Undersea Volcano Eruption Triggers Massive Shockwave, Tsunami Strikes S Pacific Island

Tsunami advisory in effect for US as waves hit Tonga following volcanic eruption

Alex Stambaugh, Laura Smith-Spark, Rhea Mogul

A tsunami has hit Tonga's largest island, Tongatapu, and reportedly sent waves flooding into the capital after an underwater volcano in the South Pacific exploded in a violent eruption on Saturday, sending a cloud of ash and gas steam into the air.

A tsunami warning has been issued for the islands of Tonga. Tsunami advisories have also been issued for New Zealand's North Island and the west coast of the United States from California to Alaska, as well as Canada's British Columbia.

Satellite imagery shows a massive ash cloud and shockwaves spreading from the eruption.

Waves crossed the shoreline of Tonga's capital, Nuku'alofa, on Saturday, flowing onto coastal roads and flooding properties, according to CNN affiliate Radio New Zealand (RNZ).

Tonga's King Tupou VI was evacuated from the Royal Palace after the tsunami flooded the capital, RNZ reported, citing local media reports that a convoy of police and troops rushed the monarch to a villa at Mata Ki Eua.

Residents headed for higher ground, RNZ said, as waves swept the palace grounds, waterfront and main street.

Ash was falling from the sky in Nuku'alofa on Saturday evening and phone connections were down, RNZ said.

The Hunga-Tonga-Hunga-Ha'apai volcano first erupted Friday, sending a plume of ash 20 kilometers (12.4 miles) into the air, according to RNZ.

A second eruption hit on Saturday at 5:26 p.m. local time, RNZ reported.

The Pacific Tsunami Warning Center said tsunami waves of 2.7 feet (83 cm) were observed by gauges at Nuku'alofa and waves of 2 feet at Pago Pago, the capital of American Samoa, Reuters reported.

Jese Tuisinu, a television reporter at Fiji One, posted a video on Twitter showing large waves washing ashore, with people trying to escape the incoming water in their vehicles. "It is literally dark in parts of Tonga and people are rushing to safety following the eruption," he said in another tweet.

The nearby island of Fiji has also issued a public advisory asking people living in low lying coastal areas to "move to safety in anticipation of the strong currents and dangerous waves."

A tsunami advisory is now in effect for the US west coast including the states of California, Oregon, Washington and Alaska, according to the NWS National Tsunami Warning Center in Palmer, Alaska. 

Dave Snider, Tsunami Warning Coordinator at the National Tsunami Warning Center in Palmer, Alaska, told CNN, "We have seen the wave moving through Hawaiian Island."

Undersea Volcano Eruption Triggers Massive Shockwave, Tsunami Strikes South Pacific Island

TYLER DURDEN

An undersea volcanic eruption occurred 40 miles off the coast of the South Pacific country of Tonga on Saturday. 

Satellite imagery shows the eruption unleashed a massive shockwave as a plume of ash was flung 12.4 miles into the atmosphere. 

Tonga's Hunga Tonga volcano just had one of the most violent volcano eruptions ever captured on satellite.

Some have compared the eruption to the "Hiroshima" nuclear bomb explosion. 

Shortly after the eruption, a tsunami warning was posted for Tonga. An advisory was issued for New Zealand's North Island. CNN affiliate Radio New Zealand (RNZ) said a tsunami hit Tonga's capital, Nuku'alofa, flooding coastal roads and properties.

RNZ said Tonga's King Tupou VI was evacuated from the Royal Palace, and residents were told to flee to higher ground. 

One Tongan resident told Yahoo News the eruption was "catastrophic," and ash and rock rained down on the capital. 

Twitter user Dr. Faka'iloatonga Taumoefolau posted a video showing waves coming ashore. 

"Can literally hear the volcano eruption, sounds pretty violent," he wrote. In another post, he said: "Raining ash and tiny pebbles, darkness blanketing the sky."

Prof Shane Cronin, a volcanologist at the University of Auckland, told BCC this eruption is the biggest Tonga has seen in three decades. 

"This is a pretty big event - it's one of the more significant eruptions of the last decade at least. 

"The most remarkable thing about it is how rapidly and violently it's spread. This one was larger, a much wider lateral spread, much more ash was produced. I expect there to be many centimetres of ash that have been deposited on Tonga,' Cronin said.

*This story is developing... 

A volcano erupts in the Pacific, triggering a tsunami advisory for the West Coast