Underwater Volcano Eruption in South Pacific Puts Entire U.S. West Coast Under Tsunami Advisory

A tsunami advisory was issued very early Saturday morning by the NWS National Tsunami Warning Center for the US west coast including the states of California, Oregon, Washington and Alaska, after the submerged Hunga-Tonga-Hunga-Ha’apai volcano in the South Pacific exploded in a violent eruption on Saturday, sending a cloud of ash and gas steam into the air.

Although officials could not produce an accurate forecast due to the event being based on a volcanic eruption, rather than an earthquake, the estimated arrival time along the California coast was 7:00am to 7:30am, Pacific Time, Saturday morning.

Satellite imagery from a Japanese weather satellite shows a massive ash cloud and shockwaves spreading from the eruption near the south Pacific nation of Tonga Saturday, January 15, 2022.

Official alerts from the NWS National Tsunami Warning Center advised that a 1-2.5 ft. wave was expected in Port Orford at apporximately 7:55am, and Crescent City at 8:00am after tsunami waves of 2 feet were observed by gauges at Pago Pago, the capital of American Samoa.  

No damage and minor flooding has been reported resulting from tsunami waves on all of the Hawaiian Islands, as initial observations of waves from one-to-two feet high were heading toward the Pacific Coast stretching from Alaska to Mexico.  

The Hunga-Tonga-Hunga-Ha’apai volcano, located just under 20 miles southeast of Tonga’s Fonuafo’ou island, first erupted Friday, sending a plume of ash over 12 miles into the air before Saturday’s eruption that generated tsunami waves into Tonga’s capital on Saturday, flowing onto coastal roads and flooding properties.