M4.0 Earthquake 186 km NW of Nago, Japan — November 9, 2021
2021-11-09 17:19:07 UTC (2021-11-09) · approx. 1:19 AM UTC+8 local
On November 9, 2021 at 17:19 UTC, a magnitude 4.0 intermediate depth earthquake struck 186 km NW of Nago, Japan, at a depth of 186.1 km and coordinates 27.7236°, 126.5696°.
Physical scale: An earthquake of magnitude 4.0 releases seismic energy equivalent to roughly 15 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 347 m — a useful intuition for the size of the slip patch on the fault.

Earthquake Details
126.5696°E
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Common Questions
How strong was the magnitude 4.0 earthquake near Nago, Japan?
The magnitude 4.0 earthquake that struck 186 km NW of Nago, Japan on November 9, 2021 at 17:19 UTC had a depth of 186.1 km. For context, this was a light earthquake commonly felt near the epicenter.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.0 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.0 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000ftlu). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, November 9, 2021). M4.0 Earthquake 186 km NW of Nago, Japan — November 9, 2021. Retrieved January 15, 2022 from https://www.earthquaketracker.org/earthquakes/event/us7000ftlu/