M4.8 Earthquake 17 km S of Yonakuni, Japan — August 12, 2021
2021-08-12 22:53:44 UTC (2021-08-12) · approx. 6:53 AM UTC+8 local
On August 12, 2021 at 22:53 UTC, a magnitude 4.8 shallow crustal earthquake struck 17 km S of Yonakuni, Japan, at a depth of 45.1 km and coordinates 24.3127°, 122.9825°.
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
122.9825°E
Technical Information
Common Questions
How strong was the magnitude 4.8 earthquake near Yonakuni, Japan?
The magnitude 4.8 earthquake that struck 17 km S of Yonakuni, Japan on August 12, 2021 at 22:53 UTC had a depth of 45.1 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 24.3127°, 122.9825°, which is 17 km S of Yonakuni, 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.
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Location
Authoritative source: USGS event page (event ID: us6000f8z6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, August 12, 2021). M4.8 Earthquake 17 km S of Yonakuni, Japan — August 12, 2021. Retrieved October 23, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f8z6/