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Erupting Volcanoes on Earth as Seen From Space

One of the most violent but beautiful reminders that we live on ageologically restless planet are volcanic tvb now,tvbnow,bttvb  v- J* H1 T% E! }9 ]; C$ x( P& [$ O
eruptions. Around 550volcanoes have erupted at least once in historic times, and around 50or 60 are
$ b5 S" }$ E( [- [4 ?+ g; e1 ftvb now,tvbnow,bttvbactive each year. On any given day, as many as 10 volcanoesmay be spewing ash or lava somewhere on Earth.tvb now,tvbnow,bttvb6 z; s, [' }. D3 r! }
Some volcanoes, such as Mount Etna in Italy, erupt almost constantlyfor years on end. Others, like Mount St. Helens, tvb now,tvbnow,bttvb9 Q( N( h$ n5 I6 i- Q' T6 b4 _
erupt rarely andsometimes extremely destructively. Like Etna and Mount St. Helens, manyof the most dangerous 4 f6 }3 u4 p( }' t  B
and explosive erupters are stratovolcanoes, whichare made of layers of ash and lava from previous eruptions.
, J/ p, a& o" O; E公仔箱論壇They tendto be steep-sided cone-shaped volcanoes and often rise strikingly abovethe surrounding landscape.5.39.217.76% ~, x4 W' g& O, \5 B8 T* v
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4 V) I3 v! f# C0 J2 j. h$ g, K% I公仔箱論壇Many of the stunning images of eruptions captured from space are ofviolent stratovolcanoes, such as the one above
# c8 Y) U$ ~# e/ 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。of Kliuchevskoi, themost active volcano on Russia’s Kamchatka peninsula. The image abovewas
. j3 v' m0 Z5 V( Atvb now,tvbnow,bttvbtaken by astronauts on the space shuttle Endeavour in 1994, as an eruption was just getting underway. The ash
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( x* r& {$ ?" n6 g/ P$ K- I5.39.217.76Augustine Volcano is a 4,100-foot-tall, 7-mile-wide stratovolcano. This eruption was captured by NASA’s Terra
2 E' e5 I( ?, N8 ?2 H- Tsatellite in 2006. Augustine’s dome collapsed in 1883, during its largest historical eruption. It has been erupting for at least 40,000
8 y! ?" N$ R) B% d, fyears. The island’s jagged edges were created by massive avalanches.
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Augustine lies in the Cook Inlet at the eastern end of the Aleutian trench which marks the northernmost portion of the Pacific Ring
. ~7 o$ I; |0 u- V; `of Fire. Volcanic activity here is caused by the subduction of the Pacific plate beneath the North American plate. As the wet
" M; ]& U  J$ [9 N* WTVBNOW 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。ocean crust descends into the molten mantle below, superheated water is squeezed out and rises up to melt the bottom of 公仔箱論壇/ `9 }. g, H  q+ b; O
the continental crust, creating magma that drives the volcanic eruptionstvb now,tvbnow,bttvb8 ]2 v1 l% r( j3 y/ {. l0 `

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5 ?4 P* y( D8 Q5 E: B5.39.217.76Astronauts aboard the International Space Station caught a lucky glimpse of the start of this eruption of Sarychev Volcano
# Z! e) C/ w9 I8 Fin the Kuril Islands, northeast of Japan, on June 12, 2009. This was the volcano’s first eruption in 30 years.
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The smooth white cloud, known as a pileus cloud, topping the eruption column may be made of water condensation caused by rising 4 t4 v. Q, k$ e  q$ a
and cooling of the air above. In contrast, a dark gray cloud of ash near the ground is probably an avalanche of hot ash and rock known
* @" }; ?. F' T" y1 [* bTVBNOW 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。as a pyroclastic flow.5.39.217.763 E! ]& ~. F2 e& b& ]7 [! ?2 \

' ^: m, o) n9 f% {+ m: Q7 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。This photo sparked a debate among scientists about what caused the hole in the clouds above the eruption. Three possible options came up:' [& I. B' v1 T7 _9 y

! |" n  A( h9 S+ `4 l8 R5.39.217.76    * It could have nothing to do with the eruption and simply be caused by the contrast in temperatures between the ocean and the island.tvb now,tvbnow,bttvb. S9 D# ~& f) @1 X. x* H. i5 x
    * A shockwave from the eruption could have blown a hole in the cloud deck.5.39.217.769 L4 g. O' m6 m6 i
    * As the plume rose, air flowed downward along the sides and became warmer and evaporated the clouds.
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% E& B! R6 ]/ p  a$ zAlaska’s Redoubt Volcano erupted five times in one night this year after almost three decades of relative quiet.
1 n- U, M( ]" xTVBNOW 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。It continued erupting on and off for weeks afterward. This image was taken by the commercial satellite GeoEye-1 on March 30 when
/ b) Z6 ]( r% N' V# W the ash reached heights of 27,000 feet. The volcano’s alert level is still “advisory,” and the aviation color code is yellow./ N0 I2 y: ?/ M

- A9 F8 M. U$ M, ~, V6 ]* @+ ]Redoubt is a 10,200-foot tall stratovolcano 100 miles southwest of Anchorage in the Aleutian Range, west of the Cook Inlet.tvb now,tvbnow,bttvb8 F* f1 ]& ^% {6 i5 E4 ?

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/ \# {7 g! ?1 A+ e6 ^, Z2 J# h/ c' v5.39.217.76Mount Etna is the second tallest volcano in Europe, at almost 11,000 feet. It is one of the most active volcanoes in
8 V. f( {) \5 J3 `5 k+ v! i8 Y公仔箱論壇 the world and is erupting nearly continuously. It is no surprise that there are many great photos of this volcano erupting, including this one
" l0 e- I5 g( {captured by astronauts on the International Space Station in 2002. The lighter colored plumes of smoke on the slope of the volcano in 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。* `$ J) V+ g& J/ H
this picture are from forest fires ignited by lava.  K+ K* X6 d3 W: T
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Etna is a stratovolcano located on the island of Sicily. It is one of the most studied volcanoes in the world and. at 500,000 years old, it may
: i; @* B# H$ ~* L0 d3 \. ]4 r5.39.217.76also be the oldest-known active volcano.
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A NASA astronaut spotted this eruption of Cleveland Volcano from the International Space Station in 2006. The volcano is 5,700 feet high
6 y5 h( R' V" e2 x( }5.39.217.76and claimed the only known eruption-related death in Alaska’s Aleutian Islands in 1944. Its symmetrical, cone shape is typical of stratovolcanoes.公仔箱論壇: b, ]! u' ?* P. S* p: s
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Popoépetcatl, which means “smoking mountain” in the Aztec language, is a very active volcano just 44 miles outside Mexico City. 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。& t: \% M9 q) M  l, a# Q, {
The second highest peak in Mexico at 17,800 feet, this glacier-covered stratovolcano has erupted at least 20 times in the last 500 years and has caused
! _% L$ o$ e; Z% R5 o0 U6 ?7 imultiple evacuations of the city. This eruption in 2001 was caught by astronauts on the International Space Station, near the end of a seven-year period 5.39.217.76# K, T6 |- X  N  S1 ]/ g
of frequent activity. The plume reached heights of around 30,000 feet.
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' S3 `; s( F. z$ X+ `* ~This eruption of Chaitén caldera in Chile was photographed from the International Space Station in May 2008. Volcanism along the
% f' |5 Q1 o9 @4 oTVBNOW 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。west coast of South America is the result of subduction of the oceanic Nazca plate beneath the South American plate.6 A& J' V% K! y( C

0 B" Y% h; N0 W) {% rChaitén was last active more than 9,000 years ago. The violent 2008 eruption inundated the small coastal town of Chaitén with ash, pyroclastic 5.39.217.763 S% R" V1 J% ]. ?2 `
flows and volcanic mudflows called lahars. The caldera is relatively small at less than two miles wide, and sits on the flank of the larger Michinmahuida volcano./ R3 C9 B1 a% {
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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。! ^, M& O: _# e2 H1 }
This image of the Sierra Negra volcano in the Galapagos Islands was taken by NASA’s Terra satellite in 2006. Sierra Negra tvb now,tvbnow,bttvb( h% V( F$ F+ P# P( s7 K/ X1 t$ \7 _
is a shield volcano, which are made mostly of previous lava flows and tend to be broad and gently sloping. The Galapagos are part of an island chain - y. g- u3 J9 f3 j  h
formed by a hot spot where a plume of hot mantle rises up and melts the base of the ocean crust. As the Pacific plate moves over the relatively 公仔箱論壇- i) z- Y: M9 t  z9 ?1 V! U- |9 h
stationary hot spot, volcanoes are formed. The Hawaiian Islands were formed — and continue forming — the same way.3 V( s: @: g: U8 ~& M5 k) |

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NASA’s Terra satellite snapped this image of Shiveluch volcano erupting on Russia’s Kamchatka peninsula at the edge of the Pacific Ring of Fire in 2004. 2 A5 }2 w( B" h  h' T  l' W
A lava dome had been growing in the volcano’s crater, followed by intermittent eruptions that lasted weeks. Shiveluch is a 10,400-foot-high stratovolcano 1 c8 S2 B3 c. M
that is at least 60,000 years old and has been erupting fairly often for the past 10 years. Its dome has collapsed multiple times, most recently in 1964, ' k' n' P9 ?! R& v
causing avalanches of debris into the crater.

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