Complex 3D Finite Element Modeling of the April 6th 2009 L'Aquila Earthquake by Inverse Analysis of Static Deformation

Abstract

On 2009 April 6 a Mw = 6.3 earthquake struck the Abruzzi region (Central Italy) and caused severe destruction in L’Aquila and the surrounding area. In this work we present a Finite Element analysis of the event based on a realistic complex 3-D model, accounting for topographic relief and rheological heterogeneities deduced from local tomography. Finite Element computed Green’s functions were implemented in a linear inversion of GPS coseismic displacements, to retrieve the slip distribution on the rupture plane. The inverted slip models basically agree with previous studies carried out on homogeneous domains, but reveal the presence of a single high slip patch, whereas half-space or 1-D approaches obtain a more complex slip pattern. Our results point out that the introduction of 3-D features significantly influences the obtained source model, suggesting a trade-off between domain complexities and source details.