Crustal deformation in Hispaniola from geodetic measurements

GNSS and InSAR have been commonly used to quantify strain accumulation in tectonically active regions in recent years. The strain accumulation is essential to evaluate the potential risk of the earthquake hazard. In this study, we use geodetic measurements of surface velocities from GNSS and InSAR to quantify the surface strain rate in Hispaniola. Hispaniola consists of Haiti and the Dominican Republic, located between the North American (NA) plate and the Caribbean (CA) plate, which obliquely converge at a rate of 18-20 mm/yr. The convergence of the NA and CA plate forms a transpressional fault system across Hispaniola and has brought severe seismic hazards to this island in recent years. To evaluate the strain accumulation on the fault system in Hispaniola, we re-estimate the GNSS velocity, including continuous stations from Nevada Geodetic Laboratory (Blewitt et al., 2018) and campaign stations from 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 modified the equation proposed by Wang and Wright (2012), considered the uncertainty of each dataset, and combined both GNSS and InSAR velocities. We use the Strain_2D repository on GitHub (Materna et al., 2021) to calculate the strain rate in Hispaniola. Preliminary results suggest diffuse strain accumulation across the island consistent with significant north-south compression.