Volcanic Eruption Cause Tsunami In Tonga


January 15, 2022


A massive volcanic eruption in Tonga that triggered tsunami waves around the Pacific caused “significant damage” to the island nation’s capital and smothered it in dust, but the full extent was not apparent with communications still cut off yesterday.

The eruption on Saturday was so powerful that it was recorded around the world, triggering a tsunami that flooded Pacific coastlines from Japan to the US.

A 1.2m wave swept ashore in the Tongan capital, with residents reporting that they fled to higher ground, leaving behind flooded houses, some with structural damage, as small stones and ash fell from the sky.

“It was massive. The ground shook, our house was shaking,” resident Mere Taufa said. “It came in waves. My younger brother thought bombs were exploding nearby.”

She said that water filled their home minutes later, and she watched the wall of a neighboring house collapse.

“We just knew straight away it was a tsunami. Just water gushing into our home,” Taufa said. “You could just hear screams everywhere, people screaming for safety.”

Tonga’s King Tupou VI was reported to have been evacuated from the Royal Palace in Nuku’alofa and taken by police convoy to a villa far from the coast.

Dramatic satellite images showed the long, rumbling eruption of the Hunga Tonga-Hunga Ha’apai volcano spew smoke and ash in the air, with a thunderous roar heard 10,000km away in Alaska.

The eruption triggered tsunamis across the Pacific with waves of 1.74m measured in Chanaral, Chile, more than 10,000km away, and smaller waves seen along the Pacific coast from Alaska to Mexico.

In California, the city of Santa Cruz was hit by flooding due to a tidal surge generated by the tsunami, videos showed.

Peru closed 22 ports as a precaution, while waves of about 1.2m hit Japan’s Pacific coast.

Taiwan’s Central Weather Bureau forecast center director Cheng Ming-dean (鄭明典) said yesterday that waves observed off Wushih (烏石) in Yilan County were 0.36m higher than usual on Saturday.

The US Geological Survey recorded Saturday’s eruption as equivalent to a magnitude 5.8 earthquake at zero depth.

The eruption lasted at least eight minutes and sent plumes of gas, ash and smoke several kilometers into the air. New Zealand scientist Marco Brenna, a senior lecturer at Otago University’s School of Geology, described the impact of the eruption as “relatively mild,” but said another eruption with a much bigger impact could not be ruled out.

The eruption was so powerful it was even heard in Alaska, the UAF Geophysical Institute said.

“A part of the pressure signal in Alaska was in the audible range. The very large signal is not that surprising considering the scale of the eruption, but the audible aspect is fairly unique,” the institute said on Twitter, citing Alaska Volcano Observatory scientist David Fee.

“He recalls only a couple other volcanic eruptions doing something like this: Krakatau and Novarupta,” it said, referring to the 19th-century eruption of Indonesia’s Krakatau, and Alaska’s Novarupta, the most powerful volcanic eruption of the 20th century.

The Fife weather station in Scotland said on Twitter that it was “just incredible to think of the power that can send a shockwave around the world” after the eruptions produced a jump in its air pressure graph.

Hunga Tonga-Hunga Ha’apai, which lies about 65km north of Nuku’alofa, has a history of volatility.