Abstract

On April 1, 2014, at 23:46:45 UTC a great earthquake (Mw 8.2) occurred near Pisagua - Chile, at the segment of the subduction zone megathrust where the 1877 mega-earthquake (Mw 8.8 - 9.0) defined a seismic gap that did not rupture for 118 years. Within the past two decades, crustal deformation has been extensively monitored through campaign and continuous GPS networks in northern Chile and southern Peru. Thus, providing constraints on the spatial and temporal evolution of crustal deformation before, during and after the recent Pisagua Mw 8.2 earthquake. We obtain time series of daily estimates of position for all the available data, from which we isolate the post-seismic deformation signal. Also, we estimate co-seismic and pre-seismic crustal deformation signals from 30s positions obtained the day of the earthquake and the 3 weeks preceding it. We present our inferences of pre-, co- and post- seismic slip associated with the Pisagua earthquake and compare it with current models of inter-seismic coupling. We analyze our results in the context of the seismotectonics of the region in order to better characterize the mechanical properties at the subduction megathrust and discuss its implications for earthquake potential in the surrounding region.