The purpose of this study is to test our hypothesis that a fundamental mechanism controlling arc volcanism is the large-scale and long-term change in tectonic loading following mega-thrust earthquakes. the switch from pre-earthquake compression to post-earthquake extension facilitates strike-slip faulting in the arc, which substantially enhances the flow properties through permeability enhancement and viscosity reductions of the non-Newtonian magmas. These mutually reinforcing processes thus accelerate arc volcanism. We plan to install the seismic array (coupled with cGPS and soil flux stations) in the Nevados de Chillan volcanic complex, in the region of the Chilean-Argentinian arc facing the main slip of the Maule earthquake. This project will redeploy, and expand on, the array that we deployed from December 2011 to April 2012 to include seismic, geodetic, and geochemical instrumentation and will conduct in-depth analyses of the new data to come. the seismic array is designed to capture long-period signals associated with tremor and magma migration (as already measured in our exploratory campaign) and accurately locate earthquake hypocenters and their migration to capture robust earthquake focal mechanisms that will highlight strike-slip deformation dynamics occuring int he volcanic complex.