M4.6 Earthquake 43 km S of Shizunai-furukawach?, Japan — December 26, 2021
2021-12-26 19:40:05 UTC (2021-12-26) · approx. 4:40 AM UTC+9 local
Aftershock of the M6.0 mainshock.
On December 26, 2021 at 19:40 UTC, a magnitude 4.6 shallow crustal earthquake struck 43 km S of Shizunai-furukawach?, Japan, at a depth of 66.0 km and coordinates 41.9435°, 142.3073°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 6.0 mainshock that occurred 24 days ago 32 km SSW of Honchō, Japan. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for weeks to months as stresses on surrounding faults redistribute.
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
142.3073°E
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Common Questions
How strong was the magnitude 4.6 earthquake near Shizunai-furukawach?, Japan?
The magnitude 4.6 earthquake that struck 43 km S of Shizunai-furukawach?, Japan on December 26, 2021 at 19:40 UTC had a depth of 66.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 41.9435°, 142.3073°, which is 43 km S of Shizunai-furukawach?, 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.
Is this the same earthquake as the M6.0 one earlier?
No. This magnitude 4.6 earthquake is an aftershock of the larger magnitude 6.0 mainshock that occurred earlier 32 km SSW of Honchō, Japan. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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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Authoritative source: USGS event page (event ID: us6000gfhx). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, December 26, 2021). M4.6 Earthquake 43 km S of Shizunai-furukawach?, Japan — December 26, 2021. Retrieved March 5, 2022 from https://www.earthquaketracker.org/earthquakes/event/us6000gfhx/