STRESS DIFFUSION FOLLOWING LARGE STRIKE-SLIP EARTHQUAKES - A COMPARISON BETWEEN SPHERICAL AND FLAT-EARTH MODELS

A comparison is performed between predictions of coseismic and post-se ismic deformations, based on two different earth models. The main purp ose of this work is to clarify in a rigorous manner the role of spheri city in the assessment of both residual deformations and large-scale p ost-seismic motions. The two models considered in this study are commo nly employed for predictions of post-seismic deformations. They exhibi t 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 influen ce of sphericity in predictions of post-seismic deformations, especial ly in the far field of major earthquakes. Second, we wish to elucidate the potential role of stress migration in earthquake triggering over great distances.