Focal mechanism of the August 1, 1975 Oroville earthquake
- Creators
- Langston, Charles A.
- Butler, Rhett
Abstract
Long-period teleseismic P and S waves from the WWSS and Canadian networks are modeled to determine the focal parameters for the main shock in the Oroville earthquake series. Using the techniques of P first motions, wave-form synthesis, and phase identification, the focal parameters are determined as follows: dip 65°; rake −70°; strike 180°; depth 5.5 ± 1.5km; moment 5.7 ± 2.0 × 10^(24) dyne-cm; and a symmetric triangular time function 3 sec in duration. This is a north-south striking, westward dipping, normal fault with a small component of left-lateral motion. The time separation between the small foreshock and mainshock appears to be 6.5 sec at teleseismic distances, rather than 8.1 sec as observed at short distances.
Additional Information
Copyright © 1976, by the Seismological Society of America. Manuscript received February 19, 1976. We would like to thank the numerous seismic station administrators throughout the world who took their valuable time to respond to our seismogram requests. We also would like to extend our gratitude to Don Helmberger and Tom Heaton for their critical reviews of the manuscript. 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 Contract F44620-72-C-0078. One of the authors (R.B.) was supported by the Fannie and John Hertz Foundation.Attached Files
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Additional details
- Eprint ID
- 48529
- Resolver ID
- CaltechAUTHORS:20140813-141713534
- Advanced Research Projects Agency (ARPA)
- F44620-72-C-0078
- Air Force Office of Scientific Research (AFOSR)
- Fannie and John Hertz Foundation
- Created
-
2014-08-14Created from EPrint's datestamp field
- Updated
-
2019-10-03Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 2718