M4.2 Earthquake south of Tonga — August 23, 2025
2025-08-23 19:59:54 UTC (2025-08-23) · approx. 7:59 AM UTC-12 local
On August 23, 2025 at 19:59 UTC, a magnitude 4.2 shallow crustal earthquake struck south of Tonga, at a depth of 35.0 km and coordinates -24.1092°, -175.7845°.
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
-175.7845°E
Technical Information
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Common Questions
How strong was the magnitude 4.2 earthquake south of Tonga?
The magnitude 4.2 earthquake that struck south of Tonga on August 23, 2025 at 19:59 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 4.2 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: us7000qwy6). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, August 23, 2025). M4.2 Earthquake south of Tonga — August 23, 2025. Retrieved November 12, 2025 from https://www.earthquaketracker.org/earthquakes/event/us7000qwy6/