The vegetated terrain seen here is the surface of the Rocky Point debris avalanche deposit, produced by collapse of the summit of Augustine about 250-450 years ago. The avalanche traveled into Cook Inlet, visible at the upper left with the Chigmit Mountains in the background, for a distance of 8 km and extended the shoreline by 2 km.

Photo by Lee Siebert, 1990 (Smithsonian Institution).

Keywords: debris avalanche deposit | deposit | outcrop | exposure | geology

Augustine