M4.1 Earthquake 66 km E of Onagawa Chō, Japan — February 25, 2026
2026-02-25 21:52:38 UTC (2026-02-25) · approx. 6:52 AM UTC+9 local
On February 25, 2026 at 21:52 UTC, a magnitude 4.1 shallow crustal earthquake struck 66 km E of Onagawa Chō, Japan, at a depth of 48.3 km and coordinates 38.3879°, 142.2024°.
Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
142.2024°E
Technical Information
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Common Questions
How strong was the magnitude 4.1 earthquake near Onagawa Chō, Japan?
The magnitude 4.1 earthquake that struck 66 km E of Onagawa Chō, Japan on February 25, 2026 at 21:52 UTC had a depth of 48.3 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.1 earthquakes can continue for several days and gradually diminish over time.
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.
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Understanding This Data
Magnitude 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000s3ge). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, February 25, 2026). M4.1 Earthquake 66 km E of Onagawa Chō, Japan — February 25, 2026. Retrieved May 13, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000s3ge/