Influence of local structures close to the source and receiver on the seismic wave field

Vlastislav Cerveny

Summary

The seismic wave field is considerably influenced by local structures close to the source and to the receiver. For sources and receivers situated close to the Earth's surface, the wavefield is strongly affected mainly by the structure of the surficial low-velocity layer in the vicinity of the source and receiver. To evaluate synthetic seismograms in such situations, the hybrid ray-reflectivity method may be used. Computer program package BEAM87 was modified to perform such computations. Examples of hybrid ray-reflectivity synthetic seismograms for a point source of the explosive type situated just under the thin surficial thin low velocity layer and the receiver situated on the thin layer (on the surface of the Earth) are presented. It is shown that the existence of the low-velocity transition layer influences drastically the recorded wave field.


In: Seismic Waves in Complex 3-D Structures, Report 1, pp. 9-27, Dep. Geophys., Charles Univ., Prague 1994.
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