Volcanic eruption of Nevado del Ruiz in Colombia, 1985 by Hanna Szelenyi

Geological Explanation/Description of Event

25szelenyih — 2024-10-15 17:33:43 UTC

Nevado del Ruiz erupted in Colombia on November 14th, 1985. The eruption itself was not considered a massive eruption. However, the eruption resulted in deadly lahars which caused most of the damage. Lahars form from the rapid melting of ice and snow due to the heat from a volcanic eruption. This leads to massive amounts of water running down the volcano and picking up mud and rocks and anything else in its path. Leading up to the eruption, scientists noticed some small signs of volcanic activity and recommended evacuation. Premonitory activity was observed prior to the eruption, which included an increase in fumes, ash eruptions, and sulfur deposition. They were ignored by the Colombian government and local authorities as none of the signs pointed to an eruption of a dangerous size. When the eruption actually occurred, it came out of the blue.

Long Term Impacts on Environment and Human Society

25szelenyih — 2024-10-15 17:33:43 UTC

The mudflows killed more than 23,000 people - the 4th largest death toll from an eruption throughout history - left 10,000 people homeless and caused a 34.94 billion pesos (US $218 million) loss. The damages and loss of life were unnecessary because the disaster was predictable, and it influenced major institutional and legislative changes in Columbia as well as the Latin American/Caribbean region. The National System for Disaster Prevention and Response and the International Volcano Disaster Assistance Program to monitor/map the world’s active volcanoes were created as a result of the disaster. This demonstrated a paradigm shift from response to risk reduction through integration of risk management and consideration. It also led to acid rain and acidified streams.

Immediate Effects on Environment and People

25szelenyih — 2024-10-15 17:33:43 UTC

The eruption spewed hot ash and lava into the atmosphere and melted parts of the volcano’s ice cap. This caused 30 meter high lahars (mudflows composed of mud, ash, and water) which killed 70% of Armero’s residents, completely destroyed the town, and left many homeless. The lahars poured into the nearby Gaulí river, causing it to swell and overflow and leading to even more damage. In total, there was an estimated cost of $1 billion, around ⅕ of Colombia’s GNP at the time.

Bibliography

25szelenyih — 2024-10-15 17:44:33 UTC

Augliere, Bethany. “Benchmarks: November 13, 1985: Nevado Del Ruiz Eruption Triggers Deadly Lahars.” Www.earthmagazine.org, 20 Oct. 2016, www.earthmagazine.org/article/benchmarks-november-13-1985-nevado-del-ruiz-eruption-triggers-deadly-lahars/.

Britannica, The Editors of Encyclopaedia. "Mount Ruiz". Encyclopedia Britannica, 14 Sep. 2023, https://www.britannica.com/place/Mount-Ruiz. Accessed 11 October 2024.

“Colombia: 1985 Nevado Del Ruiz Eruption.” Preventionweb.net, 25 Nov. 2021, https://www.preventionweb.net/collections/colombia-1985-nevado-del-ruiz-eruption.

Global Volcanism Program, 1985. Report on Nevado del Ruiz (Colombia) (McClelland, L., ed.). Scientific Event Alert Network Bulletin, 10:10. Smithsonian Institution. https://doi.org/10.5479/si.GVP.SEAN198510-351020

“The Nevado Del Ruiz Quaternary Volcanic Complex.” IUGS, iugs-geoheritage.org/geoheritage_sites/nevado-del-ruiz-quaternary-volcanic-complex/.

Sullivan, Missy. “Nevado Del Ruiz Eruptions Bury More than 20,000 in Colombia.” HISTORY, 13 Nov. 2009, https://www.history.com/this-day-in-history/volcano-erupts-in-colombia-and-buries-nearby-towns.

Williams, Stanley N., et al. "Eruption of the Nevado del Ruiz volcano, Colombia, on 13 November 1985: gas flux and fluid geochemistry." Science, vol. 233, 29 Aug. 1986, pp. 964+. Gale In Context: Environmental Studies, link.gale.com/apps/doc/A4374839/GRNR?u=mlin_m_brookhs&sid=bookmark-GRNR&xid=f8dd04ca. Accessed 11 Oct. 2024.

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