M4.3 Earthquake 128 km WNW of Neiafu, Tonga — March 28, 2026
2026-03-28 23:41:20 UTC (2026-03-28) · approx. 11:41 AM UTC-12 local
On March 28, 2026 at 23:41 UTC, a magnitude 4.3 intermediate depth earthquake struck 128 km WNW of Neiafu, Tonga, at a depth of 256.5 km and coordinates -18.3699°, -175.1678°.
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 20 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
-175.1678°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 128 km WNW of Neiafu, Tonga on March 28, 2026 at 23:41 UTC had a depth of 256.5 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: us7000sb6l). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, March 28, 2026). M4.3 Earthquake 128 km WNW of Neiafu, Tonga — March 28, 2026. Retrieved May 20, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sb6l/