Rapid deployment of a seismic array in Ecuador following the April 16th 2016 M7.8 Pedernales earthquake

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This project will rapidly deploy a seismological network at the southern end of the April 16th 2016 M7.8 Pedernales earthquake in Ecuador (Objective 1). Our project partners are currently deploying seismological stations in the central (GEOAZURE, IRD, France) and northern (IRIS, USA) regions of the fault zone. The seismological network will record earthquake activity continuously for a period of 10 months, with a service after 5 months. The dataset obtained, which will be openly shared among our project partners and the scientific community will provide unprecedented resolution on imaging aftershock activity on the subduction interface. Once collected after 5 and 10 months, the continuous data will be processed to detect earthquakes which will be located while jointly determining high-resolution 3D velocity structure in this tectonically complex subduction zone. By interpreting the spatial and temporal distribution and migration of aftershock activity we will gain valuable insight into the stress conditions at the subduction interface. Additional analysis of attenuation that the seismic waves have undergone will, when jointly interpreted with the P-wave and S-wave velocity structure, will provide information as to the chemical and mineralogical nature of the subduction zone and processes. In order to interpret the seismological data in terms of the stress and strain changes that have taken place before, during and after the M7.8 earthquake, we will use satellite interferometry to determine, for the first time, a multi-temporal InSAR time series (Objective 2). This will be done by processing multiple satellite images of the zone, from 6 months before to 12 months after the earthquake. From these images we can ascertain the ground deformation. The data collected will allow us to bring together interdisciplinary information to interpret the state of stress and its evolution in this poorly studied and instrumented part of the world. Finally, using all data and interpretations gathered we will address the question of whether the southern region of the fault zone is likely to rupture, and what the likely response of nearby volcanic zones will be to changes in the regional stress field.