Asymmetric off-fault damage generated by bilateral ruptures along a bimaterial interface

Abstract

We perform numerical simulations of spontaneous dynamic rupture governed by a slip-weakening law along a bimaterial interface (fault) with off-fault damage in the form of Coulomb plastic yielding. Off-fault plastic yielding stabilizes the wrinkle-like slip pulse in terms of a decreasing rate of slip velocity growth. With a variety of model parameters, ruptures on the fault are bilateral, while off-fault plastic strain distnibution between the two rupture directions is highly asymmetric. Copyright 2008 by the American Geophysical Union.