Volcanic winter 391431 224237135 2008-07-07T22:56:14Z BOTarate 5870361 robot Adding: [[es:Invierno volcánico]] A '''volcanic winter''' is the reduction in temperature caused by [[volcanic ash]] and droplets of [[sulfuric acid]] obscuring the [[sun]], usually following a large[[volcano| volcanic eruption]]. ==Effects on life== The causes of the [[population bottleneck|bottleneck]] phenomenon, i.e., a sharp decrease in a [[species]]' population immediately followed by a period of great genetic divergence ([[differentiation]]) among survivors&mdash;might be attributed to volcanic winters. According to [[anthropology|anthropologist]] [[Stanley Ambrose]], such events diminish the population size to "levels low enough for evolutionary changes, which occur much faster in small populations, to produce rapid population differentiation". ==Ancient case of volcanic winters== One proposed volcanic winter happened around 71,000&ndash;73,000 years ago following the [[supervolcano|supereruption]] of [[Lake Toba]] on [[Sumatra]] island in [[Indonesia]]. In the following 6 years there was the highest amount of volcanic [[sulfur|sulphur]] deposited in the last 110,000 years, possibly causing significant [[deforestation]] in [[Southeast Asia]] and the cooling of global [[temperature]]s by 1&nbsp;°C.<ref> C. Oppenheimer, 2002, Limited global change due to the largest known Quaternary eruption, Toba ~~ 74 Kyr BP, Quaternary Science Reviews, 21, 1593-1609 </ref> Some scientists hypothesize the eruption caused an immediate return to a [[Ice Age|glacial]] climate regime by accelerating an ongoing continental glaciation, thereby causing massive population reduction among animals and human beings on [[Earth]]. Others argue that the climatic effects of the eruption were too weak and brief to impact early human populations to the degree proposed. <ref> Oppenheimer (2002) </ref> This, combined with the fact that most human differentiations abruptly occurred at that same period, is a probable case of [[population bottleneck|bottleneck]] linked to volcanic winters (see [[Toba catastrophe theory]]). On average, super-eruptions with total eruptive masses of at least 10<sup>15</sup> kg (Toba eruptive mass = 6.9 × 10<sup>15</sup> kg) occur every 1 million years.<ref> B.G. Mason, D.M. Pyle, and C. Oppenheimer, 2004, The size and frequency of the largest explosive eruptions on Earth, The Bulletin of Volcanology, 66 (8), 735-748. </ref> ==Recent cases of volcanic winter== [[Image:Pinatubo early eruption 1991.jpg|thumb|200px|Pinatubo early eruption 1991]] The scales of recent winters are more modest but their effects can be significant. A paper written by [[Benjamin Franklin]] in 1783 blamed the unusually cool summer of 1783 on volcanic dust coming from [[Iceland]], where the eruption of [[Laki]] volcano had released enormous amounts of [[sulfur dioxide]], resulting in the death of much of the island's [[livestock]] and a catastrophic [[famine]] which killed a quarter of the population. Temperatures in the [[northern hemisphere]] dropped by about 1&nbsp;°C in the year following the Laki eruption. The [[extreme weather events of 535-536]] are most likely linked to a volcanic eruption. In [[1452]] or [[1453]], a cataclysmic eruption of the [[submarine volcano]] [[Kuwae]] caused worldwide disruptions. In [[1600]], the [[Huaynaputina]] in [[Peru]] erupted. Tree ring studies show that 1601 was cold. [[Russia]] had its worst famine in 1601 to 1603. From 1600 to 1602, [[Switzerland]], [[Latvia]] and [[Estonia]] had exceptionally cold winters. The wine harvest was late in 1601 in [[France]], and in Peru and [[Germany]] wine production collapsed. Peach trees bloomed late in [[China]], and [[Lake Suwa]] in [[Japan]] froze early <ref>http://www.sciencedaily.com/releases/2008/04/080423135236.htm University of California - Davis (2008, April 25). Volcanic Eruption Of 1600 Caused Global Disruption. ScienceDaily. Retrieved April 25, 2008</ref>. The 1815 eruption of [[Mount Tambora]], a [[stratovolcano]] in [[Indonesia]], occasioned mid-summer frosts in [[New York State]] and June snowfalls in [[New England]] in what came to be known as the "[[Year Without a Summer]]" of 1816. In 1883, the [[explosion]] of [[Krakatoa]] (Krakatau) also created volcanic winter-like conditions. The next four years after the explosion were unusually cold, and the winter of 1888 was the first time snow fell in the area. Record snowfalls were recorded worldwide. Most recently, the 1991 explosion of [[Mount Pinatubo]], another stratovolcano in the [[Philippines]], cooled global temperatures for about 2–3 years.<ref>[{{cite journal|author=Brohan, P., J.J. Kennedy, I. Haris, S.F.B. Tett and P.D. Jones|year=2006|title=Uncertainty estimates in regional and global observed temperature changes: a new dataset from 1850|journal=J. Geophysical Research|volume=111|pages=D12106|doi=10.1029/2005JD006548}}]</ref> ==References== <div class="references-small" style="-moz-column-count:2; column-count:2;"><references/></div> ==Further reading== *{{cite journal | author = MR Rampino, S Self & RB Stothers | year = 1988 | title = Volcanic winters | journal = Annual Review of Earth and Planetary Science | volume = 16 | pages = 73–99 | doi = 10.1146/annurev.ea.16.050188.000445 }} *C. Oppenheimer, 2002, Limited global change due to the largest known Quaternary eruption, Toba ~~ 74 Kyr BP, Quaternary Science Reviews, 21, 1593-1609. ==See also== * [[Nuclear winter]] * [[Climate changes of 535-536]] * [[Year Without a Summer]] [[Category:Volcanic events]] [[Category:Volcanology]] [[Category:Climatology]] [[de:Vulkanischer Winter]] [[es:Invierno volcánico]] [[fr:Hiver volcanique]] [[pl:Zima wulkaniczna]] [[pt:Inverno vulcânico]] [[ru:Вулканическая зима]] [[fi:Tulivuorenpurkauksen vaikutukset ilmastoon]]