Deformation Identification Due to the Pasaman Earthquake On February 25 2022, Using The DinSAR Method

Abstract

The Pasaman earthquake on February 25, 2022, had a magnitude of 6.1 with a depth of 10 km and an epicenter at 0.15 N - 99.98 BT. This earthquake was preceded by a lower magnitude earthquake with a magnitude of 5.2, with an interval of about 4 minutes before the main earthquake. Based on information updates from BMKG until March 7, 2022, there were 279 aftershocks and 10 felt times. Based on information from the Pasaman regency government, the casualties affected as many as 24 people died, 7186 people were displaced and more than 6625 houses were damaged spread across 5 districts, including West Pasaman, Pasaman, Lima Puluh Kota, Agam, and Padang Pariaman districts. This study aims to provide information on the location of deformations caused by this earthquake. Because the impact of the earthquake is quite extensive and destructive, it is very necessary to inform the information that occurs for future mitigation efforts. This research uses the DinSAR method by utilizing data from sentinel 1 type SLC (Single Look Complex) imagery before (11 and 23 February 2022) and after (7 March 2022) the earthquake occurred. In addition, we processed satellite Gravity data from GGMPlus to identify weak structures associated with low anomalies for comparison with the results of the DinSAR Method. The results of the satellite imagery process show that the areas identified as deformation at the time of the earthquake are in zones with low (negative) anomaly residual gravity values.