Alaska Volcano Observatory

Aerial view of the eastern wall of Fisher caldera. The field of view is about 4 kilometers. The eastern caldera lake is in the foreground, and the low areas outside the eastern caldera are in the background. Horizontal deposits exposed in the cliff wall are remnants of a pre-caldera stratocone. The undulating unit capping the wall is the welded pyroclastic flow deposit from the caldera-forming eruption, locally as thick as 5 meters, with pumice fall deposits from the same eruption (up to and exceeding 10 m thick) lie directly beneath the welded unit