Washington: Tsunami warnings were issued on Saturday for the entire US West Coast after a massive volcanic eruption across the Pacific Ocean in Tonga, with tsunami waves triggering low-level flooding in Hawaii.
The US National Weather Service issued tsunami advisories from California to Alaska, predicting waves of up to two feet (60 centimetres), strong rip currents and coastal flooding.
“Move off the beach and out of harbours and marinas in these areas,” it advised.
The Pacific Tsunami Warning Center said “a tsunami is currently being observed” in Hawaii, but said there was “no reported damage and only minor flooding throughout the islands.”
Earlier, an undersea volcano erupted in spectacular fashion near Tonga, sending large tsunami waves crashing across the shore and people rushing to higher ground.
New Zealand’s military said it was monitoring the situation and remained on standby, ready to assist if asked.
Satellite images showed a huge eruption, a plume of ash, steam and gas rising like a mushroom above the blue Pacific waters.
The Tonga Meteorological Services said a tsunami warning was declared for all of the archipelago, and data from the Pacific tsunami center showed waves of 80 centimeters (2.7 feet) had been detected.
In Hawaii, Alaska and along the US Pacific coast, residents were asked to move away from the coastline to higher ground and pay attention to specific instructions from their local emergency management officials, said Dave Snider, tsunami warning coordinator for the National Tsunami Warning Center 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,” he said. “I hope that elevates the importance and severity for our citizens.’’
He said the waves already slamming ashore in Hawaii were just under the criteria for a more serious tsunami warning, with measurements at 80 centimeters (2.7 feet) in Hanalei and Maui. Waves of about 91 centimeters (3 feet) or above would trigger a warning. Snider said they’re currently expecting waves of 30 centimeters (1 foot) to 61 centimeters (2 feet) along the Pacific coast.
Snider said residents in these areas should expect waves and strong and unusual currents for many hours and there could be some low areas that are inundated, such as marinas and harbors.
“The important thing here is the first wave may not be the largest. We could see this play out for several hours,’’ he added. “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.’’
Residents of American Samoa were alerted of the tsunami warning by local broadcasters as well as church bells that rang territory-wide. An outdoor siren warning system was out of service. Those living along the shoreline quickly moved to higher ground.