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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 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。0 ^' u' v, X: c6 I! M9 @
eruptions. Around 550volcanoes have erupted at least once in historic times, and around 50or 60 are
( R. h0 Q" M* N7 p& |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。active each year. On any given day, as many as 10 volcanoesmay be spewing ash or lava somewhere on Earth.7 N9 J" i, G! f# M5 I8 e1 o( x: f
Some volcanoes, such as Mount Etna in Italy, erupt almost constantlyfor years on end. Others, like Mount St. Helens, www2.tvboxnow.com+ y5 r" }$ R7 E9 I* W0 f
erupt rarely andsometimes extremely destructively. Like Etna and Mount St. Helens, manyof the most dangerous - t# W2 [! G1 v9 m
and explosive erupters are stratovolcanoes, whichare made of layers of ash and lava from previous eruptions.
3 P& r. T5 x( |) V; bThey tendto be steep-sided cone-shaped volcanoes and often rise strikingly abovethe surrounding landscape.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。/ w. S/ P9 o( E+ m$ d; L+ n

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Many of the stunning images of eruptions captured from space are ofviolent stratovolcanoes, such as the one above 公仔箱論壇  \; n4 q& [7 c1 t. o- O
of Kliuchevskoi, themost active volcano on Russia’s Kamchatka peninsula. The image abovewas
$ d: [" z! h) H; y3 Ctvb now,tvbnow,bttvbtaken by astronauts on the space shuttle Endeavour in 1994, as an eruption was just getting underway. The ash
5 \( D: [9 k9 A2 s% n* Bplume reached as high as 50,000 feet.tvb now,tvbnow,bttvb/ M) e8 R2 e  |1 B& W6 Q
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Augustine Volcano is a 4,100-foot-tall, 7-mile-wide stratovolcano. This eruption was captured by NASA’s Terra
* L4 h9 Y. |& E公仔箱論壇satellite in 2006. Augustine’s dome collapsed in 1883, during its largest historical eruption. It has been erupting for at least 40,000 公仔箱論壇( K# Q: K7 E2 m5 O
years. The island’s jagged edges were created by massive avalanches.0 V! m0 v) n/ z* [' g7 E

' `% _3 f" S( WAugustine lies in the Cook Inlet at the eastern end of the Aleutian trench which marks the northernmost portion of the Pacific Ring www2.tvboxnow.com3 d# n$ x& i9 i1 n
of Fire. Volcanic activity here is caused by the subduction of the Pacific plate beneath the North American plate. As the wet ) m7 h5 n. Q2 e9 o; q
ocean crust descends into the molten mantle below, superheated water is squeezed out and rises up to melt the bottom of 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。% ]" n$ m0 q2 d) c$ m
the continental crust, creating magma that drives the volcanic eruptions
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" z- h1 Z  E- `  l6 |( ~) g: `www2.tvboxnow.comAstronauts aboard the International Space Station caught a lucky glimpse of the start of this eruption of Sarychev Volcano
8 w& z( L. ^9 k! |7 u' Z) ain the Kuril Islands, northeast of Japan, on June 12, 2009. This was the volcano’s first eruption in 30 years.tvb now,tvbnow,bttvb8 A4 ]! B2 j' Y7 s5 ]5 T, |2 x
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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
2 V- u% a# Y& F0 [. ~: Qwww2.tvboxnow.comand 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 tvb now,tvbnow,bttvb% V" m! L* t7 J
as a pyroclastic flow.
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9 v4 M" w: }3 _; X- p7 ~This photo sparked a debate among scientists about what caused the hole in the clouds above the eruption. Three possible options came up:
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    * It could have nothing to do with the eruption and simply be caused by the contrast in temperatures between the ocean and the island.
, M" G5 t  `, W/ ?$ k* i! Y公仔箱論壇    * A shockwave from the eruption could have blown a hole in the cloud deck.tvb now,tvbnow,bttvb- W- S& A. y8 v" S$ [% ^) D. r
    * As the plume rose, air flowed downward along the sides and became warmer and evaporated the clouds.
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Alaska’s Redoubt Volcano erupted five times in one night this year after almost three decades of relative quiet.
3 s( T* O* J* f. `& c: `www2.tvboxnow.comIt continued erupting on and off for weeks afterward. This image was taken by the commercial satellite GeoEye-1 on March 30 when
! s5 n  S# |! t: T3 B+ m* s5 vtvb now,tvbnow,bttvb the ash reached heights of 27,000 feet. The volcano’s alert level is still “advisory,” and the aviation color code is yellow.公仔箱論壇( R, w8 k9 ]1 z
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Redoubt is a 10,200-foot tall stratovolcano 100 miles southwest of Anchorage in the Aleutian Range, west of the Cook Inlet.
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Mount Etna is the second tallest volcano in Europe, at almost 11,000 feet. It is one of the most active volcanoes inTVBNOW 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。! b* D- R" o! h  L& J5 K
the world and is erupting nearly continuously. It is no surprise that there are many great photos of this volcano erupting, including this one 公仔箱論壇: [: m- q* b! E, e
captured by astronauts on the International Space Station in 2002. The lighter colored plumes of smoke on the slope of the volcano in
# @, o* m1 f- J# L, Kthis picture are from forest fires ignited by lava.! z& c  t# T: v" v
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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 maywww2.tvboxnow.com7 w- c% @$ E* z9 M- E# t$ y
also be the oldest-known active volcano.www2.tvboxnow.com8 c$ f7 w- D2 I" ~" X2 p
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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   r# y1 S6 {* S! h4 j4 Z3 L& _
and claimed the only known eruption-related death in Alaska’s Aleutian Islands in 1944. Its symmetrical, cone shape is typical of stratovolcanoes.
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; @2 |) D* X3 z& v' W' ]) P2 s4 T+ Iwww2.tvboxnow.comPopoépetcatl, which means “smoking mountain” in the Aztec language, is a very active volcano just 44 miles outside Mexico City. tvb now,tvbnow,bttvb( y/ O7 o( `2 B* p3 ~3 {" R
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 ; o; ]; ?7 ^/ A
multiple 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 ! X: Z7 L7 y) {. @- e) r
of frequent activity. The plume reached heights of around 30,000 feet.
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This eruption of Chaitén caldera in Chile was photographed from the International Space Station in May 2008. Volcanism along the ) w4 J; I" m. ^. ?, V/ p
west coast of South America is the result of subduction of the oceanic Nazca plate beneath the South American plate.: x- F4 O" \7 |% h; g% L6 @
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Chaitén was last active more than 9,000 years ago. The violent 2008 eruption inundated the small coastal town of Chaitén with ash, pyroclastic
/ q+ w3 K0 E& r7 h4 K, R  Ktvb now,tvbnow,bttvbflows 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.
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1 P3 V3 d( T+ i/ d: F1 Y3 y6 D4 V/ q- `www2.tvboxnow.comThis image of the Sierra Negra volcano in the Galapagos Islands was taken by NASA’s Terra satellite in 2006. Sierra Negra 公仔箱論壇3 W( [) a' o1 i; ^( g7 V, I
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 5 f% F6 a- ^% b2 V* c
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
5 [3 P5 A1 M, c' Ctvb now,tvbnow,bttvbstationary hot spot, volcanoes are formed. The Hawaiian Islands were formed — and continue forming — the same way.
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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. 7 Y( J( X1 p1 r, u& n
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
9 l7 l1 J4 P$ F0 m  z% b( Xwww2.tvboxnow.comthat 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,
  \9 b7 ^% @4 m% o9 \3 q# z# V2 m8 _causing avalanches of debris into the crater.

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