Formation of Nevado del Ruiz Volcano

Nevado del Ruiz, Colombia's highest volcano (5,321 m / 17,457 ft), formed by the subduction of the Nazca Plate beneath the South American Plate. Melting of the Nazca Plate generated magma that rose to create a chain of volcanoes, including this stratovolcano.

It has a broad, symmetrical cone with a 2 km wide crater. Major eruptions occurred in 1595, 1845, and catastrophically in 1985 (over 25,000 deaths). It remains highly active and closely monitored due to the dense population nearby.