M4.5 Earthquake 131 km WNW of Neiafu, Tonga — April 28, 2026
2026-04-28 19:13:15 UTC (2 hours ago) · approx. 7:13 AM UTC-12 local
Aftershock of the M5.5 mainshock.
On April 28, 2026 at 19:13 UTC, a magnitude 4.5 intermediate depth earthquake struck 131 km WNW of Neiafu, Tonga, at a depth of 268.7 km and coordinates -18.3551°, -175.1875°. This earthquake was detected by 25 seismic stations with good location accuracy and was assigned a USGS significance rating of 312, placing it among routine seismic activity.
Physical scale: An earthquake of magnitude 4.5 releases seismic energy equivalent to roughly 85 metric tons of TNT. Empirical fault-scaling laws (Wells & Coppersmith, 1994) estimate the subsurface rupture length at approximately 767 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 5.5 mainshock that occurred 15 days ago 154 km W of Neiafu, Tonga. Since the mainshock, the USGS has recorded 3 aftershocks in this area. Aftershock activity is expected to continue for days to weeks as stresses on surrounding faults redistribute.
The epicenter is located in Tonga, a region characterized by the Tonga-Kermadec subduction zone, where the Pacific Plate descends at up to 240 mm per year — the fastest plate convergence on Earth. The nearest mapped fault system is the Tonga Trench. View all earthquakes in Tonga.
Learn more: Magnitude scale · Aftershock sequences
Earthquake Details
-175.1875°E
Technical Information
Nearby Earthquakes (Last 7 Days)
Common Questions
How strong was the magnitude 4.5 earthquake near Neiafu, Tonga?
The magnitude 4.5 earthquake that struck 131 km WNW of Neiafu, Tonga on April 28, 2026 at 19:13 UTC had a depth of 268.7 km. For context, this was a light earthquake commonly felt near the epicenter.
Where did the earthquake occur?
The earthquake epicenter was located at -18.3551°, -175.1875°, which is 131 km WNW of Neiafu, Tonga. View all earthquakes in Tonga.
Were there aftershocks?
Aftershock activity is monitored continuously by the USGS. Aftershock sequences from magnitude 4.5 earthquakes can continue for several days and gradually diminish over time.
Is this the same earthquake as the M5.5 one earlier?
No. This magnitude 4.5 earthquake is an aftershock of the larger magnitude 5.5 mainshock that occurred earlier 154 km W of Neiafu, Tonga. Aftershocks are smaller earthquakes triggered by stress changes from the mainshock.
Has Tonga had earthquakes this big before?
The largest recorded earthquake in Tonga was the M8.1 Tonga Trench earthquake of June 26, 1917. Today's magnitude 4.5 event is significantly smaller than that historical record.
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.
Authoritative source: USGS event page (event ID: us7000sgrr). All scientific values on this page are sourced verbatim from the USGS feed.
Cite this page: EarthquakeTracker.org. (2026, April 28, 2026). M4.5 Earthquake 131 km WNW of Neiafu, Tonga — April 28, 2026. Retrieved April 28, 2026 from https://www.earthquaketracker.org/earthquakes/event/us7000sgrr/