7.5 Magnitude Earthquake Hits Tonga: Tsunami Alert Lifted | Surfer.com

A magnitude 7.5 earthquake struck off the coast of Tonga early Tuesday morning, triggering initial tsunami warnings that were later lifted. The quake, initially reported as magnitude 7.6 by some sources, occurred at a depth of approximately 237 kilometers (148 miles), according to the United States Geological Survey (USGS).

The tremor struck at 12:37 a.m. Eastern Time, roughly 103 miles west of Neiafu, Tonga, the USGS reported. Whereas the earthquake prompted a tsunami alert and activated sirens in Nuku’alofa, Tonga’s capital, the Pacific Tsunami Warning Center determined no widespread tsunami threat existed due to the quake’s depth.

Tonga’s National Emergency Operation Centre initially issued an urgent tsunami alert, advising residents to move to higher ground and avoid coastal areas. Although the sirens have since been silenced, authorities continue to urge caution and monitoring of official announcements.

The USGS stated the earthquake resulted from “normal faulting at intermediate depth,” consistent with activity within the subducting Pacific Plate. Focal mechanism solutions suggest the rupture occurred along either a shallowly dipping fault striking southwest or a steeply dipping fault striking northeast. The location of the quake places it within the Pacific Ring of Fire, a region responsible for approximately 75 percent of the world’s earthquakes.

This event follows a significant seismic year, including an 8.7-magnitude earthquake off Russia’s Kamchatka Peninsula in 2025. That quake generated waves as high as 16 feet in Russia, smaller waves in Japan, and a 7-foot wave at Midway Atoll, demonstrating the potential for widespread impact within the Ring of Fire.

As of Tuesday afternoon, there were no immediate reports of damage in Tonga. A staff member at the Tanoa International Dateline Hotel in Nuku’alofa reported feeling the shaking but no subsequent damage to the building.

The USGS continues to monitor the region for aftershocks. The agency notes that aftershocks are common following a large earthquake and can occur for days, weeks, or even years, potentially affecting already vulnerable areas.