M4.1 Earthquake 101 km E of Yamada, Japan — April 20, 2026
2026-04-20 23:36:51 UTC (2026-04-20) · approx. 9:36 AM UTC+10 local
On April 20, 2026 at 23:36 UTC, a magnitude 4.1 shallow crustal earthquake struck 101 km E of Yamada, Japan, at a depth of 35.0 km and coordinates 39.4083°, 143.1245°.
Physical scale: An earthquake of magnitude 4.1 releases seismic energy equivalent to roughly 21 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 406 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
143.1245°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.1 earthquake near Yamada, Japan?
The magnitude 4.1 earthquake that struck 101 km E of Yamada, Japan on April 20, 2026 at 23:36 UTC had a depth of 35.0 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 4.1 earthquakes can continue for several days and gradually diminish over time.
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.
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Understanding This Data
Magnitude 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000sh00). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, April 20, 2026). M4.1 Earthquake 101 km E of Yamada, Japan — April 20, 2026. Retrieved May 21, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sh00/