Open AccessM ≥ 7.0 earthquake recurrence on the San Andreas fault from a stress renewal model
Author(s) -
Parsons Tom
Publication year - 2006
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006jb004415
Subject(s) - seismology , geology , san andreas fault , elastic rebound theory , seismic gap , predictability , geodetic datum , fault (geology) , slip (aerodynamics) , interplate earthquake , tectonics , geodesy , intraplate earthquake , mathematics , engineering , statistics , aerospace engineering
Forecasting M ≥ 7.0 San Andreas fault earthquakes requires an assessment of their expected frequency. I used a three‐dimensional finite element model of California to calculate volumetric static stress drops from scenario M ≥ 7.0 earthquakes on three San Andreas fault sections. The ratio of stress drop to tectonic stressing rate derived from geodetic displacements yielded recovery times at points throughout the model volume. Under a renewal model, stress recovery times on ruptured fault planes can be a proxy for earthquake recurrence. I show curves of magnitude versus stress recovery time for three San Andreas fault sections. When stress recovery times were converted to expected M ≥ 7.0 earthquake frequencies, they fit Gutenberg‐Richter relationships well matched to observed regional rates of M ≤ 6.0 earthquakes. Thus a stress‐balanced model permits large earthquake Gutenberg‐Richter behavior on an individual fault segment, though it does not require it. Modeled slip magnitudes and their expected frequencies were consistent with those observed at the Wrightwood paleoseismic site if strict time predictability does not apply to the San Andreas fault.