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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 & Q9 u; B7 q/ x- Y- v' K
eruptions. Around 550volcanoes have erupted at least once in historic times, and around 50or 60 are + Q8 G: P0 ]7 k
active each year. On any given day, as many as 10 volcanoesmay be spewing ash or lava somewhere on Earth.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。4 l: ]4 }7 A- ^, x. I
Some volcanoes, such as Mount Etna in Italy, erupt almost constantlyfor years on end. Others, like Mount St. Helens, 公仔箱論壇5 y0 ?! l& v8 ~6 w3 L0 e' b  z
erupt rarely andsometimes extremely destructively. Like Etna and Mount St. Helens, manyof the most dangerous
# }+ B1 o" k. d' b  _! J% f2 |公仔箱論壇and explosive erupters are stratovolcanoes, whichare made of layers of ash and lava from previous eruptions.
9 N) p5 a7 Q, j) gtvb now,tvbnow,bttvbThey 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。6 _5 C% T) Q& ~; w( `' e; Z

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Many of the stunning images of eruptions captured from space are ofviolent stratovolcanoes, such as the one above / B! \$ ]1 I& B
of Kliuchevskoi, themost active volcano on Russia’s Kamchatka peninsula. The image abovewas
/ T6 f4 Q7 F4 k. }3 u& 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。taken by astronauts on the space shuttle Endeavour in 1994, as an eruption was just getting underway. The ash 5.39.217.77& H% O" N8 n" u" s2 P- o
plume reached as high as 50,000 feet.5.39.217.77+ s  U( q" b; {8 L/ B7 @, U# T2 y

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Augustine Volcano is a 4,100-foot-tall, 7-mile-wide stratovolcano. This eruption was captured by NASA’s Terra 2 O# B- K8 O. H0 F
satellite in 2006. Augustine’s dome collapsed in 1883, during its largest historical eruption. It has been erupting for at least 40,000
8 ]+ `4 \+ k2 N1 ~6 T8 Y7 Byears. 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
1 u- m- S9 Q( G# _0 Gof Fire. Volcanic activity here is caused by the subduction of the Pacific plate beneath the North American plate. As the wet . F4 Y/ C0 U" r; X0 M8 T+ K8 u
ocean crust descends into the molten mantle below, superheated water is squeezed out and rises up to melt the bottom of
, f6 H7 {  m: s' F公仔箱論壇the continental crust, creating magma that drives the volcanic eruptions公仔箱論壇0 l3 D/ m8 I0 i, Q
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; i6 d% a1 x' ~. ?; V+ Q" b公仔箱論壇Astronauts aboard the International Space Station caught a lucky glimpse of the start of this eruption of Sarychev Volcano
4 G5 S4 g& x6 w: C( |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。in the Kuril Islands, northeast of Japan, on June 12, 2009. This was the volcano’s first eruption in 30 years.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。. Y; }; V8 v4 ^6 P8 ~  U& ?

1 }: Q# Q2 B! c0 l/ w' etvb now,tvbnow,bttvbThe 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% g# `& p& J! X( p4 v- D
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 + _3 m/ f+ x+ ]& I0 e3 L$ Q
as a pyroclastic flow.
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4 `" C! A% k$ w5 @( g; Wtvb now,tvbnow,bttvbThis photo sparked a debate among scientists about what caused the hole in the clouds above the eruption. Three possible options came up:5.39.217.77. `9 a: m+ y: u5 l6 D0 W

5 u8 W1 F7 N0 l2 u公仔箱論壇    * It could have nothing to do with the eruption and simply be caused by the contrast in temperatures between the ocean and the island.
  g/ X& b5 [. ?' Y( W* jtvb now,tvbnow,bttvb    * A shockwave from the eruption could have blown a hole in the cloud deck.1 ^* ^; P4 a, ^6 j4 v
    * As the plume rose, air flowed downward along the sides and became warmer and evaporated the clouds.$ j7 z) B7 a4 |; `

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* Z7 ~( y: L2 g9 `4 _. T) D& |$ @Alaska’s Redoubt Volcano erupted five times in one night this year after almost three decades of relative quiet.
$ u6 X- e0 }. L/ n, ?It continued erupting on and off for weeks afterward. This image was taken by the commercial satellite GeoEye-1 on March 30 when6 N: C" L" [! _8 x
the ash reached heights of 27,000 feet. The volcano’s alert level is still “advisory,” and the aviation color code is yellow., D: |: N  E2 j

# e# J/ E7 Z4 n* [0 z% |) fRedoubt is a 10,200-foot tall stratovolcano 100 miles southwest of Anchorage in the Aleutian Range, west of the Cook Inlet.1 M, e6 t/ a9 _7 s; p
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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 in
) H4 f# L( U# O the world and is erupting nearly continuously. It is no surprise that there are many great photos of this volcano erupting, including this one tvb now,tvbnow,bttvb2 Q+ S( h5 [' \5 a+ ~
captured by astronauts on the International Space Station in 2002. The lighter colored plumes of smoke on the slope of the volcano in 5.39.217.77  t6 @1 m/ n+ P, a; U' @) u
this picture are from forest fires ignited by lava.
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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公仔箱論壇. m% e5 N" Y1 @2 O& t; A
also be the oldest-known active volcano.2 L9 C! {! c- V# w
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/ @7 y" D" m. ?" H6 Q# x公仔箱論壇A NASA astronaut spotted this eruption of Cleveland Volcano from the International Space Station in 2006. The volcano is 5,700 feet high
  d3 r" I  \8 Y" _/ N; x( p公仔箱論壇and claimed the only known eruption-related death in Alaska’s Aleutian Islands in 1944. Its symmetrical, cone shape is typical of stratovolcanoes.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。6 ~# _/ p, Y  W2 C
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Popoépetcatl, which means “smoking mountain” in the Aztec language, is a very active volcano just 44 miles outside Mexico City. 5.39.217.77. h1 [* r5 b$ G/ t
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 tvb now,tvbnow,bttvb0 q: G% E, V+ @" o) A' B: _
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
/ L' ]2 P6 s# @9 M' i. F' g) K3 N. xof frequent activity. The plume reached heights of around 30,000 feet.% X  l/ i/ c; i: `1 F

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4 {) Y2 p+ r! B- p) vThis eruption of Chaitén caldera in Chile was photographed from the International Space Station in May 2008. Volcanism along the - M1 ^! l( \+ P% @- S- x
west coast of South America is the result of subduction of the oceanic Nazca plate beneath the South American plate.
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9 e  K7 C% {5 R5 x* [5 UChaitén was last active more than 9,000 years ago. The violent 2008 eruption inundated the small coastal town of Chaitén with ash, pyroclastic
/ H+ P2 A( ]! v( eflows 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.  m  K0 T4 _+ H8 v3 _

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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
/ x' D! t8 e  R9 @tvb now,tvbnow,bttvbis 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
3 x% T- i7 ^% k# Z) MTVBNOW 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。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 9 O5 G& }: E. u
stationary 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.
5 {3 `% [1 [% D& `公仔箱論壇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 5 e2 |: g. @) t7 h/ j, N: N
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,
' D9 F  `7 P; h5 ~( ecausing avalanches of debris into the crater.

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