A tsunami watch was issued for the coast from Washington to California as well as Hawaii early Tuesday after a preliminary-magnitude 8.2 earthquake struck the Gulf of Alaska.

Image: A National Weather Service map

A National Weather Service map showing the red tsunami warning zone as well as the yellow tsunami watch zone, which runs south from Washington to California and also includes Hawaii. NWS

A tsunami warning was also in effect for the coast of Alaska and the Canadian province of British Columbia.

The quake struck at 4:31 a.m. ET about 330 miles south from the coast of Alaska at a depth of six miles, the USGS said.

“Based on the preliminary earthquake parameters … widespread hazardous tsunami waves are possible,” the NWS Tsunami Warning Center said. “No areas covered by this message appear to be immediately threatened. However… the situation is still under investigation,” it said.

The Anchorage Police Department said the city was not covered by the warning and was outside the danger zone. It urged residents not to call 911.