M4.1 Earthquake 161 km S of Ōyama, Japan — September 18, 2023
2023-09-18 20:32:10 UTC (2023-09-18) · approx. 5:32 AM UTC+9 local
On September 18, 2023 at 20:32 UTC, a magnitude 4.1 intermediate depth earthquake struck 161 km S of Ōyama, Japan, at a depth of 296.8 km and coordinates 33.1479°, 138.3029°.
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
138.3029°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.1 earthquake near Ōyama, Japan?
The magnitude 4.1 earthquake that struck 161 km S of Ōyama, Japan on September 18, 2023 at 20:32 UTC had a depth of 296.8 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.
Actions
Location
Understanding This Data
Magnitude 4.1 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000kwjh). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 18, 2023). M4.1 Earthquake 161 km S of Ōyama, Japan — September 18, 2023. Retrieved December 2, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kwjh/