Coropuna

Coropuna is a prominent dormant compound volcano situated in the Andes mountain range of southeastern-central Peru. Its geological structure comprises multiple stratovolcanoes, primarily composed of ignimbrites and lava flows, built upon a Miocene basement of similar volcanic materials. The complex spans an impressive 240 square kilometers, with its highest summit reaching an altitude of 6,377 meters (20,922 feet) above sea level, ranking it as Peru's third-highest peak.

The most striking feature of Coropuna is its extensive ice cap, which is the largest in Earth's tropical zone. This perennially snowbound summit, giving rise to the Spanish name 'Nevado Coropuna,' feeds several outlet glaciers that descend to lower elevations. Below the 5,000-meter mark, the landscape transitions through diverse vegetation belts, including forests, peat bogs, grasslands, and human-modified agricultural areas and pastures, showcasing a remarkable altitudinal zonation.

The volcanic history of Coropuna is extensive, with activity dating back at least five million years. The majority of the current volcanic edifice was constructed during the Quaternary period. While considered dormant, Coropuna has experienced Holocene eruptions, with documented events approximately 2,100 ± 200 years ago and either 1,100 ± 100 or 700 ± 200 years ago, both of which produced lava flows.

There is also evidence suggesting a potential eruption around 6,000 years ago. Currently, the volcano's activity is limited to hydrothermal manifestations, primarily hot springs, indicating residual geothermal heat within the volcanic system. This ongoing geothermal activity, coupled with the glacial environment, creates a dynamic and potentially hazardous system.

Coropuna holds profound cultural and historical significance, particularly for the Inca civilization. Located approximately 150 kilometers northwest of Arequipa, its slopes have been inhabited for millennia. The Inca revered Coropuna as a sacred deity, integrating it into their religious practices.

Archaeological evidence, including the discovery of Inca sites like Maucallacta and Acchaymarca, underscores its importance as a major religious center within the Inca realm. Rituals, including human sacrifices, were performed on its sacred heights. This deep spiritual connection persists today, with Coropuna remaining a subject of local legends and continuing to be an object of worship, reflecting its enduring cultural legacy.

The extensive ice cap of Coropuna is facing significant challenges due to global climate change. During the Last Glacial Maximum, the ice cap covered over 500 square kilometers, but it has been in a state of retreat since at least 1850. Projections indicate that the ice cap may persist only until around 2120 under current warming trends.

This glacial retreat poses a critical threat to the water security of tens of thousands of people who depend on the watershed for their water supply. Furthermore, the interplay between volcanic geothermal activity and glacial meltwater can generate hazardous mudflows (lahars), endangering surrounding populations. Consequently, the Peruvian geological agency, INGEMMET, actively monitors Coropuna, maintaining a hazard map to mitigate potential risks.