Developing Comprehensive Three-Dimensional Fault Models and Simulating Seismic Wave Propagation Generated by These Earthquake Sources

Harvard University, Cambridge MA

Investigators

Abstract

Abstract for proposal EAR0087648 (PH # 31x) Title: Developing comprehensive three-dimensional fault models and simulating seismic wave propagation generated by these earthquake sources PI's: John H. Shaw, Harvard University This project aims to develop three-dimensional structural models of active fault systems in the Los Angeles basin to study earthquake behavior. The models will incorporate large amounts of formerly proprietary subsurface geophysical data, including seismic reflection profiles and well logs, that were acquired by the petroleum industry. These data, combined with earthquake seismicity, will define the positions and geometries of faults at depth. The models will include both strike-slip and blind-thrust fault systems, both of which are capable of generating destructive earthquakes. Geodetic observations (GPS and InSAR) will be compared with fault displacements to assess the accuracy of modeled fault shapes and slip rates. The new models will be used to examine the mechanical interactions of fault systems in Los Angeles including stress-triggering phenomena. This behavior suggests that major earthquakes on one fault can induce events on adjacent faults, thereby increasing seismic hazard. Finally, the model will be used to simulate earthquake wave propagation from realistic, three-dimensional fault sources for the prediction of hazardous ground shaking. Results from these types of simulations can contribute to improved earthquake engineering, thereby helping to mitigate these natural disasters.