Interseismic velocity field and coupling along the Ecuador Subduction interface in relation to the 2016 Pedernales Earthquake

Description

On April 16 2016, a magnitude 7.8 earthquake occurred along the Nazca-South America plate interface near the city of Pedernales in Ecuador. GPS measurements in the years prior to the earthquake had indeed shown a partial and spatially heterogeneous pattern of interseismic coupling in central-northern Ecuador (Nocquet et al., 2014, Chlieh et al., 2014). Here, we revisit these models using an updated velocity field including mostly continuous GPS. We find a family of models allowed by the data and discuss their correlation with the slip distribution found for the 2016 Mw 7.8 Pedernales earthquake. Additionally, we investigate if precursory signals were recorded in the GPS time-series prior to the 2016 event. Finally, we present a slip budget for the Ecuadorian subduction since the Mw 8.8 1906 earthquake and discuss its implication for the segmentation and seismic hazard along the north Ecuadorian subduction.

Abstract

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