A sizeable undersea earthquake struck south of the Alaskan coastline and west of British Columbia early this morning.

It struck at 2:02 a.m. Anchorage time (3:02 Vancouver time) today (June 18), at a depth of 10 kilometres (six miles).

According to both the Alaska Earthquake Center and the U.S. Geological Survey, it was a 5.3-magnitude temblor.

The epicentre was located 227 kilometres (141 miles) south of Sand Point, Alaska; 1080 kilometres (670 miles) southwest of Anchorage; and 1705 kilometres (1057 miles) southwest of Juneau, Alaska.

The U.S. Tsunami Warning System did not issue a tsunami alert for this quake.