M4.4 Earthquake 193 km SE of Katsuura, Japan — October 17, 2023
2023-10-17 23:41:09 UTC (2023-10-17) · approx. 8:41 AM UTC+9 local
On October 17, 2023 at 23:41 UTC, a magnitude 4.4 shallow crustal earthquake struck 193 km SE of Katsuura, Japan, at a depth of 10.0 km and coordinates 33.8075°, 141.6608°.
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
141.6608°E
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Common Questions
How strong was the magnitude 4.4 earthquake near Katsuura, Japan?
The magnitude 4.4 earthquake that struck 193 km SE of Katsuura, Japan on October 17, 2023 at 23:41 UTC had a depth of 10.0 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: us6000lg90). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, October 17, 2023). M4.4 Earthquake 193 km SE of Katsuura, Japan — October 17, 2023. Retrieved December 26, 2023 from https://www.earthquaketracker.org/earthquakes/event/us6000lg90/