Supervolcano

For the 2005 disaster television film, see Supervolcano (film).

A supervolcano is any volcano capable of producing a volcanic eruption with an ejecta mass greater than 1015 kg.[1] Supervolcanoes can occur when magma in the mantle rises into the crust from a hotspot but is unable to break through the crust, and pressure builds in a large and growing magma pool until the crust is unable to contain the pressure (this is the case for the Yellowstone Caldera). They can also form at convergent plate boundaries (for example, Toba). Large igneous provinces can cover huge areas with lava and volcanic ash, causing long-lasting climate change (such as the triggering of a small ice age or global warming), which can threaten species with extinction.

Terminology

The origin of the term "supervolcano" is linked to an early 20th-century scientific debate about the geological history and features of the Three Sisters volcanic region of Oregon in the United States. In 1925, Edwin T. Hodge suggested that a very large volcano, which he named Mount Multnomah, had existed in that region. He believed that several peaks in the Three Sisters area are the remnants left after Mount Multnomah had been largely destroyed by violent volcanic explosions, similar to Mount Mazama.[2] In 1948, the possible existence of Mount Multnomah was ignored by volcanologist Howel Williams in his book The Ancient Volcanoes of Oregon. The book was reviewed in 1949 by another volcanologist, F. M. Byers Jr.[3] In the review, Byers refers to Mount Multnomah as a supervolcano.[4] Although Hodge's suggestion that Mount Multnomah is a supervolcano was rejected long ago, the term "supervolcano" was popularised by the BBC popular science television program Horizon in 2000 to refer to eruptions that produce extremely large amounts of ejecta.[5][6]

Volcanologists and geologists do not refer to "supervolcanoes" in their scientific work, since this is a blanket term that can be applied to a number of different geological settings. Since about 2000, however, the term has been used by professionals for communicating science to the public. The term megacaldera is sometimes used for caldera supervolcanoes, such as the Blake River Megacaldera Complex in the Abitibi greenstone belt of Ontario and Quebec, Canada. Eruptions that rate VEI 8 are termed "super eruptions".[7] Though there is no well-defined minimum explosive size for a "supervolcano", there are at least two types of volcanic eruptions that have been identified as supervolcanoes: large igneous provinces and massive eruptions.[1]

Large igneous provinces

Large igneous provinces (LIP) such as Iceland, the Siberian Traps, Deccan Traps, and the Ontong Java Plateau are extensive regions of basalts on a continental scale resulting from flood basalt eruptions. When created, these regions often occupy several thousand square kilometres and have volumes on the order of millions of cubic kilometers. In most cases, the lavas are normally laid down over several million years. They release large amounts of gases. The Réunion hotspot produced the Deccan Traps about 66 million years ago, coincident with the Cretaceous–Paleogene extinction event. The scientific consensus is that a meteor impact was the cause of the extinction event, but the volcanic activity may have caused environmental stresses on extant species up to the Cretaceous–Paleogene boundary.[8] Additionally, the largest flood basalt event (the Siberian Traps) occurred around 250 million years ago and was coincident with the largest mass extinction in history, the Permian–Triassic extinction event, although it is also unknown whether it was completely responsible for the extinction event.

Such outpourings are not explosive though lava fountains may occur. Many volcanologists consider that Iceland may be a LIP that is currently being formed. The last major outpouring occurred in 1783–84 from the Laki fissure which is approximately 40 km (25 mi) long. An estimated 14 km3 (3.4 cu mi) of basaltic lava was poured out during the eruption.

The Ontong Java Plateau now has an area of about 2,000,000 km2 (770,000 sq mi), and the province was at least 50% larger before the Manihiki and Hikurangi Plateaus broke away.

Massive explosive eruptions

Location of Yellowstone hotspot over time (numbers indicate millions of years before the present).

Volcanic eruptions are classified using the Volcanic Explosivity Index, or VEI. It is a logarithmic scale, which means that an increase of one in VEI number is equivalent to a tenfold increase in volume of erupted material. VEI 7 or VEI 8 eruptions are so powerful that they often form circular calderas rather than cones because the downward withdrawal of magma causes the overlying rock mass to collapse into the empty magma chamber beneath it.

VEI 9 Despite some claims, there are no explosive eruptions known to volcanologists that are confirmed to have attained a VEI of 9. To do so, the eruption would have to release the Dense Rock Equivalent (DRE) of at least 10,000 km3 (2,400 cu mi) of ejecta. There are no known deposits of this volume that can be attributed to any single eruption.

VEI 8 eruptions are colossal events that throw out at least 1,000 km3 (240 cu mi) bulk volume.

Satellite image of Lake Toba, the site of a VEI 8 eruption ~75,000 years ago.

VEI 7 events eject bulk volume at least 100 km3 (24 cu mi).

VEI 6 eruptions occurred at Krakatoa in 1883 and Mount Pinatubo in 1991. These eruptions ejected ~10 and 25 km3 (2.4 and 6.0 cu mi) bulk volume, respectively. At Krakatoa, the Dutch colonial authorities claimed that the death toll was 36,417, but other estimates consider that the death toll is in excess of 120,000.

The 1980 Mount St. Helens eruption was a VEI 5 eruption, with 1.2 km3 (0.29 cu mi) bulk volume of ejecta.

Known supereruptions

Cross-section through Long Valley Caldera.

VEI 9

The eight eruptions at the Paraná and Etendeka traps during the Cretaceous period when taken together were well over 15,000 km³, and may have been a single event that was the largest explosion during the Phanerozoic Eon,[1] but there have been no confirmed VEI 9 eruptions.

VEI 8

This list is incomplete; you can help by expanding it.
VEI 8 eruptions have happened in the following locations.
Name Zone Location Notes Years ago (approx.) Ejecta bulk volume (approx.) Reference
La Garita Caldera San Juan volcanic field U.S., Colorado Fish Canyon eruption. 27,800,000 5,000 km³
Lake Toba Lake Toba Indonesia, Sumatra Produced 2200-4400 tons of H2SO4. 74,000 2,800 km³ [9][10][11][12][13]
Huckleberry Ridge eruption Yellowstone hotspot U.S., Idaho/Wyoming Huckleberry Ridge Tuff 2,100,000 2,500 km³ [14]
Atana Ignimbrite Pacana Caldera Chile, Northern Part of the Altiplano–Puna volcanic complex 4,000,000 2,500 km³ [15]
Whakamaru Taupo Volcanic Zone New Zealand, North Island Whakamaru Ignimbrite/Mount Curl Tephra 340,000 2,000 km³ [16]
Heise Volcanic Field Yellowstone hotspot U.S., Idaho Kilgore Tuff 4,500,000 1,800 km³. [17]
Heise Volcanic Field Yellowstone hotspot U.S., Idaho Blacktail Tuff 6,000,000 1,500 km³. [17]
Cerro Guacha Altiplano-Puna volcanic complex Bolivia Guacha ignimbrite, two smaller eruptions identified 5,700,000 1,300 km³. [18]
Oruanui eruption Taupo Volcanic Zone New Zealand, North Island Taupo Volcano (Lake Taupo) 26,500 1,170 km³
Cerro Galán Andes Central Volcanic Zone Argentina, Catamarca Province 2,500,000 1,050 km³
Lava Creek eruption Yellowstone hotspot U.S., Wyoming Lava Creek Tuff 640,000 1,000 km³ [14]

Based on incomplete statistics, at least 60 VEI 8 eruptions have been identified.[1][19]

VEI 7

VEI 7 eruptions, less colossal but still supermassive, have occurred in historical times. The only ones in the past 2,000 years are Tambora, in 1815,[20] Taupo Volcano's Hatepe eruption, c. 232,[21] Baekdu Mountain, in 946–47,[22] and the eruption of Mount Samalas in 1257.[23]

This list is incomplete; you can help by expanding it.
VEI 7 eruptions have happened in the following locations.
Name Zone Location Event / notes Years ago prior to 1950 (Approx.) Ejecta volume (Approx.)
Mount Tambora Sumbawa Island, West Nusa Tenggara Indonesia This eruption took place in 1815. 1816 became known as the Year Without a Summer. 135 120 km³
Baekdu Mountain Control by Baikal Rift Zone China/North Korea One of the largest volcanic eruptions in the past 2000 years. Millennium Eruption. 1,004 100–120 km³
Taupo Volcano (Lake Taupo) Taupo Volcanic Zone New Zealand, North Island Hatepe eruption AD 232 1,718 120 km³
[21]
Kikai Caldera Japan, Ryukyu Islands Kikai Caldera
4,300 BC		 6,300 150 km³
Macauley Island Kermadec Islands New Zealand Macauley Island 8,300 to 6,300 years ago 6,300 100 km³
[24][25]
Kurile Lake Kamchatka Peninsula Russia Kurile Lake
6,440 BC		 10,500 140–170 km³
[26]
Aira Caldera Japan, Kyūshū Aira Caldera 22,000 450 km³
Rotoiti Ignimbrite Taupo Volcanic Zone New Zealand, North Island Rotoiti Ignimbrite 50,000 240 km³
[27]
Campi Flegrei Italy, Naples 39,000 84 km³*
Mount Aso Japan, Kyūshū Four large explosive eruptions between 300,000 to 80,000 years ago. 300,000 600 km³
Reporoa Caldera Taupo Volcanic Zone New Zealand, North Island 230,000 100 km³
[28]
Mamaku Ignimbrite Taupo Volcanic Zone New Zealand, North Island Rotorua Caldera 240,000 280 km³
[29]
Matahina Ignimbrite Taupo Volcanic Zone New Zealand, North Island Haroharo Caldera 280,000 120 km³
[30]
Long Valley Caldera Bishop Tuff U.S., California 760,000 600 km³
Valles Caldera Jemez volcanic field U.S., New Mexico Two eruptions at 1.15 and 1.47 million years ago 1,150,000
[31]		 600 km³
[31]
Mangakino Taupo Volcanic Zone New Zealand, North Island Three eruptions from 0.97 to 1.23 million years ago 970,000 300 km³
[32]
Henry's Fork Caldera Yellowstone hotspot
Mesa Falls Tuff		 U.S., Idaho Yellowstone hotspot 1,300,000 280 km³
[14]
Karymshina Kamchatka Russia 1,780,000
[33]		 >1000 km³
[34]
Pastos Grandes Ignimbrite Pastos Grandes Caldera Bolivia 2,900,000 820 km³
[35]
Heise volcanic field Yellowstone hotspot
Walcott Tuff		 U.S., Idaho Yellowstone hotspot 6,400,000 750 km³
[17]
Bruneau-Jarbidge caldera Yellowstone hotspot U.S., Idaho Yellowstone hotspot
Responsible for the Ashfall Fossil Beds 1,600 km to the east[36]		 6,710,000[37] 950 km³
[38]
Cerro Panizos Altiplano-Puna volcanic complex Argentina, Bolivia 12,000,000 250 km³
Bennett Lake Volcanic Complex Skukum Group Canada, British Columbia/Yukon 50,000,000 850 km³
[39]

* means DRE (dense rock equivalent).

Media portrayal

Satellite image of San Salvador, El Salvador and the Lake Ilopango caldera (also known as the Dark Age volcano) in the Valley of the Hammocks, site of a VEI 6-8 eruption and said to be ground zero for the extreme weather events of 535–536, when a dark veil settled on the world.
Volcano, lake, and caldera locations in the Taupo Volcanic Zone

See also

References

  1. 1 2 3 4 Bryan, S.E. (2010). "The largest volcanic eruptions on Earth". Earth-Science Reviews. doi:10.1016/j.earscirev.2010.07.001.
  2. ↑ Harris, Stephen (1988) Fire Mountains of the West: The Cascade and Mono Lake Volcanoes, Missoula, Mountain Press.
  3. ↑ Byers, Jr., F. M. (1949) Reviews: The Ancient Volcanoes of Oregon by Howel Williams, The Journal of Geology, volume 57, number 3, May 1949, page 324. Retrieved 2012-08-17.
  4. ↑ supervolcano, n. Oxford English Dictionary, third edition, online version June 2012. Retrieved on 2012-08-17.
  5. ↑ Supervolcanoes. Bbc.co.uk (2000-02-03). Retrieved on 2011-11-18.
  6. ↑ USGS Cascades Volcano Observatory. Vulcan.wr.usgs.gov. Retrieved on 2011-11-18.
  7. ↑ de Silva, Shanaka (2008). "Arc magmatism, calderas, and supervolcanos". Geology 36 (8): 671–672. doi:10.1130/focus082008.1.
  8. ↑ Keller, G (2014). "Deccan volcanism, the Chicxulub impact, and the end-Cretaceous mass extinction: Coincidence? Cause and effect?". Geological Society of America Special Papers. doi:10.1130/2014.2505(03).
  9. ↑ Petraglia, M.; Korisettar, R.; Boivin, N.; Clarkson, C.; Ditchfield, P.; Jones, S.; Koshy, J.; Lahr, M. M.; et al. (2007). "Middle Paleolithic Assemblages from the Indian Subcontinent Before and After the Toba Super-Eruption". Science 317 (5834): 114–6. Bibcode:2007Sci...317..114P. doi:10.1126/science.1141564. PMID 17615356.
  10. ↑ Knight, M.D., Walker, G.P.L., Ellwood, B.B., and Diehl, J.F. (1986). "Stratigraphy, paleomagnetism, and magnetic fabric of the Toba Tuffs: Constraints on their sources and eruptive styles". Journal of Geophysical Research 91: 10355–10382. Bibcode:1986JGR....9110355K. doi:10.1029/JB091iB10p10355.
  11. ↑ Ninkovich, D., Sparks, R.S.J., and Ledbetter, M.T. (1978). "The exceptional magnitude and intensity of the Toba eruption, Sumatra: An example of using deep-sea tephra layers as a geological tool". Bulletin Volcanologique 41 (3): 286–298. Bibcode:1978BVol...41..286N. doi:10.1007/BF02597228.
  12. ↑ Rose, W.I., and Chesner, C.A. (1987). "Dispersal of ash in the great Toba eruption, 75 ka" (PDF). Geology 15 (10): 913–917. Bibcode:1987Geo....15..913R. doi:10.1130/0091-7613(1987)15<913:DOAITG>2.0.CO;2. ISSN 0091-7613.; Lee Siebert, Tom Simkin, Paul Kimberly Volcanoes of the World. University of California Press, 2011 ISBN 0-520-26877-6
  13. ↑ Williams, M.A.J., and Royce, K. (1982). "Quaternary geology of the middle son valley, North Central India: Implications for prehistoric archaeology". Palaeogeography, Palaeoclimatology, Palaeoecology 38 (3–4): 139. doi:10.1016/0031-0182(82)90001-3.
  14. 1 2 3 Global Volcanism Program | Volcanoes of the World | Large Holocene Eruptions. Volcano.si.edu. Retrieved on 2011-11-18.
  15. ↑ Lindsay, J. M.; de Silva, S.; Trumbull, R.; Emmermann, R.; Wemmer, K. (2001). "La Pacana caldera, N. Chile: a re-evaluation of the stratigraphy and volcanology of one of the world's largest resurgent calderas". Journal of Volcanology and Geothermal Research 106 (1–2): 145–173. Bibcode:2001JVGR..106..145L. doi:10.1016/S0377-0273(00)00270-5.
  16. ↑ Froggatt, P. C.; Nelson, C. S.; Carter, L.; Griggs, G.; Black, K. P. (13 February 1986). "An exceptionally large late Quaternary eruption from New Zealand". Nature 319 (6054): 578–582. Bibcode:1986Natur.319..578F. doi:10.1038/319578a0. The minimum total volume of tephra is 1,200 km³ but probably nearer 2,000 km³, ...
  17. 1 2 3 Lisa A. Morgan and William C. McIntosh (2005). "Timing and development of the Heise volcanic field, Snake River Plain, Idaho, western USA". GSA Bulletin 117 (3–4): 288–306. Bibcode:2005GSAB..117..288M. doi:10.1130/B25519.1.
  18. ↑ Salisbury, M. J.; Jicha, B. R.; de Silva, S. L.; Singer, B. S.; Jimenez, N. C.; Ort, M. H. (21 December 2010). "40Ar/39Ar chronostratigraphy of Altiplano-Puna volcanic complex ignimbrites reveals the development of a major magmatic province". Geological Society of America Bulletin 123 (5-6): 821–840. doi:10.1130/B30280.1. Retrieved 29 November 2015.
  19. ↑ BG, Mason (2004). "The size and frequency of the largest explosive eruptions on Earth". Bull Volcanol. doi:10.1007/s00445-004-0355-9.
  20. ↑ Oppenheimer, Clive (2003). "Climatic, environmental and human consequences of the largest known historic eruption: Tambora volcano (Indonesia) 1815". Progress in Physical Geography 27 (2): 230–259. doi:10.1191/0309133303pp379ra.
  21. 1 2 Hogg, A (2011). "Revised calendar date for the Taupo eruption derived by 14C wiggle-matching using a New Zealand kauri 14C calibration data set". The Holocene. doi:10.1177/0959683611425551.
  22. ↑ Xu, JD (2013). "Climatic impact of the Millennium eruption of Changbaishan volcano in China: New insights from high-precision radiocarbon wiggle-match dating". Geophysical Research Letters. doi:10.1029/2012GL054246.
  23. ↑ Vidal, CM (2015). "Dynamics of the major plinian eruption of Samalas in 1257 A.D. (Lombok, Indonesia)". Bull Volcanol. doi:10.1007/s00445-015-0960-9.
  24. ↑ Latter, J. H.; Lloyd, E. F.; Smith, I. E. M.; Nathan, S. 1992. Volcanic hazards in the Kermadec Islands and at submarine volcanoes between southern Tonga and New Zealand, Volcanic hazards information series 4. Wellington, New Zealand. Ministry of Civil Defence. 44 p.
  25. ↑ "Macauley Island". Global Volcanism Program. Smithsonian Institution.
  26. ↑ Kurile Lake on the Global Volcanism Program
  27. ↑ Froggatt, P. C. and Lowe, D. J. (1990). "A review of late Quaternary silicic and some other tephra formations from New Zealand: their stratigraphy, nomenclature, distribution, volume, and age". New Zealand Journal of Geology and Geophysics 33: 89–109. doi:10.1080/00288306.1990.10427576.
  28. ↑ I. A. Nairn; C. P. Wood; R. A. Bailey (December 1994). "The Reporoa Caldera, Taupo Volcanic Zone: source of the Kaingaroa Ignimbrites". Bulletin of Volcanology 56 (6): 529–537. Bibcode:1994BVol...56..529N. doi:10.1007/BF00302833. Retrieved 16 September 2010.
  29. ↑ Karl D. Spinks, J.W. Cole, & G.S. Leonard 2004. Caldera Volcanism in the Taupo Volcanic Zone. In: Manville, V.R. | ed. Geological Society of New Zealand/New Zealand Geophysical Society/26th New Zealand Geothermal Workshop, 6–9 December 2004, Taupo: field trip guides. Geological Society of New Zealand miscellaneous publication 117B.
  30. ↑ Bailey, R. A. and Carr, R. G. (1994). "Physical geology and eruptive history of the Matahina Ignimbrite, Taupo Volcanic Zone, North Island, New Zealand". New Zealand Journal of Geology and Geophysics 37 (3): 319–344. doi:10.1080/00288306.1994.9514624.
  31. 1 2 Izett, Glen A. (1981). "Volcanic Ash Beds: Recorders of Upper Cenozoic Silicic Pyroclastic Volcanism in the Western United States". Journal of Geophysical Research 86 (B11): 10200–10222. Bibcode:1981JGR....8610200I. doi:10.1029/JB086iB11p10200.
  32. ↑ Briggs, R.M.; Gifford, M.G.; Moyle, A.R.; Taylor, S.R.; Normaff, M.D.; Houghton, B.F.; Wilson, C.J.N. (1993). "Geochemical zoning and eruptive mixing in ignimbrites from Mangakino volcano, Taupo Volcanic Zone, New Zealand". Journal of Volcanology and Geothermal Research 56 (3): 175–203. Bibcode:1993JVGR...56..175B. doi:10.1016/0377-0273(93)90016-K.
  33. ↑ Shipley, Niccole; Bindeman, Ilya; Leonov, Vladimir (18–21 October 2009). "Petrologic and Isotopic Investigation of Rhyolites from Karymshina Caldera, the Largest "Super"caldera in Kamchatka, Russia". Portland GSA Annual Meeting.
  34. ↑ Leonov, V. L. and A. N. Rogozin; Karymshina, a giant supervolcano caldera in Kamchatka: Boundaries, structure, volume of pyroclastics, Journal of Volcanology and Seismology; October 2007, Volume 1, Issue 5, pp 296-309
  35. ↑ Ort, M. H.; de Silva, S.; Jiminez, N.; Salisbury, M.; Jicha, B. R. and Singer, B. S. Two new supereruptions in the Altiplano-Puna Volcanic Complex of the Central Andes. Portland GSA Annual Meeting, 18–21 October 2009
  36. ↑ Ashfall Fossil Beds State Historical Park. "The Ashfall Story". Retrieved 8 August 2006.
  37. ↑ Soler, M.M.; Caffe, P.J; Coira, B.L.; Onoe, A.T.; Kay, S. Mahlburg (July 2007). "Geology of the Vilama caldera: A new interpretation of a large-scale explosive event in the Central Andean plateau during the Upper Miocene". Journal of Volcanology and Geothermal Research 164 (1-2): 27–53. doi:10.1016/j.jvolgeores.2007.04.002.
  38. ↑ Ort, Michael H. (June 1993). "Eruptive processes and caldera formation in a nested downsagcollapse caldera: Cerro Panizos, central Andes Mountains". Journal of Volcanology and Geothermal Research 56 (3): 221–252. doi:10.1016/0377-0273(93)90018-M.
  39. ↑ Lambert, Maurice B. (1978). Volcanoes. North Vancouver, British Columbia: Energy, Mines and Resources Canada. ISBN 0-88894-227-3.
  40. ↑ Mystery of the Megavolcano. Pbs.org. Retrieved on 2011-11-18.

Further reading

External links

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