Tsunami reported in Tonga after underwater volcanic eruption

A 1.2-meter high tsunami wave is said to have hit Tonga’s capital, Nuku’alofa, on Saturday, prompting people to rush to higher elevations. Witnesses said ash had fallen from the sky after an underwater volcano had previously erupted near the remote Pacific country.

The volcano, Hunga Tonga-Hunga Ha’apai, is located about 40 miles north of Tongatapu, the archipelago’s main island in the Pacific Ocean.

The Bureau of Meteorology in Australia reported the tsunami on Twitter. But according to The Associated Press, communications with Tonga had been disrupted, so there were no immediate official reports of injuries or the extent of damage.

The Tonga Meteorological Service issued a tsunami warning for the archipelago on Saturday evening. On their Facebook pages, the meteorological services for nearby Fiji and Samoa also issued tsunami warnings, advising people to stay away from low-lying coastal areas.

The United States National Tsunami Warning Center issued a tsunami advisory for the West Coast, including the Washington and Oregon coasts, on Saturday morning Pacific Time. with the National Weather Service in Portland already reporting waves from one to three feet on Twitter in Newport, Oregon, Long Beach, Wash. and Seaside, Oregon. “The first wave may not be the highest, so later waves are bigger,” the tweet said.

The volcano had been relatively inactive for several years, but began to erupt intermittently in December. By Jan. 3, activity had declined significantly, according to a report by the Smithsonian Institution’s Global Volcanism Program.

In 2014, the volcano erupted, creating a new island that eventually became home to thriving vegetation and barn owls, according to the BBC.

Satellite images of Saturday’s eruption, shared on Twitter by New Zealand’s National Institute of Water and Atmospheric Research, showed a “brief spike in air pressure as the atmospheric shock wave pulsed over New Zealand.”

Other recent infrared satellite images suggested the underwater volcano was still erupting, and despite Tonga’s geographic isolation, a booming sound was heard after the initial eruption as far as New Zealand (that’s 1,100 miles northeast of Tongatapu) according to Weather Watch. , a private weather forecaster in the country.

Saturday’s eruption sent a plume of gases and ash about 12 miles (20 kilometers) into the atmosphere, according to early reports.

New Zealand’s National Emergency Management Agency issued a tsunami warning in a statement on Saturday, advising people in coastal areas to expect “strong and unusual currents and unpredictable coastal waves.”

In a thread on Twitter, Dr. Janine Krippner, a volcanologist at the Smithsonian Institution, which “most of the volcano is submarine.”

The strength and potential impact of an eruption is estimated using a volcanic explosivity index, or VEI, which takes into account the volume of material ejected during the eruption and how high the plume reaches. The VEI of Saturday’s eruption has not yet been estimated, but before the eruption, the volcano is estimated to produce an eruption with a maximum VEI of 2.

Eruptions with a VEI of 6 or higher send so much gas and particles into the atmosphere so high that they can have a cooling effect on the climate for several years by bouncing more sunlight off the Earth’s surface. But eruptions of that magnitude are very rare. The last was Mount Pinatubo in the Philippines in 1991.

Henry Fountain reporting contributed.