1993
Title:
Strutture crostali
nella zona limite Alpi-Appennini.
Conference Name: 12th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: I
Number of Volumes: 2
Pages: 83-98
Abstract: The reinterpretation of several seismic
refraction
profiles carried out in north western Italy since 1958 allowed the
outline of the
complex Lithospheric relationships in this part of the western
Mediterranean
region. The reinterpretation has been constrained by three more
reliable
sections:
a) the CROP-ECORS
profile in the Western Alps;
b) the European
geotraverse (EGT) main N-S profile;
c) the Tertiary
Piemontese Basin (BDP) seismic section.
The obtained model
depicts a fragmented lithosphere, in which the Adriatic plate shows
strong
doubling and shortening. The so called "Piemontese" lithospheric
piece is encountered in some zones and it is not yet clear its
pertinence to
the European or Adriatic plate, which also depends on the geodynamic
reconstruction in the general framework of the convergence between the
Euroasiatic and African plates.
Reference Type: Conference Proceedings
Record Number: 103
Author: Morelli, Carlo
Year: 1993
Title:
Risultati di 31 anni
(1956-86) di DSS e 7 anni (19986-92) di CROP in Italia.
Conference Name: 12° convegno
GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1
Number of Volumes: 2
Pages: 3-30
Abstract: 24,820 kms of DSS allowed to obtain the main
characteristics of the Crust in Italy and in the surrounding seas.
Namely, the
velocity inversions in the Alps, the crust doublings in the Alps and in
the
Tyrrhenian side of the Apennines, a thinned (distensional) crust on the
same
side, oceanic crust in the central and south-eastern Tyrrhenian sea.
Result for the Deep
Reflection seismic program CROP, started in 1986, are until now
available only
for the western and central Alps (where they have been performed in
collaboration with the similar programs french ECORS and swiss NFP-20);
all the
rest is under survey or processing. The main result for the Alps is the
clear
definition of the continental collision between the adriatic plate
(back/land)
and the european plate (foreland): colossal overthrustings on the
european
plate, sinking of the same for load increasing, slices of lower
european crust
embebbed into the adriatic mantle, rice of the same under the southern
Alps.
Similar overthrusts
exist over the tyrrhenian ramp of the adriatic plate (now foreland).
The
tectonic pulses are here cennected with the rise, the NE and SE
migration and
the collapse of two astenoliths (tuscanian and tyrrhenian ones).
Reference Type: Conference Proceedings
Record
Number: 183
Author:
Capuano, Paolo;
Continisio, Rossella; gasparini, Paolo; Gaudiosi, Germana
Year: 1993
Title:
Struttura crostale
dell'area Siciliana attraverso l'analisi di dati sismici, gravimetrici
e
magnetici
Conference Name: 12th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location: Rome (CNR)
Volume: 1
Number of Volumes: 2
Pages:
109-112
Abstract:
Scopo del lavoro è la
costruzione di un modello crostale semplice ed affidabile dell'area
siciliana
dall'analisi integrata di dati geofisici. In particolare sono stati
considerati
dati di:
-
stratigrafie delle perforazioni AGIP (1977)
-
sismica a rifrazione, relativi all'esperimento
realizzato nel 1984;
-
anomalie di Bouguer, tratte dalla Carta
Gravimetrica d'Italia;
-
anomalie aeromagnetiche, tratte dal Rilievo
Aeromagnetico d'Italia.
Le
analisi sono state condotte esclusivamente
lungo i profili Marsala-C.Passero (p.'I') e Milazzo-Gela (p. 'IV') in
ragione
della maggiore affidabilità dei dati DSS: esistenza del
profilo coniugato per
il primo e verifica della funzione di velocità di partenza,
per il secondo,
sulla base delle informazioni fornite da altri profili realizzati in
zona, e
precedentemente interpretati con tecniche di raytracing (Milano et al.,
1989).
Notes:
lavoro sottoposto a
Tectonophysics
Reference Type: Journal Article
Record Number: 1
Author:
Biella, Giancarlo;
Franco, Roberto de; Demartin, Martina; Minelli, Giorgio; Pialli,
Gianpaolo;
Barchi, Massimo
Year: 1993
Title:
Profilo
Perugia-Frontone: analisi integrata di dati geologici e geofisici
Journal:
Bollettino Società
Geologica Italiana
Volume: 112
Pages:
31-42
Keywords:
sismica rifrazione,
sismica riflessione, modellizzazione gravimetrica, appennino
umbro-marchigiano
Abstract:
Vengono riportati i
risultati dell'eleborazione di nuovi dati di tipo geologico/geofisico
lungo la
sezione di sismica a rifrazione Perugia-Frontone, registrata nell'81.
Reference Type: Thesis
Record Number: 113
Author: Musacchio, Gemma
Year: 1993
Title:
Modellizzazione
sismica della Crosta in un'area d'orogenesi recente: l'esempio delle
Alpi
Centro-Occidentali.
Academic Dept.: Earth Sciences Dept. - Geophysics
University:
Università degli studi
City: Milan (I)
Pages: 125
Thesis Type: PhD
Abstract: A crustal model beneath the Alpine belt, a
geodynamic collisional area, has been performed by 3-components digital
seismic
data. The two studied crustal sections have a lateral offset of about
60 km and
are both transversal to the belt. They are located along the ZE (Iseo
Lake-C.ma
di Campo) fan-profile and the C-D line profile (Colico-Constance lake)
both
having the same shot point C. The north-south oriented NFP-20 near
vertical
reflection profile and the roughly east-west oriented SUDALP-77 and
LB-LL (Lago
Bianco-Lago lagorai) wide-angle profiles are taken into account as
constraints
for the integrated (including both P and S waves data) seismic crustal
model. A
gravimetric modelling along the ZE profile has also been done.
The sophisticated
data processing includes spectral analysis (on noise, PmP and SmS
signals),
polarization analysis (on horizontal plane 3-component reoriented
recordings),
NMO corrections and reflectivity analysis.
The new method for
the identification of shear-wave phases consists mainly in a
polarization
filtering and polarization time section plottings. The filter algorithm
enhances signals which have, in a selected time window, a significant
polarization in one of the directions of the reference system (Z,R,T).
To have
a first estimation of lateral variations of Poisson's ratio the
shear-wave time
sections are plotted with the corresponding shear reduction velocity
and with a
scaled time axis, keeping a theoretical value of
g V = Vp/Vs (or
g T=
Ts/Tp)=1.73. An additional control on correlated shear-wave phases has
been
offered by the detailed spectral analysis.
The main
geophysical results are: the reconstruction of shear-waves travel time
branches; a g V crustal
model; the spectral
content of the Alpine crust; a more detailed
definition of the Alpine crust. Finally, a geological model has been
constructed by the interpretation of all geophysical information with
their
different constraints and also looking at the seismic properties of
rocks in
the Alpine tectonic frame.
........................
omissis ..........................
Notes: Vol. I: 125 pp.; Vol II: (annexed): 134 pp.
Reference Type: Report
Record Number: 214
Author:
IRRS/GA, CNR; Sismici,
Gruppo Acquisizione Dati
Year: 1994
Title:
Compilazione dati
campagna sismica 'Benevento-1992'; profilo 'Cercepiccola-Montella'.
Institution: CNR-IRRS
Date: March 1994
Report Number: Internal Report
Abstract: La
campagna di sismica
attiva 'Benevento-92' è stata effettuata nell'Ottobre del
1992 nell'Appennino
meridionale con il duplice obiettivo di definire un modello di
velocità della
crosta superiore (limitatamente all'area del fiume Sannio) e di
valutare la
risposta sismica locale nella città di Benevento mediante la
registrazione
degli scoppi effettuata con un arete sismica installata in
città.
La
campagna è stata effettuata nell'ambito del
programma di ricerca "Microzonation and hazard assessment methodology
with
application to selected areas (Italy)" finanziato dalla
Comunità Europea,
integrato da un finanziamento straordinario del Servizio Sismico
nazionale.
A
tale campagna hanno partecipato numerosi Enti di
ricerca; in particolare: Istituto di Ricerca sul Rischio Sismico del
CNR
(Milano), Istituto Nazionale di Geofisica (Roma), Istituto di
Oceanologia
dell'Istituto Universitario navale (Napoli), Osservatorio Vesuviano
(Napoli),
Dipartimento di Geofisica e Vulcanologia (UNI-NA), Istituto di Geodesia
e
Geofisica (UNI-TS), Dipartimento di Fisica (UNI-SA), Dipartimento di
Fisica
(UNI-AQ), Laboratoire de Geodynamique (UNI-Nice), Laboratoire de
Geophysique
interne et Tectonophysique (UNI-Grenoble).
La
campagna di sismica attiva 'Benevento-92' può
essere considerata composta da due esperimenti indipendenti effettuati
nell'ambito
di uno stesso programma di ricerca:
a)
esperimento 'profilo'
b)
esperimento 'città'.
Il
presente rapporto illustra i dati raccolti
durante l'esperimento 'profilo'.
................................. omissis
Reference Type: Journal Article
Record Number: 90
Author: Scarascia, Salvatore; Lozej, Alfredo;
Cassinis,
Roberto
Year: 1994
Title: Crustal structures of the Ligurian,
Tyrrhenian and
IOnian Seas and adjacent onshore areas interpreted from wide-angle
seismic
profiles.
Journal:
Bollettino di
Geofisica Teorica e Applicata (BGTA)
Volume: XXXVI
Issue: 141-144
Pages: 5-19
Abstract: A review of the results obtained from the
Deep
Seismic Soundings carried out in the Italian Seas and adjacent onshore
areas
has been attempted with the aim of producing a general chracterization
and
location of the different crustal typologies resulting from the data
interpretation. This review will be useful for comparison and
integration with
the results of the deep vertical seismic profiles in the CropMare'91
project. Results
are represented by crustal sections and a Moho depth contour map which
outlines
the following types: 1) a European continental crust under Corsica and
Sardinia; 2) an Afro-Adriatic continental crust generally dipping in
the
direction of the Ligurian and Tyrrhenian seas; 3) an oceanic crust in
the
Provençal Basin and central Tyrrhenian sea; 4) an anomalous
relatively thin
crust which can be differentiated into Ligurian, Tuscan and
peri-Tyrrhenian
typologies, in places superimposed on the Afro-Adriatic crust.
Reference Type: Report
Record Number: 223
Author:
IRRS/GA, CNR; Sismici,
Gruppo Acquisizione Dati
Year: 1995
Title:
Compilazione dati DSS
campagna CROP-03 1993/94.
Institution: CNR-IRRS
Date: July 1995
Report Number: Rapporto interno
Abstract: Nel
1993 e 1994
l'Istituto di Ricerca sul Rischio Sismico (IRRS) del CNR di Milano ha
effettuato una campagna di sismica a rifrazione/riflessione a grande
angolo
(WAR) nell'ambito del progetto CROP-03 (Monti dell'Uccellina - Gabicce).
Le
indagini crostali nell'area sono iniziate con
due campagne sismiche nel 1974 e nel 1978 i cui dati sono ancora in
corso di
digitalizzazione e reinterpretazione. L'esperimento di sismica a
rifrazione/riflessione a grande angolo CROP-03 WAR 1993-94 è
stato acquisito in
Italia centrale tra la Toscana marittima e la catena dell'Appennino
Umbro-Marchigiano. Questo esperimento è stato ideato e
realizzato allo scopo di
supportare ed estendere i risultati dell'esperimento NVR CROP-03, per
lo studio
della struttura crostale degli Appennini settentrionali, la
comprensione dei
loro rapporti con il sistema alpino e quindi la loro evoluzione
geodinamica.
Visto che lo scopo primario era quello di ottenere informazioni
prevalentemente
in crosta profonda, si è deciso di strutturare l'esperimento
in due fan ad alta
risoluzione vincolati da sei profili di cui due reciproci: la loro
ubicazione è
stata scelta in modo che gli specchi dei fan ricadessero sul tracciato
della
linea NVR del CROP-03 e le distanze di registrazione fossero tali da
garantire
l'osservazione di riflessioni pressochè critiche dalla Moho,
cosa che in base
ad esperimenti precedenti dovrebbe accadere a circa 60-80 km di
distanza. Per
la precisione si è scelta una distanza leggermente
sotto-critica (65 km) in modo
da ottenere informazioni anche da fasi infracrostali. Due dei sei
profili di
controllo sono stati estesi fino ad oltre 100 km di lunghezza per
consentire la
registrazione di fasi provenienti dal mantello superiore. La distanza
media fra
le stazioni sui profili era di 2,5 km mentre per i fan 0,75 km
(distanza
intergeofonica allo specchio).
Sono
stati utilizzati 3 punti di scoppio in cui si
sono fatte brillare cariche fino a 600 kg. In particolare durante la
seconda
fase (Maggio 1994) problemi con la Sovrintendenza ai Beni Archeologici
di
Firenze hanno costretto ad utilizzare, per gli scoppi di Chiusi,
cariche non
superiori a 100 kg, a cui si è cercato di ovviare
utilizzando stack di più
registrazioni.
L'acquisizione
dati è stata effettuata utilizzando
acquisitori digitali Lennartz Mars-88 F/D dotati di sensori
velocimetrici a 3
componenti Mark-P L4-3D, con frequenza propria di 1 Hz, smorzati a 0,7;
inoltre
sono stati usati anche acquisitori analogici Mars-66 ad 1 o 3
componenti, con
sensori uguali ai precedenti.
................................... omissis
...................
Reference Type: Report
Record
Number: 212
Author:
IRRS/GA, CNR; Sismici,
Gruppo Acquisizione Dati
Year: 1995
Title:
Compilazione dati
campagna sismica 'Tirreno-1971' (parte A); profilo: Gargano-Pantelleria.
Institution:
CNR-IRRS
Date:
Luglio 1995
Report Number: Internal Report
Abstract:
Obiettivo di questa
tesi, svolta presso l'IRRS del CNR di Milano, è la
ricostruzione del limite
crosta/mantello nell'area siciliana, mediante l'utilizzo di dati
sismici DSS. I
dati utilizzati in questo lavoro sono il risultato di due campagne
sismiche
svolte rispettivamente nel 1971 (profilo a rifrazione
Gargano-Salerno-Pantelleria) e nel 1984 (nell'ambiro del progetto EGT).
In
particolare nel 1971 venne eseguito nell'Italia
meridionale un profilo DSS a rifrazione allo scopo di studiare le zone
di
transizione tra crosta continentale e crosta oceanica ivi esistenti. Il
programma fu attuato in stretta collaborazione fra Istituti Geofisici
italiani
e tedeschi, con la partecipazione di un gruppo francese. Le stazioni di
registrazione vennero poste in terraferma (tra il promontorio del
Gargano e il
Golfo di Salerno), in Sicilia (tra Palermo e Menfi) e sull'isola di
Pantelleria.
I dati utilizzati in questo lavoro si riferiscono alle sole stazioni
siciliane
e di Pantelleria: si tratta di quelle numero 27, 28, 29, 30, 32 mentre
i dati
delle stazioni numero 25, 26, 31 non sono stati utilizzati, per motivi
tecnici.
Vennero
eseguiti 67 scoppi nel Mar Tirreno, tra
Salerno e Palermo (scoppi E1...E67) e 16 nel Canale di Sicilia, tra
Menfi e
Pantelleria (F1...F16), utilizzando differenti quantitativi di
esplosivo: da un
minimo di 25 kg ad un massimo di 675 kg. Peraltro i dati utilizzati,
anche in
questo caso, si riferiscono ai soli scoppi compresi tra E67 (vicino
alla costa
siciliana) ed E43 (nel Tirreno) a causa del fatto che l'aumento della
distanza
comporta un maggiore assorbimento di energia e quindi un minor valore
del
rapporto segnale/disturbo. I dati relativi agli scoppi F1-F16 sono
stati tutti
utilizzati.
Il
profilo così costituito presenta una lunghezza
di 420 km circa. Per le stazioni di registrazione furono utilizzati
geofoni di
tipo Berckhemer-Stroppe (versione 1970) e Mark-P, collegati ad
acquisitoriLennartz Mars-66 a 4 canali. Il segnale del tempo fu
determinato
utilizzando il codice HBG (Neuchatel, CH).
Relativamente
al 1984, i profili sismici esaminati
sono due, esplorati nell'ambito del progetto noto come "Geotraversa
Europea"
(EGT). Anche in questo caso parteciparono diversi Istituti geofisici
italiani
in stretta collaborazione.
.................................... omissis
.................................
Reference Type: Thesis
Record Number: 116
Author: Mainardi, Maria Rosaria
Year: 1995
Title:
Strutture crostali
nella zona di giunzione Alpi-Appennini da dati di sismica a rifrazione.
Academic Dept.: Earth Science Dept.; Geology Inst.
University:
Università degli studi
City: Milan (I)
Pages: 113
Abstract: Il
lavoro di tesi
riguarda l'interpretazione e reinterpretazione di linee sismiche
crostali
ottenute con la tecnica a rifrazione / riflessione a grande angolo
(DSS),
metodo utilizzato per l'indagine della Crosta profonda ed in zoe con
forti
variazioni laterali.
Sono
stati analizzati i profili in linea brevi
delle campagne Appennini '80-'87 per individuare variazioni laterali
arrivando
ad una interpretazione delle strutture della crosta superiore.
Inoltre
l'interpretazione delle linee sismiche dei
progetti EGT'83 ed EGT'86 ha permesso di giungere ad un modello
crostale più
esteso e profondo.
Questa
interpretazione è congrua con i risultati
ricavati dai profili sismici della campagna BTP'91 e dal transetto
'Torriglia-Piacenza'; inoltre si sono utilizzati come riferimento i
profili
AGIP (Cassano et al.) e le anomalie magnetiche e gravimetriche per una
valutazione dell'andamento del basamento.
Si
sono tenuti in considerazione i vincoli di
superficie e gli studi a carattere strutturale regionale degli Autori.
Si è
quindi giunti ad una interpretazione geologica del modello sismico
finale,
arrivando ad una congrua interpolazione di tutti i dati disponibili.
Notes:
A.A. 1994-1995
Relatori:
Proff. F.Forcella e G.Biella;
Correlatori: Dr. R. de Franco e Dr. P.M.Rossi
Reference Type: Journal Article
Record Number: 198
Author:
Iannaccone, Giovanni;
Improta, Luigi; Biella, Giancarlo; Castellano, Mario; Deschamps, Anne;
Franco,
Roberto de; Malagnini, Luca; Mirabile, Lorenzo; Romeo, Roberto; Zollo,
Aldo
Year: 1995
Title: A study of local site effects in benevento
(Southern
Italy) by the analysis of seismic records of explosions.
Journal:
Annali di Geofisica
Volume: XXXVIII
Issue: 3-4
Pages: 411-427
Keywords: Site effects; spectral ratio; Southern
Apennines;
Benevento
Abstract: In this paper we evaluate the seismic
amplification
effects in the town of Benevento, using records of an explosion of 500
kg fired
at about 7 km. Seismic records were obtained at 43 selected sites in
the city
by digitaò 3-component stations. A data selection performed
on the
signal-to-noise ratio reduced the available data to 26 stations. We
used the
spectral ratio techniques to evaluate the amplification effects of each
recording site compared both to the average spectrum calculated over 26
dstations and to a refraction seismic stations. The shapes of the
spectral
ratios were classified according to the geological characteristics of
the site.
A characteristic shape of the spectral ratio was observed to be related
to the
specific structure of the subsoil. In particular, the sites on basin
sediments
(Lagonegro Unit) and Middle Pleistocene conglomerates failed to show
amplification effects; the sites on thick alluvial deposits showed
amplification in the 5-9 hz range; finally, sites on
alluvial-lacustrine deposits
amplified the seismic signal at frequencies depending on the
characteristics
and the thickness of the deposit. In addition, damage distribution
caused by
the 1688 earthquake in Benevento was related to the thickness of the
surcafe
layers in the ancient built-up area of the town. The study of the
spectral
ratios showed that these deposits amplify ground motion at frequencies
between
9 and 12 hz, i.e. frequencies close to the natural period of the most
widespread buildings at that time in Benevento. Geological and seismic
data
were jointly used to carry out a zonation of the urban area of
Benevento on the
basis of homogeneous seismic responces. The validity of this analysis
is
limited to the main frequency band and amplitude of ground motion
produced by
the explosions.
Reference Type: Journal Article
Record Number: 65
Author: Ye, Sanyu; Ansorge, Jorge; Kissling, E.;
Mueller,
Stephan
Year: 1995
Title: Crustal structure beneath the eastern Swiss
Alps
derived from seismic refraction data.
Journal:
Tectonophysics
Issue:
242
Pages:
199-221
Abstract: The eastern part of the Swiss Central Alps is
densely covered by a network of seismic refraction and wide-angle
reflection
profiles recorded mostly parallel to the tectonic strike of the Alps
and along
the newly acquired N-S-oriented European Geotraverse (EGT). To obtain a
well-constrained crustal transect along the EGT an initial model was
constructed from information based mainly on the coincident reflection
seismic
profile of the Swiss National Research Program NFP20 and short-range
observations of the EGT data for the shallow structure and on the
along-strike
wide-angle profiles for the deep structure. The refinement of the
initial model
by 2-D raytracing during the subsequent interpretation of the EGT data
leads to
a detailed P-wave velocity distribution of the crustal cross-section
beneath
the Central Swiss Alps and its adjacent areas. In general, the
distinctly
layered crustal structure below the Alpine foreland thickens
considerably as
the Alps are approached, reaching a maximumthickness as nearly 60 km
below the
Insubric Line. The upper and middle crust has velocities between 6.0
and 6.2
km/s. Except for the area below the southern part of the Molasse Basin
and the
Helvetic nappes a distinct lower crust with a relatively low velocity
of
6.5-6.6 km/s is found. Below the Penninic nappes the lower crust
thickens
remarkably, merging probably with the high-velocity zone of 6.6 km/s at
a depth
of about 21 km, which has been interpreted as the top of the indenting
lower
crust of the Adriatic promontory of the African plate. A clear vertical
offset
between the smoothly south-dipping European and the more rapidly rising
Adriatic crust-mantle boundaries is found. The complex xtructures of
the upper
crust beneath the Alps caused by the nappe tectonics can only be partly
resolved by the refraction seismic data. A south-dipping high-velocity
zone
within the Penninic nappe pile and a reflector beneath the northern
front of
the Aar Massif can possibly be interpreted as incomplete images of the
shallow
heterogeneous 3-D structure.
Reference Type: Conference Proceedings
Record
Number: 62
Author:
Capone, E.; Delfrati,
Luca; Biella, Giancarlo; Caielli, Grazia; Franco, Roberto de
Year: 1995
Title:
Interpretazione
sismico-gravimetrica di profili EGT'83 e EGT'86 nel settore
Nord-Occidentale
della Penisola italiana.
Conference Name: 14thConvegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location: Roma (CNR)
Volume: 2
Number of Volumes: 2
Pages: 729-740
Abstract: A three-dimensional outline of the
relationships
between the lithospheric fragments in Northwestern Italy is presented.
The
final models have been obtained by the interpretation of the Bouguer
gravimetric data along the EGT'83 and EGT'86 main profiles, E-W and N-S
oriented.
The gravimetric
analysis support the presence of a fragmented adriatic lithosphere,
marginally
lying and distinctly separated from the deep seated european plate.
Furtheron,
the so-called 'Ligure' and 'Piemontese' crust/mantle boundaries are
evidenced
between the european and adriatic plates.
Reference Type: Journal Article
Record Number: 152
Author: Cassinis, Roberto
Year: 1995
Title: La
prospezione sismica
per obiettivi profondi: alcune riflessioni su ...riflessione e
rifrazione.
Journal:
Atti Ticinesi Scienze
della Terra
Volume: 38
Pages: 129-147
Keywords: Seismic prospecting; Deep crust
Abstract: Some comments are made on the potential,
characteristics, limitations and constraints of seismic methods applied
to
crustal exploration. The history and results of the main national and
international programmes are briefly reviewed, endeavouring to
illustrate their
achievements and failures. In particular, the reasons of the need of
complementary data (especially the refraction-wide angle
reflection-WAR) to be
integrated with the near vertical reflections (NVR) are explained.
While in the
beginning the exploration programmes were based almost exclusively on
NVR
profiles, at present it is widely aknowledged that the integration with
WAR is
essential. The higher the complexity of the structural and
compositional
problems, the more stringent the need of integration.
All the examples
shown are taken from the published reports or scientific papers, with
comments
on the quality of data and their reliability. It is stressed that,
while WAR
can obtain almost in every case a coarse velocity model of the deep
crust, the
NVR data can show a more detailed geometrical picture (especially on
the upper
sedimentary and cristalline crust) but, in some instances, are unable
to obtain
a clear response from the lower crust and from the mantle lid. The
character of
the high frequency events reflected from the crystalline and deep crust
is
compared to the one from the sedimentary layers.
This note is
particularly dedicated to the geologists who are presently involved in
the
evaluation and interpretation of geophysical crustal surveys already
performed
or programmed in the very complex Italian region.
Reference Type: Journal Article
Record Number: 177
Author:
Ponziani, Francesco;
Franco, Roberto de; Minelli, Giorgio; Biella, Giancarlo; Federico, C.;
Pialli,
Gianpalo
Year: 1995
Title: Crustal shortening and duplication of the
Moho in
the Northern Apennines: a view from seismic refraction data.
Journal:
Tectonophysics
Issue:
252
Pages:
391-418
Abstract: A reappraisal of the DSS refraction seismic
campaigns of 1978 and 1974 in the Northern Apennines and the northern
Tyrrhenian Sea, after digitization of the original analog data, and a
new
interpretation of crustal structures are presented in this paper. The
layering
of the Adria crust consists of a low-velocity lower crust topped by a
6.7 km/s
horizon and an upper crust again formed by a low-velocity layer capped
by a
faster one. In the Tuscany sector the crust-mantle boundary and lower
crust
show attenuated velocities and a reduced thickness with respect to the
Adriatic
counterpart. These differences are due to the extensional tectonics,
restricted
to Tuscany and occurred in a high heat flow regime related to an
uplifting
astenosphere.
It has been
confirmed that a deep thrust is responsible for Moho doubling in
correspondence
with the zero-Bouguer anomaly line: the Tuscan Moho overlaps the
Umbro-Marchean
one for a length of about 30 km. It is hypothesized that another
shallower
thrust involves upper crust in the Mid-Tuscany Range, Mt. cetona and
Perugia
Massifs had their roots in the mantle and that subsequent extensional
tectonics
obliterated every trace of thrusting in lower crust and mantle rocks.
No conclusive proff
of the existence of a European Moho below a Tuscan one in the area
underneath
Elba has yet been found. Revision of DSS data excludes the presence of
a
refractor-reflector 60 km deep; the same data, however, are compatible
with the
existence of a crust-mantle boundary at 30-35 km depth.
Reference Type: Conference Proceedings
Record
Number: 25
Author:
Osculati, Luca; Biella,
Giancarlo; Franco, Roberto de
Year: 1995
Title:
Digitalizzazione e
revisione critica dei dati DSS registrati in Sicilia dal 1968 al 1986
Conference Name: 14th GNGTS meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: 2
Number of Volumes: 2
Pages: 685-696
Abstract: This work proposes a critical review and a
preliminary interpretation of DSS data carried out in Sicily from 1968
to 1984.
The analogical data have been digitized and controlled with respect to
their
confidence level for both time and space axis. The original 'Sicilia
1968'
recording tapes were not available. Thus they have been converted in a
more
suitable digital form by means of a scanner procedure, followed by a
single
seismogram resampling in order to obtain the data in a standard format.
A
preliminary kinematic interpretation of the controlled data set allow
us to
subdivide the study area in three main tectonic domains as a function
of the
different Moho depth.
Reference Type: Journal Article
Record Number: 18
Author:
Zollo, Aldo;
Gasparini, Paolo; Biella, Giancarlo; Franco, Roberto de; Buonocore, B.;
Mirabile, Lorenzo; Natale, Giuseppe De; Milano, Giuseppe; Pingue, F.;
Vilardo,
Giuseppe; Bruno, Pier Paolo; Matteis, R. De; Meur, H. Le; Iannaccone,
G.;
Deschamps, Anne; Virieux, Jean; A., Nardi; A., Frepoli; Hunstad, I.;
Guerra,
Ignazio
Year: 1996
Title: 2D seismic tomography of Somma-Vesuvius -
description of the experiment and preliminary results.
Journal:
Annali di Geofisica
Volume: 39
Issue: 3
Pages: 471-486
Keywords: Vesuvius, Tomography
Abstract: A multidisciplinary project for the
investigation of
Mt. Vesuvius structure was started in 1993. The core of the project is
represented by a high resolution seismic tomography study by using
controlled
and natural sources. The main research objective is to investigate the
feeding
sustem of the volcano and to retrieve details of the upper crustal
structure in
the area. A first 2D active seismic experiment was performed in May
1994, with
the aim of studing the feasibility of using tomographic techniques for
exploring the volcano interiors. Particularly, this experiment was
designed to
obtain information on the optimal source-receivers configuration and on
the
depth extension of the volume sampled by shot-generated seismic waves.
66 three-component
seismic stations and 16 single component analog instruments were
installed by
several Italian and French groups to record signals generated by three
on-land,
underground explosions. Sources and geophones were deployed along a 30
km NW-SE
profile, passing through the volcano crater. Receivers were placed at
an
average spacin of 250 m in the middle of the recording line and at 500
m
outside. The arrival time data base was complemented by first P and S
readings
of microearthquakes which occurred in the recent past within the
volcano. The
first arrival data set was preliminarily used to determine the shallow
structure of the volcano by applying Thurber's (1983) tomographic
inversion
technique. This analysis shows evidence for a high-velocity body which
extends
vertically from about 400 m below the crater down to at least 3000 m
and for a
shallow 300-500 m thick low-velocity cover wich borders the edifice.
Data from
the distant shot show evidence for arrivals of deep reflected/converted
phases
and provide information on the deeper structure under the volcano. The
results
from the interpretation of 2D data are used for planning a 3D
tomographic
survey wich will be carried out in 1996.
Reference Type: Journal Article
Record Number: 16
Author: Cernobori, Licio; Hirn, Alfred; McBride,
J.H.;
Nicolich, Rinaldo; Petronio, L.; W.G., M. Romanelli &
'Streamer'/'Profiles'
Year: 1996
Title: Crustal image of the Ionian basin and its
Calabrian
margins.
Journal:
Tectonophysics
Volume:
264
Pages: 175-189
Keywords: ionian basin; multi-channel seismic
reflection;
calabrian margin; lower crust seismic structure; crustal thinning
Abstract: Previous seismic investigation of the crustal
structure in the Ionian basin has been limited to shallow penetration
seismics
of the 1970's, characterized by inadequate source power and low fold.
Earlier
OBS and ESP seismic refraction experiments have not been able to firmly
resolve
one of the principal scientific problems for this region which is
whether the
Ionian basin is floored by oceanic crust or by higly attenuated
continental
crust. A second elusive problem is the nature of the transition of the
boundaries between the Ionian basin and its margin.
In this paper we
describe and interpret new deep seismic reflection and wide-angle data
collected in the Western Ionian Sea and the Calabria region of Italy
(EC
contracts: 'Streamers' and 'Profiles', 1992)....
Notes: copyright 1996, Elsevier Sc. B.V.; doi:
0040-1951/96/$15.00
Reference Type: Journal Article
Record Number: 136
Author:
Chiarabba, Claudio;
Amato, Alessandro
Year: 1996
Title: Crustal velocity structure of the Apennines
(Italy)
from P-wave travel time tomography.
Journal:
Annali di Geofisica
Volume: XXXIX
Issue: 6
Pages: 1133-1148
Keywords: P-wave tomography; Deep structure; Apennines
Abstract: In this paper we provide P-wave velocity
images of
the Crust underneath the Apennins (Italy), focusing on the lower
crustal
structure and Moho topography. We inverted P-wave arrival times of
earthquakes
which occurred from 1986 to 1993 within the Apenninic area. To overcome
inversion instabilities due to noisy data (we used bulletin data) we
decided to
resolve a minimum number of velocity parameters, inverting for only
two-layers
in the crust and one in the upper mantle underneath the Moho. A partial
inversion of only 55% of the overall dataset yelds velocity images
similar to
those obtained with the whole dataset, indicating that the depicted
tomograms
are stable and fairly insensitive to the number of data used. We found
a
low-velocity anomaly in the lower crust extending underneath the whole
Apenninic belt. This feature is segmented by a relative high-velocity
zone in
correspondence with Ortona-Roccamonfina line, that separates the
Northern from
the Southern Apenninic arcs. The Moho has a variable depth in the study
area,
and is deeper (more than 37 km) in the Adriatic side of the Northern
Apennines
with respect to the Tyrrhenian side, where it is found in the depth
interval
22-34 km.
Notes: The research was carried out in the framework
of
Project GeoModAp (EC contract EVSV-CT94-0464)
Reference Type: Report
Record Number: 107
Author: Asudeh, I.; White, D.; Roberts, B.; Forsyth,
D.;
Kay, I.; Cartwright, T.; Carroll, P.; Hainal, Z.; Koperwhats, B.;
Musacchio,
Gemma; Farrell, D.
Year: 1996
Title: 1996 LITHOPROBE Western Superior seismic
refraction
survey: field acquisition and processing Report.
Institution: Geological Survey of Canada
Date: 1996
Type of Work: GSC Report
Report Number: 916
Abstract: The LITHOPROBE Western Superior transect is
located
in well-exposed and geologically well-studied areas of the Superior
Province in
northwestern Ontario, Canada. The largest Archean craton of North
America, the
Superior Province is characterized by a number of east-west
subprovinces, with
distinct lithology and aeromagnetic signature. One of the principal
objectives
of the transect is to study the deep crust and upper mantle structure
of the
sub-provinces to determine their role in the development of Archean
crust.
The seismic
refraction component of the Western Superior transect was completed in
1996. A
total of 510 portable seismographs were deployed along two long-range
profiles, in the
north-south and
east-west directions crossing the Superior subprovinces. To sample the
deeper
lithosphere, explosive shots in the weight range of 1000 to 3000 kg
were fired
in drilled holes at 30-50 km spacing along the profiles with maximum
shot to
receiver spacing approaching 650 km.
This Report is a
summary of the survey procedures, data processing and creation of the
standard
SEG-Y files that are available from the LITHOPROBE Seismic Processing
Facility
in Calgary (CA).
For information
about this report or the Geological Survey of Canada refraction
program,
contact Isa Asudeh at asudeh@cg.nrcan.gc.ca
Notes: Open File No. 3583
Reference
Type:
Magazine Article
Record
Number: 203
Author:
Zollo, Aldo;
Gasparini, Paolo; Virieux, Jean; Meur, H. le; Natale, Giuseppe de;
Biella,
Giancarlo; Boschi, Enzo; Capuano, Paolo; Franco, Roberto de;
dell'Aversana, P.;
Matteis, Raffaella De; Guerra, Ignazio; Iannaccone, Giovanni; Mirabile,
Lorenzo; Vilardo, Giuseppe
Year: 1996
Title: Seismic evidence for a low-velocity zone in
the
upper Crust beneath Mount Vesuvius.
Magazine:
Science
Volume:
274
Issue Number: 5287
Pages: 592-594
Date: 25 October 1996
Abstract: A two dimensional active seismic experiment
was
performed on Mount Vesuvius: explosive charges were set off at three
sites and
the seismic signal along a dense line of 82 seismometers was recorded.
A
high-velocity basement, formed by mesozoic carbonates, was identified 2
to 3 km
beneath the volcano. A slower (P-wave velocity Vp 3.4 to 3.8 km/s) and
shallower high-velocity zone underlies the central part of the volcano.
Large
amplitude late arrivals with a dominant horizontal wave motion and
low-frequency content were identified as a P to S phase converted at a
depth of
about 10 km at the top of a low-velocity zone (Vp<3 km/s, which
might
represent a melting zone.
Reference Type: Brochure
Record Number: 200
Editor:
Capuano, Paolo;
Natale, Giuseppe De; Gasparini, Paolo; Iannaccone, Giovanni; Zollo, Aldo
Year: 1996
Title:
TOMOVES '96 -
Tomografia Sismica del Vesuvio.
Series
Author:
GNV, CNR, PCM
Publisher: De
Frede Ed., Napoli
City:
Napoli (I)
Number of Pages: 14
Notes:
brochure di
presentazione del progetto, a cura del Comitato Scientifico.
Reference Type: Journal Article
Record Number: 6
Author:
Biella, Giancarlo;
Polino, Roberto; Franco, Roberto de; Rossi, Pietro Maria; Clari,
Pietro; Corsi,
Adelmo; Gelati, Romeo
Year: 1997
Title: The crustal structure of the Po Plain:
reconstruction from integrated geological and seismic data
Journal: Terra Nova (Blackwell Science)
Volume: 9
Issue: 1
Pages: 28-31
Abstract: A reflection/refraction seismic experiment
performed
in 1991 in the western Po plain gave basic data to constrain the
interpretation
of the crustal structure across the Alps/Apennines junction zones. Two
different seismic domains, north and south of the western supposed
prosecution
of the Villavernia-Varzi line, are evidenced from the interpretation of
the
data. The boundary between the two domains is characterized by strong
lateral
variations from southern high to northern low velocity layers....
Reference Type: Journal Article
Record Number: 104
Author: Morelli, Carlo
Year: 1997
Title: Recent deeper geophysical results better
account for
the tectonics in the Italian area.
Journal:
Annali di Geofisica
Volume: XL
Issue: 5
Pages: 1345-1358
Keywords: Alpine orogeny - collisional tectonics -
extensional
tectonics - rifting
Abstract: Results from extended DSS profiles
(1956-1986) in
Italy and surrounding land and sea areas offer good constraints for
other
geophysical and geological data. Integrated interpretations outline the
main
tectonic features. Collisional tectonics is predominant in the Alps,
for which
the Adriatic plate acted as hinterland against the European plate
foreland. Main
results: W-wards,
NW- and N-wards
oriented overthrusting on the European crust, bending of the lower
European
crust, European Moho to 70 km depth with the Adriatic mantle indented
above,
crustal doubling (Adriatic over the European one). In the Apennines, on
the contrary,
the Adriatic plate acted as a foreland, against the overthrusts
generated by
the Tuscanian and Tyrrhenian mantellic bodies, heated, elevated and
migrated
NE-wards and SE-wards, respectively. Also the Adriatic plate bends
under this
load-centripetally towards the Tyrrhenian sea, so that the Adriatic
Moho from
35 km depth is presumed to descend through a flexure till 40-50 km
below the
Tuscanian and Tyrrhenian land areas. The external peri-Apenninic area
is still
in compression and includes thick sedimentary basins, from the Po.plain
to
Sicily. The internal area is in extension, overlapped by thin,
stretched crusts
of Ligurian and Tyrrhenian origin, whose remmants occupy most of both
seas
areas, with two areas of oceanic crust in the SE-Tyrrhenian. Rifting
and
opening is in action also in the Ligurian Sea and Sicily Strait.
Reference Type: Report
Record Number: 224
Author:
IRRS/GA, CNR; Sismici,
Gruppo Acquisizione Dati
Year: 1997
Title:
Pseudo compilazione
dati 'Bolsena-90'.
Institution: CNR-IRRS
Abstract: In June 1990 (18-22) a seismic experiment was
carried out in the Bolsena region (Central Apennines, Italy) by the
CNR-IRRS
applied-geophysics Team, in collaboration with ING (Rome).
A total of 6 shots,
ranging from 400 to 500 kg each, in 5 shot-points were fired and 54 recording sites were
used, using both
analog and digital instrumentation furnished by the two Institutions.
In this report, we
present source data, regarding two in-line profiles explored: 'P-T' and
'G-V'. Also
raw and processed seismic-sections are presented.
Reference Type: Journal Article
Record Number: 86
Author:
Scarascia, Salvatore;
Cassinis, Roberto
Year: 1997
Title: Crustal structures in the Central-Eastern
Alpine
sector: a revision of the available DSS data.
Journal:
Tectonophysics
Issue:
271
Pages:
157-188
Keywords: central-eastern Alps; collision belt; crustal
structure; Moho discontinuity; explosion seismology; seismic modelling
Abstract: In the Alpine sector east of the Giudicarie
line the
investigation of crustal structure is less developed than in the west
and
central sectors because seismic Near vertical reflection (NVR) profiles
are not
yet available. However, it is felt that a revision, by a complete,
homogeneous
reinterpretation of several refraction wide-angle reflection profiles
or Deep
Seismic Soundings (DSS), recorded during different phases of the early
exploration, will help in defining a model of the deep crust and of the
Moho
boundary in the whole area from the central to the eastern Alps.
Six interpretative
cross sections are proposed as the final output of the seismic
modelling as
well as a map of the crust-mantle boundary. The main results of this
investigation are the following:
- the lower crust
and the Moho beneath the northern Alps show a fairly homogeneous
structure; the
seismic velocity of the European lower crust is anomalously low. While
in the
north the southward dip of the European crust is of about 12°,
in the center of
the investigated area its dip is reduced to about 6°. In this
zone of flatter
Moho a complex crust-mantle transition is observed;
- the Northern
strip of the Adriatic crust appears highly fragmented into small
blocks, each
block dipping in different directions (N, NE, NW);
- as far as the
relationship between the surface tectonic features and the deep crustal
structure is concerned, it is found that, while the edge of the
Adriatic Moho
is fairly coincident with the Periadriatic lineament in its western
sector
(Tonale line), it appears to be strongly displaced in the eastern one
(Pustertal
line);
- also in the
eastern Alps, in agreement with the interpretation of the European
geotraverse
(crossing eastern Swiss Alps and Lombardian southern alps), a wedge of
the
Adriatic lower crust overrides the more ductile European crust,
protruding
northwards beyond the edge of the Adriatic Moho.
These results can
help to better investigate the complex interactions between the
European and
Adriatic plates, as well as to study the relationships between deep and
surface
structures.
Reference Type: Report
Record Number: 222
Author: Sea-Land-Group, CROP-M-II
Year: 1997
Title: Wide angle reflection 'Sea-Land Crop-M-II'
and
'Lisa' Project - Section Atlas.
Institution:
R. de Franco
G.
Caielli
A.
Corsi
Abstract: Objective of this Atlas is to give a summary
of Wide
Angle Reflection-Refraction (WARR) SEA LAND Working Group activity and
to
provide the reader with a concise and complete overview of WARR CROP
MARE II
lines and their data without geological and geophysical
interpretations. It
intends leave the reader space and freedom for individual
interpretation and
evaluation of the recorded data.
The SEA-LAND W.G.
activity started in 1993. It was formed to coordinate recording,
processing and
interpretation of the seismic data of the marine lines recorded on land
with
far-offsets in the frame of NVR CROP MARE II Project.
This Project, in
which the acronym CROP stands for "Crosta Profonda" (deep Crust), had
the objective to acquire deep crustal reflections profiles in the
Adriatic,
Ionian and Tyrrhenian Seas, to contribute to a better study of the
crustal
structures in the coastal areas of the Italian Peninsula.
In this Atlas,
besides, are shown the seismic lines acquired in the Northern
Tyrrhenian Sea,
in the frame of European Project LISA (France and Italy) to complete
CROP lines
(Mauffret, 1995).
..............................
omissis ...............
The acquisition of
the CROP MARE I lines by the permanent seismometric array of the
Geophysical
Institute of UNI-Genova demonstrated that, using CROP MARE powerful
air-gun
sources, it was possible to record good quality arrivals to great
distances
(Augliera et al., 1992).
............................... omissis
................
Reference
Type:
Journal Article
Record
Number: 7
Author:
Ferrari, Riccardo;
Miglioli, Paolo; Maistrello, Mariano; Franco, Roberto de; Corsi, Adelmo
Year: 1998
Title:
L'esplorazione sismica
profonda in Italia: dati 'Deep Seismic Soundings' in rete!
Journal:
Bollettino CILEA
Issue: 63
Pages: 5-12
Keywords:
profili,
registrazione, database
Abstract: Il
progetto
'DSS-ON-LINE' mette a disposizione dei ricercatori italiani e stranieri
un
moderno strumento di ricerca e reperimento dei dati sismici di
interesse
(comprese le forme d'onda numeriche) dell'intera esplorazione sismica
crostale
italiana (dati dal 1968 al '98).
Reference Type: Conference Proceedings
Record Number: 88
Author: Morelli, Carlo
Year: 1998
Title:
Prospettive aperte
dalle nuove conoscenze geofisiche in profondità nella
Penisola Italiana.
Conference Name: 17th
GNGTS meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1°
Number of Volumes: 1
Pages: 1-16
Abstract: The deep seismic refraction profiles 1956-'86
(DSS
and WA) permitted a regional knowledge of the Earth's crust in Italy.
The
revision and the digital processing of some profiles perpendicular to
the
Peninsula gave further information on the position and nature of the
longitudinal, almost continuous along all the peninsula, suture between
the
thick Adriatic crust and the thinned one to the west. The CROP-03
profile
(Punta Ala-Gabicce) has also pointed out the correlation between the
seismic
activity and the superficial and deep structure in the Northern
Apennines. The
same profile has too displayed the regional meaning of the tuscanian
geothermal
area, with new prospects for geothermal energy. Likewise the successes
obtained
by AGIP in Basilicata with 3D seismics open new horizons for oil
prospecting in
the carbonatic series of central-southern Italy.
Reference Type: Journal Article
Record Number: 199
Author:
Iannaccone, Giovanni;
Improta, Luigi; Capuano, Paolo; Zollo, Aldo; Biella, Giancarlo; Franco,
Roberto
de; Deschamps, Anne; Cocco, Massimo; Mirabile, Lorenzo; Romeo, Roberto
Year: 1998
Title: A P-wave velocity model of the upper crust of
the
Sannio region (Southern Apennines, Italy).
Journal:
Annali di Geofisica
Volume: 41
Issue: 4
Pages: 567-582
Keywords: Southern Apennines; Upper crust structure; 2D
P-wave
velocity model
Abstract: This paper describes the results of a seismic
refraction profile conducted in October 1992 in the Sannio region,
Southern
Italy, to obtain a detailed P-wave velocity model of the upper crust.
The
profile, 75 km long, extended parallel to the Apenninic chain in a
region
frequently damaged in historical time by strong earthquakes. Six shots
were
fired at five sites and recorded by a number of seismic stations
ranging from
41 to 71 km with a spacing of 1-2 km along the recording line. We used
a
two-dimensional raytracing technique to model travel times and
amplitudes of
first and second arrivals. The obtained P-wave velocity model has a
shallow
structure with strong lateral variations in the southern portion of the
profile. Near surface sediments of the Tertiary age are cgaracterized
by
seismic velocities in the 3.0-4.1 km/s range. In the northern part of
the
profile these deposits overlie a layer with a velocity of 4.8 km/s that
has
been interpreted as a Mesozoic sedimentary succession. A high velocity
body,
corresponding to the limestones of the Western Carbonate Platform with
a
velocity of 6 km/s, characterizes the southernmost part of the profile
at
shallow depths. At a depth of about 4 km the model becomes laterally
homogeneous showing a continuous layer with a thickness in the 3-4 km
range and
a velocity of 6 km/s corresponding to the Meso-Cenozoic limestone
succession of
the Apulia Carbonate Platform. This plattform appears to be layered, as
indicated by an increase in seismic velocity from 6 to 6.7 km/s at
depths in
the 6-8 km range, that has been interpreted as a lithological
transition from
limestones to Triassic dolomites and anhydrites of the Burano
formation. A
lower P-wave velocity of about 5.0-5.5 km/s is hypothesized at the
bottom of
the Apulia Plattform at depths ranging from 10 down to 12,5 km; these
low
velocities could be related to Permo-Triassic siliciclastic deposits of
the
Verrucano sequence drilled at the bottom of the Apulia Plattform in the
Apulia
Foreland.
Reference Type: Journal Article
Record Number: 24
Author:
Waldhauser, F.; Kissling, E.; Ansorge, Jorge; Mueller,
Stephan
Year: 1998
Title: Three-dimensional interface modelling with
two-dimensional seismic data: the Alpine crust-mantle boundary
Journal: Geophys. J. Int.
Issue: 135
Pages: 264-278
Keywords: Alps, Crustal structure, Moho reflection,
Seismic
modelling, Seismic resolution, Topography
Abstract: We present a new approach to determine the
3-D
topography and lateral continuity of seismic interfaces using 2-D
derived
controlled-source seismic reflector data. The aim of the approach is to
give
the simplest possible structure consistent with all reflector data and
error
estimates. We define simplicity of seismic interfaces by the degree of
interface continuity (i.e. shortest length of offsets) and by the
degree of
interface roughness). The method is applied to structural information
of the
crust-mantle boundary (Moho) obtained from over 250 controlled-source
seismic
reflection and refraction profiles in the greater Alpine region. The
reflected
and refracted phases from the Moho interface and their interpretation
regarding
crustal thickness are reviewed and their reliability weighted. Weights
assigned
to each reflector element are transformed to depth errors considering
Fresnel
volumes. The 2-D derived reflectors elements are relocated in space
(3-D
migration) and in terpolation is performed between the observed
reflector
elements to obtain continuity of model parameters. Interface offsets
are
introduced only where required according to the principle of simplicity.
The resulting 3-D
model of the Alpine crust-mantle boundary shows two offsets that divide
the
interface into a European, an Adriatic and a Ligurian Moho, with the
European
Moho subducting below the Adriatic Moho, and with the Adriatic Moho
underthrusting the Ligurian Moho. Each sub-interface depicts the
smoothest
possible (i.e. simplest) surface, fitting the reflector data within
their
assigned errors. The results are consistent with previous studies for
those regions
with dense and reliable controlled-source seismic data. The newly
derived
Alpine Moho interface, however, surpasses earlier studies by its
lateral extent
over an area of about 600 km by 600 km, by quantifying reliability
estimates
along the interfaces, and by obeying the principle of being
consistently as
simple as possible.
Reference Type: Journal Article
Record Number: 134
Author:
Morelli, Carlo
Year: 1998
Title:
Contributi e vincoli
dalla Geofisica profonda all'origine e distribuzione dei terremoti
nella
Penisola italiana.
Journal:
Rendiconti Fis.
Accademia Lincei
Volume: 9
Pages: 5-25
Label: Serie 9
Keywords: Overthrustings; Delaminations; ramp
tectonics;
Crustal thinning; Mantellic bodies
Abstract: The static structural features of the italian
Peninsula
have been obscured for decades by the overthrusts, centrifugal from the
ligurian-tyrrhenian area. These difficulties have been surpassed for
the upper
part (0-10 km) with the integrated application of the advanced
geophysical
methodologies (reflection 3D seismics, aeromagnetism, gravity)
calibrated on
many thousands of drill-holes. In the same time (last 30 years) more
than
30.000 km of deep refraction and reflection seismics sponsored by CNR
have
revealed a structural model with an adriatic crust of normal thickness
(30-35
km) rigid and stable, and a ligurian-tyrrhenian thinned crust (20-25
km) heated
and fractured, with mantellic windows in the SE-Tyrrhenian. The contact
between
the two crusts is a strongly tectonized suture, to which at the surface
corresponds a band of seismicity maxima on the Peninsula, 30-60 km wide
(larger
to the North and narrower to the South), separated in Central Italy by
an area
of more spread deformations and rotations. These data, derived from the
ING
seismic network, allowed also to demonstrate that the seismic release
in the
peninsular Italy is only weakly connected with the Africa-Europe
convergence,
but is better explained with the activity of two subduction/collision
areas
(Northern Apennine and Southern Apennine-Calabria-Sicily). The
sub-horizontal
crustal discontinuities revealed by experimental seismics and by high
accuracy
seismology give the means for understanding other seismicity
chracteristics and
the ramp-tectonics.
[ top ]
Reference Type: Journal Article
Record Number: 58
Author:
Ponziani, Francesco;
Franco, Roberto de; Biella, Giancarlo
Year: 1998
Title: Geophysical re-interpretation of 1974 and
1978 DSS
experiments along CROP-03 profile.
Journal:
Mem. Soc. Geologica
Italiana
Issue: 52
Pages: 193-203
Keywords: refraction-wide angle reflection; deep
structures
Northern Apennines
Abstract: This work concerns the digitalization and
reinterpretation of DSS (Deep Seismic Soundings) data from a joint
Italian-French-German experiment, carried out in 1974 and 1978. The aim
was to
investigateand reconstruct the crustal structure of a wide area from
the
Ligure-Provenzale basin to the Adriatic foredeed, crossing Corsica,
Elba and
the Umbro-Marchigian Apennines, in order to reach a more precise
definition of
the geometry and relationship between the European plate and the
Adriatic micro
plate (N-W offshoot of the African plate) in the Corsican Basin and the
deep
structures of the Northern Apennines.
In particular we
tried to provide an answer to three main questions:
- the significance
of the jump in the depth of the Moho between the Tuscan and the
Adriatic
sectors;
- the significance
of the Mantle anomaly in the Tuscan sector;
- the supposed
presence of an East-verging slab between Elba island and the Tuscan
coast.
In conclusion, the
seismic model of a transect from the Ligure-Provenzale basin to the
Adriatic
crust, based on the presence of a subduction plane with a delamination
mechanism toward East, and an astenospheric rise in the Tuscan sector
is
presented in this paper.
Reference Type: Journal Article
Record Number: 67
Author: Makris, Jan; Egloff, F.; Nicolich, Rinaldo;
Rihm, R.
Year: 1998
Title: Crustal structure from the Ligurian Sea to
the
Northern Apennines - a wide angle seismic transect.
Journal:
Tectonophysics
Issue:
301
Pages:
305-319
Keywords: wide-angle seismic data; plate tectonics;
continent-ocean transition; Ligurian Sea; Alps/Apennines
Abstract: A new wide-angle seismic reflection profile,
250 km
long, was shot along a line extending from Parma in the Apennines to
the
deepest part of the Ligurian Sea. Thirty seismic land stations (LOBS)
and 25
ocean bottom seismographs (OBS) recorded 54 shots fired at sea. The
resulting
55 record sections allowed the definition of the transition from
continental to
oceanic crust in a geologically complex, and hitherto poorly
understood,
region. The subducted continental crust beneath the Northern Apennines
has a
thickness of 40 km, consisting of 30 km of igneous crust overlain by 10
km of
sediments. Two sedimentary layers are identified with Vp-velocities in
the
range from 2.8 to 5.5 km/s. The igneous portion of continental criust
thins
gradually to approx. 11 km across a 120-km-wide zone extending from the
southwestern part of the Apennines (some 20 km inland) into the
Ligurian Sea. An
easterly-thinning low-velocity body (7.2-7.5 km/s) immediately beneath
the base
of the crust is interpreted as an underplated unit, emplaced prior to
the onset
of seafloor spreading. This may have been initiated by magmatic
activity along
the incipient continental-oceanic boundary. A basement high coincides
with the
northeastern edge of the Ligurian Sea and is interpreted as part of the
Alpine
ophiolite belt, indicating strike-slip motion. The two sedimentary
layers above
the transition zone are tipically 5 km thick and have slightly lower
velocitiesthan those further to the northeast. A sharp
continental-ocean break
is recognised in the Ligurian Sea. Oceanic crust is 6-7 km thick and is
overlain by a two-layered sedimentary succession approx. 5 km thick.
Mantle
velocities in the region range from 7.9 km/s beneath the thinned crust
to 8.1
km/s beneath the thick crust. The ratio Tc/o of continental to oceanic
crustal
thickness at the continent-ocean transition is approx. 1.5 and the
overall
crust stretching factor ( ß ) at that boundary is approx.
3.5. These values are
similar to other continat-ocean boundaries and indicate that the
oceanic crust
in the Ligurian Sea formed largely by stretching, with a small
pull-apart
component..
Reference Type: Journal Article
Record Number: 142
Author: Klemperer, S.L.; Mooney, Walter D.
Year: 1998
Title: Preface to the 7th Intern Symposiumon "Deep
Seismic Profiling of the Continents"
Journal:
Tectonophysics
Volume:
286
Pages: ix-xiv
Abstract: The 7th International Symposium on "Deep
Seismic Profiling of the Continent" continued the series of biennal
meetings that involve specialists in the acquisition, processing and
interpretation of crustal-scale seismic reflection data, and
geoscientists interested
in the application of deep seismic reflection results to geological
problems
throughout the world. 197 delegates from 23 countries registered for
the
Symposium, held September 15-20 at the Asilomar Conference Center, on a
dramatic granite headland jutting into the Pacific Ocean at Monterey
Bay,
California. 61 oral
and 142 poster
contributions were presented exclusively in plenary sessions, and all
delegates
were hosted on the Asilomar campus to encourage continual interaction.
The
scientific themes of the meeting around which the presentations were
organised,
and which the 11 invited speackers were encouraged to discuss, were:
(1) New
methodologies in reflection seismology (acquisition, processing and
inversion
advances, and statistical and scattering analyses);
(2): Extending
traditional reflection surveys with the incorporation of vertical
seismic
profiles (VSPs), wide-angle seismic data, local and teleseismic
earthquake
data, rock physics and electromagnetic data;
(3) Precambrain
orogens and crustal evolution, including geological and geochemical
perspectives;
(4)
Intra-continental collisions;
(5) Rifts, basins
and extensional provinces;
(6) Bright-spots in
the crust;
(7) Lower Crust,
Moho and lithospheric upper mantle;
(8) Western North
America continental margin, featuring the numerous recent
onshore-offshore
seismic transects from Mexico to Alaska;
In addition to the
formal scientific presentations, evening discussions were irganised on
several
topics:
(1) What are the
priority global targets for seismic profiling, and what mode of
operation does
our community need to tackle them?
(2) Designing the
deep seismic survey for the 21st century: what technology do we require?
(3) Deep seismic
data in cyberspace: global, digital data repositories and atlases;
(4) Obtaining and
utilizing oil exploration data.
................................. omissis
............
Reference Type: Journal Article
Record Number: 61
Author: Boschi, Enzo; Morelli, Andrea; Piersanti, A.;
Rovelli, A.
Year: 1999
Title: Seismology and Physics of the Earth's
Interior. Italian
research activity 1995-1998. report to IASPEI.
Journal:
Bollettino di
Geofisica Teorica ed Applicata (BGTA)
Volume: 40
Issue: 2
Pages:
93-158
Keywords:
seismic sources;
earth's structure; seismotectonics; strong motion seismology;
earthquake
geology; tectonophysics; seismi hazard; seismic risk; volcano
seismology.
Reference Type: Conference Proceedings
Record
Number: 93
Author:
Caielli, Grazia;
Franco, Roberto de; Group, Giancarlo Biella
and TOMOVES
Year: 1999
Title:
Processing ed
interpretazione dei dati sismici a rifrazione/riflessione a grande
angolo
(Mareves 1997) nell'area del monte Vesuvio.
Conference Name: 18th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1
Number of Volumes: 1
Pages:
93-94
Abstract:
Nell'ambito del
progetto di tomografia sismica del Monte Vesuvio (TOMO VES '96), nel
Febbraio
1997 è stato effettuato dalla nave oceanografica NADIR
(IFREMER, Brest, F) un
esperimento sismico offshore (MAREVES'97).
La
motonave NADIR equipaggiata con 8 air-guns da
16 litri ha realizzato nel Golfo di Napoli una fitta rete di profili
effettuando 1690 scoppi, uno ogni circa 60 s corrispondente ad una
interdistanza tra gli scoppi di circa 150 m. Gli scoppi sono stati
registrati a
terra in 16 siti localizzati attorno al cratere del vulcano, nella
piana
Campana e sulla catena Appenninica. In ogni sito sono state utilizzate
una o
più stazioni mobili equipaggiate con sensori velocimetrici a
tre componenti. La
geometria di acquisizione è stata studiata per ottenere
un'immagine delle
strutture crostali fino alla Moho nella Baia di Napoli e nell'area del
Monte
Vesuvio.
In
quetso lavoro si presentano i risultati del
processing dei dati sismici a rifrazione e riflessione a grande angolo
acquisiti lungo due linee, D e F (fig.1), utilizzando le stazioni in
linea. Il
processamento ha permesso di ottenere un'immagine bidimensionale di
eventi di
crosta profonda (Moho) sotto il complesso vulcanico del Monte Vesuvio.
::::::::::::::
Reference Type: Conference Proceedings
Record
Number: 194
Author:
Milano, Giuseppe;
Gaudiosi, Germana
Year: 1999
Title:
Integrazione di dati
DSS e telesismi per la definizione della struttura crostale dell'area
vulcanica
Napoletana.
Conference Name: 18th GNGTS Meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1
Number of Volumes: 1
Pages:
95-97
Edition:
CDrom 05.07
Abstract: In this paper the crustal structure of the
Campanian
area was investigated by means of active (Deep Seismic Sounding) and
passive
(teleseismic) data focusing our attention on the Camapian volcanic
area. The
results of both DSS and teleseismic data put in evidence the existence
of:
a) a general
thickening of the crust from the Gulf of Napoli and the Gulf of Salerno
towards
E-NE and N, respectively;
b) lateral velocity
variations in the crust;
c) an intermediate
crustal discontinuity at a depth ranging between 12 and 14 km;
d) a shallow
discontinuity (about 3 km depth) beneath the Vesuvius.
Reference Type: Journal Article
Record Number: 148
Author:
Morelli, Carlo
Year: 2000
Title:
Contributi della
Geofisica della terra solida alle Scienze della Terra, all'Economia ed
alla
Protezione dell'Ambiente.
Journal: Geoitalia (FIST web journal)
Issue: 5
Abstract:
Nell'ambito della
Associazione Geofisica Italiana (AGI) la parte della Geofisica della
Terra
Solida è di pertinenza del Gruppo Nazionale di Geofisica
della Terra Solida
(GNGTS) del C.N.R. Il Gruppo ha lo scopo di promuovere e coordinare
attività
scientifiche e applicative esplicantesi nel campo della Geofisica della
terra
solida. I compiti istituzionali abbracciano quindi tutti i campi della
ricerca
sopraddetta, ed interessano più di 400 ricercatori, operanti
in 6 sottogruppi
tematici; le proposte, gli avanzamenti ed i risultati sono discussi e
pubblicati negli Atti dei Convegni Nazionali annuali (dal 16° -
1997 anche su
CD-rom).
Notes:
http://www.dst.unipi.it/fist/geoitalia5/indice.htm
Reference
Type:
Journal Article
Record
Number: 197
Author:
Improta, Luigi;
Iannaccone, Giovanni; Capuano, Paolo; Zollo, Aldo; Scandone, Paolo
Year: 2000
Title: Inferences on the upper structure of Southern
Apennines (Italy) from seismic refraction investigations and subsurface
data.
Journal:
Tectonophysics
Volume:
317
Pages: 273-297
Keywords: Crustal structure; Italy; Seismic refraction;
Southern Apennines.
Abstract: This paper presents an interpretation of
crustal
seismic refraction data from the northern sector of the Southern
Apennines
thrust belt, a region that in historical times experienced large
destructive
earthquakes. The data were acquired in 1992, along a seismic line 75 km
long
and parallel to the Apenninic chain, in order to determine a detailed
2-D
P-wave velocity model of the upper crust in an area that had not been
deeply
investigated by geophysical methods previously. We have used a 2D ray
tracing
technique based on asymptotic ray theory to model travel times of first
and
reflected P-wave arrivals. Synthetic seismograms have been produced by
finite
difference simulations in order to check the reliability of the
velocity model
inferred by ray-tracing modelling. The interpretation of the velocity
model is
constrained by stratigraphic and sonic velocity logs from wells for oil
exploration located close to the seismic line.
Gravity data
modelling allows to check the velocity model and to extend the
structural
interpretation in 3-D. In the shallow crust, up to a depth of 3-4 km,
strong
lateral variations of the modelled velocities are produced by the
overlapping
of thrust sheets formed by:
1) Cenozoic
flyshoid cover and basinal successions that underlie the seimsic
profile with
P-wave velocities in the 2.8-4.1 km/s range and thickness varying
between 0,5
and 4.5 km;
2) Mesozoic basinal
sequences with a velocity of 4.8 km/s and a depth of 1.5-2.1 km in the
northern
part of the profile;
3) Mesozoic
limestones of the Western Carbonate Platform with a velocity of 6.0
km/s and a
depth of 0.1-0.8 km in the southern part of the profile. At a greater
depth,
the model becomes more homogeneous.
A continuous
seismic interface 3.0-4.5 km deep with a velocity of 6.0 km/s is
interpreted as
the top of the Meso-Cenozoic Carbonate Multilayer of the Apulia
Platform,
characterized by an increase in seismic velocity from 6.2 to 6.6 km/s
at depths
of 6-7 km. A lower P-wave velocity (about 5.0 km/s) is hypothesized at
depths
ranging between 9.5 and 11 km. As
inferred by commercial seismic lines and data from two deep wells
located in
the Apulia foreland and Bradano foredeep, this low-velocity layer can
be
related to Permio-Triassic clastic deposits drilled at the bottom of
the Apulia
Platform. Seismic data do not allow us to identify possible deeper
seismic
interfaces that could correspond to the top of the Paleozoic
crystalline basement;
this is probably due to the low-velocity layer at the bottom of the
Carbonate
Muiltilayer that reflects and attenuates a great part of the seismic
energy. The
joint interpretation of seismic refraction and well data, in accordance
with
gravity data, provides the first detailed P-wave velocity model of the
upper
crust of the northern sector of the Southern Apennines, which differs
considerably from previous 1-D velocity models used to study the
seismicity of
the region, and reveals new informationabout the structure of the
thrust belt.
Reference Type: Book Section
Record
Number:
201
Author:
Zollo, Aldo; Matteis, Raffaella De; D'Auria, Luca;
Virieux, Jean
Year: 2000
Title: A 2D non linear method for travel time
tomography:
application to Mt. Vesuvius active seismic data.
Book Title: Problems in Geophysics for the new Millennium.
Editor: E.Bosci, Göran Ekström,
A.Morelli
Publisher: Compositori Editrice (for INGV)
City: Bologna (I)
Volume: 1
Number of Volumes: 1
Pages: 125-140
Abstract: We developed a non linear 2D tomographic
method to
interpret the first arrival times from the Mt. Vesuvius active seismic
experiments. The use of a non-linear technique is justified by the lack
of a
refined reference model of the volcano and the weak data redundancy.
The method
is based on a spectral representation of the velocity field while the
forward
problem (travel time and ray computation) is solving using the
asymptotic
approximation for the wave equation solution. The velocity field is
represented
by the sum of polynomial and wavenumber spectral Fourier decomposed
functions
which account for the long wavelength velocity variations and short
wavelength
anomalies. In this case the ray vector equation is resolved locally by
setting
the initial conditions for ray position and parameter. We provide the
iterative
analytic expression for computing ray coordinates in a heterogeneous
elastic 3D
medium. The inverse method is based on a global/local optimization
technique
(Genetic Algorithm and Downhill Simplex) which explores the whole
parametre
space i.e. the coefficients of the polynomial and spectral Fourier
functions. This
spectral approach turns to be very efficient for applications to
seismic
tomography problems where the medium spectral content and the minimum
resolved
wavelength are generally unknown. In fact, a medium description through
a
Fourier series enables one to estimate by arrival time data inversion
both the
medium properties and the minimum resolvable wavelength in the
tomographic
study. The method was tested numerically simulating two canonical
acquisition
geometries and was then applied to a subset of data collected during
the active
seismic experiment performed in the Mt. Vesuvius area.
Reference Type: Journal Article
Record Number: 202
Author:
Matteis, Raffaella De;
latorre, Diana; Zollo, Aldo; Virieux, Jean
Year: 2000
Title: 1-D P-velocity models of Mt. Vesuvius volcano
from
the inversion of TomoVes96 first arrival time data..
Journal: Pure and Applied Geophysics (PAGEOPH)
Volume: 157
Pages: 1643-1661
Abstract: We applied a revised version of the 1-D t-p
inversion method to first P-arrival times from the active seismic
experiment
performed at Mt. Vesuvius (Southern Italy) in 1996 (TomoVes Project).
The main
objective of this work is to obtain 1-D velocity models of Mt.
Somma-Vesuvius
volcano complex and surrounding area. Moreover we show that combining
the 1-D
information we provide a reliable 2-D initial model for perturbative
tomographic inversions. Seismic and geological surveys suggest the
presence of
a refractor associated with the contrast between carbonate basement and
volcanic/alluvial sediments; synthetic simulations, using a realistic
topography and carbonate top morphology, allowed us to study the effect
of
topography on the retrieved velocity models and to check that the 1-D t-pmethod
can also approximately retrieve the refractor depth and velocity
contrast. We
analysed data from 14 on-land shots recorded at stations deployed along
the
il-profile direction. We grouped the obtained models in three subsets
according
to the geology of the sampling area: models for carbonate outcrop area,
models
for the Campanian Plain surrounding the volcano edifice and models for
the Mt.
Somma-Vesuvius volcano complex. The found 1-D P-velocity models show
important
vertical and lateral variations. Very low velocities (1.5-2.5 km/s) are
observed in the upper 200-500 m thick shallow layer. At greater depths
(3 km is
the maximum investigated depth) P velocities increase to values in the
range of
4-6 km/s which are related to the presence of the carbonatic basement. Finally we interpolated
the 1-D models to
demonstrate an example of misfit for a 2-D interpolated model whose
residuals
are confined in a narrow band around zero.
Reference Type: Conference Proceedings
Record
Number: 53
Author:
Gaudiosi, Germana;
Guerra, Ignazio; Luzio, Dario; Milano, Giuseppe; Musacchio, Gemma
Year: 2000
Title:
Struttura crostale del
Tirreno sud-orientale.
Conference Name: 19th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Volume: 1'
Number of Volumes: 1
Pages:
97-99
Abstract: La
struttura crostale
del basso Tirreno è stata investigata da numerose indagini
DSS. In particolare,
nell'area sud-orientale del bacino, sono stati realizzati i seguenti
profili:
- 1972:
profilo Puglia/Calabria/Eolie (Morelli et al., 1975; Presta M.,
1992-'93);
- 1979:
Traversa OBS Tirrenica (Steinmetz et al., 1983) e profili in Calabria
(Milano
et al., 1989);
-
1986: profilo NW-SE attraverso le isole Eolie e
profili ENE-WSW nella Sicilia nord-orientale (Milano et al., 1988);
Ferrucci et
al., 1991);
-
1994: profilo M27 (Gruppo 'Sealand' Crop M II,
1995); profilo M26 (Gruppo 'Sealand' 1996; Chironi et al., 2000).
L'analisi
congiunta del profilo coniugato NNW-SSE
attraveso le Eolie meridionali, di un profilo lineare ed uno a
ventaglio registrati
lungo il margine settentrionale della Sicilia (1986), la
re-interpretazione di
un profilo registtrato in Calabria meridionale nel 1979
(C.vaticano/Tirreno;
Milano et al., 1989), del profilo Tirreno '72 (Filicudi-costa Calabra
WSW-ENE;
Presta 1993) e la traversa OBS nel Tirreno meridionale (Steinmetz et
al., 1983)
aveva permesso di evidenziare importanti caratteristiche strutturali
dell'area
e di realizzare una mappa preliminare della Moho del basso Tirreno
(Gaudiosi et
al., 1986).
..................
Reference Type: Journal Article
Record Number: 204
Author:
Lomax, Anthony; Zollo,
Aldo; Capuano, Paolo; Virieux, Jean
Year: 2001
Title: Precise, absolute earthquake location under
Somma-Vesuvius volcano using a new three-dimensional velocity model.
Journal:
Geophysical Journal International
Volume:
146
Pages:
313-331
Keywords: crustal structure; earthquake location;
earthquake
source mechanism; focal depth; inhomogeneous media; volcanic structure.
Abstract: The Somma-Vesuvius volcanic complex and
surroundings
are characterized by topographic relief of over 1000 m and strong 3-D
structural variations. This complexity has to be taken into account
when
monitoring the background volcano seismicity in order to obtain
reliable
estimates of the absolute epicenters, depths and focal mechanisms for
events
beneath the volcano. We have developed a 3-D P-wave velocity model for
Vesuvius
by interpolation of 2-D velocity sections obtained from non-linear
tomographic
inversion of the Tomoves 1994 and 1996 active seismic experiments data.
The
comparison of predicted and observed 3-D traveltime data from active
and
passive seismic data validate the 3-D interpolated model. We have
relocated
about 400 natural seismic events from 1989 to 1998 under Vesuvius using
the new
interpolated 3-D model with two different Vp/Vs ratios and a global
search, 3-D
location method. The solution quality, station residuals and hypocentre
distribution for these 3-D locations have been compared with those for
a
representative layered model.
A relatively high
Vp/Vs ratio of 1.90 has been obtained. The highest-quality set of
locations
using the new 3-D model falls in a depth range of about 1-3.5 km below
sea
level, significantly shallower than the 2-6 km event depths determined
in
previous studies. The events are concentrated in the upper 2 km of the
Mesozoic
carbonate basement underlying the Somma-Vesuvius complex. The
first-motion
mechanism for a subset of these events, although highly variable, give
a weak
indication of predominantly N-S to near-vertical directions for the
tension
axes, and ESE-WNW near-vertical directions for the compression axes.
Reference Type: Report
Record Number: 132
Author:
Amato, Alessandro;
Selvaggi, Giulio
Year: 2001
Title:
Terremoti probabili in
Italia tra il 2000 e il 2030: elementi per la definizione di
priorità degli
interventi di riduzione del rischio sismico.
Institution: INGV
Type of Work: INGV Report
Abstract: Il
Rapporto
dell'attività svolta nel secondo anno del progetto
è suddivisa nei tre gruppi
di lavoro in cui è articolato il progetto. Per gli
approfondimenti metodologici
e per una descrizione dei risultati si rimanda agli allegati. Gli
obiettivi dei
singoli gruppi per il secondo anno di attività sono
riassunti di seguito:
GdL 1
Approfondimento
su sorgenti in aree poco note e
loro formalizzazione (task 1.1)
Analisi
del ruolo dei livelli informativi di nuova
introduzione (1.1)
Preparazione
input calcoli di pericolosità (1.1)
Ricerche
storiche in aree di lacuna (1.1 e 1.2)
Approfondimento
punti di intensità critici per
terremoti significativi (1.2)
Rivalutazione
intensità macrosismiche a partire da
nuovi dati (1.2)
Stima
delle deformazioni geodetiche in Sicilia e
Appennino meridionale (1.3)
.....
omissis .....
GdL 2
Catalogo
strumentale integrato 1981-2000 (task
2.1)
Relazioni
emtiriche Md-Ml (2.1)
Modelli
3D di velocità regionali e modello di
attenuazione (2.1)
Database
tempi d'arrivo P delle linee sismiche a
rifrazione 1968-2002 (2.2)
Modelli
Vp 2D con parametrizzazione minima e primi
modelli 3D regionali (2.2)
GdL 3
Calcolo
leggi d'attenuazione in Italia (3.1
........................ omissis
.....................
Notes:
2° anno di attività:
relazione Annuale
Reference Type: Conference Proceedings
Record Number: 78
Author: Morelli, Carlo
Year: 2001
Title: La
geofisica profonda
offre le basi per la comprensione della Geodinamica in atto.
Conference Name: 20th GNGTS meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Abstract: The superficial motions are those that
influence
more the environment and more easily can be detected and followed by
the modern
geodetical and geophysical surface methods. Mostly, they are of local
character, also if they can interest very extended areas (e.g.:
subsidence). When
the causes study requests the use of geophysical methods, the
informations
derived by them are generally in Italy revolutionary ones, for the
reason that
Italy has been fast completely "covered" - in different times: mainly
from 20 to 5 My - by orogenic transports of different origin. Leaving
out
meteorological causes, to the unitary comprehension of the Geodynamics
in
action has contributed (from 1956) the CNR's Research Group for Deep
Geophysics, with the organizatory support of OGS (now-a-day National
Institute)
and with the participation of the University Institutes interested. The
following exposition is dedicated to the main realizations.
Notes: on-line
Reference Type: Stage
Record Number: 178
Author: Chiappa, Fabio; D'Attoma, Matteo
Year: 2001
Title:
Toscana-'78:
elaborazione dati sismici crostali ed interpretazione geofisica
preliminare
Publisher: CNR-IRRS
Place Published: Milan (I)
Pages:
1 CD
Date:
Nov. 2001
Type of Work: stage/tesi
Abstract: Lo
stage è basato
sull'elaborazione dei dati, convertiti in forma digitale, riguardanti
il
profilo sismico a rifrazione svolto durante il 1978 nell'Italia
centrale
attraverso l'Appennino, dall'isola d'Elba fino nei pressi di Ancona.
Com'è
noto l'area mediterranea è oggetto di
numerose ricerche sia di carattere geologico che geofisico, dato il suo
complesso iter evolutivo ed in questo variegato
mosaico sicuramente
l'Appennino rappresenta un tassello fondamentale e vincolante per la
comprensione dell'evoluzione del'intera regione.
Lo
scopo dello stage non è ovviamente la
contestualizzazione geologica e tettonica dell'Appennino entro l'area
Mediterranea, ma l'elaborazione di dati sismici crostali, seguita da
una
interpretazione geofisica preliminare volta a definire la superficie di
separazione
fra la crosta inferiore ed il mantello; ovvero la geometria e la
profondità
della Moho.
L'analisi
dei dati verrà eseguita tramite
l'utilizzo di Matlab, un linguaggio di programmazione molto versatile
per il
trattamento dei segnali.
Notes:
dall'originale su
CD-rom di Grazia C.
Reference Type: Conference Proceedings
Record
Number: 76
Author:
Cassinis, Roberto;
Scarascia, Salvatore
Year: 2001
Title:
Alcune considerazioni
sul contributo della sismica a rifrazione-riflessione grande angolo
alla
conoscenza della struttura geologica profonda della regione Italiana.
Conference Name: 20th Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location:
Roma
(CNR)
Abstract: A
più di un decennio
dalla fine delle grandi campagne di esplorazione crostale e litosferica
con la
tecnica di rifrazione-riflessione a grande angolo (WARR o DSS) ed anche
alla
luce delle esperienze di simili programmi effettuati nel frattempo in
altri
Paesi, appare forse più agevole valutare l'importanza dei
risultati ottenuti nel
corso di più di un trentennio....
Notes: CDrom
Reference Type: Conference Proceedings
Record
Number: 60
Author:
Gaudiosi, Germana;
Biella, Giancarlo; Bruno, Pierpaolo; Caielli, Grazia; Tondi, Rosaria;
Franco,
Roberto de; Milano, Giuseppe
Year: 2001
Title: The upper Lithosphere imaging of Mt Vesuvio
volcanic
area (Italy) by active and passive seismic data.
Conference Name: E.G.S. 26th Gen.
Assembly
Editor: EGS
Publisher: EGS
Conference Location: Nice (F)
Abstract: The Vesuvio is an active volcano, located in
the
southern sector of the Campanian Plain, a Plio-Quaternary graben
bounded by
NW-SE and NE-SW trending faults. Tha Campanian plain is bordered to SW
by the
Mid-Miocene, partly ocean-type, Tyrrhenian Basin and to NE and SW
(Sorrentina
Peninsula) by the Oligo-Miocene nappes chain of the Apennines.
................
The interpretation
of seismic profiles carried out in the area in the frame of national
and
International Project (Campania DSS Project 1985-'87; CROP-M-II Sealand
1993-'95; Tomo-Mare-Ves 1994-'96-'97) allows us to highlight a detailed
picture
of the crustal structure beneath Mt. Vesuvio and surrounding areas. All
profiles were joint modelled and interpreted to obtain a reliable
crustal
picture of the area.
..........
Notes:
Poster session
Reference
Type:
Journal Article
Record Number: 15
Author: Levin, V.; Margheriti, L.; Park, J.; Amato,
Alessandro
Year: 2002
Title: Anisotropic seismic structure of the
lithosphere
beneath the Adriatic coast of Italy constrained with mode-converted
body waves.
Journal: Geophysical Research Letters
Volume:
29
Issue:
22, 2058
Pages:
15-1/15-4
Label:
doi: 10.1029/2002GL015438, 2002
Keywords: body wave propagation, lithospgere and upper
mantle,
continental contractional orogenic belts
Abstract: Ps convertes waves observed near Ancona on
the
Adriatic coast of central Italy, as revealed by teleseismic receiver
functions
(RFs), vary with earthquake back-azimuth and epicentral distance in a
manner
consistent with a 1-D anisotropic seismic structure. Using relectivity
calcluations, we develop a profile of anisotropic seismic velocity
through the
Adriatic lithosphere at this locality. We infer crustal thickness of
~ 45
km. Anisotropy within the crust appears
at ~ 15-km, suggesting a decollement between the subducting Adriatic
lithosphere and the overriding crustal wedge.....
Notes: Copyright 2002 by AGU;
0094-8276/02/2002GL015438$05.00
Reference Type: Journal Article
Record Number: 87
Author:
Morelli, Carlo
Year: 2003
Title:
Alcuni esempi di
realizzazioni CNR con ricadute e banche-dati.
Journal: Geoitalia
Issue: 11
Abstract:
Introduzione.
Era
il settembre 1938 quando fui assunto al CNR
come ricercatore inc. e destinato alla Stazione sismica di Trieste. Da
allora,
tutta la mia attività di ricerca, diretta ed indiretta, (col
passaggio
all'Università) è dipesa in modo determinante dal
CNR. I risultati raggiunti
sono stati giudicati meritevoli, nonostante i mezzi a disposizione
sempre
limitati, talvolta addirittura da creare.
Essendo
il mio campo la Geodesia e la Geofisica, e
come oggetto la Terra, le ricerche sono state quasi sempre in
collaborazione
internazionale, spesso globale. Le ricadute sono ancor oggi valide in
alcuni
campi. Ne riassumiamo alcune, in termini di interesse generale: con la
premessa
che le conoscenze della Terra per profondità maggiori di
qualche km sono basate
su metodi geofisici che sono quasi tutti 'indiretti' e che la
indeterminazine
connessa diminuisce applicando più metodi diversi
('interpretazione
integrata').
Reference Type: Journal Article
Record Number: 156
Author: Nicolich, Rinaldo
Year: 2003
Title: TRANSALP Conference: a crustal section
through the
Eastern Alps.
Journal: Episodes (IUGS)
Volume: 26
Issue: 4
Pages: 318-319
Abstract: The TRANSALP Conference was held in Trieste
(Italy)
from 10 to 12 February, 2003, and was dedicated to the presentation of
the
results of the TRANSALP Project, a multidisciplinary international
research for
investigating the deep structure of the Eastern Alps and the
interrelated
orogenic and postorogenic processes. The Conference provided a
comprehensive
forum where the new data were debated within the framework of the
entire Alpine
mountain belt.
..................
omissis ...................
Notes: The Extended Abstracts of oral (33) and
poster (35)
presentations at the Conference are offered in the special Volume
(N.54) of the
Memorie di Scienze Geologiche, Padova, February 2003 (268 pp., 212
figs, 8
tabs).
Reference Type: Conference Proceedings
Record Number: 82
Author: Cassinis, Roberto
Year: 2003
Title: La
struttura crostale
profonda nel settore centro-orientale dell'Arco Alpino.
Conference Name: 22nd Convegno GNGTS
Editor: CNR
Publisher: OGS
Conference Location: Roma (CNR)
Abstract: The interpretation of DSS profiles recorded
in the
past in Central and Eastern Alps is recalled and the model of the lower
crust
and Moho proposed in 1997 is compared with the results of the TRANSALP
seismic
reflection profile. This comparison highlights a good agreement as far
as the
geometry of the deep structure is concerned. Therefore, the reliability
of the
interpretation, previously based solely on DSS profiles, becomes
stronger for
the whole area.
The same results
seem to discard the hypothesis of an inversion of the lithospheric
subduction
west of the TRANSALP profile. In other words, the transition from the
Adriatic
to the Dinaric domain should be found further eastwards, where reliable
data
are not available.
Reference Type: Journal Article
Record Number: 14
Author:
Cassinis, Roberto;
Scarascia, Salvatore; Lozej, Alfredo
Year: 2003
Title: The deep crustal structure of Italy and
surrounding
areas from seismic refraction data. A new synthesis
Journal: Boll. Soc. Geol. It.
Issue: 122
Pages: 365-376
Keywords: crustal structure, deep seismic soundings,
italian
region
Abstract: The aim of this paper is a new synthesis of
the
results obtained in Italy and in the surrounding areas during more than
thirty
years (1956-1987) by the seismic exploration method of wide angle
reflection-refraction generally known as DSS - deep seismic Soundings.
Italy is
amoung the countries most intensively surveyed by this method. During
the long
period of application, the techniques experienced remarkable
modifications with
regard to the instrumentation (from analog to digital), the acquisition
procedures (density and type of layouts), as well as processing and
interpretation (ray-tracing and modelling)......
Notes: In
memoriam: Salvatore
Scarascia (1926-2002).
Reference Type: Journal Article
Record Number: 50
Author:
Lavecchia, Giusi;
Boncio, P.; Creati, N.; Brozzetti, F.
Year: 2003
Title: Some aspects of the Italian Geology not
fitting with
a subduction scenario.
Journal: Journal of the Virtual Explorer
Issue: 10
Pages: 1-14
Abstract: In this paper we recall some aspects of the
geology
of Central Italy, not fully consistent with the inperpretation of the
Tyrrhenian-Apennins system in the frame of a subduction context.
Available
near-vertical and deep-sounding seismic profiles across the Apennines
of
Central Italy (e.g. CROP 03 and DSS'78) do not show any evidence of an
accretionary wedge above a subducting plane, but rather show a
thick-skinned
thrust belt with involvement of the overall crust in the deformation
and with
modest amounts of horizontal shortening.
The relatively deep
(<90 km) seismicity registered in Central Italy cannot be
interpreted in
terms of ongoing subduction. In fact the hypocentral distributions do
not mark
the underthrusting of the Adriatic continental lithosphere beneath the
Tyrrhenian lithosphere, but rather depict a seismogenic west-dipping
thrust
zone within the Adriatic lithosphere.
The presence within
the Apennine mountains chain of a carbonatic-potassic melitite rock
association, middle Pleistocene in age, points to a different
geodynamic
environment than subduction. In fact, this rock association is very
rare and
exclusively found in intra-continental rift context.
The possibility to
explain the evolution of the Tyrrhenian-Apennine system applying either
a
passive or an active (plume-related) rift context as alternative to
subduction
is briefly addressed. All considering, the evolution of the area is
interpreted
as the result of a peculiar combination of large-scale plume-induced
lithospheric stretching and of local-scale rift push-induced crustal
shortening, the latter progressively developed at the outer border of
the
extending region.
Reference Type: Journal Article
Record Number: 20
Author: Kokinou, E.; Vafidis, A.; Loucogiannakis, M.;
Louis,
I.
Year: 2003
Title: Deep seismic Imaging and Velocity estimation
in
Ionian Sea.
Journal: Journal of the Balkan Geophysical Society
Volume: 6
Issue: 2
Pages: 100-116
Keywords: Ionian basin, Deep reflection profiling,
Velocity
model, Stacked section, Migrated section
Abstract: The seismic data from a deep seismic
profiling (DSP)
survey in Ionian Sea which crosses the western border of the Hellenic
arc have
been reprocessed and interpreted. The processing flow includes multiple
elimination techniques such as wave equation multiple rejection and
adaptive
deconvolution.
Special processing
helped in delineating complex structures in the Pre-Apulian and Ionian
zones. Surface
consistent deconvolution, Kirchoff migration and attributes proved
useful in
imaging deeper horizons, in the area near the Zakynthos and Kefallinia
islands
where Mounta fault constructional structure and Kefallinia diapir are
present. In
this area the seismic section indicates that the Plio-Quaternary
sediments are
distorted by diapiric movements of high velocity Triassic ecaporates,
namely
the Kefallinia Diapir. Also the eastern boundary of IOnian zone is
observed
under the Mounta anticline.
The celocity model
along the seismic line ION-7, wich crosses the IOnian basin is also
presented. The
Moho discontinuity is estimated in the western part of the seismic
section,
while Moho reflections are absent in the eastern part.
Reference Type: Conference Proceedings
Record Number: 10
Author: Morelli, Carlo
Year: 2003
Title:
Alcuni esempi nelle
geodiscipline di risultati notevoli tramite collaborazioni
interdisciplinari
nazionali ed internazionali.
Conference Name: 22nd GNDT meeting
Editor: CNR
Publisher: OGS
Conference Location:
Roma
Volume: 1
Number of Volumes: 1
Pages: 59
Abstract: E'
noto che
l'applicazione di ogni metodo di geofisica attiva comporta un grado di
indeterminazione tanto maggiore quanto più i temi per cui
viene impiegato sono
'al limite'. Ciò vale in particolare quando la Geofisica
viene impiegata per
risolvere temi crostali profondi, con costi molto elevati e vincoli
inesistenti. Il ricorso alla integrazione con altri metodi geofisici
specifici
risluta però anche sempre indispensabile, per poter
beneficiare di quella
'interpretazione geofisica integrata' che spesso può essere
risolutiva. Questo
asserto viene illustrato sulla base di alcuni esempi di ricerche
impegnative
nell'area italiana....
Notes:
http://www.dst.unipi.it/fist/geoitalia11/pagina31.pdf
Reference
Type:
Journal Article
Record
Number: 205
Author:
Natale, Giuseppe De;
Troise, Claudia; Trigila, Raffaello; Dolfi, Daniela; Chiarabba, Claudio
Year: 2004
Title: Seismicity and 3-D substructure at
Somma-Vesuvius
volcano: evidence for magma quenching.
Journal: Earth and Planetary Science Letters (Elsevier)
Volume: 221
Pages: 181-196
Keywords: Seismic tomography; Vesuvius volcano; Magma
quenching.
Abstract: We present new results on the velocity
structure of
the Somma-Vesuvius volcano, obtained by joint inversion of P- and
S-wave
arrival times from both local earthquakes and shot data collected
during the
TOMOVES 1994 and 1996 experiments. The use of a large set of
earthquakes,
recorded over a period of ten years by both temporary and permanent
seismic
stations, allowed us to enhance the resolution of the structure beneath
the
Somma-Vesuvius down to 5 km depth. The results obtained show the
presence of a
high Vp and Vp/Vs anomaly located around the crater axis, between 0 and
5 km
depth, involving the volcano edifice and the carbonate basement wesward
deepening from the adjacent Apenninic belt. The whole available seismic
catalogue between 1878 to 2000 (1003 events) has been relocated in the
obtained
3-D velocity model. Seismicity appears to be clustered around the
anomalous
high rigidity body. Laboratory experiments at high temperatures and
pressures
on 1944 eruption lava samples, taken representative in composition of
the magma
masses erupted through the cycle 1631-1944, support the interpretation
of this
anomaly in terms pf magma quenching along the main conduit, because of
the
exsolution of magmatic colatiles. The effect of volatiles from the melt
at the
eruption onset and through its explosive phases is to increase the
solidus
temperature well above its eruptive temperature, causing the immediate
quenching of the system. This paper shows a good example of how seismic
tomography and experimental petrology constrain magmatic models.
Results have
important implications for the hazard assessment at Somma-Vesuvius, and
at
other volcanoes worldwide where similar seismological evidence has been
recently observed.
Reference Type: Journal Article
Record Number: 81
Author:
DeLuca, L.; Franco,
Roberto de; Biella, Giancarlo; Corsi, Adelmo; Tondi, Rosaria
Year: 2004
Title: An analysis of the first-arrival times picked
on the
DSS and wide-angle seismic sections recorded in Italy since 1968.
Journal: Annals of Geophysics
Volume:
47
Issue:
6 (Dicembre 2004)
Pages:
1699-1711
Keywords: DSS and WARR profiles; P-wave first arrivals;
1-D
velocity models; database
Abstract: We performed an analysis of refraction data
recorded
in Italy since 1968 in the frame of the numerous deep seismic sounding
and
wide-angle reflection/refraction projects. The aims of this study are
to
construct a parametric database including the recording geometric
information
relative to each profile, the phase pickings and the results of some
kinematic
analyses performed on the data, and to define a reference 1D velocity
model for
the Italian territory from all the available refraction data. As
concerns the
first goal, for each seismic section we picked the P-wave first-arrival
times,
evaluated the uncertainties of the arrival-times pickings and
determined from
each travel time-offset curve the 1D velocity model. The study was
performed on
419 seismic sections. Pickings were carried out manually by an
algorithm which
includes the computation of three picking functions and the
picking-error
estimation. For each of the travel-time offset curves a 1D velocity
model has
been calculated. Actually, the 1D velocity-depth functions were
estimated in
three different ways which assume: a constant velocity-gradient model,
a
varying velocity-gradient model and a layered model. As regards the
second
objective of this work, a mean 1D velocity model for the Italian crust
was
defined and compared with those used for earthquake hypocentre
locations and
seismic tomographic studies by different institutions operating in the
Italian
area, to assess the significance of the model obtained. This model can
be used
in future works as input for a next joint tomographic inversion of
active and
passive seismic data.
(1)
Software used: 'EndNote2 plus' (www.niles.com)