Trade--Off Between Seismic Source Detail and Crustal Heterogeneities in Spherical 3D Finite Element Modeling: the 2004 Sumatra Earthquake case-study

Abstract

Finite Element methods (FEMs) are a powerful numerical simulation tool for modeling seismic events as they allow to solve three-dimensional complex models. We used a 3D Finite Element approach to evaluate the co-seismic displacement eld produced by the devastating 2004 Sumatra Andaman earthquake, which caused permanent deformations recorded by continuously operating GPS networks in a region of unprecedented extent. Previous analysis of the static displacement fi eld focused on the heterogeneous distribution of moment release on the fault plane; our intention here is to investigate how much the presence of crustal heterogeneities trades off seismic source details. To this aim, we adopted a quite simple source model in modeling the event. The key feature of our analysis is the generation of a complex three dimensional spherical domain. More-over, we also made an accurate analysis concerning boundary conditions, which are crucial for FE simulations.