Moderate M5.6 earthquake strikes northwest of Hihifo, Tonga on March 25, 2026

An earthquake measuring M5.6 was recorded at 10:10 UTC on March 25, 2026, about 80 km (50 miles) northwest of Hihifo, Tonga. The event struck at an intermediate depth of 198.3 km (123.2 miles), as reported by USGS.

The coordinates of the earthquake place the epicenter at 15.5°S, 174.4°W, in the vicinity of the northern islands of Tonga, lying northwest of Hihifo. The region is sparsely populated, with the closest settlements concentrated along the island chain of Tonga.

Given the remote, oceanic location near the Tonga Trench, notable infrastructure in the direct vicinity is limited. Critical infrastructure in Tonga, such as airports, ports, and energy facilities, is primarily located on the larger inhabited islands to the south and southeast.

There is no tsunami threat associated with this earthquake, based on its location and available data.

USGS issued a green alert for this event, indicating a low likelihood of casualties or damage. The maximum estimated intensity was III on the Modified Mercalli Intensity scale. The significance index is 482 (on a scale that runs through 1 000), based on magnitude, felt reports, and estimated impact.

Tonga is situated along the Tonga-Kermadec subduction zone, one of the most seismically active regions on Earth. Earthquakes in this area are caused by the subduction of the Pacific Plate beneath the Indo-Australian Plate, resulting in frequent seismic events at varying depths.

This information was last updated at 12:29 UTC on March 25, 2026.