INGEOMINAS reported that during 13-14 April seismicity associated with fluid movement beneath Nevado del Ruiz was detected along with volcano-tectonic earthquakes. The earthquakes were located NW of Arenas Crater at depths between 5 and 9 km; the largest was a M 2.6, felt by officials of Los Nevados National Park in the area of Brisas (50 km SW). During the early morning of 14 April webcams recorded a gas-and-ash plume that rose 630 m and drifted NW. On 15 April a M 3 volcano-tectonic earthquake was located NW of Arenas Crater at a depth of 6.6 km. Later that day a M 2.5 volcano-tectonic earthquake was located again NW of Arenas Crater at a depth of 5.78 km. On 16 April at 0714 a M 3.2 earthquake was located in the same area at a depth of 6.22 km. Earthquakes continued to be felt by officials in the National Park. A gas-and-steam plume rose 1 km above the crater and drifted SW. Sulfur dioxide emissions were significant and deformation was detected. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").

10 April 2013            Back to Top

INGEOMINAS reported that during 13-14 April seismicity associated with fluid movement beneath Nevado del Ruiz was detected along with volcano-tectonic earthquakes. The earthquakes were located NW of Arenas Crater at depths between 5 and 9 km; the largest was a M 2.6, felt by officials of Los Nevados National Park in the area of Brisas (50 km SW). During the early morning of 14 April webcams recorded a gas-and-ash plume that rose 630 m and drifted NW. On 15 April a M 3 volcano-tectonic earthquake was located NW of Arenas Crater at a depth of 6.6 km. Later that day a M 2.5 volcano-tectonic earthquake was located again NW of Arenas Crater at a depth of 5.78 km. On 16 April at 0714 a M 3.2 earthquake was located in the same area at a depth of 6.22 km. Earthquakes continued to be felt by officials in the National Park. A gas-and-steam plume rose 1 km above the crater and drifted SW. Sulfur dioxide emissions were significant and deformation was detected. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

16 January 2013            Back to Top

Based on analysis of satellite imagery, the Washington VAAC reported that on 16 January a diffuse plume from Nevado del Ruiz possibly contained ash and drifted almost 55 km NE. A thermal anomaly was also detected. INGEOMINAS reported significant emissions of mostly gas and steam during 14-20 January; plumes rose 1.6 km above the crater and drifted E and SE, and then W during the later part of the week.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) , Washington Volcanic Ash Advisory Center (VAAC)

14 November 2012            Back to Top

Based on analysis of satellite imagery and reported seismic activity, the Washington VAAC issued a notice about a possible eruption from Nevado del Ruiz on 15 November. Cloud cover prevented observations of a possible ash plume but elevated seismicity was detected. A few hours later seismicity decreased and a faint thermal anomaly was detected. About six hours after that seismic activity remained low and no anomaly was detected.

Sources: Washington Volcanic Ash Advisory Center (VAAC)

5 September 2012            Back to Top

According to INGEOMINAS, on 5 September the Observatorio Vulcanológico and Sismológico de Manizales reported that seismicity at Nevado del Ruiz significantly decreased, both in the number and magnitude of the earthquakes. Field measurements and analysis of satellite imagery continued to show a significant amount of sulfur dioxide in the atmosphere. A steam-and-gas plume rose 400 m and drifted W. Later that day, INGEOMINAS decreased the Alert Level to III (Yellow; "changes in the behavior of volcanic activity").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

29 August 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 30-31 August variations in volcanic tremor amplitude were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. Seismic activity was low during 2-4 September. Cloud cover mostly prevented observations of the volcano; a white gas plume rose 200 m on 4 September and drifted W and SW. During 3-4 September field measurements and analysis of satellite imagery showed a significant amount of sulfur dioxide in the atmosphere. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

22 August 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 22-28 August variations in volcanic tremor amplitude were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. Cameras located near the volcano showed gas plumes rising 800 m above the crater and drifting NE on 23 August, and rising 1 km the next day. Gas plumes rose 300-500 m and drifted W and N during 26-28 August. Field measurements and analysis of satellite imagery showed a significant amount of sulfur dioxide in the atmosphere during 24 and 26-27 August. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

15 August 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 15-16 and 18-21 August variations in volcanic tremor amplitude were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. Earthquakes indicative of fracturing rock were located SE at depths of 1.5-4 km, with magnitudes less than 1. One event on 18 August was a M 2, located 1.17 km SW of Arenas Crater at a depth of 3.6 km. Web cameras showed gas-and-ash plumes rising 400 m and drifting W and NW during 15-16 August. A gas plume rose 400 m and drifted NW on 19 August. During 20-21 August field measurements and analysis of satellite imagery showed a significant amount of sulfur dioxide in the atmosphere. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

8 August 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 10-13 August low levels of tremor were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. On 12 August a total of 140 low-magnitude earthquakes (M < 1.8) were detected in a seismic swarm that began at 0956 and ended at 1800. The earthquakes were located about 4 km WSW of Arenas Crater at depths of less than 5 km. A gas-and-ash plume observed with a web camera rose 1 km above the crater and drifted W. Ashfall was reported in Brisas (50 km SW). Satellite images showed continuing sulfur dioxide emissions. On 13 August a seismic swarm was characterized by events less than M 1, and located NE of Arenas Crater at depths between 3 and 5 km. A thin layer of ash was deposited at the observatory in Manizales. Weather conditions prevented observations of the volcano. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

1 August 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 3-6 August low levels of tremor were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. Ashfall and a strong sulfur odor were reported in Manizales (30 km NW) and in the municipality of Chinchiná (30 km WNW). Satellite images showed continuing sulfur dioxide emissions on 6 August. Web cameras near the volcano recorded a gas-and-steam plume rising 700 m that drifted SW on 8 August. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

25 July 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that on 31 July web cameras at Nevado del Ruiz showed gas-and-ash plumes rising 300 m above the crater. Seismicity was low. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

18 July 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 22-24 July low levels of tremor were detected at Nevado del Ruiz, possibly associated with continuing gas and ash emissions. Satellite imagery and ground-based observations on 22 July showed high levels of sulfur dioxide emissions. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

11 July 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that on 11 July seismicity at Nevado del Ruiz decreased, however the data continued to indicate gas and ash emissions during 11-17 July. Satellite imagery and ground-based observations showed sulfur dioxide emissions. On 11 July ashfall was reported in Pereira (40 km WSW). The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

4 July 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 5-9 July seismic signals at Nevado del Ruiz indicated continuing gas and ash emissions. On 6 July a gas-and-ash plume rose 400 m above the crater and drifted SW. On 8 July gas-and-ash plumes rose 400-500 m above the crater and drifted NW and W. The Washington Volcanic Ash Advisory Center (VAAC) reported that a gas-and-ash plume was observed in satellite imagery drifting 65 km. On 9 July INGEOMINAS noted that a gas-and-ash plume, observed with a web camera, rose around 400 m above the crater. On 10 July satellite imagery and ground-based observations showed sulfur dioxide emissions. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) , Washington Volcanic Ash Advisory Center (VAAC)

27 June 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that a significant concentration of sulfur dioxide was detected rising from Nevado del Ruiz during 28-29 June. Seismic signals indicated continuing gas and ash emissions.

On 30 June an eruption produced an ash plume that rose 8 km above the crater and drifted SW. The Alert Level was raised to I (Red; "imminent eruption or in progress"). Ashfall was reported in areas near the volcano including Manizales (30 km NW) and Villamaría (28 km NW). According to news reports, communities around the volcano evacuated, and airports in Manizales, Pereira, and Armenia closed. By 2 July seismicity had decreased to low levels; the Alert Level was lowered to II (Orange; "eruption likely within days or weeks"). The Washington VAAC reported that a 7.5-km-wide ash plume was detected in satellite imagery drifting 75 km W. INGEOMINAS noted that seismic signals indicated continuing gas and ash emissions on 3 July.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) , Reuters , Washington Volcanic Ash Advisory Center (VAAC) , Colombia Reports

20 June 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that a high concentration of sulfur dioxide was detected during 20-22 June. Reports on 22 and 25 June stated that seismic signals had indicated continuing gas and ash emissions. Web camera images showed steam-and-gas plumes rising 300 m and drifting NW on both days. On 26 June seismicity was low. Sulfur dioxide emissions continued to be significant. The Alert Level remained at II (Orange; "eruption likely within days or weeks") on 26 June.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) , Washington Volcanic Ash Advisory Center (VAAC)

13 June 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported on 15 June that satellite image analyses and field observers of Nevado del Ruiz indicated significant sulfur dioxide emissions. Seismic signals on 15 and 18 June indicated continuing ash emissions. Based on analysis of satellite imagery and web camera views, the Washington VAAC reported that on 17 June a 5.5-km-wide gas plume, possibly containing ash, drifted more than 90 km NW. The VAAC noted on 18 June that INGEOMINAS reported a gas-and-ash plume drifting N and NW at an altitude of 6.1 km (20,000 ft) a.s.l. The plume was later detected in satellite imagery drifting more than 90 km NW. The Alert Level remained at II (Orange; "eruption likely within days or weeks") on 19 June.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) , Washington Volcanic Ash Advisory Center (VAAC)

6 June 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that a satellite image of Nevado del Ruiz acquired on 6 June showed an ash plume rising from the crater and drifting NW, and ash deposits on the N, NW, W and SW flanks. Based on analysis of satellite imagery and information from INGEOMINAS, the Washington VAAC reported that gas plumes possibly containing some ash drifted 75-110 km W, WNW, and N during 7 and 9-10 June. Ash plumes drifted almost 30 km SE on 8 June. INGEOMINAS reported that on 11 June seismic signals indicated continuing ash emissions. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS) , Washington Volcanic Ash Advisory Center (VAAC)

30 May 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that on 4 June observations of Nevado del Ruiz during an overflight and through web cameras located in the vicinity of Arenas Crater revealed that gas-and-ash plumes rose at most 1 km above the crater and drifted W and NW. The next day seismic signals indicated that ash emissions continued. Field observers noted that sulfur dioxide emissions were significant. Based on analysis of satellite imagery, the Washington VAAC reported that an ash plume drifted 40 km W. The VAAC also noted that the Bogota MWO reported ash emissions drifting NNW at an altitude of 9.1 km (30,000 ft) a.s.l. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

23 May 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that on 22 May a seismic signal possibly indicated an ash emission from Nevado del Ruiz, though it was not confirmed due to poor weather conditions. On 29 May activity significantly increased; at 0307 seismic signals indicated ash emissions that were confirmed by officials and residents near the volcano as well as with a web camera. The Alert Level was raised to II (Orange; "eruption likely within days or weeks"). A gas-and-ash plume rose 1 km above the crater and ashfall was reported in Anserma (65 km NW), Aranzazu (45 km NNW), Chinchiná (30 km WNW), Dosquebradas (40 km W), Filadelfia, La Merced (60 km NNW), Manizales (30 km NW), Marmato (70 km NNW), Neira (37 km NW), Palestina (40 km WNW), Pereira (40 km WSW), Risaralda (78 km WNW), Salamina (60 km NNW), San José (56 km NW), Santagueda (40 km NW), Santa Rosa de Cabal (33 km W), Supia (72 km NNW), Villamaria (28 km NW), and Viterbo (65 km WNW). Ash also fell in all municipalities in the department of Risaralda (76 km WNW) and El Aguila (85 km W, N of Valle del Cauca). Sulfur dioxide plumes were detected by satellite and a sulfur dioxide odor was reported in multiple towns. Later that day ash emissions rose 600 m above the crater.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

2 May 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 1-2 May both satellite images and field observers indicated that steam and sulfur dioxide emissions rose from Nevado del Ruiz. Seismicity continued to decrease. On 3 May the Alert Level was lowered to III (Yellow; "changes in the behavior of volcanic activity").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

25 April 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 25-26 and 28-30 April video data and observers in the city of Manizales (25 km NW) indicated that gas-and-steam plumes rose 0.5-2 km above Nevado del Ruiz's crater. Cloud cover prevented observations on 27 April. Seismic signals indicated that an ash plume was emitted at 1248 on 30 April however cloud cover prevented observations. Seismicity fluctuated, but decreased. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

18 April 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 18-19 April multiple seismic signals recorded at Nevado del Ruiz possibly indicated ash emissions, but they could not be verified due to weather conditions. Video data and observers in the city of Manizales (25 km NW) indicated that gas-and-steam plumes rose 900 m above the crater and drifted SE during the morning on 18 April. Satellite imagery detected a steam and sulfur dioxide plume the next day. During 20-24 April high levels of sulfur dioxide were detected in satellite images. Gas-and-steam plumes rose 1-2 km above the crater. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

11 April 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that seismicity at Nevado del Ruiz decreased during 11-15 April then slightly increased during 16-17 April. Earthquakes were located below or N of Arenas crater at depths of 1.5-2 km during 11-12 April. Earthquake events at 1146 and 1149 on 15 April were possibly associated with ash emissions which were not verified due to weather conditions. Earthquakes detected on 16 April occurred E of Arenas crater at depths of 1.5-4 km.

Gas-and-steam plumes were observed mainly in satellite imagery, by cameras located near the volcano, and from the city of Manizales (25 km NW). On 12 April a sulfur odor was reported in the towns of Lebanon, Palocabildo, and Fresno (Tolima). Observes in Manila reported a gas-and-steam plume that rose 1.8 km above the crater on 16 April. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

4 April 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 4-10 April seismicity at Nevado del Ruiz fluctuated but remained elevated. Sulfur dioxide emissions also remained high; occasionally a sulfur odor was reported in Manizales, about 25 km NW. On 5 April a volcano-tectonic earthquake, M 2.8, occurred below Arenas crater at a depth of 1 km, and was the highest magnitude earthquake recorded since February. During 4-6 April gas-and-steam plumes drifted NW. Gas-and-steam plumes rose 3 km above the crater on 7 April and 1.5 km above the crater on 10 April; the plumes drifted SE both days. The Alert Level remained at II (Orange; "eruption likely within days or weeks").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

28 March 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 24-31 March seismicity at Nevado del Ruiz increased significantly. Earthquakes indicating rock fracturing occurred W of Arenas crater, exhibiting a pattern observed prior to the eruptions in 1985 and 1989, although less energetic. Starting at 1054 on 29 March, and lasting for about 25 minutes, more than 135 earthquakes were detected S of Arenas crater at a depth of 4 km. At 0400 on 31 March earthquake signals indicating rock fracturing and fluid movement markedly increased. The Alert Level was raised to II (Orange; "eruption likely within days or weeks"). Seismicity remained elevated during 1-3 April; earthquakes were located below Arenas crater at depths between 0.5 and 3 km.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

21 March 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 19-25 March seismicity at Nevado del Ruiz increased and gas emissions remained at significant levels. Gas plumes rose 2 km above Arenas crater and sulfur dioxide odors were reported by local people. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

14 March 2012            Back to Top

According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 12-18 March seismicity at Nevado del Ruiz decreased but gas emissions remained at significant levels. Gas plumes rose 2 km above the crater and sulfur dioxide odors were reported by local people. The Alert Level remained at III (Yellow; "changes in the behavior of volcanic activity").

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

7 March 2012            Back to Top

INGEOMINAS reported a significant increase in seismicity at Nevado del Ruiz during 5-11 March. On 8 March scientists aboard an overflight observed a gas plume that rose 1.4 km above Arenas crater, originating from multiple emission sources and thermally anomalous areas within the crater. They noted ash deposits on the glacier, near the crater rim and on the E flank, likely from an explosion on 22 February. Later that day a small explosion detected by the seismic network produced an ash emission that was observed with a camera installed in La Piranha (NW). Increased sulfur dioxide emissions were also detected. Fieldwork revealed ash deposits at the headwaters of Gualí River, SW of Arenas crater.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

29 September 2010            Back to Top

INGEOMINAS reported a gradual increase in seismicity from Nevado del Ruiz on 30 September. Earthquakes were located beneath the Arenas crater at depths of 0.5-2 km. The largest earthquake was M 1.9. A plume of white gas rose 700 m above the caldera and a sulfur odor around the volcano was reported. The Alert Level was raised to III (Yellow; "changes in the behavior of volcanic activity") on 1 October. The report also noted changes in deformation and geochemistry during the previous few months. Seismic levels fluctuated during 2-3 October.

Sources: Instituto Colombiano de Geología y Minería (INGEOMINAS)

14 July 2010            Back to Top

The Washington VAAC reported that a plume at an altitude of 7 km (23,000 ft) a.s.l. from a possible eruption from Nevado del Ruiz on 17 July was stated in a Bogota MWO SIGMET notice. A second VAAC report less than an hour later noted a brief seismic signal alert had been issued and that meteorological cloud cover prevented observations of the volcano. Ash was not seen in satellite imagery later that day nor were there any additional reports of activity. [INGEOMINAS later confirmed that no eruption had occurred.]

Sources: Washington Volcanic Ash Advisory Center (VAAC)

12 June 2002            Back to Top

On 9 June beginning at 2300 a swarm of volcano-tectonic earthquakes was recorded at Nevado del Ruiz. Next, hundreds of hybrid earthquakes were recorded, with more than 1,300 earthquakes occurring in 16 hours. High seismicity persisted for the following 3 days, with ~2,300 earthquakes recorded. This was the highest daily number of events recorded at Nevado del Ruiz since 1985. At the height of the activity the Alert Level was at Orange. In addition to heightened seismicity felt by residents near the volcano, jet-like sounds were reportedly heard that corresponded with some of the hybrid earthquakes, and the strong scent of SO2 was reported near the summit. No ash emissions were reported. By 13 June seismicity had decreased.

Sources: El Tiempo , Instituto Colombiano de Geología y Minería (INGEOMINAS)

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Cuellar-Rodriguez J V, Ramirez-Lopez C, 1987. Descripcion de los volcanes Colombianos. {Rev CIAF, Bogota}, p 189-222

Hantke G, Parodi I, 1966. Colombia, Ecuador and Peru. {Catalog of Active Volcanoes of the World and Solfatara Fields}, Rome: IAVCEI, 19: 1-73

Herd D G, 1982. Glacial and volcanic geology of the Ruiz - Tolima volcanic complex Cordillera Central, Colombia. {Pub Geol Especiales INGEOMINAS}, Bogata, 8: 1-48

Herd D G, Comite de Estudios Vulcanologicos, 1986. The 1985 Ruiz volcano disaster. {Eos, Trans Amer Geophys Union}, 67: 457-460

Huggel C, Cegballos J L Pulgarin B, Ramirez J, Thouret J-C, 2007. Review and reassessment of hazards owing to volcano-glacier interactions in Colombia. {Annals Glaciology}, 45: 128-136

Mendez Fajury R A, 1989. Catalogo de los volcanes activos en Colombia. {Bol Geol INGEOMINAS, Colombia}, 30: 1-75

Thouret J-C, Cantagrel J-M, Salinas R, Murcia A, 1990. Quaternary eruptive history of Nevado del Ruiz (Colombia). {J Volc Geotherm Res}, 41: 225-251

Vatin-Perignon N, Goemans P, Oliver R A, Parra Palacio E, 1990. Evaluation of magmatic processes for the products of the Nevado del Ruiz volcano, Colombia from geochemical and petrological data. {J Volc Geotherm Res}, 41: 153-176

Nevado del Ruiz is a broad, glacier-covered volcano in central Colombia that covers >200 sq km. Three major edifices, composed of andesitic and dacitic lavas and andesitic pyroclastics, have been constructed since the beginning of the Pleistocene. The modern cone consists of a broad cluster of lava domes built within the summit caldera of an older Ruiz volcano. The 1-km-wide, 240-m-deep Arenas crater occupies the summit. The prominent La Olleta pyroclastic cone is located on the SW flank, and may also have been active in historical time. Steep headwalls of massive landslides cut the flanks of Nevado del Ruiz. Melting of its summit icecap during historical eruptions, which date back to the 16th century, has resulted in devastating lahars, including one in 1985 that was South America's deadliest eruption.