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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
: e3 Q: O! h2 R+ @7 g- F公仔箱論壇eruptions. Around 550volcanoes have erupted at least once in historic times, and around 50or 60 are 8 f: I5 g6 L( C; J9 ~
active each year. On any given day, as many as 10 volcanoesmay be spewing ash or lava somewhere on Earth.( I) m2 H; X. f, E& F1 q  u
Some volcanoes, such as Mount Etna in Italy, erupt almost constantlyfor years on end. Others, like Mount St. Helens, - c" W/ ^: q) S/ P/ b
erupt rarely andsometimes extremely destructively. Like Etna and Mount St. Helens, manyof the most dangerous
0 W4 ^  Z7 h  D% u$ \# }+ Uand explosive erupters are stratovolcanoes, whichare made of layers of ash and lava from previous eruptions. . L( N5 |/ e+ _( T  i! \! P
They tendto be steep-sided cone-shaped volcanoes and often rise strikingly abovethe surrounding landscape.
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Many of the stunning images of eruptions captured from space are ofviolent stratovolcanoes, such as the one above www2.tvboxnow.com- T9 X; b/ T# p9 C0 J5 s0 F2 J' d
of Kliuchevskoi, themost active volcano on Russia’s Kamchatka peninsula. The image abovewas
- {4 S4 E. d0 W( etaken by astronauts on the space shuttle Endeavour in 1994, as an eruption was just getting underway. The ash
! K/ u/ k0 h- K' w, g  Wplume reached as high as 50,000 feet.tvb now,tvbnow,bttvb) T" i! j* L& z
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Augustine Volcano is a 4,100-foot-tall, 7-mile-wide stratovolcano. This eruption was captured by NASA’s Terra tvb now,tvbnow,bttvb* ?  o" R/ @- ?
satellite in 2006. Augustine’s dome collapsed in 1883, during its largest historical eruption. It has been erupting for at least 40,000
0 q. |4 ^! @& k( jyears. The island’s jagged edges were created by massive avalanches.! W1 M$ f! g3 e: Y& N! a4 y

( z" V. M1 U7 dwww2.tvboxnow.comAugustine lies in the Cook Inlet at the eastern end of the Aleutian trench which marks the northernmost portion of the Pacific Ring
$ r9 Q( L, {; f  r% R公仔箱論壇of Fire. Volcanic activity here is caused by the subduction of the Pacific plate beneath the North American plate. As the wet tvb now,tvbnow,bttvb- D/ ~0 Z" }! U( s; p
ocean crust descends into the molten mantle below, superheated water is squeezed out and rises up to melt the bottom of
$ }, e! |, W# C  s0 t公仔箱論壇the continental crust, creating magma that drives the volcanic eruptions
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Astronauts aboard the International Space Station caught a lucky glimpse of the start of this eruption of Sarychev Volcano
& ~' K6 V+ b. V5 a1 H  }in the Kuril Islands, northeast of Japan, on June 12, 2009. This was the volcano’s first eruption in 30 years.公仔箱論壇( Z& W. c( b+ w8 p  Q
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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 公仔箱論壇5 P2 s' Y$ s5 U' k. ]- Y
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
- G. h: }& |6 ]& l: Ztvb now,tvbnow,bttvbas a pyroclastic flow.公仔箱論壇6 d4 r! x, w5 n( _$ L

# H. _5 O# s. o4 j  E$ D( x" b/ x+ U5 NTVBNOW 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:
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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.
8 Q& J- y/ [  z! x8 ?$ M) fwww2.tvboxnow.com    * A shockwave from the eruption could have blown a hole in the cloud deck.
6 w6 z3 u2 r  l4 L    * 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.
/ F' d' P3 ^& c4 a9 g% e; x2 H; R- gwww2.tvboxnow.comIt continued erupting on and off for weeks afterward. This image was taken by the commercial satellite GeoEye-1 on March 30 when
; Y/ D8 x  o! `) y- \: Y$ [tvb 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., I+ O7 `2 T" _

& J3 H- F, X, U/ ttvb now,tvbnow,bttvbRedoubt is a 10,200-foot tall stratovolcano 100 miles southwest of Anchorage in the Aleutian Range, west of the Cook Inlet.www2.tvboxnow.com2 u4 s- T; V3 l* ]( [4 G! ~3 c

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+ d! t9 E4 }' C+ t5 OMount Etna is the second tallest volcano in Europe, at almost 11,000 feet. It is one of the most active volcanoes in; b7 C  d+ y. C& ~; h' l5 @
the world and is erupting nearly continuously. It is no surprise that there are many great photos of this volcano erupting, including this one www2.tvboxnow.com4 I7 e, s9 Q4 ?
captured by astronauts on the International Space Station in 2002. The lighter colored plumes of smoke on the slope of the volcano in tvb now,tvbnow,bttvb4 N  _) a& f5 ~; Q8 g
this picture are from forest fires ignited by lava.tvb now,tvbnow,bttvb* |. C$ D5 |5 p
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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
$ m0 c  Q7 O$ Ualso be the oldest-known active volcano.
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+ z/ k+ Z8 c8 T# mA NASA astronaut spotted this eruption of Cleveland Volcano from the International Space Station in 2006. The volcano is 5,700 feet high
  s2 A8 d2 @2 e& y( ^8 A+ uTVBNOW 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。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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' V" ^3 X7 d4 B2 l3 _Popoépetcatl, which means “smoking mountain” in the Aztec language, is a very active volcano just 44 miles outside Mexico City.
8 f& p0 [0 N5 r  }7 W$ wThe 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
5 H5 B. j! h" t9 ~9 Y  X* l2 B) smultiple 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  O/ v9 H5 V0 a
of frequent activity. The plume reached heights of around 30,000 feet.
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  L1 b' g/ t" Z: N6 E6 xtvb now,tvbnow,bttvbThis eruption of Chaitén caldera in Chile was photographed from the International Space Station in May 2008. Volcanism along the
8 s! s3 }4 C) E; y9 o公仔箱論壇west coast of South America is the result of subduction of the oceanic Nazca plate beneath the South American plate.
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2 Z; u/ a, P4 o9 w. Y9 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。Chaitén was last active more than 9,000 years ago. The violent 2008 eruption inundated the small coastal town of Chaitén with ash, pyroclastic
  ^0 D/ K/ _6 [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.
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This image of the Sierra Negra volcano in the Galapagos Islands was taken by NASA’s Terra satellite in 2006. Sierra Negra 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。3 n( O% L' e4 ^! Y( c$ p
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 公仔箱論壇( N4 P- U/ P6 y2 X- [9 ]
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
4 {. @( [5 ^& C- \5 RTVBNOW 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。stationary hot spot, volcanoes are formed. The Hawaiian Islands were formed — and continue forming — the same way.
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9 M3 B6 L4 f/ R公仔箱論壇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.
, j9 w# W) L! Q3 Wwww2.tvboxnow.comA 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 6 f- l2 ]* @. D6 E
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,
  }2 h$ A7 U/ H7 G) t3 J5 dwww2.tvboxnow.comcausing avalanches of debris into the crater.

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