M4.1 Earthquake in the Bonin Islands, Japan region — September 19, 2025
2025-09-19 19:43:34 UTC (2025-09-19) · approx. 4:43 AM UTC+9 local
On September 19, 2025 at 19:43 UTC, a magnitude 4.1 deep-focus earthquake struck in the Bonin Islands, Japan region, at a depth of 486.6 km and coordinates 28.0704°, 139.5489°.
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
139.5489°E
Technical Information
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Common Questions
How strong was the magnitude 4.1 earthquake in the Bonin Islands, Japan region?
The magnitude 4.1 earthquake that struck in the Bonin Islands, Japan region on September 19, 2025 at 19:43 UTC had a depth of 486.6 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: us6000rgd4). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, September 19, 2025). M4.1 Earthquake in the Bonin Islands, Japan region — September 19, 2025. Retrieved May 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rgd4/