View from the north rim of Katmai Caldera, a collapse feature that formed during the catastrophic eruption of nearby Novarupta volcano in June, 1912. Katmai Caldera is a steepwalled,1.5-km (1 mi)-diameter crater that truncates a formerly 2,290-m (7,513 ft)-high stratovolcano. The caldera is partially filled by a blue-green lake about 250 m (820 m) deep. The lake level was still rising when last measured in the mid-1970's. The south interior wall of the caldera is visible in this view. Photograph by Game McGimsey, U.S. Geological Survey, July 16, 1990.
Image courtesy of AVO / U.S. Geological Survey.