Comparison of fault models of the 2008 Wenchuan earthquake (Ms8.0) and spatial distributions of co-seismic deformations

Abstract

A proper slip fault model and a reasonable dislocation theory are necessary to compute and investigate co-seismic deformations caused by the 2008 Wenchuan earthquake (Ms8.0). To find such a model, several comparisons are made of different dislocation theories, seismic fault models, and earth models. Results indicate that the fault model determined by combining GPS and seismic waveform data is the best. The spherical dislocation theory yields better results than that of a half-space theory, and the results obtained from a revised PREM earth model are better than those from PREM. According to results of earlier investigations, co-seismic deformations such as the displacement, geoid, gravity, and strain changes caused by the 2008 Wenchuan earthquake (Ms8.0) are computed, described, and discussed. Results show that the earthquake generated considerable co-seismic deformation in a large area around the epicenter. The modeled deformations are applicable as a reference for other researchers to study inter-structural inversion, crustal deformation, etc. The effects of the curvature and layer structure are great. Moreover, spherical dislocation theory is necessary for studying co-seismic deformations caused by a large event.