UPDATE, 6:30 a.m.
The National Tsunami Center has canceled a tsunami warning that was triggered by a powerful earthquake off the coast of Alaska.
Mickey Varnadao, a computer specialist with the warning center in Palmer, Alaska, said early Tuesday that an advisory remains in effect for parts of Alaska, from Kodiak Island to Prince William Sound.
Watches have been canceled for British Columbia in Canada, Washington, Oregon, California and Hawaii. Officials in Japan say there is no tsunami threat there.
Varnadao says the agency canceled the alert after waves failed to show up in coastal Alaska communities.
The earthquake was recorded about 12:30 a.m. about 170 miles (270 kilometers) southeast of Kodiak Island in the Gulf of Alaska. It had a preliminary magnitude of 8.2 but has been downgraded to magnitude 7.9.
A magnitude 8.2 earthquake off Alaska's Kodiak Island prompted a tsunami warning for a large swath of coastal Alaska and Canada's British Columbia while the remainder of the U.S. West Coast was under a watch.
ABC News reports the strong earthquake was recorded about 175 miles southeast of Kodiak Island early Tuesday morning. Warnings from the National Weather Service sent to cellphones in Alaska warned: "Emergency Alert. Tsunami danger on the coast. Go to high ground or move inland."
According to the Associated Press, Kodiak officials warned residents to evacuate if they lived in low-lying areas.
People reported on social media that the quake was felt hundreds of miles away, in Anchorage.