Crustal deformation in Hispaniola from geodetic measurements

GNSS and InSAR are both commonly used in recent years to quantify strain accumulation in tectonically active regions. In this study, we use both GNSS and InSAR to quantify strain accumulation rate in Hispaniola, located between the North American (NA) and Caribbean (CA) plates. The NA plate subducts obliquely around 20 mm/yr under the CA plate, forming a transpressive fault system in Hispaniola and Puerto Rico. We use GNSS and InSAR velocities to estimate the surface strain rate on the island of Hispaniola. We access GNSS time-series available for Hispaniola from the Nevada Geodetic Laboratory (Blewitt et al., 2018) and estimate the secular velocity for each GPS station. We supplement these with campaign station velocities provided by Benford et al. (2012). We process InSAR data using ISCE to process the initial interferograms and MintPy to do the time series for InSAR. Then, we follow the method of Wang and Wright (2012) to combine both GNSS and InSAR velocities and calculate strain rate. Preliminary results confirm strain accumulation on the Sepentrional-Oriente fault zone and the Enriquillo-Plantain Garden fault zone, and also suggest that central Hispaniola has non-negligible strain, possibly resulting from uplift on the islands fold-and-thrust belt or deformation from the northern subduction zone. We use the method of Savage and Simpson (1997) to estimate the total moment rate from surface strain rate, providing quantitative bounds on the seismic hazard in the region.