Tonga: tsunami floods streets and cuts communication after undersea volcano erupts

An undersea volcano erupted in spectacular fashion on Saturday near the Pacific nation of Tonga, sending tsunami waves crashing across the shore and people rushing to higher ground. Tsunami advisories were issued for other Pacific islands, the Australian east coast, Hawaii, Alaska and the US Pacific coast.

There were no immediate reports of injuries or on the extent of the damage because all internet connectivity with Tonga was lost at about 6.40pm local time.

The Fiji-based Islands Business news site reported that a convoy of police and military troops evacuated King Tupou VI from his palace near the shore. He was among the many residents who headed for higher ground.

On Tonga, home to about 105,000 people, video posted to social media showed large waves washing ashore in coastal areas, swirling around homes, a church and other buildings. Satellite images showed a huge eruption, with a plume of ash, steam and gas rising like a mushroom above the blue Pacific waters.

Authorities in the nearby island nations of Fiji and Samoa also issued warnings, telling people to avoid the shoreline due to strong currents and dangerous waves. In New Zealand, officials warned of possible storm surges from the eruption.

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 started erupting early on Friday. Satellite images showed a 5km-wide plume rising into the air to about 20km.

The Hunga Tonga Hunga Ha’apai volcano is about 64km north of the capital, Nuku’alofa. In late 2014 and early 2015, a series of eruptions in the area created a small new island and disrupted international air travel to the Pacific archipelago for several days.

The Tonga Meteorological Services said a tsunami warning was declared for all of the archipelago, and data from the Pacific tsunami centre said waves of 80cm (2.7ft) were detected.

A Twitter user identified as Dr Faka’iloatonga Taumoefolau posted video showing waves crashing ashore.

“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 was the latest in a series of dramatic eruptions.

Earth imaging company Planet Labs PBC had watched the island in recent days after a new volcanic vent there began erupting in late December.

Satellite images captured by the company show 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% 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 and to pay attention to specific instructions from their local emergency management officials, said Dave Snider, tsunami warning coordinator for the National Tsunami Warning Centre in Palmer, Alaska.

“We don’t issue an advisory for this length of coastline as we’ve done – I’m not sure when the last time was – but it really isn’t an everyday experience,” Snider said.

He said the waves slamming ashore in Hawaii were just under the criteria for a more serious tsunami warning.

“It looks like everything will stay below the warning level, but it’s difficult to predict because this is a volcanic eruption, and we’re set up to measure earthquake or seismic-driven sea waves,” Snider said.

Australia’s Bureau of Meteorology issued an evacuation order for Lord Howe Island, 780km north-east of Sydney, and warnings for a huge stretch of the mainland’s east coast. Sydney’s Bondi beach was evacuated overnight, and a marine threat warning remained in place on Sunday morning Australian time.

The Bureau of Meteorology said a tsunami wave height of 1.27m was observed on Norfolk Island, 900 kilometres from Lord Howe Island, at 9pm AEDT and an 82cm wave was registered on Queensland’s Gold Coast at 10.54pm AEDT on Saturday.

It said 1.10m-high waves were recorded at Ned’s Beach on Lord Howe Island about 11pm AEDT and a 50cm surge was observed at Hobart’s Derwent Park about 11.44pm AEDT.

On Sunday morning, however, the bureau cancelled its tsunami alert for Queensland, which takes in the northern part of the country’s east coast. In New South Wales to the south, the state emergency service just urged residents to stay out of the water. It said “an initial land tsunami warning for low-lying coastal areas of Lord Howe Island has since been downgraded to a marine tsunami warning” on Sunday.

Smaller waves were recorded in Hawaii, Alaska and California.

Beaches and piers were closed across southern California as a precaution. The National Weather Service tweeted there were “no significant concerns about inundation”. Strong rip currents were possible, however, and officials warned people to stay out of the water.