Communities along a 1,126-kilometre stretch of Alaska's southern coast ordered residents to higher ground after a powerful offshore earthquake Wednesday, but officials quickly downgraded and then cancelled a tsunami warning for the region.

A major earthquake off Alaska with a preliminary magnitude of 7.2 has prompted a tsunami advisory for the state's southern peninsula.The tsunami advisory was downgraded from an initial tsunami warning Wednesday afternoon after the earthquake struck about 50 miles south of Sand Point,

An earthquake measuring magnitude 7.3 was recorded off the Alaska coast on Wednesday, July 16, according to the USGS.