M4.3 Earthquake 150 km E of Yamada, Japan — August 23, 2021
2021-08-23 23:49:36 UTC (2021-08-23) · approx. 9:49 AM UTC+10 local
On August 23, 2021 at 23:49 UTC, a magnitude 4.3 shallow crustal earthquake struck 150 km E of Yamada, Japan, at a depth of 19.7 km and coordinates 39.3093°, 143.6793°.
Physical scale: An earthquake of magnitude 4.3 releases seismic energy equivalent to roughly 43 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 558 m — a useful intuition for the size of the slip patch on the fault.
Earthquake Details
143.6793°E
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Common Questions
How strong was the magnitude 4.3 earthquake near Yamada, Japan?
The magnitude 4.3 earthquake that struck 150 km E of Yamada, Japan on August 23, 2021 at 23:49 UTC had a depth of 19.7 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 4.3 earthquakes can continue for several days and gradually diminish over time.
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Understanding This Data
Magnitude 4.3 earthquakes are often felt but rarely cause damage.
Authoritative source: USGS event page (event ID: us7000f2tw). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2021, August 23, 2021). M4.3 Earthquake 150 km E of Yamada, Japan — August 23, 2021. Retrieved November 2, 2021 from https://www.earthquaketracker.org/earthquakes/event/us7000f2tw/