Nevado del Tolima

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  • 4.67°N
  • 75.33°W

  • 5200 m
    17056 ft

  • 351030
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Most Recent Bulletin Report: June 2013 (BGVN 38:06)


Non-eruptive during 2005-2012; hazard assessment and glacial retreat

During 2005-2012, Nevado del Tolima was non-eruptive and the Alert Level remained at IV (Green; "volcanically active with stable behavior") due to minimal seismicity and deformation. The Servicio Geológico Colombiano (SGC) monitored Tolima with a seismic network, tilt measurements, and regular field observations. The greatest changes at Tolima during this time period were related to the summit glacier that generated significant seismicity and surface activity. Volcano-tectonic (VT) and long-period (LP) earthquakes were also detected with the monitoring network, although these events were frequently too small to locate.

In this report, we also highlight geological hazards investigations by Thouret and others (1995); among the hazards, runout distances for lahars were determined as well as potential ash distribution areas. Further, we include the results of long-term studies focused on the summit glacier (figure 2); investigators noted significant retreat based on aerial photos and later, with Landsat image analysis.

Figure 2. A) A view toward the S flank of the glacier-clad summit of Tolima taken on 18 February 2010. Fresh snowfall highlights the morphology that includes lava flows and debris fans. B) A view of the N flank taken on 22 January 2010. The extent of the glacier appears in bright contrast to the yellow-gray and red colors of the altered summit rock. Courtesy of SGC.

Seismicity during March 2006 - December 2012. Based on volcano-tectonic (VT) and long-period (LP) earthquake counts, the SGC reported that low-level seismicity persisted during this reporting period (table 1). The occurrence of earthquakes was highest during 2006 when 22-90 VT and 5-20 LP events per month were recorded. From 2007 through 2012, VT and LP events occurred at a lower rate (0-73 VT per month and 0-17 LP per month).

Table 1.Monthly seismicity at Nevado del Tolima was tabulated by the occurrence of events: volcano-tectonic (VT), long-period (LP), Glacier & Rockfall, Unclassified, and Largest Earthquake magnitude. Events considered "Unclassified" are attributed to icequakes or rockfalls that do not fulfill the amplitude or duration parameters in order to be included in the SGC database. Note that these values have been corrected by the SGC database and differ from "Technical Bulletin" reports. Courtesy of SGC.

 Year Month VT LP Glacier & Rockfall Unclassified Largest EQ
2006 March 48 17 1717 3295 1.58
  April 22 20 1150 2572 0.64
  May 35 17 1460 2331 0.95
  June 43 8 675 1551 1.08
  July 39 8 340 729 1.14
  August 26 9 352 927 0.81
  September 31 5 565 1254 1.01
  October 81 7 904 1639 1.35
  November 77 8 644 1735 1.53
  December 90 9 632 2221 1.45
2007 January 0 12 1218 2615 1.72
  February 4 0 979 3825 1.65
  March 7 1 1345 6513 0.64
  April 1 1 1171 5939 1.01
  May 21 0 1544 4129 1.02
  June 5 0 615 2107 0.64
  July 2 2 746 2165 1.14
  August 6 0 524 1692 2.27
  September 5 1 522 1472 0.7
  October 4 1 472 1115 1.96
  November 3 2 270 966 0.86
  December 7 0 434 1080 1.73
2008 January 3 0 318 968 0.55
  February 2 0 210 805 0.73
  March 1 0 275 1083 -0.4
  April 7 0 256 1453 1.62
  May 5 0 265 1931 2.63
  June 2 0 109 1207 0.88
  July 6 0 125 1148 1.4
  August 73 0 158 974 1.14
  September 12 0 118 864 1.02
  October 12 2 204 1157 0.81
  November 2 0 263 1515 0.35
  December 7 0 197 1242 0.45
2009 January 7 0 185 1490 0.64
  February 1 0 117 1017 0.45
  March 3 0 257 2272 0.88
  April 6 0 279 2245 1.3
  May 8 0 275 2360 0.73
  June 1 0 212 1846 0.88
  July 10 0 100 1127 0.95
  August 3 0 146 1881 2.2
  September 8 0 127 1867 0.64
  October 1 0 176 2757 0.23
  November 0 0 329 1994 0
  December 1 0 414 2055 -0.21
2010 January 4 0 678 1703 0.35
  February 0 1 637 1551 0.75
  March 6 1 698 1638 1.08
  April 0 1 878 1344 0.43
  May 1 2 742 1746 1.4
  June 0 1 491 1307 0.91
  July 0 1 505 1173 1.46
  August 0 0 329 1337 0
  September 0 1 425 860 0.7
  October 0 1 204 434 0.1
  November 5 2 314 1286 0.73
  December 2 2 256 1075 1.3
2011 January 0 0 197 1002 0
  February 3 2 393 1805 0.81
  March 1 3 978 443 1.45
  April 0 1 1370 1043 0.91
  May 1 4 1114 659 0.96
  June 2 1 692 252 1.02
  July 7 0 709 246 1.58
  August 0 1 897 216 0.81
  September 0 5 1404 388 1.22
  October 1 0 1665 427 0.88
  November 2 2 1890 601 0.73
  December 3 2 1923 927 0.96
2012 January 2 0 2033 740 0.55
  February 2 0 1471 159 0.81
  March 4 15 1348 95 0.75
  April 9 17 1379 310 1.65
  May 30 6 1740 417 1.58
  June 2 0 1290 372 1.02
  July 3 2 888 519 0.88
  August 0 0 792 988 0
  September 27 0 1077 847 1.45
  October 3 4 1920 1359 0.64
  November 2 4 1332 1289 1.08
  December 12 1 1873 na 1.2

Seismic signals attributed to glacial changes ("icequakes") and rockfalls dominated the records during 2006-2012. Frequently, more than 1,000 events were recorded per month. During 2008-2010, such events were slightly less frequent; an average of 313 earthquakes occurred per month. Coincidentally, LP events were significantly less frequent during that time period as well (less than one event per month). From March 2006 to July 2007, rockfall signals were attributed to surface activity mainly occurring on the N flank and related to small avalanches of ice and rock. The SGC noted that the general summit area was the source of shallow seismicity from mid 2010 through 2012.

Because of sparse activity and low-magnitude events, hypocentral depths of VT earthquakes were rarely calculated during 2006-2012 (table 2). Five earthquakes were located in September 2012, the most to be located in a single month. Three of these earthquakes were located > 5 km of the summit (NW and SE), while 2 were within 1 km (figure 3). That month, seismicity was relatively high compared with previous months; the SGC reported 27 VT earthquakes and 1,077 "Glacier & Rockfall" signals.

Table 2.The number of located VT earthquakes from Tolima during 2011-2012. Located earthquake information was not available for 2006-2010. Courtesy of SGC.

# of EQs Depths (km) Location from Summit Date
1 2 ~1 km, N Mar. 2011
1 4 ~6 km, NW Jul. 2012
5 3 & 4   Sept. 2012
2 ~3.5   Oct. 2012
Figure 3. This map shows five located VT earthquakes in the region of Tolima during September 2012. Red and yellow circles indicate hypocenters and epicenters (colors relate to depths; circle size relates to event magnitude); black squares mark the locations of two seismic stations (ESME and NIDO); the summits of Nevado del Tolima and Nevado del Quindío (~10 km NW) are labeled and marked with green stars; approximate locations of towns are indicated by blue text. Courtesy of SGC.

Surface deformation monitoring. An electronic tilt station was installed in 2011 and, by May 2011, data from the Esmeralda station (~2 km W) was being relayed to the SGC Manizales observatory (figure 4). Through the rest of 2011 and 2012, tilt data suggested the effects of local temperatures and fluctuations were within the expected range of the instrument. Changes of 70-95 and 75-100 μrad from the N and E components, respectively, were recorded on a monthly basis. During August-December 2012, fluctuations in tilt were associated with changes in the summit glacier's mass as well as variability due to local temperature changes.

Figure 4. Tilt data from Nevado del Tolima was recorded from the Esmeralda (ESME) station during May 2011 through December 2012. Primary fluctuations in this data were caused by local temperature variations and changes in glacial mass; a data gap occurred during August-October 2012 due to network problems. Courtesy of SGC.

Hazard assessment. Geologic mapping and a hazards analysis were conducted by Thouret and others (1995) (figure 5). They emphasized that they relied on the same appraisal methods as applied by Parra and others (1986) for Nevado del Ruiz. Three scenarios were developed based on three known events of different magnitudes (VEI 3, VEI 3-4, and VEI 4-5); the two plots within the lower left-hand inset map of figure 6 show the major characteristics of those scenarios.

Figure 5. Stratigraphic, volcanic, and geomorphic map of Nevado del Tolima. Town locations are marked with yellow circles. Abbreviations of labeled faults within the blue-outlined inset map refer to the following: P.F.=Palestina Fault; O.-T.-F.=Otun-Pereira Fault; T.F.=Toche Fault; R.-T.F.=Recio-Tolima Fault. Modified from Thouret and others, 1995.
Figure 6. This hazard map for Nevado del Tolima also includes Cerro Machín (located ~20 km SSW). Based on the work by Thourest and others (1995), the small circles drawn around Nevado del Tolima and Cerro Machín encompass areas likely to be affected by subplinian ballistic ejecta, whereas larger circles encompass areas likely to be seriously affected by plinian tephra-fall. Modified from Thouret and others, 1995.

Parameters for possible pyroclastic surges and ash-cloud surges were assessed for major valleys in the region, particularly Río Combeima, Río Totare and Río San Romualdo valleys, and the headwaters of Río Toche valleys (figure 6).

Rock or debris avalanches and lahars were also considered in the study; the authors stated that such events could be triggered by an earthquake or intrusion, and mobilized material had the likelihood of channelization within the deep Río Combeima gorge, a dangerous scenario due to the connectivity of the drainages that influence areas as distant as Ibague and Río Coello. Recent debris-flow deposits from volcanic and glacial sources dominated the aerial extent of the mapped region, particularly along the N slopes and within channels.

Thouret and others (1995) determined that lava flows would be the least hazardous phenomenon likely to occur; "extrusive activity [at Tolima] has been short-lived and is likely to produce block-lava flows such as those of young-Tolima age. Highly viscous and slow-moving block-lava flows could reach only 5-6 km when channeled, and likely move to the southeast or south. However, the very steep south flank would enable lava flows to travel more than 6 km if the chemical composition, physical properties, and hence viscosity of erupted magma changed."

Tolima glacial retreat. While hazards due to glacial ice interactions and volcanism were noted by some investigators (Thouret and others, 1995), other investigations of glaciers were conducted in this region due to interests in global climate change. An assessment conducted in 1976 concluded that five snowcapped volcanoes were present within the Parque Nacional de los Nevados: Tolima, Nevado del Ruiz (~25 km N of Tolima), Santa Isabel (~18 km NNW of Tolima), El Cisne (~20 km N of Tolima), and El Quindío (~10 km W of Tolima) (Hoyos-Patiño, 1998). According to Hoyos-Patiño (1998), El Cisne and El Quindío had almost lost their ice caps by 1976, maintaining less than 1 km2 of ephemeral snow- and ice-covered areas.

Glaciers and snowfields mapped by Landsat images of Tolima's summit in 1976 calculated a total area of 3.8 km2; aerial photo analysis from 1978 determined that 11 glaciers were present with a total area of 2.22 km2. Based on 2001 Landsat 7 image analysis by Morris and others (2006), the area of glacial extent was 1.26 km2; they calculated a loss of 43% from 1959 to 2001 (figure 7). For comparison, the largest ice loss from this region of Colombia occurred at Nevado del Ruiz, where ice coverage decreased from 21.4 km2 to 10.92 km2 during 1959-2001.

Figure 7. Glacier and generalized drainages of Tolima as drawn from 1959 aerial photography. Area 1 represents the total icecap area of 7 km2 as determined in 1959. Area 2 was thin ice that deglaciated between 1959 and 1987. Area 3 was glaciated during the Little Ice Age. Area 4 was Holocene and uppermost Pleistocene tephra incised by snowmelt-fed, narrow, deep gullies. Area 5 represents the prehistorical scar, mounds, and deposits resulting from a rockslide-debris avalanche off the NE flank. Area 6 includes young and deeply carved deposits from debris flows and tephra-laden ice-and-snow avalanches near the crater and on the SW flank. Area 7 includes high, steep, eroded intrusions, necks, and lava flows, from the pre-existing summit. From Thouret and others, 1995.

References. Hoyos-Patiño, F., 1998: Glaciers of Colombia, p. I:11-30, in R. S. Williams and J. G. Ferrigno, eds: Satellite Image Atlas of Glaciers of the World: South America, U.S. Geological Survey Prof. Paper 1386-1, 1206 pp.

Morris, J.N., Poole, A.J., and Klein, A.G., 2006, Retreat of Tropical Glaciers in Colombia and Venezuela from 1984 to 2004 as Measured from ASTER and Landsat Images, 63rd Eastern Snow Conference, Newark, Delaware.

Thouret, J.C., Cantagrel, J-M., Robin, C., Murcia, A., Salinas, R., and Cepeda, H., 1995, Quaternary eruptive history and hazard-zone model at Nevado del Tolima and Cerro Machín volcanoes, Colombia. Journal of Volcanology Geothermal Research, 66 (1-4):397-426.

Information Contacts: María Luisa Monsalve, Gloria Patricia Cortés, and Lina Constanza García, Servicio Geológico Colombiano (SGC), Volcanological and Seismological Observatory, Avenida 12 Octubre 15-47, Manizales, Colombia (URL: http://www.ingeominas.gov.co/Manizales.aspx).

The Global Volcanism Program has no Weekly Reports available for Nevado del Tolima.

Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

10/1988 (SEAN 13:10) Occasional seismicity; minor fumarolic activity

06/2013 (BGVN 38:06) Non-eruptive during 2005-2012; hazard assessment and glacial retreat




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


10/1988 (SEAN 13:10) Occasional seismicity; minor fumarolic activity

Seismicity at Tolima was recorded in December 1987 and September-October 1988 by a telemetric station 2 km SE of the summit (figure 1). During October, as many as seven high-frequency events/day were recorded and minor fumarolic activity was observed. A 50-m-thick ice cap with an area of ~ 2 km2 covers the summit.

Figure 1. Number of earthquakes/day recorded by a seismic station 2 km SE of the summit, December 1987-October 1988. Courtesy of the Observatorio Vulcanológico de Colombia.

Information Contacts: C. Carvajal and F. Muñoz, INGEOMINAS, Manizales.
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06/2013 (BGVN 38:06) Non-eruptive during 2005-2012; hazard assessment and glacial retreat

During 2005-2012, Nevado del Tolima was non-eruptive and the Alert Level remained at IV (Green; "volcanically active with stable behavior") due to minimal seismicity and deformation. The Servicio Geológico Colombiano (SGC) monitored Tolima with a seismic network, tilt measurements, and regular field observations. The greatest changes at Tolima during this time period were related to the summit glacier that generated significant seismicity and surface activity. Volcano-tectonic (VT) and long-period (LP) earthquakes were also detected with the monitoring network, although these events were frequently too small to locate.

In this report, we also highlight geological hazards investigations by Thouret and others (1995); among the hazards, runout distances for lahars were determined as well as potential ash distribution areas. Further, we include the results of long-term studies focused on the summit glacier (figure 2); investigators noted significant retreat based on aerial photos and later, with Landsat image analysis.

Figure 2. A) A view toward the S flank of the glacier-clad summit of Tolima taken on 18 February 2010. Fresh snowfall highlights the morphology that includes lava flows and debris fans. B) A view of the N flank taken on 22 January 2010. The extent of the glacier appears in bright contrast to the yellow-gray and red colors of the altered summit rock. Courtesy of SGC.

Seismicity during March 2006 - December 2012. Based on volcano-tectonic (VT) and long-period (LP) earthquake counts, the SGC reported that low-level seismicity persisted during this reporting period (table 1). The occurrence of earthquakes was highest during 2006 when 22-90 VT and 5-20 LP events per month were recorded. From 2007 through 2012, VT and LP events occurred at a lower rate (0-73 VT per month and 0-17 LP per month).

Table 1.Monthly seismicity at Nevado del Tolima was tabulated by the occurrence of events: volcano-tectonic (VT), long-period (LP), Glacier & Rockfall, Unclassified, and Largest Earthquake magnitude. Events considered "Unclassified" are attributed to icequakes or rockfalls that do not fulfill the amplitude or duration parameters in order to be included in the SGC database. Note that these values have been corrected by the SGC database and differ from "Technical Bulletin" reports. Courtesy of SGC.

 Year Month VT LP Glacier & Rockfall Unclassified Largest EQ
2006 March 48 17 1717 3295 1.58
  April 22 20 1150 2572 0.64
  May 35 17 1460 2331 0.95
  June 43 8 675 1551 1.08
  July 39 8 340 729 1.14
  August 26 9 352 927 0.81
  September 31 5 565 1254 1.01
  October 81 7 904 1639 1.35
  November 77 8 644 1735 1.53
  December 90 9 632 2221 1.45
2007 January 0 12 1218 2615 1.72
  February 4 0 979 3825 1.65
  March 7 1 1345 6513 0.64
  April 1 1 1171 5939 1.01
  May 21 0 1544 4129 1.02
  June 5 0 615 2107 0.64
  July 2 2 746 2165 1.14
  August 6 0 524 1692 2.27
  September 5 1 522 1472 0.7
  October 4 1 472 1115 1.96
  November 3 2 270 966 0.86
  December 7 0 434 1080 1.73
2008 January 3 0 318 968 0.55
  February 2 0 210 805 0.73
  March 1 0 275 1083 -0.4
  April 7 0 256 1453 1.62
  May 5 0 265 1931 2.63
  June 2 0 109 1207 0.88
  July 6 0 125 1148 1.4
  August 73 0 158 974 1.14
  September 12 0 118 864 1.02
  October 12 2 204 1157 0.81
  November 2 0 263 1515 0.35
  December 7 0 197 1242 0.45
2009 January 7 0 185 1490 0.64
  February 1 0 117 1017 0.45
  March 3 0 257 2272 0.88
  April 6 0 279 2245 1.3
  May 8 0 275 2360 0.73
  June 1 0 212 1846 0.88
  July 10 0 100 1127 0.95
  August 3 0 146 1881 2.2
  September 8 0 127 1867 0.64
  October 1 0 176 2757 0.23
  November 0 0 329 1994 0
  December 1 0 414 2055 -0.21
2010 January 4 0 678 1703 0.35
  February 0 1 637 1551 0.75
  March 6 1 698 1638 1.08
  April 0 1 878 1344 0.43
  May 1 2 742 1746 1.4
  June 0 1 491 1307 0.91
  July 0 1 505 1173 1.46
  August 0 0 329 1337 0
  September 0 1 425 860 0.7
  October 0 1 204 434 0.1
  November 5 2 314 1286 0.73
  December 2 2 256 1075 1.3
2011 January 0 0 197 1002 0
  February 3 2 393 1805 0.81
  March 1 3 978 443 1.45
  April 0 1 1370 1043 0.91
  May 1 4 1114 659 0.96
  June 2 1 692 252 1.02
  July 7 0 709 246 1.58
  August 0 1 897 216 0.81
  September 0 5 1404 388 1.22
  October 1 0 1665 427 0.88
  November 2 2 1890 601 0.73
  December 3 2 1923 927 0.96
2012 January 2 0 2033 740 0.55
  February 2 0 1471 159 0.81
  March 4 15 1348 95 0.75
  April 9 17 1379 310 1.65
  May 30 6 1740 417 1.58
  June 2 0 1290 372 1.02
  July 3 2 888 519 0.88
  August 0 0 792 988 0
  September 27 0 1077 847 1.45
  October 3 4 1920 1359 0.64
  November 2 4 1332 1289 1.08
  December 12 1 1873 na 1.2

Seismic signals attributed to glacial changes ("icequakes") and rockfalls dominated the records during 2006-2012. Frequently, more than 1,000 events were recorded per month. During 2008-2010, such events were slightly less frequent; an average of 313 earthquakes occurred per month. Coincidentally, LP events were significantly less frequent during that time period as well (less than one event per month). From March 2006 to July 2007, rockfall signals were attributed to surface activity mainly occurring on the N flank and related to small avalanches of ice and rock. The SGC noted that the general summit area was the source of shallow seismicity from mid 2010 through 2012.

Because of sparse activity and low-magnitude events, hypocentral depths of VT earthquakes were rarely calculated during 2006-2012 (table 2). Five earthquakes were located in September 2012, the most to be located in a single month. Three of these earthquakes were located > 5 km of the summit (NW and SE), while 2 were within 1 km (figure 3). That month, seismicity was relatively high compared with previous months; the SGC reported 27 VT earthquakes and 1,077 "Glacier & Rockfall" signals.

Table 2.The number of located VT earthquakes from Tolima during 2011-2012. Located earthquake information was not available for 2006-2010. Courtesy of SGC.

# of EQs Depths (km) Location from Summit Date
1 2 ~1 km, N Mar. 2011
1 4 ~6 km, NW Jul. 2012
5 3 & 4   Sept. 2012
2 ~3.5   Oct. 2012
Figure 3. This map shows five located VT earthquakes in the region of Tolima during September 2012. Red and yellow circles indicate hypocenters and epicenters (colors relate to depths; circle size relates to event magnitude); black squares mark the locations of two seismic stations (ESME and NIDO); the summits of Nevado del Tolima and Nevado del Quindío (~10 km NW) are labeled and marked with green stars; approximate locations of towns are indicated by blue text. Courtesy of SGC.

Surface deformation monitoring. An electronic tilt station was installed in 2011 and, by May 2011, data from the Esmeralda station (~2 km W) was being relayed to the SGC Manizales observatory (figure 4). Through the rest of 2011 and 2012, tilt data suggested the effects of local temperatures and fluctuations were within the expected range of the instrument. Changes of 70-95 and 75-100 μrad from the N and E components, respectively, were recorded on a monthly basis. During August-December 2012, fluctuations in tilt were associated with changes in the summit glacier's mass as well as variability due to local temperature changes.

Figure 4. Tilt data from Nevado del Tolima was recorded from the Esmeralda (ESME) station during May 2011 through December 2012. Primary fluctuations in this data were caused by local temperature variations and changes in glacial mass; a data gap occurred during August-October 2012 due to network problems. Courtesy of SGC.

Hazard assessment. Geologic mapping and a hazards analysis were conducted by Thouret and others (1995) (figure 5). They emphasized that they relied on the same appraisal methods as applied by Parra and others (1986) for Nevado del Ruiz. Three scenarios were developed based on three known events of different magnitudes (VEI 3, VEI 3-4, and VEI 4-5); the two plots within the lower left-hand inset map of figure 6 show the major characteristics of those scenarios.

Figure 5. Stratigraphic, volcanic, and geomorphic map of Nevado del Tolima. Town locations are marked with yellow circles. Abbreviations of labeled faults within the blue-outlined inset map refer to the following: P.F.=Palestina Fault; O.-T.-F.=Otun-Pereira Fault; T.F.=Toche Fault; R.-T.F.=Recio-Tolima Fault. Modified from Thouret and others, 1995.
Figure 6. This hazard map for Nevado del Tolima also includes Cerro Machín (located ~20 km SSW). Based on the work by Thourest and others (1995), the small circles drawn around Nevado del Tolima and Cerro Machín encompass areas likely to be affected by subplinian ballistic ejecta, whereas larger circles encompass areas likely to be seriously affected by plinian tephra-fall. Modified from Thouret and others, 1995.

Parameters for possible pyroclastic surges and ash-cloud surges were assessed for major valleys in the region, particularly Río Combeima, Río Totare and Río San Romualdo valleys, and the headwaters of Río Toche valleys (figure 6).

Rock or debris avalanches and lahars were also considered in the study; the authors stated that such events could be triggered by an earthquake or intrusion, and mobilized material had the likelihood of channelization within the deep Río Combeima gorge, a dangerous scenario due to the connectivity of the drainages that influence areas as distant as Ibague and Río Coello. Recent debris-flow deposits from volcanic and glacial sources dominated the aerial extent of the mapped region, particularly along the N slopes and within channels.

Thouret and others (1995) determined that lava flows would be the least hazardous phenomenon likely to occur; "extrusive activity [at Tolima] has been short-lived and is likely to produce block-lava flows such as those of young-Tolima age. Highly viscous and slow-moving block-lava flows could reach only 5-6 km when channeled, and likely move to the southeast or south. However, the very steep south flank would enable lava flows to travel more than 6 km if the chemical composition, physical properties, and hence viscosity of erupted magma changed."

Tolima glacial retreat. While hazards due to glacial ice interactions and volcanism were noted by some investigators (Thouret and others, 1995), other investigations of glaciers were conducted in this region due to interests in global climate change. An assessment conducted in 1976 concluded that five snowcapped volcanoes were present within the Parque Nacional de los Nevados: Tolima, Nevado del Ruiz (~25 km N of Tolima), Santa Isabel (~18 km NNW of Tolima), El Cisne (~20 km N of Tolima), and El Quindío (~10 km W of Tolima) (Hoyos-Patiño, 1998). According to Hoyos-Patiño (1998), El Cisne and El Quindío had almost lost their ice caps by 1976, maintaining less than 1 km2 of ephemeral snow- and ice-covered areas.

Glaciers and snowfields mapped by Landsat images of Tolima's summit in 1976 calculated a total area of 3.8 km2; aerial photo analysis from 1978 determined that 11 glaciers were present with a total area of 2.22 km2. Based on 2001 Landsat 7 image analysis by Morris and others (2006), the area of glacial extent was 1.26 km2; they calculated a loss of 43% from 1959 to 2001 (figure 7). For comparison, the largest ice loss from this region of Colombia occurred at Nevado del Ruiz, where ice coverage decreased from 21.4 km2 to 10.92 km2 during 1959-2001.

Figure 7. Glacier and generalized drainages of Tolima as drawn from 1959 aerial photography. Area 1 represents the total icecap area of 7 km2 as determined in 1959. Area 2 was thin ice that deglaciated between 1959 and 1987. Area 3 was glaciated during the Little Ice Age. Area 4 was Holocene and uppermost Pleistocene tephra incised by snowmelt-fed, narrow, deep gullies. Area 5 represents the prehistorical scar, mounds, and deposits resulting from a rockslide-debris avalanche off the NE flank. Area 6 includes young and deeply carved deposits from debris flows and tephra-laden ice-and-snow avalanches near the crater and on the SW flank. Area 7 includes high, steep, eroded intrusions, necks, and lava flows, from the pre-existing summit. From Thouret and others, 1995.

References. Hoyos-Patiño, F., 1998: Glaciers of Colombia, p. I:11-30, in R. S. Williams and J. G. Ferrigno, eds: Satellite Image Atlas of Glaciers of the World: South America, U.S. Geological Survey Prof. Paper 1386-1, 1206 pp.

Morris, J.N., Poole, A.J., and Klein, A.G., 2006, Retreat of Tropical Glaciers in Colombia and Venezuela from 1984 to 2004 as Measured from ASTER and Landsat Images, 63rd Eastern Snow Conference, Newark, Delaware.

Thouret, J.C., Cantagrel, J-M., Robin, C., Murcia, A., Salinas, R., and Cepeda, H., 1995, Quaternary eruptive history and hazard-zone model at Nevado del Tolima and Cerro Machín volcanoes, Colombia. Journal of Volcanology Geothermal Research, 66 (1-4):397-426.

Information Contacts: María Luisa Monsalve, Gloria Patricia Cortés, and Lina Constanza García, Servicio Geológico Colombiano (SGC), Volcanological and Seismological Observatory, Avenida 12 Octubre 15-47, Manizales, Colombia (URL: http://www.ingeominas.gov.co/Manizales.aspx).
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The steep-sided, glacier-clad Nevado del Tolima volcano contrasts with the broad profile of Nevado del Ruiz volcano to the north. The andesitic-dacitic younger Tolima volcano formed during the past 40,000 years, rising above and largely obscuring a 3-km-wide late-Pleistocene caldera. The summit consists of a cluster of late-Pleistocene to Holocene lava domes that were associated with thick block-lava flows on the northern and eastern flanks and extensive pyroclastic-flow deposits. The summit contains a funnel-shaped crater 200-300 m deep. Holocene activity has included explosive eruptions ranging in size from moderate to plinian. The last major eruption took place about 3600 years ago. Lava dome growth has produced block-and-ash flows that traveled primarily to the NE and SE. Minor explosive eruptions have been recorded from Tolima in the 19th and 20th centuries.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1943 Mar Unknown Confirmed 2 Historical Observations
1826 May 1826 Jun 17 (in or after) Confirmed 2 Historical Observations
1825 Mar 2 (?) Unknown Confirmed 2 Historical Observations
1822 Nov (?) Unknown Confirmed 2 Historical Observations
0260 ± 150 years Unknown Confirmed 3 Radiocarbon (corrected)
0200 BCE ± 200 years Unknown Confirmed 3 Radiocarbon (corrected)
0610 BCE ± 200 years Unknown Confirmed 3 Radiocarbon (corrected)
1990 BCE ± 200 years Unknown Confirmed 5 Radiocarbon (corrected)
3500 BCE ± 300 years Unknown Confirmed   Radiocarbon (corrected)
5160 BCE ± 200 years Unknown Confirmed   Radiocarbon (corrected)
5310 BCE ± 100 years Unknown Confirmed   Radiocarbon (uncorrected)
7800 BCE ± 300 years Unknown Confirmed 4 Radiocarbon (uncorrected)

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.


Craters

Feature Name Feature Type Elevation Latitude Longitude
Hoyo, El Crater 4° 39' 0" N 75° 23' 0" W
Nevado del Tolima volcano rises to the south above the forested mountains of the Central Cordillera of Colombia. The andesitic-dacitic younger Tolima volcano formed within the past 40,000 years. The summit consists of a cluster of late-Pleistocene to Holocene lava domes that were associated with thick block-lava flows and extensive pyroclastic-flow deposits. The last major eruption took place about 3600 years ago, although moderate historical eruptions have occurred in the 19th and 20th centuries.

Photo by Norm Banks, 1895 (U.S. Geological Survey).
The steep-sided, glacier-clad Tolima volcano is seen here from the slopes of Nevado del Ruiz volcano to the north. The summit of Tolima consists of a cluster of late-Pleistocene to Holocene lava domes and contains a funnel-shaped crater 200-300 m deep. Holocene activity has ranged from moderate explosions to plinian eruptions. The last major eruption took place about 3600 years ago. Minor explosive eruptions took place in the 19th and 20th centuries.

Photo by Tom Pierson, 1985 (U.S. Geological Survey).

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. 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.

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.

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, Robin C, Murcia A, Salinas R, Cepeda H, 1995. Quaternary eruptive history and hazard-zone model at Nevado del Tolima and Cerro Machin volcanoes, Colombia. J Volc Geotherm Res, 66: 397-426.

Volcano Types

Stratovolcano
Caldera
Lava dome(s)

Tectonic Setting

Subduction zone
Continental crust (> 25 km)

Rock Types

Major
Andesite / Basaltic Andesite
Dacite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
1,660
6,563
441,916
4,258,333

Affiliated Databases

Large Eruptions of Nevado del Tolima Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.