The 10,200-foot Redoubt Volcano lies about about 100 miles southwest of Anchorage-in Alaska- at a point where the the Pacific plate dips beneath, or subducts, the North American plate. The Aleutian Islands are part of the Pacific Ring of Fire.
The volcano erupted in 1989-1990. Volcanic ash was so thick that it turned daylight into darkness. The volcano also erupted in 1902, 1966 and 1967-68.