M5.4 Earthquake 54 km SSE of Ulaangom, Mongolia — August 28, 2025

On August 28, 2025 at 02:22 UTC, a magnitude 5.4 shallow crustal earthquake struck 54 km SSE of Ulaangom, Mongolia, at a depth of 10.0 km and coordinates 49.5620°, 92.4647°. The earthquake was reported felt by 1 personacross nearby locations, with a maximum shaking intensity of Modified Mercalli Intensity (MMI) 6.5 (very strong). This earthquake was detected by 94 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 449, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 5.4 releases seismic energy equivalent to roughly 2 kilotons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 3.2 km — a useful intuition for the size of the slip patch on the fault.