Alaska Volcano Observatory

Semisopochnoi Island, in November 2012. Photograph courtesy of Roger Clifford. Aerial view, north-northeast at the top, of Semisopochnoi caldera. The large lake in the distance is Fenner Lake. Weakly thermal springs are found downstream along the lake outlet. In the foreground is Sugarloaf Peak, the likely location of the 1987 eruption reported from Semisopochnoi. Details of this eruption are few and far between. At the left margin of the photo are the three summits of cones that make up Mount Cerberus, another young post-caldera vent complex.