Augustine, seen here from the NW, is the most active volcano of the eastern Aleutian arc. It consists of a complex of overlapping lava domes surrounded by an apron of volcaniclastic debris that reach the sea on all sides. The hummocky deposit in the foreground is a roughly 450-year-old debris avalanche deposit, one of many that surround the island as a result of repetitive collapse of the summit lava dome. Twentieth-century eruptions included explosive activity with pyroclastic flows and lava dome extrusion.

Photo by Lee Siebert, 1987 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Galleries: Debris Avalanches / Landslides | Stratovolcanoes

Keywords: plume | gas | gas plume | stratovolcano | emissions | deposit | debris avalanche deposit | hummock | lava dome

Augustine