Probabilities for jumping fault segment stepovers

Abstract

Seismic hazard analysis relies heavily on the segmentation of faults. The ability of ruptures to break multiple segments has a big impact on estimated hazard. Current practice for estimating multiple segment breakage relies on panels of experts voting on their opinions for each case. Here, we explore the probability of elastodynamic ruptures jumping segment stepovers in numerical simulations of segmented fault systems. We find a simple functional form for the probability of jumping a segment stepover as a function of stepover distance: an exponential falloff with distance. We suggest this simple parameterization of jumping probabilities, combined with sparse observational data to fix the lengthscale parameter, as a new approach to estimating multisegment earthquake hazard. Copyright 2007 by the American Geophysical Union.