One of the most violent but beautiful reminders that we live on ageologically restless planet are volcanic os.tvboxnow.com: C* O' d- U" w2 G" M& q0 K: D: f
eruptions. Around 550volcanoes have erupted at least once in historic times, and around 50or 60 are 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# d* g) E& O. v
active each year. On any given day, as many as 10 volcanoesmay be spewing ash or lava somewhere on Earth.os.tvboxnow.com7 u- _/ p; _2 {
Some volcanoes, such as Mount Etna in Italy, erupt almost constantlyfor years on end. Others, like Mount St. Helens,
3 t/ r4 k* s4 O6 g4 @) |7 otvb now,tvbnow,bttvberupt rarely andsometimes extremely destructively. Like Etna and Mount St. Helens, manyof the most dangerous 公仔箱論壇6 \, Z+ l) [ U# T
and explosive erupters are stratovolcanoes, whichare made of layers of ash and lava from previous eruptions.
. Q* b7 M3 E' b$ @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。They tendto be steep-sided cone-shaped volcanoes and often rise strikingly abovethe surrounding landscape.
% i7 D, ^1 ~1 ?os.tvboxnow.com
9 @# a4 D8 B otvb now,tvbnow,bttvb
. m* z0 |+ \5 ?- q- ]0 xos.tvboxnow.com
* t1 G2 \: m' t& _) @* `Many of the stunning images of eruptions captured from space are ofviolent stratovolcanoes, such as the one above
. |% B* M4 X: h$ G. kos.tvboxnow.comof Kliuchevskoi, themost active volcano on Russia’s Kamchatka peninsula. The image abovewas
6 k, r0 }/ u9 J2 I. h! v- c公仔箱論壇taken by astronauts on the space shuttle Endeavour in 1994, as an eruption was just getting underway. The ash & i# Y# C8 a4 M- d: i8 R
plume reached as high as 50,000 feet.
, D* h5 U# U+ y+ Gos.tvboxnow.com
# \) U6 B+ b9 J2 B5 o4 J/ ~0 h公仔箱論壇
/ l: j0 Z# {( M3 B' P; J( S3 X公仔箱論壇
: W& J( z7 w- E9 y( P# J) ]tvb now,tvbnow,bttvbAugustine Volcano is a 4,100-foot-tall, 7-mile-wide stratovolcano. This eruption was captured by NASA’s Terra
* P/ n8 K7 v% S& R7 x! pos.tvboxnow.comsatellite in 2006. Augustine’s dome collapsed in 1883, during its largest historical eruption. It has been erupting for at least 40,000
0 Y# [, D0 C7 k! ?& T6 hyears. The island’s jagged edges were created by massive avalanches.
# T& G- {% k$ Bos.tvboxnow.com4 ?4 H- k- T4 d0 [4 N3 d8 u
Augustine lies in the Cook Inlet at the eastern end of the Aleutian trench which marks the northernmost portion of the Pacific Ring / }4 o N' k$ _% c
of Fire. Volcanic activity here is caused by the subduction of the Pacific plate beneath the North American plate. As the wet 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。 i0 z1 t& k2 m- s' V7 p
ocean crust descends into the molten mantle below, superheated water is squeezed out and rises up to melt the bottom of
8 a5 m% m2 U2 n3 ^' Y# F2 z! i' \' P6 kTVBNOW 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 continental crust, creating magma that drives the volcanic eruptionsTVBNOW 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。- D J8 x' K; _" d* g
4 v( G% Q" |1 T) A; @ 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。8 x9 I6 z: T. I: z6 u a
公仔箱論壇, `% _- q0 }. ~. a3 Z$ S
Astronauts aboard the International Space Station caught a lucky glimpse of the start of this eruption of Sarychev Volcano 1 G1 S0 @( G- F- d( X
in the Kuril Islands, northeast of Japan, on June 12, 2009. This was the volcano’s first eruption in 30 years.tvb now,tvbnow,bttvb- j" f. v I* v3 G# c# O, {
tvb now,tvbnow,bttvb8 p! q$ Z1 I( ]4 q" s( C& k4 ^
The smooth white cloud, known as a pileus cloud, topping the eruption column may be made of water condensation caused by rising
+ c! k2 e' g& p4 ~6 s/ @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。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 公仔箱論壇) h7 u& x% \ ?+ _2 e
as a pyroclastic flow.% \8 j- H* H8 h$ r0 X, v
% P! t; G; ?% z7 @/ w# E% [公仔箱論壇This photo sparked a debate among scientists about what caused the hole in the clouds above the eruption. Three possible options came up:公仔箱論壇: k% S/ i2 r0 L8 e
; |- \* f: \0 D% P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.
" V. J1 s# e l7 N * A shockwave from the eruption could have blown a hole in the cloud deck.
+ i2 |* i! S4 |5 x/ B * As the plume rose, air flowed downward along the sides and became warmer and evaporated the clouds.
V- p! n* G) H* H* O5 {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 R( p9 q/ w, ^1 T# ~- r

b2 L- k/ i6 c' @3 |- O2 Uos.tvboxnow.com
3 |9 c# c; o9 o! k. G# U }0 qtvb now,tvbnow,bttvbAlaska’s Redoubt Volcano erupted five times in one night this year after almost three decades of relative quiet. os.tvboxnow.com" M% r1 O$ m; i; H
It continued erupting on and off for weeks afterward. This image was taken by the commercial satellite GeoEye-1 on March 30 when公仔箱論壇2 X$ v4 E# Z# i( E, d- G% b
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6 F( i- K0 S( _8 j) r% s" J' O
( ?/ Q0 g% k0 `+ ]# \0 Btvb now,tvbnow,bttvbRedoubt is a 10,200-foot tall stratovolcano 100 miles southwest of Anchorage in the Aleutian Range, west of the Cook Inlet.
% A& g; A/ q z$ `9 x7 s. S1 r2 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。" S4 v# q/ z" o, {# A" v4 \
' F+ t0 m) l! K% c
os.tvboxnow.com* c! X& ^$ I: X/ v
Mount Etna is the second tallest volcano in Europe, at almost 11,000 feet. It is one of the most active volcanoes inos.tvboxnow.com% N: k% v6 Y4 W B2 v
the world and is erupting nearly continuously. It is no surprise that there are many great photos of this volcano erupting, including this one 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。; F! Y- N7 e# l, N Y% {
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。0 B$ c9 L" D7 b/ i
this picture are from forest fires ignited by lava.8 f/ S. D x2 T/ ^3 j& T' Q
公仔箱論壇 O6 ]0 \- i$ q; K+ }$ m) ]* P( N# U! Y
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* y* A7 F; A7 e6 w; s& a, O& f
also be the oldest-known active volcano.公仔箱論壇1 t, V* [6 c$ O4 h. U( j7 k
公仔箱論壇6 I/ K: J. K+ v9 ?6 Z+ L/ n
) p+ @* d" L# M0 g% L% a: |! P
8 g. }- I# c; K9 e$ l! A; Y9 G
A NASA astronaut spotted this eruption of Cleveland Volcano from the International Space Station in 2006. The volcano is 5,700 feet high tvb now,tvbnow,bttvb7 r4 H, h* R3 b- A
and claimed the only known eruption-related death in Alaska’s Aleutian Islands in 1944. Its symmetrical, cone shape is typical of stratovolcanoes.
$ ^4 K E. i7 f; V9 L! \+ {; I J; D% D

; a* u' O: d6 E公仔箱論壇os.tvboxnow.com; V( R5 Y: D( P2 z7 b$ }
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。 p- j+ {/ q! 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 ! @4 R3 p; m0 X* A- \0 m7 d
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 公仔箱論壇* S/ B/ _; i7 i; j0 Q. x# J& N9 \) \ \
of frequent activity. The plume reached heights of around 30,000 feet.公仔箱論壇7 d0 H/ l9 Z( Q' A- M
tvb now,tvbnow,bttvb! a& g9 d7 e) k8 R) |4 V4 V
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。2 d- L0 b% q9 J, ~
+ i; J' `% ]) M
. S" J% Y k0 etvb now,tvbnow,bttvb
2 X! i5 w. |* |1 Z+ I* h公仔箱論壇This eruption of Chaitén caldera in Chile was photographed from the International Space Station in May 2008. Volcanism along the 3 E3 V( ]2 k G2 U& S
west coast of South America is the result of subduction of the oceanic Nazca plate beneath the South American plate.
' ~. G8 W6 |5 fTVBNOW 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。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。$ ~5 v" k+ h3 P5 a' j6 [
Chaitén was last active more than 9,000 years ago. The violent 2008 eruption inundated the small coastal town of Chaitén with ash, pyroclastic
8 K$ |9 F6 x- p3 `4 C) m5 j ATVBNOW 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。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.os.tvboxnow.com! @8 i" {$ B. Y8 X: `
& O) a8 Z1 v' _os.tvboxnow.com , ?+ G; w) s$ I
7 K" p2 i: ]2 |1 Atvb now,tvbnow,bttvbThis 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。& z+ t9 d, Q# a/ D4 a0 D6 s
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
/ d; w. ]; b9 J: k; E) f# G: L* oformed 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% \) K5 H6 ~" x" |8 G8 i# d
stationary hot spot, volcanoes are formed. The Hawaiian Islands were formed — and continue forming — the same way.
( Z$ W/ ]& N& a& a& A5 Ios.tvboxnow.com
' j2 R$ Y+ k" o0 _7 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。6 c' i/ w N) u9 |1 ]4 T, T8 P% S$ F
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。2 o# D( q2 |/ o7 V4 N" v- t9 ]
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.
$ r7 S3 W- g& T4 f" s& J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 os.tvboxnow.com2 }$ q+ B- \! R. g. C: I& a$ ?
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, 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。8 e$ z7 e! Z. o# {' ]) C
causing avalanches of debris into the crater. |