“What we would expect from now is that we really just need to keep an eye on what is happening with this volcano,” Associate Professor Hannah Power told Today.
“Because eruptions like this don’t often happen as a one-off, they often come in clusters.
“So we would expect to see that we might get some future eruptions.”
And she said that future eruptions might be the same size as the one that prompted tsunami warnings yesterday from Australia to the US.
“So we need to keep a really careful eye on what is happening there in terms of what that volcano is doing,” she said.
The tsunami threat around the Pacific has receded, but the massive ash cloud covering the tiny island nation prevented surveillance flights from New Zealand to assess the extent of damage.
In Tonga, the eruption sent tsunami waves crashing across the shore and people rushing to higher ground.
The eruption cut the internet to Tonga, leaving friends and family members around the world anxiously trying to get in touch to figure out if there were any injuries. Even government websites and other official sources remained without updates on Sunday afternoon.
New Zealand Prime Minister Jacinda Ardern said there had not yet been any official reports of injuries or deaths in Tonga, but cautioned that authorities hadn’t yet made contact with some coastal areas and smaller islands.
“Communication with Tonga remains very limited. And I know that is causing a huge amount of anxiety for the Tongan community here,” Ms Ardern said.
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.
“It’s really bad. They told us to stay indoors and cover our doors and windows because it’s dangerous,” she said.
“I felt sorry for the people. Everyone just froze when the explosion happened. We rushed home.”
Outside the house, people were seen carrying umbrellas for protection.
Ms Ardern said New Zealand was unable to send a surveillance flight over Tonga on Sunday because the ash cloud was 19km high but they hoped to try again on Monday, followed by supply planes and navy ships.
Australia also has a flight scheduled for the area this morning to assess the extent of the damage.
One complicating factor to any international aid effort is that Tonga has so far managed to avoid any outbreaks of COVID-19. Ms Ardern said New Zealand’s military staff were all fully vaccinated and willing to follow any protocols established by Tonga.
Australia is also working to send crucial aid, Prime Minister Scott Morrison said this morning.
Mr Morrison told 2GB that the Australian Defence Force and officials from the Department of Foreign Affairs and Trade were assessing the situation.
“They will be examining what the best ways are we can help.”
He said Australians were thinking about the impact of the natural disaster on Tonga’s population after the eruption sent tsunami waves crashing across the shore forcing people to seek shelter to higher ground.
“Tonga is part of the Pacific family that Australian cherishes so much,” Mr Morrison said.
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. Mr Snider said he anticipated the tsunami situation in the US and elsewhere to continue improving.
Tsunami advisories were earlier issued for Australia, 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 are relatively rare.
Rachel Afeaki-Taumoepeau, who chairs the New Zealand Tonga Business Council, said she hoped the relatively low level of the tsunami waves would have allowed most people to get to safety, although she worried about those living on islands closest to the volcano. She said she hadn’t yet been able to contact her friends and family in Tonga.
“We are praying that the damage is just to infrastructure and people were able to get to higher land,” she said.
US Secretary of State Antony Blinken wrote on Twitter he is “deeply concerned for the people of Tonga as they recover from the aftermath of a volcanic eruption and tsunami. The United States stands prepared to provide support to our Pacific neighbors.”

Tonga gets its internet via an undersea cable from Suva, Fiji. All internet connectivity with Tonga was lost at about 6.40pm local time Saturday, said Doug Madory, director of internet analysis for the network intelligence firm Kentik.
“Can literally hear the volcano eruption, sounds pretty violent,” he wrote, adding in a later post: “Raining ash and tiny pebbles, darkness blanketing the sky.”
The explosion of the Hunga Tonga Hunga Ha’apai volcano, about 64km north of Nuku’alofa, was the latest in a series of dramatic eruptions. In late 2014 and early 2015, eruptions created a small new island and disrupted international air travel to the Pacific archipelago for several days.
Earth imaging company Planet Labs PBC had watched the island in recent days after a new volcanic vent began erupting in late December. Satellite images showed how drastically the volcano had shaped the area, creating a growing island off Tonga.
“The surface area of the island appears to have expanded by nearly 45 per cent due to ashfall,” Planet Labs said days before the latest activity.

Following Saturday’s eruption, residents in Hawaii, Alaska and along the US Pacific coast were advised to move away from the coastline to higher ground.
Savannah Peterson watched in shock as the water rose several feet in a matter of minutes in front of her oceanfront house in Pacifica, California, just south of San Francisco.
“It came up so fast, and a few minutes after that it was down again. It was nuts to see that happen so quickly,” she said. “I’ve never had water come all the way up to my front door, and today it did.”
In northern Peru’s Lambayeque region, two women drowned after being swept away by ″abnormal waves″ following the eruption, authorities said. A dozen restaurants and a coastal street were also flooded along El Chaco beach in Paracas district.