On April 15, 2008, at 22:59 UTC (2:59 pm ADT) a strong earthquake, magnitude 6.4, occurred in the Andreanof Islands region of the Aleutian Islands. It was followed by a larger earthquake of magnitude 6.6 on April 16 at 5:54 UTC (April 15, 9:54 pm ADT).

The These events occurred in the area separating rupture zones of the 1965 M8.7 Rat Islands earthquake to the west and the 1957 M8.6 Andreanof Islands earthquake to the east