t 9:43 p.m. AST (06:43 11/17 UTC) on Sunday evening, November 16, 2003, a major earthquake, M7.7, occurred in the Rat Islands region of the Aleutian Islands.

This earthquake was the largest to occur in North America since the magnitude 7.9 Denali Fault, Alaska earthquake of November 3, 2002, and the largest in the Aleutian Islands since the June 1996 magnitude 7.9 Adak earthquake.