M4.3 Earthquake 139 km NW of Neiafu, Tonga — October 25, 2025
2025-10-25 18:50:28 UTC (2025-10-25) · approx. 6:50 AM UTC-12 local
On October 25, 2025 at 18:50 UTC, a magnitude 4.3 intermediate depth earthquake struck 139 km NW of Neiafu, Tonga, at a depth of 182.1 km and coordinates -17.9030°, -175.0440°.
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.
This earthquake is part of an ongoing aftershock sequence following the magnitude 5.0 mainshock that occurred 26 days ago 135 km WNW of Neiafu, Tonga. Since the mainshock, the USGS has recorded 1 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
-175.0440°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.3 earthquake near Neiafu, Tonga?
The magnitude 4.3 earthquake that struck 139 km NW of Neiafu, Tonga on October 25, 2025 at 18:50 UTC had a depth of 182.1 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 4.3 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.0 one earlier?
No. This magnitude 4.3 earthquake is an aftershock of the larger magnitude 5.0 mainshock that occurred earlier 135 km WNW of Neiafu, Tonga. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
What should I do after an earthquake?
If you were in the affected area: check yourself and others for injuries, inspect your home for damage, and be prepared for aftershocks. For detailed guidance, see our earthquake safety guide and emergency planning resources.
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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: us6000rnb8). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, October 25, 2025). M4.3 Earthquake 139 km NW of Neiafu, Tonga — October 25, 2025. Retrieved May 26, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rnb8/