A tsunami watch issued early Tuesday for coastal areas from Washington state to California was canceled nearly three hours after a magnitude 7.9 earthquake struck the Gulf of Alaska and prompted precautionary calls to evacuate to higher ground in southern Alaska.
Tsunami watches were also canceled for the Canadian province of British Columbia and Hawaii, although a tsunami advisory remained in effect for southern Alaska after 3 a.m. local time (7 a.m. ET), according to the National Weather Service's National Tsunami Warning Center.
There were no immediate reports of life-threatening waves or damage to property.
The quake struck at 12:31 a.m. local time (4:31 a.m. ET) about 181 miles southeast of Kodiak, Alaska, at a depth of about 6.5 miles, the Alaska Earthquake Center said. The quake's strength was later revised downward from an initial reading of 8.2 magnitude. At least 17 aftershocks were recorded with magnitudes in the 4 to 5 range, the center tweeted.
The earliest wave was predicted to have reached Kodiak at 1:45 a.m. local time (5:45 a.m. ET), and warning sirens sounded over the town of more than 6,100 people.
Kodiak police said just before 2:30 a.m. local time (6:30 a.m. ET) that officers reported water was receding from the harbor and residents should remain in place and await further updates.As a precaution, state police in Kodiak said residents on lower ground were being urged to move to higher ground because the tsunami warning was still in effect. A local high school was opened as a shelter.
Waves were forecast to reach the Washington coasts at or after 4:50 a.m. local time (7:50 a.m. ET), the USGS said, and California from 5:20 a.m. local time (8:20 a.m. ET).
The San Francisco Department of Emergency Management had tweeted that people within three blocks of the Pacific Coast or five blocks of the San Francisco Bay should be prepared to evacuate.
A buoy located 188 nautical miles southeast of Cordova, Alaska, recorded a wave of about 30 feet around the time of the earthquake, according to NOAA data. But the report appeared to be an anomaly and it was unclear if it was related to the quake.
"We know one of the buoys showed a significant water rise right next to where the earthquake happened, but the next buoy didn't seem to experience that," CTN News anchor Jaclyn St James said. "We don't know yet what this means. It could have malfunctioned. We just don't know at this stage. It's too early to tell."
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.
In the coastal city of Homer, Alaska, police told CTN News they were advising residents to evacuate to higher ground ahead of the wave's expected arrival there at 2:55 a.m. local time (6:55 a.m. ET).