M5.2 Earthquake in the Volcano Islands, Japan region — January 23, 2023

On January 23, 2023 at 02:59 UTC, a magnitude 5.2 shallow crustal earthquake struck in the Volcano Islands, Japan region, at a depth of 44.9 km and coordinates 23.4481°, 142.9353°. This earthquake was detected by 195 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 416, placing it among routine seismic activity.

Physical scale: An earthquake of magnitude 5.2 releases seismic energy equivalent to roughly 951 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.3 km — a useful intuition for the size of the slip patch on the fault.

This earthquake is part of an ongoing aftershock sequence following the magnitude 5.6 mainshock that occurred 19 days ago in the Volcano Islands, Japan region. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.

The epicenter is located in Japan, a region characterized by the intersection of four tectonic plates — Pacific, Philippine Sea, Eurasian, and North American — creating multiple subduction zones. The nearest mapped fault system is the Japan Trench. View all earthquakes in Japan.

Learn more: Magnitude scale · Aftershock sequences