Effect of the Loma Prieta earthquake on surface slip along the Calaveras fault in the Hollister area
- San Francisco State Univ., CA (USA)
Over the past ten years the author has made over 800 measurements of slip rates at 20 sites on various faults in the San Francisco Bay region. This data set enables them to compare rates and amounts of slip on these various faults before and after the Loma Prieta earthquake (LPEQ) on the San Andreas fault. No surface slip rate changes associated with the earthquake occurred at any of the sites on the San Andreas, Hayward, northern Calaveras, Concord-Green Valley, Seal Cove-San Gregorio, Antioch, Rodgers Creek, or West Napa faults. The LPEQ apparently triggered up to 12-14 mm of right slip on the southern Calaveras fault at two sites in the Hollister area less than 50 km from the epicenter. Most of this slip was probably coseismic or nearly so. About the same amount of slip was triggered at these sites in 1984 by the Morgan Hill earthquake. This slip, in contrast, occurred as afterslip within about a 2.5-month interval. The Calaveras fault in the Hollister area moves episodically, with shorter times of more rapid slip alternating with longer times of slower slip. The alternation occurs whether or not the times of faster slip are triggered by any nearby seismic event(s).
- OSTI ID:
- 6205937
- Journal Information:
- Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 17:8; ISSN 0094-8276; ISSN GPRLA
- Country of Publication:
- United States
- Language:
- English
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