ReWARD Project
Refraction/Wide-Angle Reflections Database
the Milan Section 
INGV - Rome

R/WAR italian deep seismic data

E.G.T. data compilation:

Guidelines for the compilation of the EGT deep seismic sounding data
by J. Ansorge and R. Freeman(*)

At the Sixth EGT Workshop in Einsiedeln the seismic data compilers agreed to collect all the seismic refraction data obtained within the EGT project in the most suitable and inexpensive form as possible. The purpose of the compilation is to have a set of data available at the final Study Center (in Rauischholzhausen, 26/3-7/4 1990) for quick reference and, subsequently, as a basis for further detailed interpretations.

The seismic data compilers agreed to catalog the seismic refraction data separately for each Segment of the EGT as Open File Reports. The compilation should include all the seismic refraction data collected on land and at sea. The Reports will be edited as a publication of the Institution that is responsible for the compilation and can be cited as such in the literature. The reports should also include the main references for older data collected in the same area prior to the EGT project. These same institutions will then also provide copies of the digital data upon request. The data will be public and available to everybody after their first publication in a scientific journal. The A3 format and the scale of the plots (given below) were chosen such that the sections can be used directly for a crude identification of phases and can be easily rescaled on a photocopy machine.

The compilation must include the following technical data for shots and recordings:
  1. A table with SHOT PARAMETERS:  coordinates, elevation, special boreholes or quarry shots, depth of borehols, depth of shots in water, water depth, charge size, single or dispersed charges, date and shot time.
  1. For each profile the following information:
    1. A LISTING of recording stations with coordinates, elevation, the recorded shots, distance from shotpoint, azimuth from shotpoint, type of recording instrument;
    2. Three record sections, one each for the vertical (Z), radial (R) and transverse (T) components. Each record section is plotted with the following parameters:
      • Amplitudes normalized so that the main phases stand out clearly.
      • Reduction velocities of 6.0 km/s for Z, and 3.46 km/s for R and T. For profiles longer than 500 km the reduction velocity should be 8.0 km/s for Z and 4.62 km/s for R and T, and the plot should start at a distance of 200 km.
      • A fixed ratio of travel time versus distance scale of:
        • 1 second corresponding to 5 km, for normal crustal profiles or
        • 1 second corresponding to 10 km for long-range profiles > 500 km.
      • The time scale of radial and transsverse components should be reduced by a factor of 1.732 so that these phases can be compared directly with the P-waves.
      • Filter setting should be chosen such that only the main high and low frequency noise is cut out.
      • The plot size is A3.

At the time of writing (December 15, 1989) none of these compilations are complete. In some cases the S-wave data have yet to be digitized, in other cases the compilation is almost complete. A tentative list of the persons and the institutes responsible for the compilation of EGT refraction seismic data is given below.

POLAR Profile
U.Luosto (Institute of Seismology, UNI-Helsinki
F.Hauser (Institute of Geophysics, UNI-Karlsruhe)
C.Lund (Institute of Geophysics, UNI-Uppsala)
S.Gregeresen (Geodaetik Institute, Charlottenland)
H.Thybo (Institute of General Geology, Copenhagen)
EGT Central Segment
B.Aichroth (Institute of Geophysics, UNI-Karlsruhe) and
S.Ye (Institute of Geophysics. ETH - Zurich)
PO PLAIN - Western Alps
H.Buness (Institute of Geophysics, FU-Berlin, responsible for 1983 data)
S.Scarascia (IGL-CNR Milano, responsible for 1986 data)
EGT-S (Southern Segment)
from Ligurian Sea to  Sardinia Channel
A.Egger (Institute of Geophysics, ETH - Zurich)
EGT-S (Southern Segment)
F.Thouvenot (LGIT-IRIGM, Observatoire Grenoble)
S.Scarascia (IGL-CNR Milano)

E.S.F. - Proceedings of the Sixth EGT Workshop (Einsiedeln, 29/XI-5/XII 1989)
- Data compilations and synoptic interpretation; p. 211-212

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