Energy constraints on kinematic models of oblique faulting: Loma Prieta versus Parkfield-Coalinga

Journal Article · Wed Aug 01 04:00:00 EDT 1990 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL017i009p01453· OSTI ID:6400488

Michael, A J ^[1]

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1. Geological Survey, Menlo Park, CA (USA)

The Loma Prieta earthquake was a combination of right lateral strike-slip and reverse faulting. This oblique motion has been explained by a kinematic model that has the fault accommodate both the translation and convergence required by the Pacific-North American plate motions and a local bend in the San Andreas Fault. However, in other areas of California, such as Parkfield-Coalinga, this combination of motions is taken up by decoupled strike-slip and thrust faults. In this paper the author develops a simple physical model, based on applying Hamilton's principle to the energy released in earthquakes, that allows one to determine if a region should undergo oblique or decoupled faulting. This determination depends on the dip of available faults and the amount of convergence relative to the amount of translation. These energy constraints correctly predict the different types of faulting at Loma Prieta and Parkfield-Coalinga.

• OSTI ID: 6400488
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 17:9; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

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