M4.2 Earthquake in the Bonin Islands, Japan region — August 31, 2021
2021-08-31 21:42:46 UTC (2021-08-31) · approx. 7:42 AM UTC+10 local
On August 31, 2021 at 21:42 UTC, a magnitude 4.2 shallow crustal earthquake struck in the Bonin Islands, Japan region, at a depth of 10.0 km and coordinates 28.4488°, 143.5681°.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
143.5681°E
Technical Information
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Common Questions
How strong was the magnitude 4.2 earthquake in the Bonin Islands, Japan region?
The magnitude 4.2 earthquake that struck in the Bonin Islands, Japan region on August 31, 2021 at 21:42 UTC had a depth of 10.0 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 4.2 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000f9dz). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, August 31, 2021). M4.2 Earthquake in the Bonin Islands, Japan region — August 31, 2021. Retrieved November 6, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000f9dz/