Predicted reversal and recovery of surface creep on the hayward fault following the 1906 San Francisco earthquake

Abstract

Offset cultural features suggest that creep rates along the Hayward fault have remained constant since 1920 until the 1989 Loma Prieta earthquake despite evidence in the earthquake record of an enduring stress shadow after 1906. We re-construct the stressing history on the Hayward fault in order to predict when creep, assumed to have slowed, likely resumed at historical rates. The resumption of creep is dependent on the stressing history imposed from postseismic processes. Basic viscoelastic models produce stress histories that allow creep to resume within a couple decades. A detachment zone model for the Bay Area predicts that creep would not resume for 70+ years after the 1906 earthquake, in disagreement with historical creep observations. The recovery of creep is also advanced by potential left-lateral slip that could have been induced by the 1906 earthquake. Calculations for a friction-less fault suggest that 30-210 mm of left-lateral slip could have occurred. Copyright 2008 by the American Geophysical Union.