Orogens at ocean-continent plate boundaries like the Andes accommodate lateral shortening not only in the forearc near the plate-interface but also in the continental hinterland, the so-called backarc. Back-arc deformation and faulting style mirror forearc processes at a much slower rate, resulting in a significant underestimation of the seismic potential of these structures. However, our understanding of how back- and forearc deformation processes are coupled is poor.

We quantify ongoing Central Andean backarc deformation by satellite-based observation methods and numerical modeling. We use radar interferometric (InSAR) and accurate positioning (GNSS) time-series combined into rate maps of mm-scale accuracy and high resolution in time (days) and space (~100 m). The primary focus of this project are the differences, respectively, the transition from thin- to thick-skinned backarc faulting style north and south of 23°S. Customized kinematic models will constrain the geometry and slip rates of the major active backarc faults and deduce an improved locking map of the forearc plate interface. A second focus lies on transient backarc processes as, for example, initiated by the large 2014 Iquique plate-interface earthquake: We will scan the our observations for evidence of spatio-temporal fore- and backarc coupling, such as transient slip hidden in the steady-state strain accumulation.