Supervolcano 28625 225766827 2008-07-15T08:49:02Z 79.71.45.157 /* Known super eruptions */ {{for|the docudrama|Supervolcano (docudrama)}} <!-- Deleted image removed: [[Image:Supervolcano1.jpg|thumb|300px|A computer generated image of the supervolcanic Yellowstone Caldera erupting.|{{deletable image-caption|1=Friday, 4 July 2008}}|{{deletable image-caption|1=Friday, 11 July 2008}}]] --> A '''supervolcano''' or super volcanic eruption is a volcanic eruption which is [[orders of magnitude]] greater than any volcano in [[historic]] times (> 200 cubic kilometers). This kind of eruption typically being sufficient to cause long-lasting change to weather (like the triggering of an ice age) adequate enough to threaten the extinction of [[species]], and cover huge areas with lava and ash. == Word origin == The term was originally used in the [[BBC]] [[popular science]] program, [[Horizon (BBC TV series)|''Horizon'']], in 2000 to refer to these types of eruption.<ref>[http://www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml BBC TV Horizon, 3 February 2000, Supervolcanoes]</ref><ref>[http://vulcan.wr.usgs.gov/Volcanoes/Yellowstone/description_yellowstone.html USGS Cascades Volcano Observatory]</ref> That programme introduced the subject of large scale eruptions to the general public. [[Volcanologists]] and [[geologists]] do not refer to "super volcanoes" or "megacalderas" in their scientific work, but sometimes do in public presentations. However, they do describe eruptions that rate [[Volcanic Explosivity Index| VEI]] 7 or 8 as "super eruptions". * Until 2003, ''supervolcano'' was not a technical term used in [[volcanology]]. 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]]. * Though there is no well-defined minimum explosive size for a "supervolcano", there are at least two types of [[volcanic eruption]] that have been identified as supervolcanoes: large igneous provinces and massive eruptions. * Supervolcanoes were seen on other planets via the [[Voyager program]] craft on the moons of Jupiter and Saturn. However, this kind of volcano on earth was not discovered until long after the Voyager had gone on to their interstellar missions. The outer Solar System volcanoes were mostly cryovolcanoes, not magma volcanoes. Theoretically a supervolcano could be a [[cryovolcano]], but none has been found within the solar system. == Large Igneous Provinces == {{main|Large igneous province}} Large igneous provinces (LIP) e.g. [[Iceland]], the [[Siberian Traps]], [[Deccan Traps]], [[Ontong Java Plateau]] are extensive regions of [[basalt]]s on a continental scale resulting from [[flood basalt]] eruptions. When created, these regions often occupy several thousand km<sup>2</sup> and have volumes on the order of millions km<sup>3</sup>. In most cases, the lavas are normally laid down over several million years. They do release massive amounts of gases. The [[Réunion]] hotspot produced the [[Deccan Traps]] about 65 Mya. Research continues into the effect of the outpourings and whether they impacted upon the extinction of the [[dinosaur]]s at the end of the Cretaceous. Such outpourings are not explosive though fire fountains may occur. Many volcanologists consider that [[Iceland]] may be a LIP that is currently being formed. The last major outpouring occurred in 1783-1784 from the [[Laki fissure]] which is ~40 km long. An estimated 14 km<sup>3</sup>of basaltic lava was poured out during the eruption. The [[Ontong Java]] Plateau has an area of about 2 million km<sup>2</sup> . ===Massive eruptions=== Eruptions with a [[Volcanic Explosivity Index]] of 8 (VEI-8) are colossal events that throw out at least 1,000 km <sup>3</sup> Dense Rock Equivalent (DRE) of ejecta; VEI-7 events eject at least 100 km <sup>3</sup> (DRE). VEI-7 or 8 eruptions are so powerful that they often form circular [[caldera]]s rather than [[Volcanic cone|cone]]s because the downward withdrawal of magma causes the overlying mass to collapse and fill the void [[magma chamber]] beneath. One of the classic calderas is at [[Glen Coe]] in the Grampian Mountains of Scotland. First described by Clough et al (1909)<ref>Clough, C. T; Maufe, H. B. & Bailey, E. B; 1909. The cauldron subsidence of Glen Coe, and the Associated Igneous Phenomena. Quart. Journ. Geol. Soc. 65, 611-678.</ref> its geology and volcanic succession has recently been re-analysed in the light of new discoveries.<ref>Kokelaar, B. P and Moore, I. D; 2006. Glencoe caldera volcano, Scotland. British Geological Survey, Keyworth, Nottingham. ISBN 0852725252.</ref> There is an accompanying 1:25000 solid geology map. By way of comparison, the [[1980 Mount St. Helens eruption]] was at the lower end of VEI-5 with 1.2 km <sup>3</sup>, and both [[Mount Pinatubo]] in 1991 and [[Krakatoa]] in 1883 were VEI-6 with 25 km <sup>3</sup>. ===Known super eruptions=== [[Image:Toba overview.jpg|thumb|300px|right|Satellite image of [[Lake Toba]], the site of a VEI-8 eruption ~75,000 years ago.]] '''VEI-8 volcanic events''' have included eruptions at the following locations. Estimates of the volume of ejected material are given in parentheses. * [[Lake Taupo]], [[North Island]], [[New Zealand]] - [[Oruanui eruption]] ~26,500 years ago (~1,170 km<sup>3</sup>) * [[Lake Toba]], [[Sumatra]], [[Indonesia]] - ~75,000 years ago (~2,800 km<sup>3</sup>) * [[Yellowstone Caldera]], [[Wyoming]], [[United States]] - ~2.2 million years ago (2,500 km<sup>3</sup>) and ~640,000 years ago (1,000 km<sup>3</sup>). Also ~1.3 million years ago (280 km<sup>3</sup>, VEI-7) * [[La Garita Caldera]], [[Colorado]], [[United States]] - Source of the truly enormous eruption of the Fish Canyon Tuff ~27.8 million years ago (~5,000 km<sup>3</sup>) The Lake Toba eruption plunged the Earth into a [[volcanic winter]], eradicating an estimated 60%<ref>Stanley H. Ambrose, University of Illinois at Urbana-Champaign, 1998</ref><ref>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, v. 91, p. 10,355-10,382.</ref><ref>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, v. 41, p. 286-298.</ref><ref>Rose, W.I., and Chesner, C.A., 1987, Dispersal of ash in the great Toba eruption, 75 ka: Geology, v. 15, p. 913-917. Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.</ref><ref>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, v. 38, p. 139-162.</ref> of the human population (although humans managed to survive, even in the vicinity of the volcano<ref>Michael Petraglia et al., Science v.317, p.114 (2007)</ref>), and was responsible for the formation of sulfuric acid in the atmosphere. '''VEI-7 volcanic events''', less colossal but still supermassive, have occurred in the geological past. The only ones in historic times are Tambora, in 1815, and Lake Taupo (Hatepe), around 180 AD [http://www.nature.com/nature/journal/v288/n5788/abs/288252a0.html]. * [[Aira Caldera]], [[Kyūshū]], [[Japan]] - ~22,000 years ago (~110 km<sup>3</sup>) * [[Lake Taupo]], [[North Island]], [[New Zealand]] - [[Hatepe eruption]] ~181 C.E (120 km<sup>3</sup>) (Wilson, C. J. N.; Ambraseys, N. N.; Bradley, J.; Walker, G. P. L. (1980). "A new date for the Taupo eruption, New Zealand". Nature 288: 252–253. doi:10.1038/288252a0.) * [[Kikai Caldera]], [[Ryukyu Islands]], [[Japan]] - ~6,300 years ago (150 km<sup>3</sup>) * [[Mount Aso|Aso]], [[Kyūshū]], [[Japan]] - four large explosive eruptions between 300,000 to 80,000 years ago (Total volume ~600 km<sup>3</sup>) *[[Mount Tambora|Tambora]], [[West Nusa Tenggara]], [[Indonesia]] - [[1815]] (160 km<sup>3</sup>) * [[Bruneau-Jarbidge]], [[Idaho]], [[United States]] - ~10-12 million years ago (>250 km<sup>3</sup>) (responsible for the [[Ashfall Fossil Beds]] ~1,600 km to the east<ref>{{cite web | url=http://www.ashfall.unl.edu/ashfallstory.html | title=The Ashfall Story | author=[[Ashfall Fossil Beds|Ashfall Fossil Beds State Historical Park]] | accessdate=2006-08-08}}</ref>) * [[Campi Flegrei]], [[Naples]], [[Italy]] - ~12,000 years ago (Could be as much as 300 km<sup>3</sup>) * [[Long Valley Caldera]], [[California]], [[United States]] - ~760,000 years ago (600 km<sup>3</sup>) * [[Valles Caldera]], [[New Mexico]], [[United States]] - ~1.12 million years ago (~600 km<sup>3</sup>) * [[Bennett Lake Volcanic Complex]], [[British Columbia]]/[[Yukon]], [[Canada]] - ~50 million years ago (850 km<sup>3</sup>) For large [[flood basalt]] eruptions, see [[large igneous province]]. == Media portrayal == A [[National Geographic]] documentary called ''Earth Shocks'' portrayed the destructive impact of the rapid eruption at [[Lake Toba]] approximately 75,000 years ago, which caused a phenomenon known as the [[Millennial Ice Age]] that lasted for ~1000 years and killed an estimated 60 to 75%<ref>Stanley H. Ambrose, University of Illinois at Urbana-Champaign, 1998</ref><ref>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, v. 91, p. 10,355-10,382.</ref><ref>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, v. 41, p. 286-298.</ref><ref>Rose, W.I., and Chesner, C.A., 1987, Dispersal of ash in the great Toga eruption, 75 ka: Geology, v. 15, p. 913-917. Simkin, T., and Siebert, L., 1994, Volcanoes of the World: Geoscience Press, Tucson, Arizona, 349 p.</ref><ref>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, v. 38, p. 139-162.</ref> of the human population of the time. An eruption of the Yellowstone supervolcano was originally one of the scenarios depicted in the docu-drama ''[[End Day]]'', but was excluded from all transmissions to date for unknown reasons and is only presently mentioned at the show's [http://www.bbc.co.uk/bbcthree/tv/end_day.shtml BBC website] (dead as of May 18, 2007; [http://web.archive.org/web/20060528185847/http://www.bbc.co.uk/bbcthree/tv/end_day.shtml Internet Archive version]). In 2005 a two-part television [[docudrama]] entitled ''[[Supervolcano (docudrama)|Supervolcano]]'' was shown on BBC, the [[Discovery Channel]], and other television networks worldwide. It looked at the events that could take place if the [[Yellowstone Caldera|Yellowstone supervolcano]] erupted. It featured footage of volcano eruptions from around the world and [[computer-generated imagery]] depicting the event. According to the program, such an [[eruption]] would have devastating effect across the [[globe]] and would cover virtually all of the [[United States]] with at least 1 cm of [[volcanic ash]], causing mass destruction in the nearby vicinity and killing [[plants]] and [[wildlife]] across the [[continent]]. The dramatic elements in the program were followed by ''Supervolcano: The Truth About Yellowstone'', a documentary about the evidence behind the [[Film|movie]]. The program had originally been scheduled to be transmitted in early [[2005]], but it was felt that this would be insensitive so soon after the [[2004 Indian Ocean tsunami]]. The program and its accompanying [[documentaries]] were released on [[DVD region code|DVD region 2]] simultaneously with its broadcast. ''[[Nova (TV series)|Nova]]'' featured an episode ''Mystery of the Megavolcano'', examining such eruptions in the last 100,000 years.<ref>[http://www.pbs.org/wgbh/nova/megavolcano/ ''Mystery of the Megavolcano'' official site, ''PBS.org'']</ref> In 2006 the [[Sci Fi Channel (United States)|Sci Fi Channel]] aired the documentary ''[[Countdown to Doomsday (documentary)|Countdown to Doomsday]]'' which featured a segment called "Supervolcano". In the ''[[Stargate Atlantis]]'' episode ''[[Inferno (Stargate Atlantis)|Inferno]]'', the main characters are caught in the eruption of a supervolcano and escape using an Ancient warship. In 2008 the Yellowstone supervolcano was featured in the BBC program ''10 things you didn't know about Volcanoes'', presented by Dr Iain Stewart, a volcanologist. ==See also== *[[Hotspot (geology)|Hotspot]] *[[Toba catastrophe theory]] *[[Disaster#Causes of hypothetical future disasters|Causes of hypothetical future disasters]] ==References== {{reflist|2}} ==Sources== *{{cite journal | author = Ben G. Mason | coauthors = David M. Pyle, and Clive Oppenheimer | year = 2004 | title = The size and frequency of the largest explosive eruptions on Earth | journal = Bulletin of Volcanology | volume = 66 | issue = 8 | pages = 735–748 | doi = 10.1007/s00445-004-0355-9 }} == External links == *[http://www.bbc.co.uk/science/horizon/1999/supervolcanoes.shtml Overview and Transcript of the original BBC program] *[http://www.solcomhouse.com/yellowstone.htm Yellowstone Supervolcano and Map of Supervolcanoes Around The World] *[http://pubs.usgs.gov/fs/2005/3024/ USGS Fact Sheet - Steam Explosions, Earthquakes, and Volcanic Eruptions - What's in Yellowstone's Future?] *[http://dsc.discovery.com/convergence/supervolcano/supervolcano.html Discovery Channel's site on "Supervolcano"] *[http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=0006E0BF-BB43-146C-BB4383414B7F0000 Scientific American's The Secrets of Supervolcanoes] *{{imdb title|id=419372|title=Supervolcano}} [[Category:Volcanology]] [[Category:Geological hazards]] [[Category:Supervolcanoes| ]] [[de:Supervulkan]] [[es:Supervolcán]] [[fr:Supervolcan]] [[it:Supervulcano]] [[nl:Supervulkaan]] [[no:Supervulkan]] [[pl:Superwulkan]] [[pt:Supervulcão]] [[ru:Супервулкан]] [[fi:Supertulivuori]] [[sv:Supervulkan]] [[tr:Süper yanardağ]] [[zh:超级火山]]