The 7.4 magnitude earthquake hit about 75 miles south of Chignik in Alaska. Officials have now issued a tsunami warning for South Alaska and the Alaska Peninsula, from Kennedy Entrance to Unimak Pass.
The US Tsunami Warning System said tsunami activity was predicted to hit within the next hour at points along the Alaskan coast.
It said Sand Point could be hit at 11.15pm local time (8.15am BST), Kodiak at 12.05am (9.05am BST) and Cold Bay at 12.15am (9.15am BST).
Witnesses recorded their experiences on earthquake-tracking website EMSC-CSEM.
One said: “Bed and curtains were going. Felt like a very long quake! Felt at Homer, Ak at the end of the Spit at Lands End.”
Another said: “Felt very dizzy.”