The Nevado del Ruiz Quaternary Volcanic Complex


Crater Arenas

The iconic “Crater Arenas” and surrounding ice cap of the Nevado del Ruiz Volcanic Complex stratovolcano.

Geological Period


Main geological interest



Caldas and Tolima departments, Colombia.
5°24’00.0″N, 75°17’24.0″W

The iconic “Crater Arenas” and surrounding ice cap of the Nevado del Ruiz Volcanic Complex stratovolcano.

One of the most emblematic and beststudied volcanoes in the world, a model for volcanic risk management.

The Nevado del Ruiz expelled an estimated 3.5×1010 kg of mixed andesite and dacite tephra on November 13, 1985 (Melson et al., 1990). This small plinian explosion melted 10% of approximately 19 km2 of glacier ice (Pierson et al., 1990), generating a lahar that claimed at least 25,000 human lives (Naranjo et al., 1986). The eruption was classified as the second largest disaster of volcanic origin in the 20th Century, leaving a lesson of the importance of promoting community awareness of, and involvement in, volcanic hazard management (Voight, 1990. In addition, it promoted the creation of several volcanological observatories around the world.

Ash emission from the Nevado del Ruiz volcano during May 2017.

Nevado del Ruiz is a stratovolcano of andesitic composition and with a height of 5,321 meters above sea level, of andesitic composition. It is 66,000 years old, and during the last 13,000 years its activity has been mainly explosive with the generation of at least 14 subplinian-style eruptions and the occurrence of recurring eruptive phenomena of pyroclastic density currents, lahars, pyroclastic falls, and non-magmatic debris avalanches. The main crater, which is 750 m in diameter and 200 m deep, is called “Cráter Arenas” (Ceballos et al., 2020). Currently, the volcano has an ice cap covering 8.37 km2. It activity is manifested by its record of seismicity, emission of gases and ash, and the presence of hot springs. This volcano is part of the so-called “Nevado del Ruiz Volcanic Complex”. It corresponds to a series of structures and volcanic deposits genetically related to each other within the framework of a history of construction and destruction of 1.8 Ma. Four eruptive periods have left a record of lava flows, domes, pyroclastic density sucrrents, falls of balits, wind projection, debris avalanches, and lahars (Ceballos et al., 2020).

The first geoscientific description of the Nevado del Ruiz volcanic activity was made by Joaquin Acosta (1846). Later, as a result of the eruption on November 13, 1985, the formal beginning of vulcanology in Colombia took place (in 1986). Since then, Nevado del Ruiz has been kept under constant monitoring by the Volcanic Network of the Colombian Geological Survey, with the participation of national and international researchers. Their investigations have produced 130 publications in scientific journals.

Acosta, J. (1846) ‘Relation de l’eruption boueuse sortie du volcán du Ruiz et de la catastrophe de Lagunilla dans la republique de la Nouvelle Grenade’, C.R. Acad. Sc. Paris, 2, pp. 709–710.

Ceballos–Hernández, J.A. et al. (2020) ‘Geological evolution of the Nevado del Ruiz Volcanic Complex’, in The Geology of Colombia. Gómez, J. & Pinilla–Pachon, A.O. (eds). Bogotá: Servicio Geológico Colombiano (Publicaciones Geológicas Especiales, 38), pp. 267–296. Available at:

Melson, W.G. et al. (1990) ‘Water contents, temperatures and diversity of the magmas of the catastrophic eruption of Nevado del Ruiz, Colombia, November 13, 1985’, Journal of Volcanology and Geothermal Research, 41(1), pp. 97–126. Available at:

Naranjo, J.L. et al. (1986) ‘Eruption of the Nevado del Ruiz Volcano, Colombia, On 13 November 1985: Tephra Fall and Lahars’, Science, 233(4767), pp. 961–963. Available at:

Pierson, T.C. et al. (1990) ‘Perturbation and melting of snow and ice by the 13 November 1985 eruption of Nevado del Ruiz, Colombia, and consequent mobilization, flow and deposition of lahars’, Journal of Volcanology and Geothermal Research, 41(1), pp. 17–66. Available at:

Voight, B. (1990) ‘The 1985 Nevado del Ruiz volcano catastrophe: anatomy and retrospection’, Journal of Volcanology and Geothermal Research, 44(3), pp. 349–386. Available at:

Marcela Gómez-Pérez
Servicio Geológico Colombiano

Manuel Gómez Guerrero
Servicio Geológico Colombiano

Marianela Vargas Anaya
Servicio Geológico Colombiano

Gloria Cortes
Servicio Geológico Colombiano