Huaynaputina

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Huaynaputina
Huaynaputina.jpg
View of the crater and part of the nearby valley.
Highest point
Elevation~ 4,850 metres (15,900 ft)[1]
ListingList of volcanoes in Peru
Coordinates16°36′51″S 70°51′14″W / 16.61417°S 70.85389°W / -16.61417; -70.85389Coordinates: 16°36′51″S 70°51′14″W / 16.61417°S 70.85389°W / -16.61417; -70.85389[1]
Naming
Native nameWaynaputina  (Quechua)
Geography
Huaynaputina is located in Peru
Huaynaputina
Huaynaputina
Location in Peru
LocationPeru
Parent rangeAndes
Geology
Age of rock500,000
Mountain typeStratovolcano
Volcanic arc/beltCentral Volcanic Zone
Last eruptionFebruary to March 1600
Ash falling on the city of Arequipa in 1600

Huaynaputina[nb 1] (Spanish: [wainapuˈtina]) is a stratovolcano in a volcanic upland in southern Peru. The volcano does not have an identifiable mountain profile but instead is a large volcanic crater. It has produced high-potassium andesite and dacite.[2] On 19 February 1600, it exploded catastrophically (Volcanic Explosivity Index [VEI] 6), in the largest volcanic explosion in South America in historical times.[3] The eruption continued with a series of events into March. An account of the event was included in Fray Antonio Vázquez de Espinosa's Compendio y Descripción de las Indias, which was translated into English as Compendium and description of the West Indies in 1942.

Name[edit]

The name "Huaynaputina" was given to the volcano after the fact.[4]

Geography and structure[edit]

Huaynaputina lies within the Moquegua Region of southern Peru.[5] The town of Omate lies west of Huaynaputina.[4] Generally, the region is remote and the terrain extreme and thus not easily accessible.[6]

The volcano is part of the Central Volcanic Zone of the Andes. Ubinas is the most active volcano of Peru.[6]

Huaynaputina consists of a nested volcano, with an outer composite volcano/[4] stratovolcano[5] and three younger volcanic vents nested within a 2.5 kilometres (1.6 mi) wide amphitheatre that is set in the older volcano.[4] One of these vents is a 70 metres (230 ft) large trough that cuts into the amphitheatre and appears to be a remnant of a fissure vent. The second appears to have been about 400 metres (1,300 ft) wide before the development of the third vent which has mostly obscured the first two. The third vent is a steep valled, about 80 metres (260 ft) wide and about 200 metres (660 ft) wide pit within a small mound that is in part nested within the second vent. This third vent is surrounded by concentric faults.[7] In addition, a fourth vent lies on the southern slope of the composite volcano, outside of the amphitheatre.[4] It is about 70 metres (230 ft) wide and 30 metres (98 ft) deep and appears to have formed during a phreatomagmatic eruption.[7] These vents lie at about 4,200 metres (13,800 ft) elevation, making them among the highest vents of a Plinian eruption in the world.[4] Slumps have buried parts of the amphitheatre.[8] Dacitic dykes crop out within the amphitheatre[9] and are aligned along a northwest-south trending lineament that the younger vents are also located on.[10] A number of faults with recognizable scarps occur within the amphitheatre and have offset the younger vents.[11]

The terrain west of the volcano is formed by a high plateau, while the peaks Cerro El Volcan and Cerro Chen are situated south of it;[4] Cerro El Volcan is a lava dome.[12] East of Huaynaputina, the terrain drops off steeply into the Rio Tambo valley which runs southward and then westward as it rounds Huaynaputina. Some tributary valleys join the Rio Tambo from Huaynaputina; clockwise from the east these are the Quebradas Huaynaputina, Quebrada Tortoral, Quebrada Aguas Blancas and Quebrada del Volcán.[4]

The existence of a volcano was not recognized before the 1600 eruption, with the topography described as "a low ridge in the center of a Sierra".[4]

Geology[edit]

The Nazca Plate is subducting at a rate of 10.3 centimetres per year (4.1 in/year) beneath the South American Plate, and this process is responsible for volcanic activity and the uplift of the Andes and Altiplano. The subduction is oblique, leading to strike-slip faulting.[6]

The basement underneath Huaynaputina is formed by almost 2 kilometres (1.2 mi) thick sediments and volcanic intrusions of Paleozoic to Mesozoic age[9] including the Yura Group,[13] as well as the Cretaceous Matalaque Formation of volcanic origin.[14] During the Tertiary, these were first overlaid by a total of 0.3–0.5 kilometres (0.19–0.31 mi) ignimbritic Capillune, Llallahui[6] and Sencca Formation during the Miocene, followed by the Miocene-Pliocene Capillune Formation and the Plio-Pleistocene Barroso Group, which includes the composite volcano that hosts Huaynaputina.[9]

Local[edit]

The vents of Huaynaputina form a northnorthwest-southsoutheast trend which also encompasses the neighbouring volcanoes Ubinas and Ticsani[4] and which constitutes a volcanic field which is located behind the main volcanic arc and is associated with faults at the margin of the Rio Tambo graben[15] as well as regional strike-slip faults.[16] In addition, the volcanic rocks produced by these volcanoes have similar composition[6] and recent seismic and volcanic activity at Ubinas and Ticsani indicates that they share a magma reservoir.[17] The faults associated with the volcanic complex have influenced the evolution of the component volcanoes, including Huaynaputina[16] by acting as conduits for ascending magma especially at fault intersections.[18]

Composition[edit]

The eruption products of the 1600 eruption are dacites which define a calc-alkaline[19] potassium-rich suite and which also contain rhyolite inclusions[20] and a rhyolite matrix. Phenocrysts include biotite, chalcopyrite, hornblende, ilmenite, magnetite and plagioclase.[21] Aside from new volcanic rocks, Huaynaputina in 1600 also erupted material that comes from rocks underlying the volcano, including sediments.[22]

A large amount of sulfur appears to have been carried in a volatile phase associated with the magma rather than in the magma proper,[21] although the great pressure that the Huaynaputina magmas formed under likely reduced its importance. But an even larger amount of sulfur may have originated from a relic hydrothermal system that the volcano erupted through, and whose accumulated sulfur would have been mobilized by the 1600 eruption.[23] The amount of volatiles in the magma appears to have decreased during the course of the 1600 eruption, indicating that the magmas originated either in two separate magma chambers or from one zoned magma chamber. This compositional change may explain changes in the eruption phenomena during the course of the 1600 activity.[24]

The rocks had a temperature of about 780–815 °C (1,436–1,499 °F) when they were erupted[25] and their formation may be stimulated by the entry of mafic magmas into the magmatic system.[24] The magmas erupted early during the 1600 event appear to originate from depths of over 20 kilometres (12 mi);[26] petrological analysis indicates that some magmas came from over 15–25 kilometres (9.3–15.5 mi) depth and others from shallower depths of about 4–6 kilometres (2.5–3.7 mi).[13] It appears that the entry of new dacitic magma into a pre-existent dacitic magma system triggered the 1600 eruption; furthermore movement of deep andesitic magmas that had generated the new dacite produced movements within the volcano.[27]

Eruption history[edit]

After the Miocene, the Pastillo volcanic complex developed in the form of 0.5 kilometres (0.31 mi) thick andesitic rocks; these form the composite volcano.[28] The composite volcano underwent sector collapses and glacial erosion which altered its appearance; in fact the amphitheatre which contains the Huaynaputina vents was probably a glacial cirque rather than a caldera,[9] a sector collapse scar[29] or another kind of structure that was altered by fluvial and glacial erosion.[15] Other extinct volcanoes in the area have similar structures.[9] The Cerro El Volcán dome formed during the Quaternary.[30]

Recently emplaced, postglacial dacite bodies occur in the Huaynaputina area.[4] A dacite lava dome and a dyke with similar composition within the amphithreatre pre-date the 1600 eruption.[7] It is likely that the occurrence of these bodies within the composite volcano is coincidental,[9] although a similar tectonic stress field controlled the younger vents.[7]

The 1600 eruption is considered to be an instance of monogenetic volcanism.[29][9] A report of an eruption in 1667 is unclear owing to the sparse historical information and may reflect an eruption at Ubinas instead.[31] Presently, fumaroles occur in the amphitheatre close to the three vents,[9] such as on the third vent and in association with dykes that crop out in the amphitheatre.[7]

1600 eruption[edit]

Based on historical records, the eruption commenced on the 16th February 1600 and ended on the 6th of March with ash fall.[4] Some reports of late ash falls may be due to wind-transported ash.[31]

In the prelude to the eruption, magma moving upwards to the future vents caused earthquakes; once it had reached the surface the eruption quickly became intense[32] as it was channelled by a fracture.[13] Possibly, the second vent formed during this stage[33] but another interpretation is that the second vent is actually a collapse structure that formed late during the eruption.[34] The rising magma appears to have intercepted an older hydrothermal system[32] which existed down to depths of about 3 kilometres (1.9 mi) below the vents.[33] A first Plinian stage took place on the 19th and 20th February and formed 18–23 metres (59–75 ft) thick pumice deposits close to the vent.[35] The pumice was then buried by the ash erupted during this stage, which has been recorded as far as Antarctica.[36] This stage of the eruption produced at least 26 cubic kilometres (6.2 cu mi) of rocks,[37] rhus it makes up the bulk of the output from the 1600 eruption,[38] and generated an eruption column about 34–46 kilometres (21–29 mi) high[25] and likely also a mushroom cloud. Afterwards, collapses in the amphitheatre and within the vent enlarged both features and caused a slowdown in eruptive activity.[32]

After a hiatus the volcano began erupting pyroclastic flows, which were mostly constrained by the topography and were erupted in various stages interrupted by ash fall that extended to larger distances. Most of these pyroclastic flows accumulated in valleys radiating away from Huaynaputina;[36] pyroclastic flows running down the slopes of the volcano entered the Rio Tambo valley and formed dams on the river course, probably mainly at the mouth of the Quebrada Aguas Blancas.[4] The volume of the ignimbrites has been estimated to be about 2 cubic kilometres (0.48 cu mi), without counting the ash that was erupted during this stage.[39] The pulses of pyroclastic flow emission were probably caused by brief obstructions of the vent;[13] at this time a lava dome formed within the second vent.[24] In the third stage, Vulcanian eruptions took place at Huaynaputina and deposited another ash layer, which is thinner than that produced by the first stage eruption and appears to be in part of phreatomagmatic origin. During this stage the volcano also emitted lava bombs; the total volume of erupted tephra is about 1.5 cubic kilometres (0.36 cu mi).[39] This third stage destroyed the lava dome and formed the third vent, which then began to settle along the faults as the magma underneath the vent was exhausted.[24] The fourt vent outside of the amphitheatre formed late during the eruption as well.[13] Various estimates have been made for the dense rock equivalent of the eruption, they range from 4.6–10 cubic kilometres (1.1–2.4 cu mi).[40]

The 1600 eruption has a volcanic explosivity index 6 and is considered to be the largest volcanic eruption in South America in historical time, as well as one of the largest in the last millennium.[41] It was larger than the more recent 1883 eruption of Krakatau in Indonesia and 1992 eruptions of Pinatubo in the Philippines.[42] The eruption column was high enough to penetrate the tropopause.[40]

Notably, caldera collapse did not occur at Huaynaputina and the vent structure is still preserved; normally very large volcanic eruptions are accompanied by the formation of a caldera.[43] This might reflect either the regional tectonics or the absence of a shallow magma chamber.[24] Some collapse structures did nevertheless form, in the form of two not readily recognizable circular areas within the amphitheatre and around the three vents,[44] probably when the magmatic system depressurized during the eruption.[27]

Fallout record[edit]

Thick (8–12 centimetres (3.1–4.7 in)) ash layers were noted in the ice caps of Quelccaya in Peru and Sajama in Bolivia.[41] The Huaynaputina ash layer has been used as a tephrochronology marker for the region.[4] It appears that the bulk of the fallout originated during the first stage of the eruption, with the second and third stage only contributing a relatively small portion thereof.[45]

Anomalies in the sun were observed after the eruption in Europe and China, often described as a "dimming", "reddening" or a "haze" that reduced its luminosity even in a cloudless sky and reduced the visibility of shadows,[46] as well as vivid sunsets and sunrises and sunspots becoming visible.[47] A darkened lunar eclipse described from Graz, Austria, in 1601 may also be the consequence of the Huaynaputina aerosols.[46]

Acid layers in ice cores from Antarctica and Greenland have been attributed to Huaynaputina and their discovery led to the first discussions about whether the 1600 eruption had effects on climate.[48] Ice cores with evidence of the Huaynaputina eruption have been recovered at various sites in Greenland and Antarctica;[46] in Antarctica these include both acid layers and volcanic tephra.[40] The total amount of sulfuric acid erupted by Huaynaputina was calculated to amount to 100 million tons in the southern and about 42 million tons in the northern.[31] Petrological records indicate that Huaynaputina erupted about 26 - 55 million tons of sulfur, more than the sulfur release estimated from ice core data; several explanations for this discrepancy exist.[49]

Impact[edit]

The eruption had a noticeable impact on growth conditions in the Northern Hemisphere, which were the worst of the last 600 years,[4] with summers being on average 0.8 °C (1.4 °F) colder than in the mean.[21] The climate impact has been noted in tree rings from the Urals and Yamal Peninsula in Russia, Canada and the Sierra Nevada in California.[50] The summer 1601 was among the coldest in the northern hemisphere during the last six centuries.[31]

South America[edit]

The eruption had devastating impact on the region.[4] Ash fall was reported in an area of 300,000 square kilometres (120,000 sq mi) of Peru, Chile and Bolivia mostly west and south from the volcano, including La Paz,[5] Lima, Cuzco, Camana where it was thick enough to cause palm trees to collapse, Potosi and Arica, in Lima accompanied by sounds of explosions. Ships observed ash as far as 1,000 kilometres (620 mi) west from the coast.[41] Ash fall, debris flows and pyroclastic flows devastated the area and claimed over 1,000 fatalities. Flooding ensued when volcanic dams in the Rio Tambo broke. A colonial wine industry in southern Peru was wiped out,[31] and damage to infrastructure and economic resources of southern Peru was severe.[5] Recovery only began towards the end of the 16th century.[40]

North America[edit]

Thin tree rings and frost rings[a] have been found in trees of the Western USA and correlate to the Huaynaputina eruption. 1601 and 1603 tree rings close to the tree line in Quebec indicate cold temperatures as well.[46]

Europe[edit]

In Fennoscandia, the summer 1601 was one of the coldest in the last four centuries.[46] Frost continued into summer in Italy and England.[50]

Northern China[edit]

Chronicles from northern China mention severe frosts in 1601 and frequently cold weather, including snowfall in Huai'an County that occurred in summer.[47] The frosts destroyed crops, causing famines[51] severe enough that cannibalism took place.[52] The cold snap was apparently limited to 1601, as there are no reports of unduly cold weather in the subsequent years.[53]

See also[edit]

Notes[edit]

  1. ^ /wnəpʊˈtnə/ WY-nə-puu-TEE-nə; from Quechua Waynaputina, meaning 'young volcano'.

References[edit]

Citations[edit]

  1. ^ a b "Huaynaputina". Global Volcanism Program. Smithsonian Institution. Retrieved 29 December 2008.
  2. ^ "The Geochemistry of Huaynaputina Volcano, Southern Peru" (PDF). Third ISAG. Archived (PDF) from the original on 26 February 2009. Retrieved 18 February 2009.
  3. ^ Thouret, J.-C.; Davilla, J.; Eissen, J.-P. (May 1999). "Largest explosive eruption in historical times in the Andes at Huaynaputina volcano, A.D. 1600, southern Peru" (PDF). Geology. 27 (5): 435–438. Bibcode:1999Geo....27..435T. doi:10.1130/0091-7613(1999)027<0435:LEEIHT>2.3.CO;2. Archived (PDF) from the original on 12 March 2012. Retrieved 22 June 2011.
  4. ^ a b c d e f g h i j k l m n o p Adams et al. 2001, p. 495.
  5. ^ a b c d de Silva 1998, p. 455.
  6. ^ a b c d e Lavallée et al. 2009, p. 255.
  7. ^ a b c d e Adams et al. 2001, p. 514.
  8. ^ Lavallée et al. 2006, p. 339.
  9. ^ a b c d e f g h Adams et al. 2001, p. 496.
  10. ^ Lavallée et al. 2006, p. 337.
  11. ^ Lavallée et al. 2006, p. 338.
  12. ^ Lavallée et al. 2009, p. 260.
  13. ^ a b c d e Lavallée et al. 2006, p. 336.
  14. ^ Lavallée et al. 2006, p. 335.
  15. ^ a b Lavallée et al. 2006, p. 334.
  16. ^ a b Lavallée et al. 2009, p. 259.
  17. ^ Lavallée et al. 2009, pp. 262-263.
  18. ^ Lavallée et al. 2009, p. 263.
  19. ^ Dietterich & de Silva 2010, pp. 307-308.
  20. ^ Adams et al. 2001, p. 504.
  21. ^ a b c Costa, Scaillet & Gourgaud 2003, p. 1.
  22. ^ Lavallée et al. 2006, p. 343.
  23. ^ Dietterich & de Silva 2010, p. 310.
  24. ^ a b c d e Adams et al. 2001, p. 517.
  25. ^ a b Adams et al. 2001, p. 512.
  26. ^ Dietterich & de Silva 2010, p. 308.
  27. ^ a b Lavallée et al. 2006, p. 346.
  28. ^ Lavallée et al. 2006, pp. 334-335.
  29. ^ a b Lavallée et al. 2009, p. 257.
  30. ^ Lavallée et al. 2009, p. 261.
  31. ^ a b c d e Adams et al. 2001, p. 497.
  32. ^ a b c Adams et al. 2001, p. 515.
  33. ^ a b Dietterich & de Silva 2010, p. 307.
  34. ^ Lavallée et al. 2006, p. 340.
  35. ^ Adams et al. 2001, p. 498.
  36. ^ a b Adams et al. 2001, p. 501.
  37. ^ Adams et al. 2001, p. 508.
  38. ^ Dietterich & de Silva 2010, p. 306.
  39. ^ a b Adams et al. 2001, p. 503.
  40. ^ a b c d Fei & Zhou 2009, p. 927.
  41. ^ a b c Adams et al. 2001, p. 494.
  42. ^ Dietterich & de Silva 2010, p. 305.
  43. ^ Lavallée et al. 2006, pp. 333-334.
  44. ^ Lavallée et al. 2006, p. 338,341.
  45. ^ Dietterich & de Silva 2010, pp. 306-307.
  46. ^ a b c d e f de Silva 1998, p. 456.
  47. ^ a b Fei & Zhou 2009, p. 928.
  48. ^ Adams et al. 2001, pp. 494-495.
  49. ^ Costa, Scaillet & Gourgaud 2003, p. 4.
  50. ^ a b Fei & Zhou 2009, p. 931.
  51. ^ Fei & Zhou 2009, p. 929.
  52. ^ Fei & Zhou 2009, p. 930.
  53. ^ Fei & Zhou 2009, p. 932.

Sources[edit]

Bibliography[edit]

External links[edit]


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