Tonga: Tsunami threat recedes after huge underwater volcano eruption in Pacific

15 January 2022, 07:05 | Updated: 16 January 2022, 06:07

The tsunami threat around the Pacific from a giant underwater volcano eruption has begun to recede, but the extent of damage to Tonga remains unclear.

Satellite images showed the spectacular eruption that took place on Saturday evening, with a huge plume of ash, steam and gas.

A sonic boom could be heard as far away as Alaska.

In Tonga, it triggered tsunami waves that crashed ashore and sent people rushing to higher ground.

In Hawaii, the Pacific Tsunami Warning Center reported half a metre (a foot) wave slamming ashore in some areas.

There have been no official reports of injuries or the extent of the damage in Tonga as communications with the small nation remain problematic.

The Tonga Meteorological Services said a tsunami warning had been put in force for all of Tonga on Saturday.

New Zealand Prime Minister Jacinda Ardern said: "Communication with Tonga remains very limited. And I know that is causing a huge amount of anxiety for the Tongan community here."

She said there had been significant damage to boats and shops along the Tongan coastline.

The capital, Nuku'alofa, was covered in a thick film of volcanic dust, Ms Ardern said, contaminating water supplies and making fresh water a vital need.

Aid agencies said thick ash and smoke had prompted authorities to ask people to wear masks and drink bottled water.

Ms Ardern said New Zealand was unable to send a military surveillance flight over Tonga on Sunday because the ash cloud was 63,000 feet (19,000 meters) high but they hoped to send the flight on Monday, followed by supply planes and navy ships.

Speaking to Sky News, Roger Musson, seismologist at the British geological survey, said of the eruption: "There was an eruption of the same volcano about a year or so ago, but this one is seven times larger, which is really rather big.

"Tonga lies in what's known as the Kermadec subduction zone. It's a very seismically active area. And where you have subduction - where one crustal plate dips below another one - you also get volcanoes.

"This submarine volcano has been active for a few years now, but this is far and away the largest eruption it's produced."

The tsunami advisory was also issued for British Columbia in Canada.

Authorities in nearby Fiji also issued a warning, telling people to avoid the shoreline due to strong currents and dangerous waves.

Tsunami waves of 2.7ft (83 cm) were observed by gauges at Nuku'alofa and waves of 2ft at Pago Pago, the capital of American Samoa, the Pacific Tsunami Warning Centre said.

Dr Faka'iloatonga Taumoefolau posted footage on Twitter showing water crashing on to the shore and flooding properties.

"Can literally hear the volcano eruption, sounds pretty violent," he wrote.

A convoy of police and military troops reportedly evacuated Tonga's King Tupou VI from his palace near the shore as residents headed for higher ground.

Scientists had observed massive explosions, thunder and lightning near the volcano after it started erupting early on Friday, the Matangi Tonga news site reported.

The site said satellite images showed a three-mile wide plume of ash, steam and gas rising up to 12-miles into the air.