1MonMap LLC, Mongolia
2Department of Geography, National University of Mongolia, Mongolia
Abstract
This study estimates vertical ground surface displacement caused by the Mw 4.4 earthquake that occurred on May 19, 2024, in Bogd soum, Ovorkhangai Province, central Mongolia. The selected area lies along active segments of the Ikh Bogd fault system, which is associated with the historic 1957 Mw 8.1 Gobi-Altay earthquake. Specifically, deformation patterns were examined along Fault 20 (north) and Fault 21 (south), as defined in the Mongolian Seismic Fault Map. The analysis utilized Level-1 Single Look Complex (SLC) data acquired in Interferometric Wide Swath (IW) mode by the Sentinel-1A satellite. Two acquisitions from May 15, 2024 (pre-event) and June 7, 2024 (post-event) were processed using the Differential Interferometric Synthetic Aperture Radar (DInSAR) technique within the ESA SNAP software environment to estimate vertical displacement. Results from interferometric processing revealed measurable vertical surface movements, with subsidence reaching up to 7.38 cm and uplift up to 4.29 cm. These findings demonstrate the potential of DInSAR for detecting subtle surface deformations induced by moderate-magnitude seismic events. The study contributes to seismic risk assessment in tectonically active regions of Mongolia and supports the use of SAR-based time-series approaches for long-term ground deformation monitoring.
