M4.4 Earthquake 115 km ESE of Iwaki, Japan — May 4, 2025
2025-05-04 21:14:50 UTC (2025-05-04) · approx. 6:14 AM UTC+9 local
On May 4, 2025 at 21:14 UTC, a magnitude 4.4 shallow crustal earthquake struck 115 km ESE of Iwaki, Japan, at a depth of 35.0 km and coordinates 36.7184°, 142.1148°.
Physical scale: An earthquake of magnitude 4.4 releases seismic energy equivalent to roughly 60 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 655 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
142.1148°E
Technical Information
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Common Questions
How strong was the magnitude 4.4 earthquake near Iwaki, Japan?
The magnitude 4.4 earthquake that struck 115 km ESE of Iwaki, Japan on May 4, 2025 at 21:14 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 4.4 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.4 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000px58). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, May 4, 2025). M4.4 Earthquake 115 km ESE of Iwaki, Japan — May 4, 2025. Retrieved July 12, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000px58/