Application of the DInSAR method for determining coseismic displacement after the earthquake on January 7, 2025, in the South Tibet region

On January 7, 2025, a magnitude 7.1 earthquake struck the southern Tibetan Plateau, near the boundary between the Eurasian and Indian tectonic plates. The rupture occurred along a roughly north–south trending fault with moderate dip, consistent with regional tectonic patterns driven by the ongoing collision between the Indian and Eurasian plates. This area is known for frequent large-magnitude earthquakes, and the January 2025 event is among the most significant in recent decades. This study employs Differential Interferometric Synthetic Aperture Radar (DInSAR) to analyze co-seismic ground displacements using Sentinel-1 TOPS SAR imagery acquired from both ascending and descending orbital paths. A total of six radar images were processed, covering the fault system and surrounding area. The observed line-of-sight (LoS) displacements were decomposed into vertical and east–west components, revealing a deformation pattern typical of a normal faulting event, with dominant subsidence on the western side and uplift on the eastern side. These findings provide important insights into the seismic behavior and tectonic evolution of the region.