M4.6 Earthquake 62 km WNW of Yonakuni, Japan — September 4, 2023
2023-09-04 07:50:58 UTC (2023-09-04) · approx. 3:50 PM UTC+8 local
On September 4, 2023 at 07:50 UTC, a magnitude 4.6 shallow crustal earthquake struck 62 km WNW of Yonakuni, Japan, at a depth of 36.9 km and coordinates 24.7500°, 122.4667°. This earthquake was detected by 32 seismic stations with excellent location accuracy and was assigned a USGS significance rating of 326, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.6 releases seismic energy equivalent to roughly 120 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 899 m — 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
122.4667°E
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Common Questions
How strong was the magnitude 4.6 earthquake near Yonakuni, Japan?
The magnitude 4.6 earthquake that struck 62 km WNW of Yonakuni, Japan on September 4, 2023 at 07:50 UTC had a depth of 36.9 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 24.7500°, 122.4667°, which is 62 km WNW of Yonakuni, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.6 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 4.6 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000ku8m). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 4, 2023). M4.6 Earthquake 62 km WNW of Yonakuni, Japan — September 4, 2023. Retrieved November 17, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000ku8m/