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Preliminary report on the 28 September 2004, M 6.0 Parkfield, California earthquake

John Langbein·Roger D. Borcherdt·Douglas Dreger·J. Fletcher·Jeanne L Hardebeck·Margaret Hellweg·C. Ji·Malcolm J. S. Johnston·Jessica R. Murray·Robert Nadeau·Michael J. Rymer·Jerome A. Treiman
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Abstract

The M w 6.0 Parkfield earthquake struck central California at 17:15:14 UTC on 28 September 2004. The epicenter was located 11 km southeast of the rural town of Parkfield, adjacent to Gold Hill and on the San Andreas Fault ( Figure 1 ). The California Integrated Seismic Network (CISN) reported that the hypocenter was located at 35.819°N, 120.364°W at a depth of 8.8 km. From the distribution of aftershocks and from models of seismograms, strain changes, and geodetic displacements from the earthquake, it appears that the rupture propagated to the northwest along the San Andreas Fault from its hypocenter beneath Gold Hill to Middle Mountain. Because of the earthquake's moderate size and the low population density, only minimal damage was reported, but strong ground motions of approximately 1 g were recorded at a few isolated points (Shakal et al. , 2005, this issue).

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Seismological Research LettersArticle
90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 35.689648586960935° to 36.15007354140755° latitude; -120.74798583984375° to -120.091552734375° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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John Langbein, Roger D. Borcherdt, Douglas Dreger, J. Fletcher, Jeanne L Hardebeck, Margaret Hellweg, C. Ji, Malcolm J. S. Johnston, Jessica R. Murray, Robert Nadeau, Michael J. Rymer, Jerome A. Treiman. 2005. Preliminary report on the 28 September 2004, M 6.0 Parkfield, California earthquake. https://doi.org/10.1785/gssrl.76.1.10

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