M4.9 Earthquake 108 km S of Honchō, Japan — March 31, 2023
2023-03-31 15:29:40 UTC (2023-03-31) · approx. 1:29 AM UTC+10 local
On March 31, 2023 at 15:29 UTC, a magnitude 4.9 shallow crustal earthquake struck 108 km S of Honchō, Japan, at a depth of 50.3 km and coordinates 41.1562°, 142.7896°. This earthquake was detected by 81 seismic stations with good location accuracy and was assigned a USGS significance rating of 369, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.9 releases seismic energy equivalent to roughly 338 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.4 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
142.7896°E
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Common Questions
How strong was the magnitude 4.9 earthquake near Honchō, Japan?
The magnitude 4.9 earthquake that struck 108 km S of Honchō, Japan on March 31, 2023 at 15:29 UTC had a depth of 50.3 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 41.1562°, 142.7896°, which is 108 km S of Honchō, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.9 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 4.9 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us6000k15z). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, March 31, 2023). M4.9 Earthquake 108 km S of Honchō, Japan — March 31, 2023. Retrieved June 3, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000k15z/