M4.8 Earthquake 139 km SSE of Koshima, Japan — November 28, 2025
2025-11-28 22:40:44 UTC (2025-11-28) · approx. 7:40 AM UTC+9 local
On November 28, 2025 at 22:40 UTC, a magnitude 4.8 shallow crustal earthquake struck 139 km SSE of Koshima, Japan, at a depth of 9.8 km and coordinates 29.1143°, 131.2005°. This earthquake was detected by 85 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 km — a useful intuition for the size of the slip patch on the fault.
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
Earthquake Details
131.2005°E
Technical Information
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Common Questions
How strong was the magnitude 4.8 earthquake near Koshima, Japan?
The magnitude 4.8 earthquake that struck 139 km SSE of Koshima, Japan on November 28, 2025 at 22:40 UTC had a depth of 9.8 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 29.1143°, 131.2005°, which is 139 km SSE of Koshima, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 earthquakes can continue for several days and gradually diminish over time.
Has Japan had earthquakes this big before?
The largest recorded earthquake in Japan was the M9.1 Tohoku earthquake of March 11, 2011. Today's magnitude 4.8 event is significantly smaller than that historical record.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Authoritative source: USGS event page (event ID: us7000reif). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, November 28, 2025). M4.8 Earthquake 139 km SSE of Koshima, Japan — November 28, 2025. Retrieved May 24, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000reif/