Alaska's Mount Redoubt erupted Sunday, spewing clouds of ash and sending forth torrents of muddy meltwater. The volcano, which lies about 100 miles (160 kilometers) southwest of Anchorage, erupted several times in the 20th century and had been threatening to blow again for months. A week before the eruption, officials at the Alaska Volcano Observatory (AVO) bumped Redoubt's threat level from yellow to orange, indicating an escalation of unrest.

In several eruptions, Mount Redoubt belched out a plume of ash nine miles (14 kilometers) high, according to the AVO. Take an image tour of the fallout from the eruptions in a series of pictures from the observatory and the U.S. Geological Survey.

View the photo slide show here.