The warnings - affecting coastal regions of the US state and the Pacific region - were lifted hours later.
Authorities said the quake - which was recorded at 10:15 pm on Wednesday local time (6.15am GMT Thursday) - struck under the surface of the ocean off the coast of Alaska.
There were no immediate reports of injuries or damage to property, although several Alaskan coastal communities were evacuated following the earthquake.
Good morning and welcome to our rolling coverage of the Alaska earthquake and tsunami warnings in the region.
BREAKING: Tsunami warning as 8.2-magnitude tremor strikes off coast
An earthquake of magnitude 8.2 has struck off the coast of Alaskan peninsula
Details of earthquake
The US Geological Survey (USGS) said the earthquake was magnitude 8.2 and hit 91km east southeast of Perryville, Alaska.
The quake was about 46km below the surface of the ocean, according to USGS.
Two other earthquakes with preliminary magnitudes of 6.2 and 5.6 occurred in the same area within a half hour of the first one, the body reported.
Countries investigating potential tsunami threat
Other countries are investigating whether there is a potential tsunami threat following the quake off the coast of Alaska.
In New Zealand, authorities said they were assessing if there was any danger to coastal regions.
Japan’s Meteorological Agency said it was investigating whether there was a possibility of a tsunami hitting Japan, according to public broadcaster NHK.
Additional reporting by Reuters
Residents have shared videos of tsunami alarms ringing following the quake:
Tsunami watch for Hawaii
A tsunami watch has been issued for Hawaii following a large earthquake off the Alaska peninsula.
The Pacific Tsunami Warning Centre (PTWC) listed the magnitude as 8.1 and said “an investigation is under way to determine if there is a tsunami threat to Hawaii”, according to the Honolulu Star Advertiser.
Watch as tsunami sirens blare
Tsunami sirens have blared in Alaska following the earthquake that has triggered warnings across the region.
You can watch on Independent TV here:
An 8.2 magnitude earthquake struck off the coast of Alaska on Thursday morning, triggering a tsunami warning in the area.The chilling alarm can be heard in footage shared from the city of Kodiak, where residents have been urged to move away from coastal areas and seek higher land. The earthquake struck at 10.15pm Wednesday local time, with its epicentre around 50 miles south-east of Perryville on the Alaskan Peninsula.Tsunami warnings have also been issued for Hawaii and southern parts of Alaska.
No tsunami risk in Japan - broadcaster
There is no risk of tsunami damaging the Japanese coast after a magnitude 8.2 earthquake struck the Alaska Peninsula, the Japanese public broadcaster NHK said.
There might be small changes to tide levels, it added.
Hawaii warning cancelled
The tsunami warning for Hawaii has now been cancelled.
Alaska coastline alerts cancelled
All tsunami alerts for the Alaska coastline have also been cancelled:
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