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Initial rupture of earthquakes in the 1995 Ridgecrest, California Sequence

Mori, Jim and Kanamori, Hiroo (1996) Initial rupture of earthquakes in the 1995 Ridgecrest, California Sequence. Geophysical Research Letters, 23 (18). pp. 2437-2440. ISSN 0094-8276. doi:10.1029/96GL02491.

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Close examination of the P waves from earthquakes ranging in size across several orders of magnitude shows that the shape of the initiation of the velocity waveforms is independent of the magnitude of the earthquake. A model in which earthquakes of all sizes have similar rupture initiation can explain the data. This suggests that it is difficult to estimate the eventual size of an earthquake from the initial portion of the waveform. Previously reported curvature seen in the beginning of some velocity waveforms can be largely explained as the effect of anelastic attenuation; thus there is little evidence for a departure from models of simple rupture initiation that grow dynamically from a small region. The results of this study indicate that any “precursory” radiation at seismic frequencies must emanate from a source region no larger than the equivalent of a M0.5 event (i.e. a characteristic length of ∼10 m). The size of the nucleation region for magnitude 0 to 5 earthquakes thus is not resolvable with the standard seismic instrumentation deployed in California.

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Kanamori, Hiroo0000-0001-8219-9428
Additional Information:© 1996 The American Geophysical Union. Paper number 96GL02491. Received: 27 May 1996; Revised: 5 Aug 1996; Accepted: 5 Aug 1996. R. Geller, J. Gomberg, M. Kikuchi, M. Nakatani, and J. Vidale provided helpful suggestions on the manuscript. Data are available from the Southern California Earthquake Center Data Center. Contribution 5779, Division of Geological and Planetary Sciences, California Institute of Technology.
Group:Division of Geological and Planetary Sciences
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Caltech Division of Geological and Planetary Sciences5779
Issue or Number:18
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Official Citation:Mori, J., & Kanamori, H. (1996). Initial rupture of earthquakes in the 1995 Ridgecrest, California Sequence. Geophysical Research Letters, 23(18), 2437-2440. doi: 10.1029/96gl02491
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:51338
Deposited On:06 Nov 2014 00:26
Last Modified:01 Jun 2023 22:49

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