The National Tsunami Warning Center issued a tsunami advisory for the entire West Coast and Alaska in the wake of an undersea volcanic eruption near Tonga.
The volcano has been erupting for the last month, but this was its most explosive event, according to Lucy Jones, a seismologist who’s been observing the events in the Pacific.
“This is the largest tsunami from a volcano that I have been aware of,” Jones told ABC News.
The advisory means that a tsunami could produce strong currents or waves near the coastline, but a tsunami advisory doesn’t indicate a major tsunami event where water is actively entering coastal communities. In this circumstance, the tsunami is only dangerous to those in the water or on the immediate beach — likely swimmers or boaters.
British Columbia also is under advisory. Japan’s Meteorological Agency issued a tsunami warning for the southern Amami Island and Tokara island chain in Kagoshima Prefecture and a tsunami advisory for all coastal areas facing the Pacific Ocean. Tsunami waves of 1.2 meters (about 4 feet) were reported near those islands around 11:30 a.m. ET.
It took hours for the first waves to reach the U.S., where coastal sea levels during high tide rose 1 to 3 feet, Jones said.
“It’s probably dangerous to be out in a boat, but it’s not a significant impact to us,” she said.
Jones cautioned there could be strong currents for the next 24 to 48 hours due to sloshing waves but said she believed the worst threat has passed unless there is another eruption.
ABC News’ Daniel Manzo, Jenna Harrison and Zohreen Shah contributed to this report.
Editor’s note: This story’s headline has been updated to report that a tsunami advisory, not a warning, was issued.