Postseismic relaxation of the 2007 Central Peru earthquake

Abstract

We present a comprehensive modeling of coseismic and postseismic effects of the 2007 Central Peru earthquake on deformation, gravity and stress fields obtained with a semi-analytical spherical self-gravitating Earth model. We discuss the expected signature of different stratification profiles including Maxwell and Burgers rheologies and find that measurements of short-term relaxation on horizontal deformations should provide a discrimination between different rheologies. We compute the time-dependent stress transfer of the 2007 earthquake on the 1868 and 1877 seismic gaps in terms of the Coulomb Failure Function (CFF). We find significant levels of stress transfer only on the 1868 seismic gap due to its proximity to the 2007 source, even if the sign of CFF variation is dependent on the depth of the receiver plane, which is not univocally fixed by geological evidences.