Rapid estimation of parameters related to the 28 March 2025 M7.9 earthquake in Myanmar

At 14:20 (Beijing time) on March 28, 2025, a magnitude 7.9 earthquake struck the Mandalay region in central Myanmar. In response, the Institute of Geophysics, China Earthquake Administration, initiated a rapid scientific assessment involving multidisciplinary teams. Source parameters, focal mechanism, rupture process, and seismic radiated energy were estimated. According to the inferred source model, ground shaking intensity map and coseismic deformation field were simulated. The results indicate that the earthquake occurred along the Sagaing fault and was characterized by predominant right-lateral strike-slip motion. Both the moment energy ratio and the slowness parameter exceed global averages, suggesting a relatively high level of energy dissipation. The estimated intensity in the epicentral region may have reached or exceeded level Ⅹ (on the Modified Mercalli Intensity scale), potentially affecting an area of approximately three hundred thousand km2. Significant coseismic displacement was shown with the maximum horizontal offset reaching 1.09 m.