NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Earthquake recurrence on the southern San Andreas modulated by fault-normal stressEarthquake recurrence data from the Pallett Creek and Wrightwood paleoseismic sites on the San Andreas fault appear to show temporal variations in repeat interval. We investigate the interaction between strike-slip faults and auxiliary reverse and normal faults as a physical mechanism capable of producing such variations. Under the assumption that fault strength is a function of fault-normal stress (e.g. Byerlee's Law), failure of an auxiliary fault modifies the strength of the strike-slip fault, thereby modulating the recurrence interval for earthquakes. In our finite element model, auxiliary faults are driven by stress accumulation near restraining and releasing bends of a strike-slip fault. Earthquakes occur when fault strength is exceeded and are incorporated as a stress drop which is dependent on fault-normal stress. The model is driven by a velocity boundary condition over many earthquake cycles. Resulting synthetic strike-slip earthquake recurrence data display temporal variations similar to observed paleoseismic data within time windows surrounding auxiliary fault failures. Our simple model supports the idea that interaction between a strike-slip fault and auxiliary reverse or normal faults can modulate the recurrence interval of events on the strike-slip fault, possibly producing short term variations in earthquake recurrence interval.
Document ID
19950056330
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Palmer, Randy
(University of Oregon, Eugene, Oregon United States)
Weldon, Ray
(University of Oregon, Eugene, Oregon United States)
Humphreys, Eugene
(University of Oregon, Eugene, Oregon United States)
Saucier, Francois
(University of Oregon, Eugene, Oregon United States)
Date Acquired
August 16, 2013
Publication Date
March 1, 1995
Publication Information
Publication: Geophysical Research Letters
Volume: 22
Issue: 5
ISSN: 0094-8276
Subject Category
Geophysics
Accession Number
95A87929
Funding Number(s)
CONTRACT_GRANT: NAG5-1903
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available