Volcanos are cony-ish mountains! Cool right? Well thats what you thought... VOLCANOS ARE KILLERS!!
they kill people animals
destroy building, homes and forests, etc | | | | | |
BUT>>>>> THEY ALSO DO GREAT THINGS!!! OMG VVVVV
make building material
SO KNOW YOU KNOW VOLCANOS ARENT GOOD AND ARENT BAD!!! :))
Read important stuff down here VVVV:P
A supervolcano or super volcanic eruption is a volcanic eruption with ejecta greater than 1,000 cubic kilometers (240 cubic miles), which is millions of times larger than any volcanic event in historic times. Supervolcanoes can occur when magma in the Earth rises into the crust from a hotspot but is unable to break through the crust. Pressure builds in a large and growing magma pool until the crust is unable to contain the pressure. They can also form at convergent plate boundaries (for example, Toba). Supervolcanoes are relatively new to science.
The Discovery Channel has documented seven known supervolcanoes: the Yellowstone, Long Valley, and Valles Calderas in the United States; Lake Toba, North Sumatra, Indonesia; Taupo Volcano, North Island, New Zealand; Aira Caldera, Kagoshima Prefecture, Kyūshū, Japan; and the Siberian Traps, Russia. Although there are only a handful of supervolcanoes, super volcanic eruptions typically cover huge areas with lava and volcanic ash and cause a long-lasting change to weather (such as the triggering of a small ice age) sufficient to threaten the extinction of species.
Word origin Edit
The term was originally used in the BBC popular science television programme Horizon in 2000 to refer to these types of eruptions. That programme introduced the subject of large-scale volcanic 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 VEI 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 interplanetary missions. The outer Solar System volcanoes were mostly cryovolcanoes, not magma .
Large igneous provinces Edit
- Main article: Large igneous province
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 kilometres. 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 million years ago. Research continues into the effect of the outpourings and whether they contributed to the extinction of the dinosaurs 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 1783–84 from the Laki fissure which is ~40 km long. An estimated 14 km3 of basaltic lava was poured out during the eruption.
Massive explosive eruptionsEdit
Eruptions with a Volcanic Explosivity Index of 8 (VEI-8) are colossal events that throw out at least 1,000 km3 Dense Rock Equivalent (DRE) of ejecta; VEI-7 events eject at least 100 km3 (DRE).
VEI-7 or 8 eruptions are so powerful that they often form circular calderas rather than cones 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) its geology and volcanic succession has recently been re-analysed in the light of new discoveries. There is an accompanying 1:25000 solid geology map.
Known super eruptionsEditEstimates of the volume of ejected material are given in parentheses.
VEI 8 eruptions have happened in the following locations.
- Lake Taupo, North Island, New Zealand - Oruanui eruption ~26,500 years ago (~1,170 km³)
- Lake Toba, Sumatra, Indonesia - ~74,000 years ago (~2,800 km³)
- Whakamaru North Island, New Zealand - Whakamaru Ignimbrite/Mount Curl Tephra ~254,000 years ago (1,200-2,000 km³)
- Yellowstone Caldera, Wyoming, United States - 640,000 years ago (1,000 km³)
- Island Park Caldera, Idaho/Wyoming, United States - 2.1 million years ago(2,500 km³)
- Kilgore Tuff, Idaho, United States - 4.5 million years ago (1,800 km³)
- Blacktail Creek, Idaho, United States - 6.6 million years ago (1,500 km³)
- La Garita Caldera, Colorado, United States - Source of the truly enormous eruption of the Fish Canyon Tuff ~27.8 million years ago (~5,000 km³)
The Lake Toba eruption plunged the Earth into a volcanic winter, eradicating an estimated 60% of the human population (although humans managed to survive, even in the vicinity of the volcano), and was responsible for the formation of sulfuric acid in the atmosphere. However the coincidental agreement in above sources about percentage value of extinction is contrary to differing estimates of human population size at that time.
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, Lake Taupo (Hatepe), around 180 AD, and possibly Baekdu Mountain, 969 CE (± 20 years).
- Tambora, Sumbawa Island, West Nusa Tenggara, Indonesia - 1815 (160 km³), the following year 1816 became known as the "Year Without a Summer"
- Baekdu Mountain, China/North Korea - ~969 CE (96±19 km³)
- Lake Taupo, North Island, New Zealand - Hatepe eruption ~181 CE (120 km³)
- Kikai Caldera, Ryukyu Islands, Japan - ~6,300 years ago (~ 4,300 BCE) (150 km³)
- Laacher See, Rhineland-Palatinate, Germany - ~12,900 years ago (~300 km³), coincides with the onset of the Younger Dryas reglaciation event
- Aira Caldera, Kyūshū, Japan - ~22,000 years ago (~110 km³)
- Campi Flegrei, Naples, Italy - 39,280 ± 110 years ago (500 km³)
- Reporoa caldera, New Zealand - 230,000 years ago (~100 km³)
- Aso, Kyūshū, Japan - four large explosive eruptions between 300,000 to 80,000 years ago (last one > 600 km³)
- Long Valley Caldera, California, United States - ~760,000 years ago (600 km³)
- Valles Caldera, New Mexico, United States - ~1.12 million years ago (~600 km³)
- Mangakino, North Island, New Zealand - three eruptions from 0.97 to 1.23 million years ago (each > 300 km³)
- Henry's Fork Caldera, Idaho, United States - 1.3 million years ago (280 km³)
- Walcott Tuff, Idaho, United States - 6.4 million years ago (750 km³)
- Bennett Lake Volcanic Complex, British Columbia/Yukon, Canada - ~50 million years ago (850 km³)
- Bruneau-Jarbidge, Idaho, United States - ~10-12 million years ago (>250 km³) (responsible for the Ashfall Fossil Beds ~1,600 km to the east)
Media portrayal Edit
A National Geographic documentary called Earth Shocks portrayed the destructive impact of the rapid eruption at Lake Toba approximately 75,000 years ago, which is thought to have caused a phenomenon known as the Millennial Ice Age that lasted for ~1000 years and killed an estimated 60 to 75% of the human population of the time.
In 2005, a two-part television docudrama entitled 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 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 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 2 simultaneously with its broadcast.
Also in 2006, the television show Stargate Atlantis aired an episode called Inferno (Stargate Atlantis) whose plot revolves around the discovery and subsequent eruption of a supervolcano on another planet.
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.
In 2009, the Toba supervolcano was featured in the episode Fire and Ice on Animal Armageddon.
- ↑ http://volcanoes.usgs.gov/yvo/about/faq/faqsupervolcano.php#supervolcano
- ↑ "Supervolcano: Yellowstone's Super Sisters". Discovery Channel. Retrieved on 30 September 2009.
- ↑ BBC TV Horizon, 3 February 2000, Supervolcanoes
- ↑ USGS Cascades Volcano Observatory
- ↑ 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.
- ↑ Kokelaar, B. P and Moore, I. D; 2006. Glencoe caldera volcano, Scotland. British Geological Survey, Keyworth, Nottingham. ISBN 0852725256.
- ↑ 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: 578–582. doi:10.1038/319578a0. "The minimum total volume of tephra is 1,200 km³ but probably nearer 2,000 km³, ...". .
- ↑ 8.0 8.1 Stanley H. Ambrose, University of Illinois at Urbana-Champaign, 1998
- ↑ 9.0 9.1 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.
- ↑ 10.0 10.1 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.
- ↑ 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.
- ↑ 12.0 12.1 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.
- ↑ Michael Petraglia et al., Science v.317, p.114 (2007)
- ↑ 14.0 14.1 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.
- ↑ Horn, Susanne; Schmincke, Hans-Ulrich (2000). "Volatile emission during the eruption of Baitoushan Volcano (China/North Korea) ca. 969 AD". Bulletin of Volcanology 61 (8): 537–555. doi:10.1007/s004450050004. "The 969±20 AD Plinian eruption of Baitoushan Volcano (China/North Korea) produced a total tephra volume of 96±19 km³ [magma volume (DRE): 24±5 km³].".
- ↑ Briggs, R.M.; Gifford, M.G.; Moyle, A.R.; Taylor, S.R.; Normaff, M.D.; Houghton, B.F.; and Wilson, C.J.N. (1993). "Geochemical zoning and eruptive mixing in ignimbrites from Mangakino volcano, Taupe Volcanic Zone, New Zealand". Journal of Volcanology and Geothermal Research 56: 175–203. doi:10.1016/0377-0273(93)90016-K. .
- ↑ Ashfall Fossil Beds State Historical Park. "The Ashfall Story". Retrieved on 2006-08-08.
- ↑ 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.
- ↑ Mystery of the Megavolcano official site, PBS.org
- ↑ "Is the apocalypse a real and present danger? A menacing bubble of magma rumbling beneath Yellowstone Park really does threaten to blow its top and wreak havoc upon the planet. But when?"
- 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. doi:10.1007/s00445-004-0355-9.
- Timmreck, C.; Graf, H.-F. (2006). "The initial dispersal and radiative forcing of a Northern Hemisphere mid-latitude super volcano: a model study". Atmospheric Chemistry and Physics 6: 35–49, http://www.atmos-chem-phys.net/6/35/2006/acp-6-35-2006.html.
- Overview and Transcript of the original BBC program
- Yellowstone Supervolcano and Map of Supervolcanoes Around The World
- USGS Fact Sheet - Steam Explosions, Earthquakes, and Volcanic Eruptions - What's in Yellowstone's Future?
- Discovery Channel's site on "Supervolcano"
- Scientific American's The Secrets of Supervolcanoes
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- Armageddon Online - Latest news covering super volcano activity since 1999
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