The Long-Term Dynamics and Evolution of Dip-Slip Faults

University Of California-Riverside, Riverside CA

Investigators

Abstract

Abstract for proposal EAR0106828 (PH #31x) Title: The Long-Term Dynamics and Evolution of Dip-Slip Faults PI's: Oglesby, David D., and Xu, Guanshui, University of California, Riverside The goal of this project is to investigate the effects of multiple earthquakes on the dynamics of dip-slip faults. Observations and models of dip-slip earthquakes have shown that non-vertical faults behave in ways that are quite different from vertical strike-slip faults. In particular, these faults display higher motion on the hanging wall, marked changes in the direction of slip along strike, and greater motion for thrust events than for otherwise equivalent normal events. This project will help determine if these and other effects persist over multiple earthquake cycles. Additionally, the researchers will investigate whether (under reasonable physical assumptions) dip-slip faults will reach a steady state over time, or if complexity in stress and slip will grow. Finally, the researchers will analyze the effect that the long-term evolution of the fault has on near-source ground motion. The project will use a combination of the finite element and variational boundary integral methods to model the dynamics of the rupture and slip process, as well as loading and nucleation during the interseismic period. The results will have implications for both the basic physics of the earthquake process as well as seismic hazard.