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Generalized ray theory for shear dislocations

Helmberger, Donald V. (1974) Generalized ray theory for shear dislocations. Bulletin of the Seismological Society of America, 64 (1). pp. 45-64. ISSN 0037-1106.

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Generalized ray expansions of the P, SH, and SV displacement potentials resulting from a point-source dislocation are evaluated at the surface of a layered half-space. The Cagniard-de Hoop technique is used to obtain the transient response. The results of this analysis are used to construct synthetic seismograms for a shear dislocation on a vertical fault plane. Comparisons of synthetic and observed seismograms for the Borrego Mountain earthquake (April 9, 1968) at teleseismic distances indicate an equivalent point-source depth of 9 km with the far-field time function approximated by a step function with an exponential decay. This time function fits both the P and S wave forms. The apparent shift in corner frequency between the P and S waves for shallow events, as reported by some investigators, is explained by surface reflections.

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Additional Information:Copyright © 1974, by the Seismological Society of America. Manuscript received July 19, 1973. I thank Dave Harkrider for his results on potential representations in advance of publication. I am also grateful to Ralph Wiggins for use of his deconvolution program and Gladys Engen who assisted in the numerical analysis. This research was supported by the Advanced Research Projects Agency of the Department of Defense and was monitored by the Air Force Office of Scientific Research under Contracts F44620-72-C-0078 and F44620-72-C-0083.
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Advanced Research Projects Agency (ARPA)UNSPECIFIED
Air Force Office of Scientific Research (AFOSR)F44620-72-C-0078
Air Force Office of Scientific Research (AFOSR)F44620-72-C-0083
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Caltech Division of Geological and Planetary Sciences2365
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ID Code:48383
Deposited By: George Porter
Deposited On:12 Aug 2014 19:49
Last Modified:03 Oct 2019 07:03

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