The quake occurred about 60 miles southwest of Port Alexander at a depth of about 6 miles at 0858 GMT, according to the U.S. Geological Survey, which downgraded the magnitude from an initial 7.7.
The West Coast and Alaska Tsunami Warning Center in Palmer, Alaska, issued a tsunami warning for coastal areas of southeast Alaska and Canada’s British Columbia, but this was later cancelled.
So far there had been no reports of damage from the earthquake, tsunami warning center scientist Bill Knight said.
Officials in Sitka, southern Alaska, were urging evacuations in low-lying areas, local radio station KCAW reported.
An earthquake of magnitude 7.7 struck British Columbia on October 27. A tsunami warning was issued but no damage ensued.
(Reporting by Yereth Rosen; Editing by Pravin Char)