Assessment of ground deformation in Mandalay, Myanmar, using InSAR with Sentinel-1 data after the March 2025 earthquake

This study quantifies coseismic ground deformation associated with the 28 March 2025 earthquake sequence (Mw 6.7–7.7) in the Mandalay Region of Myanmar. Differential interferometric synthetic-aperture radar (DInSAR) was applied to Sentinel-1A single-look complex (SLC) data, using pre-event images acquired six and four days before the earthquakes and post-event images acquired five and nineteen days after. The interferograms were processed in ESA SNAP, phase-unwrapped with SNAPHU, and geocoded using the 30 m SRTM digital elevation model (DEM). A coherence threshold of 0.35 was applied to ensure reliable phase retrieval. Peak line-of-sight (LOS) displacements reach +0.24 m (uplift) and –0.62 m (subsidence) for the ascending pair, and +0.22 m (uplift) and –0.64 m (subsidence) for the descending pair. Decomposition of the paired LOS maps yields vertical motion between +0.74 m and –1.57 m and east–west offsets between –1.99 m (westward) and +1.29 m (eastward), corresponding to a horizontal-to-vertical displacement ratio of 1.27. The deformation field closely follows the surface trace of the dextral Sagaing Fault, confirming it as the primary seismogenic structure. Opposite-sense deformation is observed across the fault, with subsidence and eastward motion on the western block and uplift and westward motion on the eastern block. These results provide a high-resolution deformation field for this event and highlight the value of open-access Sentinel-1 data for rapid seismic hazard assessment in data-scarce regions. • Sentinel-1 InSAR maps co-seismic deformation from the 2025 Mandalay earthquake. • Vertical motion ranges from +0.74 m uplift to −1.57 m subsidence. • E–W ground shifts reach 1.99 m westward and 1.29 m eastward. • Deformation patterns align with the Sagaing Fault rupture zone.