M4.3 Earthquake 11 km NE of Nagahama, Japan — August 15, 2021
2021-08-15 20:03:13 UTC (2021-08-15) · approx. 5:03 AM UTC+9 local
Felt by 14 people across nearby locations.
On August 15, 2021 at 20:03 UTC, a magnitude 4.3 shallow crustal earthquake struck 11 km NE of Nagahama, Japan, at a depth of 10.0 km and coordinates 35.4524°, 136.3642°.
Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 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
Did You Feel It? — community-reported shaking
Aggregated felt-report intensity from 14 citizen responses to the USGS Did You Feel It? system. Each colored zone represents the average MMI from reports in that area.
Source: U.S. Geological Survey Did You Feel It?. View on USGS · submit your own report
Earthquake Details
136.3642°E
Technical Information
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Common Questions
How strong was the magnitude 4.3 earthquake near Nagahama, Japan?
The magnitude 4.3 earthquake that struck 11 km NE of Nagahama, Japan on August 15, 2021 at 20:03 UTC had a depth of 10.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 35.4524°, 136.3642°, which is 11 km NE of Nagahama, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.3 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 4.3 event is significantly smaller than that historical record.
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Location
Authoritative source: USGS event page (event ID: us6000f6pd). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, August 15, 2021). M4.3 Earthquake 11 km NE of Nagahama, Japan — August 15, 2021. Retrieved November 17, 2021 from https://www.earthquaketracker.org/earthquakes/event/us6000f6pd/