Aguilera (volcano)

Last updated
Aguilera
Aguilera Volcano.jpg
The volcano is visible in the leftmost portion of the image.
Highest point
Elevation 2,546 m (8,353 ft) [1]
Coordinates 50°20′0″S73°45′0″W / 50.33333°S 73.75000°W / -50.33333; -73.75000
Geography
Location Chile
Parent range Andes
Geology
Mountain type Stratovolcano
Last eruption 3,000 ± 1,000 years before present, but even more recent activity likely
Climbing
First ascent 2014

Aguilera (e. 2546 m/8353 ft.) is a stratovolcano in southern Chile, which rises above the edge of the Southern Patagonian Ice Field. It is a remote volcano that was identified as such in 1985, but the first ascent only occurred in 2014, making it the last unclimbed major Andean volcano.

Contents

It is located west of Lake Argentino and northeast of Peel Fjord in the southern Andes and erupted mainly dacites and pyroclastic tephra. It has erupted several times in the Holocene, with a major eruption taking place 3,000 ± 1,000 years before present. Its eruptions have spread ashfalls over Patagonia.

Geography and geomorphology

Aguilera lies west of the city of Calafate, [2] northwest of Peel Fjord [3] and within the commune of Natales. [4] There is not much knowledge on volcanism in southernmost Chile/Patagonia [5] as the volcanoes are poorly mapped, difficult to access and the weather conditions hostile. [6] Aguilera was named in 1933 by Alberto Maria de Agostini, but its volcanic nature was first established in 1985. [7] [8]

Aguilera is part of the Andean Austral Volcanic Zone, which lies in the southernmost territory of Chile. It consists of six volcanoes, from north to south these are Lautaro, Viedma, Aguilera, Reclus, Monte Burney and Cook; [9] only the first has clearly documented historical activity, in 1959-1960. [10] The first five are located on the South America Plate at increasing distances from the trench, while Cook is on the Scotia Plate [11] and is a complex of lava domes unlike the other volcanoes which are stratovolcanoes. [12] North of Lautaro lies a 300 kilometres (190 mi) long gap without volcanism and then Cerro Hudson, the southernmost volcano of the Southern Volcanic Zone. [2]

The volcano is a 2,545 metres (8,350 ft) [3] /2,546 metres (8,353 ft) high [1] stratovolcano that rises from the Southern Patagonian Ice Field, [13] reaching a height of about 1,500 metres (4,900 ft) above its base and almost entirely covered with ice. [7] [8]

Geology

Off southwesternmost South America, the Antarctic Plate subducts beneath the South America Plate at a rate of 2–2.5 centimetres per year (0.79–0.98 in/year). This subduction is responsible for the volcanism in the Austral Volcanic Zone, [9] [5] whereas earthquake activity is low; this is possibly because the subducting plate is too hot and too slow moving. [11]

The basement below Aguilera is of Paleozoic-early Mesozoic age and consists of metamorphic rocks. The volcano sits at the easterly margin of the Patagonian Batholith, a Mesozoic-Cenozoic igneous rock province. [12]

Volcanism occurs along much of the Andes, partly due to the subduction of the Antarctic Plate and partly due to the subduction of the Nazca Plate, in each case beneath the South America Plate. The latter subduction gives rise to the Northern Volcanic Zone, the Central Volcanic Zone and the Southern Volcanic Zone of the Andes, [14] the Austral Volcanic Zone was once considered part of the Southern Volcanic Zone. [15]

Composition

Aguilera has erupted dacites with intermediate contents of potassium, [5] defining a calc-alkaline suite [16] with adakitic characteristics. [11] Phenocrysts include amphibole, biotite, [16] clinopyroxene, [17] hornblende and plagioclase; plagioclase and also orthoclase and pyroxene often occur as xenoliths. [16]

Melts of subducted sediment and from the subducting slab give rise to the magmas of Aguilera and other volcanoes of the northern Austral Volcanic Zone, [18] but they are subsequently modified by interactions with the mantle wedge [19] and in the case of Aguilera, Lautaro and Viedma further interaction takes place with the Paleozoic crust. [20] [21]

Climate and vegetation

Aguilera lies within the Southern Hemisphere Westerlies belt and the average temperature of the region is about 4–10 °C (39–50 °F). There is a west-east precipitation gradient from 1,400 millimetres per year (55 in/year) to less than 200 millimetres per year (7.9 in/year) in the region; frontal systems and cyclones within the westerlies deliver most precipitation in the region, but precipitation rates are controlled by orographic precipitation and the rainshadow effect resulting in the west-east gradient. [22]

Vegetation in the region ranges from Magellanic subpolar forests to semidesert, depending on the amount of moisture available; Nothofagus species form most of the woods, including Nothofagus antarctica , Nothofagus betuloides and Nothofagus pumilio . [22]

Eruption history

Aguilera erupted during the Holocene, depositing tephra in the region of Lago Argentino and Torres del Paine. [23] The composition of rocks erupted by Aguilera are similar to these from Lautaro and Viedma, and the linkage of specific ash deposits to Aguilera is based mainly on geographical considerations. [24] Other volcanoes have left tephra deposits in the wider region, including Cerro Hudson, Monte Burney and Reclus. [25]

A 70 millimetres (2.8 in) thick tephra from Laguna Potrok Aike may testify to an eruption of Aguilera between 42,400 - 51,747 years before present. [26] Later, two ash layers emplaced 5,700 and 5,150 years before present in the Vega Ñandú mire in Torres del Paine National Park may have been erupted at Aguilera. [27] A tephra layer found at archeological sites around Lago Argentino and deposited there 4,091 - 4,566 years before present originated at Aguilera and probably disrupted local human communities. [28] Farther away in Antarctica, a tephra found in Talos Dome and deposited there 4,420 years before present may have originated at this volcano as well. [29]

Another smaller eruption occurred at Aguilera after the A1 event and deposited ash in the Lago Argentino area; the date of its eruption is unknown. [30] There are no known historical eruptions [31] although Aguilera is a candidate volcano for an eruption that occurred in 1886. [32]

A1 eruption

A major eruption occurred at Aguilera less than 3,596 ± 230 years before present, [25] it was later constrained to have occurred 3,000 ± 100 years before present, and is known as the A1 eruption of Aguilera. [33] It was a large eruption and deposited tephra east of the volcano [25] and as far south as the Strait of Magellan; [34] other Aguilera tephras are less widespread. [35] Its volume has been estimated to be between 3.6–9.5 cubic kilometres (0.86–2.28 cu mi), [34] larger than the 1991 eruption of Cerro Hudson, [35] and it is classified as level 5 on the volcanic explosivity index. [1]

Tephra deposits from this eruption have been found in the Cordillera Baguales (6–8 centimetres (2.4–3.1 in) thickness), [36] at Gran Campo Nevado (1.5 millimetres (0.059 in) thickness), [25] Lago Argentino (6–8 centimetres (2.4–3.1 in) thickness), Lago Cardiel (1 centimetre (0.39 in) thickness), Lago Roca (10 centimetres (3.9 in) thickness), Lake Viedma (2 centimetres (0.79 in) thickness), Brunswick Peninsula (1 centimetre (0.39 in) thickness), Seno Skyring (2 centimetres (0.79 in)), Torres del Paine National Park (2–3 centimetres (0.79–1.18 in) thickness) [36] and Isla Grande de Tierra del Fuego (1 centimetre (0.39 in) thickness). On Isla Grande de Tierra del Fuego apparently the eruption did not impact human populations to a large degree. [37] Furthermore, a sulfur dioxide-rich layer in ice cores from Talos Dome, Antarctica, dated to 3,600 years before present may have been a consequence of the Aguilera eruption. [25]

First climb

Aguilera was the last major volcano in the Andes to be climbed, with the first successful attempt occurring in August 2014 by a group of Chilean climbers. [8] [7]

Related Research Articles

Viedma (volcano) mountain in Patagonia

Viedma is a subglacial volcano located below the ice of the Southern Patagonian Ice Field, an area disputed between Argentina and Chile. The 1988 eruption deposited ash and pumice on the ice field and produced a mudflow that reached Viedma Lake. The exact position of the edifice is unclear, both owing to the ice cover and because the candidate position, the "Viedma Nunatak", does not clearly appear to be of volcanic nature. Numerous ash layers in the Viedma lake indicate numerous past eruptions.

Cerro Azul (Chile volcano) mountain in Curicó Province Chile

Cerro Azul, sometimes referred to as Quizapu, is an active stratovolcano in the Maule Region of central Chile, immediately south of Descabezado Grande. Part of the South Volcanic Zone of the Andes, its summit is 3,788 meters (12,428 ft) above sea level, and is capped by a summit crater that is 500 meters (1,600 ft) wide and opens to the north. Beneath the summit, the volcano features numerous scoria cones and flank vents.

Ampato dormant Peruvian volcano

Ampato is a dormant 6,288-metre (20,630 ft) stratovolcano in the Andes of southern Peru. It lies about 70–75 kilometres (43–47 mi) northwest of Arequipa and is part of a north-south chain that includes the volcanoes Hualca Hualca and Sabancaya, the last of which has been active in historical time.

Corcovado Volcano mountain in Palena Province Chile

Corcovado Volcano is a stratovolcano located about 25 kilometres (16 mi) south of the mouth of Yelcho River, in the Palena Province, Los Lagos Region, Chile. The glacially eroded volcano is flanked by Holocene cinder cones. The volcano's base has likely prehistoric lava flows that are densely vegetated. The most distinctive feature of this volcano is its stepped top, similar to that of Puntiagudo Volcano. At its foot lies a series of beautiful lakes. Corcovado dominates the landscape of Gulf of Corcovado area and is visible from the Chiloé Island, weather allowing.

Quetrupillán mountain in Cautín Province Chile

Quetrupillán is a stratovolcano located in the La Araucanía Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is located in a tectonic basement block between the main traces of Liquiñe-Ofqui Fault and Reigolil-Pirihueico Fault.

Melimoyu mountain in Chile

Melimoyu is a stratovolcano in Chile. It is an elongated volcanic complex that contains two nested calderas of 1 kilometre (0.62 mi) and 8 kilometres (5.0 mi) width. An ice cap has developed on the volcano with a couple of outlet glaciers. Melimoyu has not erupted in recent times, but during the Holocene two large eruptions took place and ejected ash at large distances from the volcano.

Mentolat mountain in Aysén Province Chile

Mentolat is an ice-filled, 6 km (4 mi) wide caldera in the central portion of Magdalena Island, Aisén Province, Chilean Patagonia. This caldera sits on top of a stratovolcano which has generated lava flows and pyroclastic flows. The caldera is filled with a glacier.

Cerro Macá mountain in Aysén Province Chile

Cerro Macá is a stratovolcano located to the north of the Aisén Fjord and to the east of the Moraleda Channel, in the Aysén del General Carlos Ibáñez del Campo Region of Chile. This glacier-covered volcano lies along the regional Liquiñe-Ofqui Fault Zone.

Andean Volcanic Belt Volcanic belt in South America

The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones that are separated from each other by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a broad range of volcano-tectonic settings, as it has rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains as well as a large range of crustal thicknesses and magma ascent paths and different amounts of crustal assimilations.

Taapaca Volcano in Chile

Taapaca is a Holocene volcanic complex in northern Chile's Arica y Parinacota Region. Located in the Chilean Andes, it is part of the Central Volcanic Zone of the Andean Volcanic Belt, one of four distinct volcanic chains in South America. The town of Putre lies at the southwestern foot of the volcano.

Sollipulli mountain

Sollipulli is an ice-filled volcanic caldera and volcanic complex, which lies southeast of the small town of Melipeuco in the La Araucanía Region, Chile. It is part of the Southern Volcanic Zone of the Andes, one of the four volcanic belts in the Andes chain.

Reclus (volcano) mountain

Reclus, also written as Reclús, is a volcano located in the Southern Patagonia Ice Field, Chile. Part of the Austral Volcanic Zone of the Andes, its summit rises 1,000 metres (3,300 ft) above sea level and is capped by a crater about 1 kilometre (0.62 mi) wide. Close to the volcano lies the Amalia Glacier, which is actively eroding Reclus.

Cay (volcano) volcanic mountain in Chile

Cay is a stratovolcano in the South Volcanic Zone of the Andes in Aysén del General Carlos Ibáñez del Campo Region, Chile. The volcano is located 15 km northeast of the larger Maca Volcano and about 230 km of the Chile Trench at the intersection of NW-SE and NE-SW faults of the Liquiñe-Ofqui Fault Zone. The volcano is composed from basalt and dacite and there is no evidence of Holocene activity. Below 1000m, several parasitic cones lie on the southwest flank of the volcano.

Calabozos mountain in Chile

Calabozos is a Holocene caldera in central Chile's Maule Region. Part of the Chilean Andes' volcanic segment, it is considered a member of the Southern Volcanic Zone (SVZ), one of the three distinct volcanic belts of South America. This most active section of the Andes runs along central Chile's western edge, and includes more than 70 of Chile's stratovolcanoes and volcanic fields. Calabozos lies in an extremely remote area of poorly glaciated mountains.

Crater Basalt volcanic field is a volcanic field in Argentina in the Chubut province.

Irruputuncu mountain shared by Bolivia and Chile

Irruputuncu is a volcano in the commune of Pica, Tamarugal Province, Tarapacá Region, Chile, as well as San Pedro de Quemes Municipality, Nor Lípez Province, Potosí Department, Bolivia. The mountain's summit is 5,163 m (16,939 ft) high and has two summit craters—the southernmost 200 m (660 ft)-wide one has active fumaroles. The volcano also features lava flows, block and ash flows and several lava domes. The volcano is part of the Andean Central Volcanic Zone (CVZ).

Monte Burney Stratovolcano in southern Chile

Monte Burney is a volcano in southern Chile, part of its Austral Volcanic Zone which consists of six volcanoes with activity during the Quaternary. This volcanism is linked to the subduction of the Antarctic Plate beneath the South America Plate and the Scotia Plate.

Fueguino is a volcanic field in Chile. The southernmost volcano in the Andes, it lies on Tierra del Fuego's Cook Island and also extends over nearby Londonderry Island. The field is formed by lava domes, pyroclastic cones, and a crater lake.

Sabancaya Peruvian stratovolcano

Sabancaya is an active 5,976-metre-high (19,606 ft) stratovolcano in the Andes of southern Peru, about 70 kilometres (43 mi) northwest of Arequipa. It is considered part of the Central Volcanic Zone of the Andes, one of the three distinct volcanic belts of the Andes. The Central Volcanic Zone includes a number of volcanoes, some of which like Huaynaputina have had large eruptions and others such as Sabancaya and Ubinas have been active in historical time. Sabancaya forms a volcanic complex together with Hualca Hualca to the north and Ampato to the south and has erupted andesite and dacite. It is covered by a small ice cap which leads to a risk of lahars during eruptions.

Tocomar

Tocomar is a Pleistocene volcano in the Jujuy Province, Argentina. Located in the Argentine segment of the Andean Volcanic Belt, it is part of the Central Volcanic Zone of the Andes which is one of four distinct volcanic belts in South America. The Central Volcanic Zone consists of about 44 active volcanoes and large calderas of the Altiplano-Puna volcanic complex. Its volcanism is caused by the subduction of the Nazca Plate beneath the South America Plate in the Peru-Chile Trench, but at Tocomar volcanism is further influenced by a large fault zone, the Calama-Olacapato-El Toro fault, which runs diagonally across the volcanic arc.

References

  1. 1 2 3 "Aguilera". Global Volcanism Program . Smithsonian Institution.
  2. 1 2 Kilian 1990, p. 302.
  3. 1 2 Harambour 1988, p. 178.
  4. "Sernageomin comienza marcha blanca para monitoreo del volcán Burney". Intendencia Región de Magallanes y de la Antárctica Chilena (in Spanish). 6 November 2015.
  5. 1 2 3 Kilian 1990, p. 301.
  6. Harambour 1988, p. 173.
  7. 1 2 3 Griffin, Lindsay (1 October 2014). "Winter in Patagonia - a coveted first ascent of Aguilera". www.thebmc.co.uk. British Mountaineering Council.
  8. 1 2 3 Rada, Camilo (23 September 2014). "Volcan Aguilera, first ascent in Patagonia by the Uncharted expedition". PlanetMountain.com. Retrieved 24 January 2018.
  9. 1 2 Kilian 1994, p. 477.
  10. Stern 2008, p. 435.
  11. 1 2 3 Stern & Kilian 1996, p. 264.
  12. 1 2 Stern & Kilian 1996, p. 265.
  13. Perucca, Laura; Alvarado, Patricia; Saez, Mauro (1 July 2016). "Neotectonics and seismicity in southern Patagonia". Geological Journal. 51 (4): 553. doi:10.1002/gj.2649. ISSN   1099-1034.
  14. Stern, Futa & Muehlenbachs 1984, p. 31.
  15. Stern, Futa & Muehlenbachs 1984, p. 32.
  16. 1 2 3 Kilian 1990, p. 303.
  17. Stern & Kilian 1996, p. 267.
  18. Stern & Kilian 1996, p. 278.
  19. Stern & Kilian 1996, p. 280.
  20. Stern, Futa & Muehlenbachs 1984, p. 42.
  21. Kilian 1994, p. 478.
  22. 1 2 Tonello, Mancini & Seppä 2009, p. 411.
  23. Tonello, Mancini & Seppä 2009, p. 413.
  24. Stern 2008, p. 441.
  25. 1 2 3 4 5 Kilian, Rolf; Hohner, Miriam; Biester, Harald; Wallrabe-Adams, Hans J.; Stern, Charles R. (2003). "Holocene peat and lake sediment tephra record from the southernmost Chilean Andes (53-55°S)". Revista Geológica de Chile. 30 (1): 23–37. doi:10.4067/S0716-02082003000100002. ISSN   0716-0208.
  26. Wastegård, S.; Veres, D.; Kliem, P.; Hahn, A.; Ohlendorf, C.; Zolitschka, B. (July 2013). "Towards a late Quaternary tephrochronological framework for the southernmost part of South America – the Laguna Potrok Aike tephra record". Quaternary Science Reviews. 71: 84. doi:10.1016/j.quascirev.2012.10.019. ISSN   0277-3791.
  27. Villa-Martínez, Rodrigo; Moreno, Patricio I. (November 2007). "Pollen evidence for variations in the southern margin of the westerly winds in SW patagonia over the last 12,600 years". Quaternary Research. 68 (3): 404. doi:10.1016/j.yqres.2007.07.003. ISSN   0033-5894.
  28. Franco, Nora Viviana; Borrero, Luis Alberto; Brook, George A.; Mancini, María Virginia (2018). Changes in the Technological Organization and Human Use of Space in Southern Patagonia (Argentina) During the Late Holocene. Lithic Technological Organization and Paleoenvironmental Change. Studies in Human Ecology and Adaptation. 9. pp. 308–309. doi:10.1007/978-3-319-64407-3_14. ISBN   978-3-319-64405-9.
  29. Narcisi, Biancamaria; Petit, Jean Robert; Delmonte, Barbara; Scarchilli, Claudio; Stenni, Barbara (August 2012). "A 16,000-yr tephra framework for the Antarctic ice sheet: a contribution from the new Talos Dome core". Quaternary Science Reviews. 49: 61. doi:10.1016/j.quascirev.2012.06.011. ISSN   0277-3791.
  30. Stern 2008, p. 450.
  31. Martinic, Mateo (1 December 1988). "Actividad volcanica historica en la Region de Magallanes". Andean Geology (in Spanish). 15 (2): 184. ISSN   0718-7106.
  32. Mayr, Christoph; Smith, Rebecca E.; García, M. Luján; Massaferro, Julieta; Lücke, Andreas; Dubois, Nathalie; Maidana, Nora I.; Meier, Wolfgang J.-H.; Wissel, Holger; Zolitschka, Bernd (1 August 2019). "Historical eruptions of Lautaro Volcano and their impacts on lacustrine ecosystems in southern Argentina". Journal of Paleolimnology. 62 (2): 215. doi:10.1007/s10933-019-00088-y. ISSN   1573-0417.
  33. Stern 2008, p. 449.
  34. 1 2 Stern 2008, p. 452.
  35. 1 2 Smith, Rebecca E.; Smith, Victoria C.; Fontijn, Karen; Gebhardt, A. Catalina; Wastegård, Stefan; Zolitschka, Bernd; Ohlendorf, Christian; Stern, Charles; Mayr, Christoph (15 August 2019). "Refining the Late Quaternary tephrochronology for southern South America using the Laguna Potrok Aike sedimentary record". Quaternary Science Reviews. 218: 144. doi:10.1016/j.quascirev.2019.06.001. ISSN   0277-3791.
  36. 1 2 Stern 2008, p. 445.
  37. Ozán, Ivana Laura; Pallo, María Cecilia (2019). "Past human populations and landscapes in the Fuegian Archipelago, southernmost South America". Quaternary Research. 92 (2): 9. doi:10.1017/qua.2018.157. ISSN   0033-5894 via ResearchGate.

Sources