M5.0 Earthquake in the Bonin Islands, Japan region — October 17, 2021
2021-10-17 21:59:51 UTC (2021-10-17) · approx. 6:59 AM UTC+9 local
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On October 17, 2021 at 21:59 UTC, a magnitude 5.0 deep-focus earthquake struck in the Bonin Islands, Japan region, at a depth of 516.0 km and coordinates 28.6965°, 138.2018°. The USGS PAGER system issued a green alert level for this event, indicating no significant casualties or damage expected.
Physical scale: An earthquake of magnitude 5.0 releases seismic energy equivalent to roughly 477 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.7 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
ShakeMap — predicted shaking intensity
Modeled ground-motion intensity contoured on the Modified Mercalli scale (MMI). Computed by the USGS from the moment-tensor solution and regional ground-motion prediction equations.
Source: U.S. Geological Survey ShakeMap. View interactive ShakeMap on USGS
Earthquake Details
138.2018°E
Technical Information
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Common Questions
How strong was the magnitude 5.0 earthquake in the Bonin Islands, Japan region?
The magnitude 5.0 earthquake that struck in the Bonin Islands, Japan region on October 17, 2021 at 21:59 UTC had a depth of 516.0 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 28.6965°, 138.2018°, which is in the Bonin Islands, Japan region. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.0 earthquakes can continue for days to weeks 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 5.0 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us6000fvi9). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, October 17, 2021). M5.0 Earthquake in the Bonin Islands, Japan region — October 17, 2021. Retrieved December 22, 2025 from https://www.earthquaketracker.org/earthquakes/event/us6000fvi9/