M4.6 Earthquake 74 km NW of Uken, Japan — October 11, 2023
2023-10-11 22:33:13 UTC (2023-10-11) · approx. 7:33 AM UTC+9 local
On October 11, 2023 at 22:33 UTC, a magnitude 4.6 intermediate depth earthquake struck 74 km NW of Uken, Japan, at a depth of 138.5 km and coordinates 28.7792°, 128.6959°. This earthquake was detected by 50 seismic stations with good 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
128.6959°E
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Common Questions
How strong was the magnitude 4.6 earthquake near Uken, Japan?
The magnitude 4.6 earthquake that struck 74 km NW of Uken, Japan on October 11, 2023 at 22:33 UTC had a depth of 138.5 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 28.7792°, 128.6959°, which is 74 km NW of Uken, 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: us6000lexu). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 11, 2023). M4.6 Earthquake 74 km NW of Uken, Japan — October 11, 2023. Retrieved December 16, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lexu/