Global Volcanism Program | Image GVP-05211
During the late Pleistocene or early Holocene Mount Spurr underwent flank collapse, resulting in the 5-6 km wide crater that opens to the south. The collapse produced a debris avalanche that traveled at least 25 km from the summit. This 1993 view from the south looks into the crater and the rim forms the left and right skylines. The snow-covered peak (center) is a post-collapse lava dome. Crater Peak, in front of it, has been the source of frequent Holocene eruptions.
Photo by Christina Neal, 1993 (U.S. Geological Survey, Alaska Volcano Observatory).