Virtual California Earthquake Simulator

Abstract

The model that would eventually become Virtual California started as a limited simulation model developed by Rundle (1988) for the distributed seismicity on the San Andreas and adjacent faults in southern California. This model included stress accumulation and release as well as stress interactions between faults. An updated version of this model was developed (Rundle et al. 2001, 2002, 2004), including the major strike‐slip faults in California, and was called Virtual California. Details of the model were given in Rundle et al. (2006a,b). Yakovlev et al. (2006) utilized Virtual California simulations to examine the recurrence time statistics on faults in California. They concluded that the distribution of return times on a fault is well approximated by a Weibull distribution. Yikilmaz et al. (2010) used Virtual California to simulate earthquakes on the Nankai trough, Japan, and found an excellent agreement with the historical sequence of 13 great earthquakes. Yikilmaz et al. (2011) gave a composite simulation of seismicity in northern California utilizing Virtual California for earthquakes on mapped faults, a random background of smaller earthquakes, and a branching aftershock sequence (BASS) model simulation of aftershocks. In its current incarnation, Virtual California is a sophisticated tool for simulating earthquakes on a wide variety of fault geometries in a high‐performance computing environment and is part of a larger effort by the Southern California Earthquake Center to unify the results from several different earthquake simulators. A description of this effort and a comparison of the results can be found in Tullis et al. (2012a) and Tullis et al. (2012b), respectively. There are three major components that make up Virtual California: a fault model, a set of quasi‐static interactions (Green’s …