M5.1 Earthquake 49 km ESE of Koseda, Japan — February 28, 2021
2021-02-28 14:30:15 UTC (2021-02-28) · approx. 11:30 PM UTC+9 local
On February 28, 2021 at 14:30 UTC, a magnitude 5.1 shallow crustal earthquake struck 49 km ESE of Koseda, Japan, at a depth of 30.2 km and coordinates 30.1656°, 131.1000°.
Physical scale: An earthquake of magnitude 5.1 releases seismic energy equivalent to roughly 674 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 2.0 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
131.1000°E
Technical Information
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Common Questions
How strong was the magnitude 5.1 earthquake near Koseda, Japan?
The magnitude 5.1 earthquake that struck 49 km ESE of Koseda, Japan on February 28, 2021 at 14:30 UTC had a depth of 30.2 km. For context, this was a moderate earthquake that could be widely felt.
Where did the earthquake occur?
The earthquake epicenter was located at 30.1656°, 131.1000°, which is 49 km ESE of Koseda, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 5.1 earthquakes can continue for days to weeks 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 5.1 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us7000decy). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, February 28, 2021). M5.1 Earthquake 49 km ESE of Koseda, Japan — February 28, 2021. Retrieved May 13, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000decy/