Andes

The Andes arose from the subduction of the Nazca Plate and Antarctic Plate beneath the South American Plate, a process that began in the Jurassic and accelerated in the Cenozoic. This ongoing convergence has produced frequent earthquakes and volcanic activity, with the range featuring over 200 potentially active volcanoes, including Cotopaxi in Ecuador and Villarrica in Chile. The orogeny is not uniform: the northern and southern segments are separated by the Central Andes, where the Altiplano plateau, the second-highest plateau on Earth, formed through crustal shortening and magmatism. The range's extreme height and aridity in the Atacama region are linked to the rain shadow effect and the cold Humboldt Current, which together create one of the driest deserts on the planet.

The Andes host an extraordinary array of ecosystems, from tropical cloud forests to high-altitude puna grasslands and Patagonian steppe. This vertical zonation supports remarkable biodiversity, including endemic species such as the Andean condor, the spectacled bear, and the Andean flamingo. The range is also a center of plant evolution, with the genus Polylepis forming high-altitude woodlands that thrive above 4,000 meters. The páramo ecosystem, found in the northern Andes, is a critical water source for millions of people, and its unique flora includes the giant rosette plants of the genus Espeletia. Climate change poses a severe threat, as tropical glaciers have retreated dramatically, affecting water supplies and ecosystems.

Human habitation of the Andes dates back at least 12,000 years, with early hunter-gatherers adapting to high-altitude life. The range was the cradle of major civilizations, including the Inca Empire, which built an extensive road network and the citadel of Machu Picchu at 2,430 meters. The Andean peoples developed sophisticated agricultural techniques, such as terraces and raised fields, to cultivate crops like potatoes and quinoa. Spanish colonization in the 16th century brought profound changes, including the introduction of livestock and mining, which led to the extraction of silver from Potosí. Today, indigenous communities continue to practice traditional livelihoods, and the Andes remain a cultural heartland, with languages such as Quechua and Aymara spoken by millions.

Beyond the well-known peaks, the Andes harbor many surprising facts. The range is home to the highest navigable lake in the world, Lake Titicaca, at 3,812 meters, and the world's highest capital city, La Paz, Bolivia, at about 3,640 meters. The Atacama Desert, lying in the rain shadow of the Andes, is so dry that NASA uses it as a Mars analog. The Andes also contain the world's largest silver mine, Potosí, which fueled the Spanish economy for centuries. In the 20th century, the range witnessed the 1972 Andes flight disaster, where survivors resorted to cannibalism, a story later told in the film Alive. The range's name may derive from the Quechua word anti, meaning "east," reflecting the Inca perspective of the mountains as the eastern region of their empire.

Altiplano

A high plateau in the central Andes, averaging about 3,800 meters in elevation.

Páramo

A tropical alpine ecosystem found in the northern Andes, characterized by unique flora and high water retention.

Puna

A high-altitude grassland ecosystem in the central Andes.

Subduction

The process by which one tectonic plate slides beneath another, driving mountain building and volcanism.