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

We study numerically the behavior of a two-dimensional elastic plate (a crustal plane) that terntinates along one of its edges at a 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 distribotion of small events and an excess of large events. For the small events, the moments scale with rupture length in a manner that is consistent with seismological observations. For the large events, rupture occurs in the form of narrow propagating pulses. [S003l-9007(96)00703-X]