The US Geological Survey (USGS) said the quake, which struck at 10:15pm (06:15 GMT Thursday), was at a depth of 35km (22 miles).
In Alaska, the National Tsunami Warning Center (NTWC) issued warnings for southern parts of the state, the Peninsula, and Pacific coastal areas from Hinchinbrook Entrance to Unimak Pass.
The Pacific Tsunami Warning Center (PTWC) also issued a warning for the US state of Hawaii and the US Pacific territory of Guam.
“Based on all available data a tsunami may have been generated by this earthquake that could be destructive on coastal areas even far from the epicenter,” PTWC said.
The NTWC said that it was evaluating the level of tsunami danger for other US and Canadian Pacific coastal areas.
The USGS had earlier pegged the magnitude of the quake at 7.2.
More to follow