Pacific Tsunami Threat Recedes, Volcano Ash Hinders Response

The tsunami threat around the Pacific from a huge undersea volcanic eruption receded Sunday, but the massive ash cloud covering the tiny island nation of Tonga prevented surveillance flights from New Zealand to assess the extent of damage.

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

In Tonga it 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.

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, 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.

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

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 U.S. and elsewhere to continue improving.

Tsunami advisories were earlier issued for Japan, Hawaii, Alaska and the U.S. Pacific coast. The U.S. 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.

The explosion of the Hunga Tonga Hunga Ha’apai volcano, about 64 kilometers (40 miles) 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.