Misti

Misti is a volcano in the southern Peruvian Andes, rising above Arequipa, Peru’s second-largest city. It has a steep conical profile and two nested summit craters. The inner crater contains an active lava plug or dome, pierced by vents that emit volcanic gases. The summit reaches above sea level, on the rim of the outer crater. Snow covers the summit but does not persist, and there are no glaciers. The upper slopes are largely barren, while lower elevations support scrub and other bushy vegetation.

The volcano grew in four stages. Each stage built the mountain with lava flows and domes, then ended with a summit collapse that formed a bowl-shaped depression. Misti forms a local volcanic group with Chachani to the northwest and Pichu Pichu to the southeast, built on debris from older volcanoes. Over the past 50,000 years, numerous intense explosive eruptions have covered the surrounding terrain with tephra (rocks fragmented by volcanic eruptions). The last two significant eruptions were 2,000 years ago and in 1440–1470AD; since then, periods of increased gas release have sometimes been mistaken for eruptions