M4.2 Earthquake 73 km SW of Yonakuni, Japan — September 19, 2023
2023-09-19 23:43:58 UTC (2023-09-19) · approx. 7:43 AM UTC+8 local
On September 19, 2023 at 23:43 UTC, a magnitude 4.2 shallow crustal earthquake struck 73 km SW of Yonakuni, Japan, at a depth of 35.1 km and coordinates 23.9720°, 122.5196°.
Physical scale: An earthquake of magnitude 4.2 releases seismic energy equivalent to roughly 30 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 476 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
122.5196°E
Technical Information
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Common Questions
How strong was the magnitude 4.2 earthquake near Yonakuni, Japan?
The magnitude 4.2 earthquake that struck 73 km SW of Yonakuni, Japan on September 19, 2023 at 23:43 UTC had a depth of 35.1 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 4.2 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.2 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000kxf8). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2023, September 19, 2023). M4.2 Earthquake 73 km SW of Yonakuni, Japan — September 19, 2023. Retrieved December 2, 2023 from https://www.earthquaketracker.org/earthquakes/event/us7000kxf8/