Neiafu: A powerful preliminary magnitude 7.6 earthquake struck on Tuesday in the South Pacific Ocean near Tonga, triggering local coastal evacuations but no widespread tsunami alerts.

The United States Geological Survey (USGS) reported that the tremor occurred early Tuesday evening local time at a depth of approximately 237 kilometres (148 miles). While deep-seated earthquakes are typically felt less intensely at the surface than shallower ones, the magnitude of the jolt prompted immediate action from local authorities.

The epicentre was located at sea, roughly 153 kilometres (95 miles) west of Neiafu, the second-largest town in the island nation.

No Tsunami Threat Detected

While the USGS did not issue a regional tsunami warning, the Pacific Tsunami Warning Centre in Hawaii clarified in a bulletin that no threat existed because the quake was “located too deep inside the earth” to generate a dangerous wave.

Despite the lack of a formal tsunami threat, Tonga’s National Disaster Risk Management Office took no chances, instructing residents in the low-lying nation to "move immediately to higher ground or inland." In a statement on its official Facebook page, the office advised citizens to avoid beaches, shorelines, and coastal zones until an official all-clear was provided.

Reports from the Ground

There were no immediate reports of structural damage or casualties. At the Tanoa International Dateline Hotel, located on the beachfront in the capital of Nuku’alofa, a staff member confirmed the building remained intact.

“The whole building shaked. No further damage. Everything was ok,” she said. Tonga police did not immediately respond to requests for further comment.

In New Zealand, located approximately 1,800 kilometres (1,100 miles) to the southwest, disaster management officials confirmed Tuesday that the earthquake posed no tsunami risk to their shores.

Geological Vulnerability

Tonga is an archipelago of 171 islands with a population of just over 100,000, the majority of whom reside on the main island of Tongatapu. Tuesday’s seismic activity was centred closer to the Vava’u island group.

The nation sits upon the "Pacific Ring of Fire," a vast arc of seismic faults known for frequent volcanic and earthquake activity. The region remains particularly vigilant following a massive volcanic eruption in 2022 that generated a tsunami, claiming three lives and causing extensive damage.

With inputs from AP