Generation of complete theoretical seismograms for SH— |
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| Authors: | Keith Nakanishi Fred Schwab Leon Knopoff |
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| Affiliation: | Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90024, USA;Box No. 131, 308 Westwood Plaza, Los Angeles, California 90024, USA;Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90024, USA |
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| Abstract: | Summary. We report the initial results of our attempts to obtain theoretical seismograms for direct comparison with the experimental time series obtained with the long-period instruments of the WWSSN. The entire theoretical seismogram, including both body waves and surface waves, can be generated for a spherical, anelastic earth by simple inverse Fourier transformation of the sum of the propagating fundamental and higher-mode surface waves. The key to success in reproducing the WWSSN records involves the number of modes, and the minimum period used in these computations; here we use eight modes and a minimum period of 2 s. Efficient computational algorithms make it possible to handle up to 2000 frequency points for each mode; approximately 200 layers are used to model the radial heterogeneity of the earth; attenuation is treated exactly. Examples are given of the SH theoretical seismograms resulting from dislocation sources buried at various depths in the Earth. |
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