According to the US Geological Survey website, the quake hit around 12:53 p.m. about 15 miles off the coast of Little Sitkin Island, which is part of the Aleutian Islands in Alaska.
The earthquake was initially measured at 7.1 magnitude, then upgraded to 8.0, and most recently downgraded to a 7.9 quake. Several aftershocks were recorded.
Following the earthquake, the Pacific Tsunami Warning Center issued a tsunami warning for the coastal communities in the immediate area of the quake. No other areas along the Pacific coast were included in the tsunami warning.
No reports of damage or injury had been reported as of Monday afternoon.