Tsunami threat recedes after underwater volcanic eruption in the Pacific

WELLINGTON, New Zealand – The threat of a tsunami around the Pacific from a massive undersea volcanic eruption began to recede on Sunday, while the extent of damage in Tonga remained unclear.

Satellite images showed the spectacular eruption that took place on Saturday evening, with a plume of ash, steam and gas rising like a mushroom above the blue waters of the Pacific. A sonic boom could be heard as far away as Alaska.

In Tonga, it sent tsunami waves crashing on the shore and people rushing for higher ground.

The eruption knocked out the internet in Tonga, leaving friends and family from around the world anxiously trying to get in touch to determine if there were any injuries and the extent of the damage. Even government websites and other official sources remained without updates as of Sunday afternoon.

New Zealand Prime Minister Jacinda Ardern said there had been no official reports of injuries or deaths in Tonga yet, but warned authorities had yet to make contact with some coastal and small areas. he is.

“Communication with Tonga remains very limited. And I know that causes tremendous anxiety for the Tongan community here,” Ardern said.

She said there had been extensive damage to boats and stores along the Tonga coast. The capital, Nuku’alofa, was covered in a thick layer of volcanic dust, Ardern said, contaminating water supplies and making fresh water a vital need.

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

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

A complicating factor for any international aid effort is that Tonga has so far managed to avoid any outbreak of Covid-19. Ardern said New Zealand military personnel are fully vaccinated and willing to follow all protocols established by Tonga.

Dave Snider, tsunami warning coordinator for the National Tsunami Warning Center in Palmer, Alaska, said it was highly unusual for a volcanic eruption to affect an entire ocean basin, and the spectacle was at both “humiliating and frightening”.

Tsunami waves damaged boats as far away as New Zealand and Santa Cruz, California, but did not appear to have caused widespread damage. Snider said he expects the tsunami situation in the United States and elsewhere to continue to improve.

Tsunami advisories have already been issued for Japan, Hawaii, Alaska and the Pacific coast of the United States. The US Geological Survey estimated that the eruption caused the equivalent of a magnitude 5.8 earthquake. Scientists said tsunamis generated by volcanoes rather than earthquakes are relatively rare.

The Tonga Meteorological Service said a tsunami warning had been declared for the entire archipelago, and data from the Pacific Tsunami Center said waves of 2.7ft had been detected.

Rachel Afeaki-Taumoepeau, who chairs the New Zealand Tonga Business Council, said she hoped the relatively low level of the tsunami waves would have brought most people to safety, although she was worried about those who live on the islands closest to the volcano. She said she had not yet been able to contact her friends and family in Tonga.

“We pray that the damage is only to infrastructure and that people can access higher ground,” she said.

US Secretary of State Antony Blinken wrote on Twitter that he was “deeply concerned for the people of Tonga as they recover from the aftermath of a volcanic eruption and tsunami”. The United States stands ready to support our Pacific neighbors.

Tonga gets its internet via an undersea cable from Suva, Fiji. All internet connectivity with Tonga was lost around 6:40 p.m. local time, said Doug Madory, director of internet analytics for network intelligence firm Kentik.

In Tonga, home to around 105,000 people, video posted on social media showed large waves washing up in coastal areas and swirling around houses, a church and other buildings. Twitter user identified as Dr Faka’iloatonga Taumoefolau video released showing waves crashing on shore.

“Can literally hear the eruption of the volcano, the sounds are quite violent,” he wrote, adding in a later post, “It’s raining ash and tiny pebbles, darkness covers the sky.”

The explosion of the Hunga Tonga Hunga Ha’apai volcano was the latest in a series of dramatic eruptions.

Terrestrial imaging firm Planet Labs PBC had observed the island in recent days after a new volcanic vent began erupting in late December.

Satellite images captured by the company show how the volcano has shaped the region, creating a growing island off the coast of Tonga.

“The area of ​​the island appears to have increased by nearly 45% due to ashfall,” Planet Labs said days before the latest activity.

After Saturday’s eruption, residents of Hawaii, Alaska and along the U.S. Pacific Coast were urged to move away from the coast to higher ground and heed the instructions of their officials. local emergency management, Snider said.

“We don’t issue reviews for this stretch of coastline like we did – I don’t know when the last time was – but it’s definitely not an everyday experience,” Snider said.

Savannah Peterson watched in shock as the water rose several feet in minutes outside her beachfront home in Pacifica, California, just south of San Francisco.

“It went up so fast, and a few minutes later it was down. It was crazy to see it happen so quickly,” she said. “I never had water until at my front door, and today it happened.”

Police have rescued a surfer whose surfboard broke in powerful waves off San Francisco.

Further south in Santa Cruz, California, authorities were taking stock of the damage after a wave damaged boats and flooded low streets and parking lots, sending cars afloat.

In southern California, rising waters sank at least one boat in the Port of Ventura, northwest of Los Angeles.

New Zealand’s private forecaster, Weather Watch, tweeted that people as far away as Southland, the country’s southernmost region, reported hearing sonic booms from the eruption. Others reported that many boats were damaged by a tsunami that hit a marina in Whangarei in the Northland region.

Earlier, the Matangi Tonga news site reported that scientists observed massive explosions, thunder and lightning near the volcano after it erupted early Friday. Satellite images showed a 3 mile wide plume rising into the air about 12 miles away.

The Hunga Tonga Hunga Ha’apai volcano is located approximately 40 miles north of Nuku’alofa. In late 2014 and early 2015, a series of eruptions in the area created a new small island and disrupted international air travel to the Pacific archipelago for several days.

There is no significant difference between submarine and terrestrial volcanoes, and submarine volcanoes grow larger as they erupt, usually reaching the surface, said Hans Schwaiger, research geophysicist at the Volcano Observatory. from Alaska.

With submarine volcanoes, however, water can add to the explosiveness of the eruption as it hits lava, Schwaiger added.

Before an explosion, there is usually an increase in small local earthquakes on the volcano, but depending on its distance from land, this may not be felt by residents along the shoreline, Schwaiger said.

In 2019, Tonga lost internet access for almost two weeks when a fiber optic cable was severed. The manager of the local cable company said at the time that a large ship may have cut the cable while dragging an anchor. Until limited satellite access was restored, people couldn’t even make international calls.

Veverka, of Southern Cross Cable Network, said limited satellite connections existed between Tonga and other parts of the world, but he was unsure whether they could be affected by power outages.