Volume of products, eruption cloud height, and qualitative observations (using terms ranging from "gentle" to "mega-colossal") are used to determine the explosivity value. The scale is open-ended with the largest eruptions in history given a magnitude of 8. A value of 0 is given for non-explosive eruptions, defined as less than 10,000 m3 (350,000 cu ft) of tephra ejected; and 8 representing a mega-colossal explosive eruption that can eject 1.0×1012 m3 (240 cubic miles) of tephra and have a cloud column height of over 20 km (66,000 ft). The scale is logarithmic, with each interval on the scale representing a tenfold increase in observed ejecta criteria, with the exception of between VEI-0, VEI-1 and VEI-2.[1]
With indices running from 0 to 8, the VEI associated with an eruption is dependent on how much volcanic material is thrown out, to what height, and how long the eruption lasts. The scale is logarithmic from VEI-2 and up; an increase of 1 index indicates an eruption that is 10 times as powerful. As such, there is a discontinuity in the definition of the VEI between indices 1 and 2. The lower border of the volume of ejecta jumps by a factor of one hundred, from 10,000 to 1,000,000 m3 (350,000 to 35,310,000 cu ft), while the factor is ten between all higher indices. In the following table, the frequency of each VEI indicates the approximate frequency of new eruptions of that VEI or higher.
About 40 eruptions of VEI-8 magnitude within the last 132 million years (Mya) have been identified, of which 30 occurred in the past 36 million years. Considering the estimated frequency is on the order of once in 50,000 years,[3] there are likely many such eruptions in the last 132 Mya that are not yet known. Based on incomplete statistics, other authors assume that at least 60 VEI-8 eruptions have been identified.[5][6] The most recent is Lake Taupō's Oruanui eruption, more than 27,000 years ago, which means that there have not been any Holocene eruptions with a VEI of 8.[5]
There have been at least 10 eruptions of VEI-7 in the last 11,700 years. There are also 58 Plinian eruptions, and 13 caldera-forming eruptions, of large, but unknown magnitudes. By 2010, the Global Volcanism Program of the Smithsonian Institution had cataloged the assignment of a VEI for 7,742 volcanic eruptions that occurred during the Holocene (the last 11,700 years) which account for about 75% of the total known eruptions during the Holocene. Of these 7,742 eruptions, about 49% have a VEI of 2 or lower, and 90% have a VEI of 3 or lower.[7]
Limitations
Under the VEI, ash, lava, lava bombs, and ignimbrite are all treated alike. Density and vesicularity (gas bubbling) of the volcanic products in question is not taken into account. In contrast, the DRE (dense-rock equivalent) is sometimes calculated to give the actual amount of magma erupted. Another weakness of the VEI is that it does not take into account the power output of an eruption, which makes the VEI extremely difficult to determine with prehistoric or unobserved eruptions.
Although VEI is quite suitable for classifying the explosive magnitude of eruptions, the index is not as significant as sulfur dioxide emissions in quantifying their atmospheric and climatic impact.[8]
^ Newhall, Christopher G.; Self, Stephen (1982). (PDF). Journal of Geophysical Research. 87 (C2): 1231–1238. Bibcode:1982JGR....87.1231N. doi:10.1029/JC087iC02p01231. Archived from the original (PDF) on December 13, 2013.
^ abDosseto, A. (2011). Turner, S. P.; Van-Orman, J. A. (eds.). Timescales of Magmatic Processes: From Core to Atmosphere. Wiley-Blackwell. ISBN978-1-4443-3260-5.
^Rothery, David A. (2010), Volcanoes, Earthquakes and Tsunamis, Teach Yourself
^ ab Mason, Ben G.; Pyle, David M.; Oppenheimer, Clive (2004). "The size and frequency of the largest explosive eruptions on Earth". Bulletin of Volcanology. 66 (8): 735–748. Bibcode:2004BVol...66..735M. doi:10.1007/s00445-004-0355-9. S2CID 129680497.
^Bryan, S.E. (2010). "The largest volcanic eruptions on Earth" (PDF). Earth-Science Reviews. 102 (3–4): 207–229. Bibcode:2010ESRv..102..207B. doi:10.1016/j.earscirev.2010.07.001.
^Miles, M. G.; Grainger, R. G.; Highwood, E. J. (2004). "Volcanic Aerosols: The significance of volcanic eruption strength and frequency for climate" (PDF). Quarterly Journal of the Royal Meteorological Society. 130 (602): 2361–2376. Bibcode:2004QJRMS.130.2361M. doi:10.1256/qj.03.60. S2CID 53005926.
The size and frequency of the largest explosive eruptions on Earth, a 2004 article from the Bulletin of Volcanology
List of Large Holocene Eruptions (VEI > 4) from the Smithsonian Global Volcanism Program 2012-01-17 at the Wayback Machine
January 21, 2023
volcanic, explosivity, index, redirects, here, company, visual, entertainment, volcanic, explosivity, index, relative, measure, explosiveness, volcanic, eruptions, devised, christopher, newhall, united, states, geological, survey, stephen, self, university, ha. VEI redirects here For the company see Visual Entertainment Inc The volcanic explosivity index VEI is a relative measure of the explosiveness of volcanic eruptions It was devised by Christopher G Newhall of the United States Geological Survey and Stephen Self at the University of Hawaii in 1982 VEI and ejecta volume correlation Volume of products eruption cloud height and qualitative observations using terms ranging from gentle to mega colossal are used to determine the explosivity value The scale is open ended with the largest eruptions in history given a magnitude of 8 A value of 0 is given for non explosive eruptions defined as less than 10 000 m3 350 000 cu ft of tephra ejected and 8 representing a mega colossal explosive eruption that can eject 1 0 1012 m3 240 cubic miles of tephra and have a cloud column height of over 20 km 66 000 ft The scale is logarithmic with each interval on the scale representing a tenfold increase in observed ejecta criteria with the exception of between VEI 0 VEI 1 and VEI 2 1 Contents 1 Classification 2 Limitations 3 Lists of notable eruptions 4 See also 5 References 6 External linksClassification EditWith indices running from 0 to 8 the VEI associated with an eruption is dependent on how much volcanic material is thrown out to what height and how long the eruption lasts The scale is logarithmic from VEI 2 and up an increase of 1 index indicates an eruption that is 10 times as powerful As such there is a discontinuity in the definition of the VEI between indices 1 and 2 The lower border of the volume of ejecta jumps by a factor of one hundred from 10 000 to 1 000 000 m3 350 000 to 35 310 000 cu ft while the factor is ten between all higher indices In the following table the frequency of each VEI indicates the approximate frequency of new eruptions of that VEI or higher VEI Ejecta volume bulk Classification Description Plume Periodicity Troposphericinjection Stratosphericinjection 2 Examples0 lt 104 m3 Hawaiian Effusive lt 100 m constant negligible noneKilauea current Mawson Peak current Dallol 2011 Holuhraun 2014 2015 Fagradalsfjall 2021 Piton de la Fournaise 2022 Mauna Loa 1975 1984 2022 1 gt 104 m3 Hawaiian Strombolian Gentle 100 m 1 km daily minor noneYakedake 1995 Raoul Island 2006 Havre Seamount 2012 Dieng Volcanic Complex 1964 1979 2017 Nyiragongo 1977 2002 2021 2 gt 106 m3 Strombolian Vulcanian Explosive 1 5 km 2 weeks moderate noneStromboli since 1934 Etna current Unzen 1792 Ruang 1871 Ritter Island 1888 Galeras 1993 El Hierro 2011 2012 Whakaari White Island 2019 3 gt 107 m3 Strombolian Vulcanian Pelean Sub Plinian Severe 3 15 km 3 months substantial possibleSurtsey 1963 1967 Nevado del Ruiz 1985 Mount Redoubt 1989 1990 Soufriere Hills 1997 Ontake 2014 Fuego 2018 Cumbre Vieja 2021 4 gt 0 1 km3 Pelean Plinian Sub Plinian Catastrophic gt 10 km 18 months substantial definiteLaki 1783 Mount Bandai 1888 Mount Pelee 1902 Mount Lamington 1951 Eyjafjallajokull 2010 Mount Merapi 2010 Taal 2020 Semeru 2021 5 gt 1 km3 Pelean Plinian Cataclysmic gt 10 km 12 years substantial significantVesuvius 79 Mount Fuji 1707 Mount Tarawera 1886 Mount St Helens 1980 El Chichon 1982 Puyehue 2011 Hunga Tonga Hunga Haʻapai 2022 6 gt 10 km3 Plinian Ultra Plinian Colossal gt 20 km 50 100 years substantial substantialLake Ilopango 450 Quilotoa 1280 Huaynaputina 1600 Krakatoa 1883 Santa Maria 1902 Novarupta 1912 Mount Pinatubo 1991 7 gt 100 km3 Ultra Plinian Super colossal gt 20 km 500 1 000 years substantial substantialLong Valley 760 kyr Campi Flegrei 37 kyr Aira 22 kyr Mazama 5700 BC Kikai 4300 BC Santorini 1620 BC Samalas 1257 Tambora 1815 8 gt 1 000 km3 Ultra Plinian Mega colossal gt 20 km gt 50 000 years 3 4 vast vastFlat Landing Brook Ordovician Wah Wah Springs 30 Mya La Garita 26 3 Mya Yellowstone 2 1 Mya 640 kyr Toba 74 kyr Taupō 26 5 kyr About 40 eruptions of VEI 8 magnitude within the last 132 million years Mya have been identified of which 30 occurred in the past 36 million years Considering the estimated frequency is on the order of once in 50 000 years 3 there are likely many such eruptions in the last 132 Mya that are not yet known Based on incomplete statistics other authors assume that at least 60 VEI 8 eruptions have been identified 5 6 The most recent is Lake Taupō s Oruanui eruption more than 27 000 years ago which means that there have not been any Holocene eruptions with a VEI of 8 5 There have been at least 10 eruptions of VEI 7 in the last 11 700 years There are also 58 Plinian eruptions and 13 caldera forming eruptions of large but unknown magnitudes By 2010 the Global Volcanism Program of the Smithsonian Institution had cataloged the assignment of a VEI for 7 742 volcanic eruptions that occurred during the Holocene the last 11 700 years which account for about 75 of the total known eruptions during the Holocene Of these 7 742 eruptions about 49 have a VEI of 2 or lower and 90 have a VEI of 3 or lower 7 Limitations EditUnder the VEI ash lava lava bombs and ignimbrite are all treated alike Density and vesicularity gas bubbling of the volcanic products in question is not taken into account In contrast the DRE dense rock equivalent is sometimes calculated to give the actual amount of magma erupted Another weakness of the VEI is that it does not take into account the power output of an eruption which makes the VEI extremely difficult to determine with prehistoric or unobserved eruptions Although VEI is quite suitable for classifying the explosive magnitude of eruptions the index is not as significant as sulfur dioxide emissions in quantifying their atmospheric and climatic impact 8 Lists of notable eruptions Edit Clickable imagemap of notable volcanic eruptions The apparent volume of each bubble is linearly proportional to the volume of tephra ejected colour coded by time of eruption as in the legend Pink lines denote convergent boundaries blue lines denote divergent boundaries and yellow spots denote hotspots Timeline of volcanism on Earth mostly VEI 6 within 2 kya List of volcanic eruptions 1500 1999 List of volcanic eruptions in the 21st century List of volcanic eruptions by death toll List of large Holocene volcanic eruptions VEI 5 7 or plume height of at least 30 km List of large volcanic eruptions mostly VEI 6 8 within 50 Mya List of largest volcanic eruptions VEI 7 8 mostly within 500 Mya See also EditSupervolcano Volcano that has erupted 1000 cubic km of lava in a single eruption Decade Volcanoes Set of sixteen volcanoes noted for their eruptive history and proximity to densely populated areas Dispersal index Indicator of spread of volcanic ejecta Lists of volcanoes List of natural disasters by death tollReferences Edit Newhall Christopher G Self Stephen 1982 The Volcanic Explosivity Index VEI An Estimate of Explosive Magnitude for Historical Volcanism PDF Journal of Geophysical Research 87 C2 1231 1238 Bibcode 1982JGR 87 1231N doi 10 1029 JC087iC02p01231 Archived from the original PDF on December 13 2013 Volcanic Explosivity Index VEI Global Volcanism Program Smithsonian National Museum of Natural History Archived from the original on November 10 2011 Retrieved August 21 2014 a b Dosseto A 2011 Turner S P Van Orman J A eds Timescales of Magmatic Processes From Core to Atmosphere Wiley Blackwell ISBN 978 1 4443 3260 5 Rothery David A 2010 Volcanoes Earthquakes and Tsunamis Teach Yourself a b Mason Ben G Pyle David M Oppenheimer Clive 2004 The size and frequency of the largest explosive eruptions on Earth Bulletin of Volcanology 66 8 735 748 Bibcode 2004BVol 66 735M doi 10 1007 s00445 004 0355 9 S2CID 129680497 Bryan S E 2010 The largest volcanic eruptions on Earth PDF Earth Science Reviews 102 3 4 207 229 Bibcode 2010ESRv 102 207B doi 10 1016 j earscirev 2010 07 001 Siebert L Simkin T Kimberly P 2010 Volcanoes of the World 3rd ed University of California Press pp 28 38 ISBN 978 0 520 26877 7 Miles M G Grainger R G Highwood E J 2004 Volcanic Aerosols The significance of volcanic eruption strength and frequency for climate PDF Quarterly Journal of the Royal Meteorological Society 130 602 2361 2376 Bibcode 2004QJRMS 130 2361M doi 10 1256 qj 03 60 S2CID 53005926 External links EditVEI glossary entry from a USGS website How to measure the size of a volcanic eruption from The Guardian The size and frequency of the largest explosive eruptions on Earth a 2004 article from the Bulletin of Volcanology List of Large Holocene Eruptions VEI gt 4 from the Smithsonian Global Volcanism Program Archived 2012 01 17 at the Wayback Machine Retrieved from https en wikipedia org w index php title Volcanic explosivity index amp oldid 1134896168, wikipedia, wiki, book, books, library,
