A magnitude 5.1 earthquake struck 132 km east-northeast of Masohi, Indonesia, at 23:17 UTC on July 31, 2026. That was about 8:17 a.m. the next morning in local time. The USGS put the depth at 10 kilometers, with the epicenter at -2.9413 latitude and 130.1101 longitude.
Fifty-three seismic stations picked it up, and the location accuracy was rated excellent. The USGS gave the event a significance rating of 400, which places it among routine seismic activity. The listing calls it a shallow crustal quake, moderate in size and one that could be widely felt.
The energy released works out to roughly 674 metric tons of TNT. Fault-scaling estimates put the rupture at about 2 kilometers long.
The setting
The epicenter sits where the Indo-Australian, Eurasian and Philippine Sea plates meet, in the Sunda-Banda arc system. The nearest mapped fault system is the Sunda megathrust.
The USGS monitors aftershocks continuously. After a quake of this size they can go on for days to weeks, fading over time.
Indonesia has seen far larger. The biggest on record there was the magnitude 9.1 Indian Ocean earthquake of December 26, 2004.
