A tsunami warning has been issued for Hawaii after an 8.2 magnitude earthquake struck off the Alaska Peninsula.

Alerts have been issued for the US state, as well as the Peninsula and Pacific coastal areas from Hinchinbrook Entrance to Unimak Pass, and the territory of Guam.

The quake struck at 10.15pm on Wednesday local time, at a depth of 46.7, the US Geological Survey said.

Preliminary seismic data suggests the quake would have been widely felt by almost everyone in the area of the epicentre and might have caused light to moderate damage.