Misti

El Misti is a symmetrical andesitic stratovolcano with nested summit craters immediately NE of the city of Arequipa, Peru. Eruptions from the active cone began about 13,700 and 11,300 years ago, within a 1.5 x 2 km caldera that underwent collapse about 50,000 years ago. A large scoria cone has grown with the 830-m-wide outer summit crater. At least 20 tephra-fall deposits and numerous pyroclastic-flow deposits have been documented during the past 50,000 years, including a pyroclastic flow that traveled 12 km S about 2,000 years ago. The most recent activity has been dominantly pyroclastic, and strong winds have formed a parabolic dune field of volcanic ash extending up to 20 km downwind. An eruption in the 15th century affected nearby Inca inhabitants. Some reported eruptions may represent increased fumarolic activity.