Accession Number:

AD0600103

Title:

SYNTHETIC EARTHQUAKE SEISMORGRAMS FOR TELESEISMIC DISTANCES.

Descriptive Note:

Corporate Author:

UNITED ELECTRODYNAMICS INC ALEXANDRIA VA

Personal Author(s):

Report Date:

1964-05-14

Pagination or Media Count:

24.0

Abstract:

The purpose of this study was to test the hypothesis that the initial train of P-waves on seismograms recorded at teleseismic distances is more complicated for earthquakes occurring in the crust than for explosions near the earths surface. Both pure compressional and pure shear sources, and some combination sources, were assumed in separate computations. Spike seismograms were first constructed and then convolved with an assumed source signal to obtain the complete synthetic seismogram. It was shown, as expected, that a buried source produces more multiply-reflected waves than does a surface source in turn, other things being equal, an SV-source yields more than a P-source. Only the first surfacereflected multiple exhibits an amplitude comparable to that of the primary wave. Synthetic seismograms using a combined SV-P source are similar to real earthquake seismograms. However, whether a near-surface earthquake yields a more complex train of P-arrivals than does an explosion depends greatly on the ratio of SVenergy to P-energy in the earthquakes source, as well as on the relationship between them. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE