Dynamic Rupture Propagation in the Presence of Thermally Driven Fluid Flow and Melting Due to Fault Slip: a Modeling Study

University Of California-Riverside, Riverside CA

Investigators

Abstract

EAR-0229391 While Seismologists have long known that friction is one of the fundamental processes operating during earthquake rupture and slip, the actual physical mechanism behind the frictional behavior we believe we see in earthquakes remains elusive. There are strong physical arguments that at the high slip rates seen in earthquakes, frictional heating of pore fluids could dynamically reduce the frictional stress, greatly increasing the stress drop. Under even more extreme conditions, frictional melting of the fault zone may further affect the frictional environment. We propose to investigate these processes by coupling a 1-D hydrothermal/poroelastic model for heat flow and fluid behavior with a 3-D dynamic faulting model for rupture and slip behavior. Using this combined method, we will be able to investigate the effects of thermal fluid pressurization and rock melting on fault stress, and determine the resulting effects on fault motion and radiated seismic waves. Behaviors predicted by our models can be compared with seismic data for verification.