About the volcano
Nevado del Ruiz is the highest active volcano in the northern Andes, crowned by an ice cap. On 13 November 1985 a moderate eruption melted part of the glacier, and water mixed with ash and rock rushed down the valleys as lahars – volcanic mudflows. A few hours later they reached the town of Armero, tens of kilometres away, and killed about 23,000 people. Hazard maps showing this danger existed, but the warnings did not lead to an evacuation. The disaster became a lesson for volcanologists and authorities around the world. The volcano has been active again since 2014.
Eruption history
VEI – Volcanic Explosivity Index: 0 = lava outpouring, 4 = like Eyjafjallajökull 2010, 6 = like Pinatubo 1991, 7 = like Tambora 1815. The scale is logarithmic – each step is about 10 times more material.
| Start | End | VEI | Vent and dating |
|---|---|---|---|
| 18 November 2014 | continuing | 2 | Arenas crater · Observations: Reported |
| 22 February 2012 | 12 July 2013 | 3 | Arenas Crater · Observations: Reported |
| 11 September 1985 | 13 July 1991 | 3 | Arenas Crater · Observations: Reported |
| 22 December 1984 | 19 March 1985 | 1 | Arenas Crater · Observations: Reported |
| 2 July 1916 | — | 2 | Observations: Reported |
| 19 February 1845 | — | 3 | Arenas and La Olleta(?) craters · Observations: Reported |
| 2 July 1831 | — | 2 | Observations: Reported |
| 18 June 1829 | — | 2 | Observations: Reported |
| 16 June 1828 | — | 2 | Observations: Reported |
| 14 March 1805 | — | 2 | Observations: Reported |
| 1623 | — | 1 | Near Arenas Crater · Observations: Reported |
| 9 March 1595 | — | 4 | Arenas Crater · Observations: Reported |
| 1570 | — | ? | Arenas Crater? · Observations: Reported |
| c. 1350 | — | 4 | Arenas Crater · Isotopic: 14C (uncalibrated) |
| 675 ± 50 years | — | 3 | Arenas Crater · Isotopic: 14C (uncalibrated) |
| 350 ± 300 years | — | 3 | West flank · Isotopic: 14C (uncalibrated) |
| 200 BCE ± 100 years | — | 4 | Arenas Crater · Isotopic: 14C (uncalibrated) |
| c. 850 BCE | — | 4 | Arenas Crater · Correlation: Tephrochronology |
| 1,245 BCE ± 150 years | — | ? | ENE flank ? (Alto la Piramide ?) · Isotopic: 14C (uncalibrated) |
| c. 6,660 BCE | — | ? | Arenas Crater · Correlation: Tephrochronology |
Data: Global Volcanism Program, Smithsonian Institution (#351020) · Wikipedia (pl) · Wikipedia (en)