NUKU’ALOFA, Tonga – A strong 7.1 magnitude earthquake struck the Pacific island nation of Tonga in the early hours of Monday morning local time (1:18 a.m., March 31), jolting residents awake and triggering a tsunami warning that had people racing to higher ground. Though no injuries were reported, fear of rising waves left the island nation on edge for hours.
The quake hit at 12:18 UTC (1:18 a.m. in Tonga), just 10 kilometers deep, making it a shallow and powerful shake, according to the U.S. Geological Survey (USGS). It struck about 90 kilometers southwest of Pangai, a town of 1,738 people, and 169 kilometers west-northwest of the capital, Nuku’alofa, which is home to over 22,000 residents. More than 1,000 people felt strong shaking, with 38,000 experiencing moderate tremors, and 65,000 noting it lightly, per data from The Watchers. In Nuku’alofa, houses swayed and dishes crashed to the ground. Some residents ran into the streets as the earth moved beneath them. “It was loud and quick,” a Pangai shopkeeper told local radio, still picking up broken jars from the floor. “We felt it good here—everyone’s talking about the sea now.”
Just 11 minutes later at 12:29 UTC, the Pacific Tsunami Warning Center (PTWC) issued a tsunami alert, warning that waves between 0.3 to 1 meter high could hit coastlines within 300 kilometers of the epicenter. This included Tonga and Niue. Tonga’s disaster response team activated tsunami sirens and quickly posted warnings on Facebook: “Get inland or up high now.” Families in Nuku’alofa packed into cars, fleeing coastal zones and seeking safety on higher ground—many recalling the devastation from the 2022 Hunga Tonga-Hunga Haʻapai volcanic eruption, which sent 50-foot waves crashing ashore.
By 13:22 UTC, just over an hour after the quake, the PTWC announced the tsunami threat had passed. “No big waves came,” they reported. The Joint Australian Tsunami Warning Centre confirmed there was no risk to mainland Australia, and the USGS issued a green alert, meaning the quake caused strong shaking but had a low chance of casualties or major economic damage. No structural damage or injuries have been reported so far, though officials continue to assess remote areas.
Tonga sits on the Tonga-Kermadec volcanic arc, where the Pacific Plate subducts beneath another tectonic plate, a zone known for producing earthquakes and volcanic eruptions. “This one’s big but not rare here,” a USGS expert said Sunday. This quake is not related to the 7.7 magnitude earthquake in Myanmar two days earlier—they occurred on different faults, thousands of kilometers apart. Aftershocks are still possible, and residents are being urged to stay alert.