ASSESSING FAULT SLIP HAZARD IN TAIWAN USING SPACE GEODESY

Abstract

Taiwan is a geologically complex region due to the continuous collision of the Eurasian Plate and the Philippine Sea Plate. This study aimed to quantify the interseismic crustal deformation of Taiwan and detail the island’s seismic hazard potential using space geodesy. Data were collected between 2016 and 2021 through C-band Copernicus Sentinel-1 synthetic aperture radar imagery and continuous GNSS data from Academia Sinica, Taiwan. I excluded major earthquake events within this time period and generated a dataset consisting of interferometric synthetic aperture radar ground motion velocities with GNSS corrections and interpolated GNSS ground motion velocities. Then, utilizing this dataset, I performed a deformation rate analysis and error analysis. Next, I explored block modeling and used a total variation regularization approach to determine the reference block model that best reduced velocity residuals and minimized the number of independently rotating blocks. Results suggested that the Taipei Basin, Ilan Basin, Western Foothills, and Longitudinal Valley were experiencing increased total strain rate accumulation and, therefore, posed increased seismic hazard.