M4.8 Earthquake 69 km E of Yamada, Japan — December 30, 2025
2025-12-30 23:51:36 UTC (2025-12-30) · approx. 9:51 AM UTC+10 local
Aftershock of the M5.1 mainshock.
On December 30, 2025 at 23:51 UTC, a magnitude 4.8 shallow crustal earthquake struck 69 km E of Yamada, Japan, at a depth of 35.0 km and coordinates 39.4639°, 142.7562°. This earthquake was detected by 65 seismic stations with good location accuracy and was assigned a USGS significance rating of 354, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.8 releases seismic energy equivalent to roughly 239 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 1.2 km — 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 5.1 mainshock that occurred 26 days ago 118 km E of Yamada, Japan. Since the mainshock, the USGS has recorded 14 aftershocks in this area. Aftershock activity is expected to continue for days to weeks 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
142.7562°E
Technical Information
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Common Questions
How strong was the magnitude 4.8 earthquake near Yamada, Japan?
The magnitude 4.8 earthquake that struck 69 km E of Yamada, Japan on December 30, 2025 at 23:51 UTC had a depth of 35.0 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at 39.4639°, 142.7562°, which is 69 km E of Yamada, Japan. View all earthquakes in Japan.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.8 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 4.8 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 118 km E of Yamada, 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 4.8 event is significantly smaller than that historical record.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
Authoritative source: USGS event page (event ID: us7000rlm7). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, December 30, 2025). M4.8 Earthquake 69 km E of Yamada, Japan — December 30, 2025. Retrieved May 17, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000rlm7/