Slip Complexity in a Crustal-Plane Model of an Earthquake Fault

Abstract

We study numerically the behavior of a two-dimensional elastic plate (acrustal plane) that terminates along one of its edges at a homogeneous fault boundary. Slip-weakening friction at the boundary, inertial dynamics in the bulk, and uniform slow loading via elastic coupling to a substrate combine to produce a complex, deterministically chaotic sequence of slipping events. We observe a power-law distribution of small to moderately large events and an excess of very large events. For the smaller events, the moments scale with the rupture length in a manner that is consistent with seismological observations. For the largest events, rupture occurs in the form of narrow propagating pulses.