Constraining Interseismic Deformation of Northern Ecuador using Interferometry from Sentinel-1 Data

Abstract

Ecuador is a country with several seismicity sources, including the Nazca – South America megathrust in the west, the Interandean Fault System (IFS), and an active back-arc fold and thrust belt in the East. The surface deformation associated with the subduction megathrust has been well constrained in prior studies, but this is not the case for the other two systems, representing a significant source of near-surface seismic hazard. The IFS runs directly under or close to several major cities, including Quito, Riobamba, and Ibarra. Earthquakes have destroyed all these cities in the past. On the order hand, the back-arc faults are under areas with active mining and petroleum infrastructure. The overarching goal of this work is develop a better understanding of these two fault systems using computational techniques for spaceborne geodetic data. In this first phase of the study, we perform interferometric synthetic aperture radar (InSAR) processing of 280 Sentinel-1 scenes in the dry Interandean Valley. Then, we use time-series analysis to obtain rates of deformation from all sources, including faults, during recent years. One specific goal is to investigate the hazard due to landslides near Quito. In general, our results contribute to having a better understanding of seismic hazards in Ecuador.