M4.3 Earthquake 103 km NE of Hihifo, Tonga — October 28, 2025
2025-10-28 17:32:19 UTC (2025-10-28) · approx. 5:32 AM UTC-12 local
On October 28, 2025 at 17:32 UTC, a magnitude 4.3 shallow crustal earthquake struck 103 km NE of Hihifo, Tonga, at a depth of 10.0 km and coordinates -15.2287°, -173.1909°.
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 5.1 mainshock that occurred 4 days ago 89 km NE of Hihifo, Tonga. Since the mainshock, the USGS has recorded 0 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
Earthquake Details
-173.1909°E
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Common Questions
How strong was the magnitude 4.3 earthquake near Hihifo, Tonga?
The magnitude 4.3 earthquake that struck 103 km NE of Hihifo, Tonga on October 28, 2025 at 17:32 UTC had a depth of 10.0 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 4.3 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.1 one earlier?
No. This magnitude 4.3 earthquake is an aftershock of the larger magnitude 5.1 mainshock that occurred earlier 89 km NE of Hihifo, Tonga. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
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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: us6000rnys). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2025, October 28, 2025). M4.3 Earthquake 103 km NE of Hihifo, Tonga — October 28, 2025. Retrieved January 15, 2026 from https://www.earthquaketracker.org/earthquakes/event/us6000rnys/