The tsunami threat around the Pacific from a huge undersea volcanic eruption has begun to recede, but the massive ash cloud covering the tiny island nation of Tonga prevented surveillance flights assessing the extent of damage from waves that are believed to have inundated entire towns.
Videos shared on social media after the eruption showed people running for higher ground as the metre-high floods hit coastal areas and made their way inland while the sky darkened with ash. A sonic boom could be heard as far away as Alaska.
There were no official reports of injuries or deaths by Sunday evening, with communications limited.
Jacinda Ardern, the prime minister of New Zealand, told a news conference on Sunday that contact had not been established with coastal areas beyond the capital, Nuku’alofa.
“Nuku’alofa is covered in thick plumes of volcanic dust but otherwise conditions are calm and stable,” Ardern said. “We have not yet received news from other coastal areas.”
She said the main undersea communications cable was affected, probably due to loss of power. She added that power was being restored in some areas on the islands and local mobile phones were slowly starting to work. The New Zealand high commission in Nuku’alofa said the tsunami has damaged boats, shops and other infrastructure.
Tonga’s cabinet held a crisis meeting on Sunday and was reaching out for assistance, said the office of Zed Seselja, Australia’s minister for the Pacific. Australia said it would send a P8 surveillance aircraft to Tonga on Monday.
Dave Snider, the tsunami warning coordinator for the National Tsunami Warning Center in Palmer, Alaska, said it was very unusual for a volcanic eruption to affect an entire ocean basin, and the spectacle was both “humbling and scary”.
The tsunami waves caused damage to boats as far away as New Zealand and Santa Cruz, California, but did not appear to cause any widespread damage. Snider said he anticipated the tsunami situation in the US and elsewhere to continue improving.
Tsunami advisories were issued earlier for Japan, Hawaii, Alaska and the US Pacific coast. The US Geological Survey estimated the eruption caused the equivalent of a magnitude 5.8 earthquake. Scientists said tsunamis generated by volcanoes rather than earthquakes were relatively rare.
As the tsunami struck on Saturday, a video shot from the roof of a building on the coast showed large waves breaching the coastal wall seconds apart, while a video shot from the New Zealand high commission in Nuku’alofa, where people ran for shelter, showed the downtown area of Patangata had been completely submerged, including the Royal Palace and Tonga’s largest bank.
Another video, shot inside a church, showed children crying out as water surrounded the building and waves began lapping against the windows. In a video posted to YouTube after the eruption, Abraham Leilua begins by telling his followers that “it’s not that bad” but within minutes, as the water rises, he says “I have to run for my life” before ending the video.
Blake Smith-Tatafi, a Tongan based in Australia, said they were praying and in fear. “If you don’t know, the island of Tonga is flat. This leaves their people with nowhere of realistic safety to evacuate. Villages completely underwater. We haven’t had contact for hours now. This is a crisis,” he said.
Pita Taufatofua, a Tongan Olympian based in Australia, said he had not heard from his father or family in Ha’apai, the lowest lying islands in Tonga.
“Initial reports of damage have been catastrophic and all communications with Tonga have been wiped out,” he said. “Whilst I can’t assist family at this moment I will focus on country as more information comes out.”
Southern Cross Cable Network said on Sunday that it had been able to confirm contact with a communications centre in Tonga and work was under way to have internet and phone links restored.
A tweet on Sunday morning stated that the Tongan prime minister, Siaosi Sovaleni, said the tsunami warning remained in place and much of the country had sustained serious damage. Australia’s foreign affairs department said its high commission had received no reports of casualties.
Ardern said the situation in Tonga was “hugely concerning”.
“Communication, as a result of the eruption, has been difficult, but our defence force team and ministry of foreign affairs are working as we speak to establish what’s needed and how we can help,” she said.
New Zealand has made an initial NZ$500,000 (£249,000) available to Tonga and has dispatched an aerial surveillance aircraft to assess the damage.
Ardern said she had been in touch with Scott Morrison, the Australian prime minister, and that both governments stood ready to respond to Tonga’s needs. But conditions were not immediately safe for aircraft.
“There’s an urgency here. We want to make sure we’re on the ground as soon as possible, but for our navy vessels it will take several days to reach Tonga, and we need to finely balance the need to get there quickly but to make sure we also get the people and resources they need there as well, and in some cases we have parts of Tonga where we just haven’t been able to establish communication.”
The US secretary of state, Anthony Blinken, said he was “deeply concerned” for the people of Tonga and that the US stood prepared to provide support.
Shairani Ali, the chief executive of Save the Children Fiji, said the charity was closely monitoring the situation and prepared to respond.
“Our thoughts have been for the safety of our Tongan brothers and sisters, and Save the Children is well placed to assist as needed,” she said, adding that the “booms from the eruption of the Tonga volcano could be clearly heard in Fiji”.
The volcano, Hunga Tonga-Hunga Ha’apai, at 1,800 metres high and 20km wide, is 65km north of Nuku’alofa. US Storm Watch said the eruption was one of the most violent ever captured on satellite, while the Tonga geological service said the gas, smoke and ash from the eruption reached 20km into the sky.
The eruption could be heard 2,300km away in New Zealand, while tsunami warnings were in force at various times across the Pacific, including in Australia, Japan and the US. Some coastal communities in Fiji and Vanuatu were damaged by large waves, while tidal surges were reported to have damaged harbours and coastal parks along the US west coast.
Satellite imagery appeared to show Tonga’s uninhabited Nuku and Tau islands completely eroded. Tonga has also been hit by two category five cyclones in the last five years: Cyclone Harold in April 2020 and Cyclone Gita in 2018.
In Japan, about 230,000 people were advised to evacuate across eight prefectures as waves of more than a metre hit coastal areas, the public broadcaster NHK reported. The alert included areas hit by the deadly 2011 tsunami.