Supervolcanoes with power to 'destroy civilisation' explode far more rapidly than scientists had believed - and one could be bubbling under U.S. right now
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- Scientists believed they took 100,000 years to build up
- Instead, figure could be just hundreds
- Supervolcano believed to be simmering under Yellowstone in U.S.
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A 'supervolcano' eruption is the most catastrophic natural disaster that can hit our planet, short of an asteroid impact - and now scientists believe they may build up a deadly head of steam far faster than we thought.
$ f. T1 `* i$ X3 cTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。
7 @! D9 U0 b5 t+ y& sTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。Instead of the process taking hundreds of thousands of years, it could take just hundreds.
9 v3 n' V' i' Y3 s7 W+ s8 N5 qTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。
* l: P! P7 v# X/ hTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。The news could be bad for the US, where a supervolcano is said to be simmering beneath Yellowstone National Park. If it erupted, two thirds of the country could be rendered uninhabitable.9 p: A9 c: r6 Y* K6 z9 |
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0 l1 K, x8 u$ F* v! E2 SEruption: Supervolcanoes with the power to destroy human civilisations may build up a deadly head of steam far faster than scientists believed
& i2 ]. Z; h7 p6 Z: A. f公仔箱論壇Supervolcanoes are fuelled by giant pools of magma that form deep underground.
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Geologists had thought it took between 100,000 to 200,000 years for a supervolcano magma pool to build up enough pressure to erupt.
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But the new study suggests that the giant magma bodies may only exist for a few thousand years, or even a few hundred, before exploding.& X& W; d O# y* z; c& s
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A magma reservoir six miles below Yellowstone has been rising at a record rate since 2004.TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。9 e0 i6 b9 P* N$ c+ L. _; u, w7 E
- L2 N2 m+ a# {. Y/ q1 g# e, `The Wyoming park sits above a gigantic plume of hot and molten rock that begins at least 400 miles beneath Earth's surface and rises to 30 miles underground, where it widens to about 300 miles across.
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) E1 T1 O$ H# Q) J2 C+ hBlobs of magma occasionally break off from the top of the plume, and rise farther, resupplying the magma chamber beneath the Yellowstone Caldera.公仔箱論壇 X" O5 s% B- P k0 j
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Steaming Mud Volcano at Yellowstone National Park in winter. Researchers now believe that the supervolcano beneath the park could be more active than thought ' y% O& H# `0 Y/ _3 b i
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The news could be bad for the US, where a supervolcano is said to be simmering beneath Yellowstone National Park. If it erupted, two thirds of the country could be rendered uninhabitable
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Castle Geyser and sunrise Yellowstone National Park Wyoming: Researchers now believe that the huge 'supervolcano' beneath the park is far more active than previously thought
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Resembling the lid of a cooking pot, the caldera formed when the last super-eruption occurred 600,000 years ago.
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The supervolcano has erupted a total of three times in the last 2.1 million years. Scientists believe it could be due to erupt again.
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8 Z+ Z" h f& _A full scale eruption at Yellowstone would be 1,000 times more powerful than the volcanic blast that tore apart Mount St Helens in 1980.
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There is evidence that a similar super-eruption in Indonesia 74,000 years ago came close to wiping out the entire human species.tvb now,tvbnow,bttvb ]" b6 `: }1 n9 p- P
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The new study was based on analysis of a super-eruption that occurred in eastern California 760,000 years ago.. {1 {( F- ?5 G
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7 z: o2 t' j' ^. I7 QSeveral independent lines of evidence indicated that the magma pool erupted within a few thousand years, perhaps within a few hundred years, covering half the North American continent with smouldering ash.TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。1 q v0 I: A7 ?. ^8 t v+ x" }8 \
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* t* j& N3 P0 y& L) g. I$ LThe scientists based their estimate on quartz crystallisation rates. Previous studies have relied on the growth of zircon crystals, which is said to be a less accurate method.
& ^: k' l6 d, S6 J' ^+ c+ l# ^TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。
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The research is published in the online journal Public Library of Science ONE.
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; y0 e9 `7 T% {+ {7 e" DTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。
4 S+ Q0 v; ^, ZTVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。Lead scientist Dr Guilherme Gualda, from Vanderbilt University in Nashville, Tennessee, said: ‘Our study suggests that when these exceptionally large magma pools form they are ephemeral and cannot exist very long without erupting.
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9 O y1 V& A; L- ^/ ^‘The fact that the process of magma body formation occurs in historical time, instead of geological time, completely changes the nature of the problem.’3 B8 R6 H6 W" Y* W% C
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6 ~5 x4 D- ^2 C. y7 _+ m) e! e公仔箱論壇He said regions such as Yellowstone should be monitored regularly to provide advance warning of a catastrophic super-eruption. |
發表於 2012-6-1 01:50 AM
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發表於 2012-6-1 08:11 PM
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