Stress diffusion following large earthquakes: a comparison between spherical and flat-earth models

Abstract

A comparison is performed between predictions of coseismic and post-seismic deformations, based on two different earth models. The main purpose of this work is to clarify in a rigorous manner the role of sphericity in the assessment of both residual deformations and large-scale post-seismic motions. The two models considered in this study are commonly employed for predictions of post-seismic deformations. They exhibit the common feature of a layered viscoelastic structure but differ in their global geometrical features, the first being characterized by a flat-earth approximation and the second by a spherical geometry. The purpose of this study is twofold. First, we wish to assess the influence of sphericity in predictions of post-seismic deformations, especially in the far field of major earthquakes. Second, we wish to elucidate the potential role of stress migration in earthquake triggering over great distances.