One of the most violent but beautiful reminders that we live on ageologically restless planet are volcanic
: e2 S, w! \, @) Ztvb now,tvbnow,bttvberuptions. Around 550volcanoes have erupted at least once in historic times, and around 50or 60 are
* X: i$ V* N( l& g% ?www3.tvboxnow.comactive each year. On any given day, as many as 10 volcanoesmay be spewing ash or lava somewhere on Earth.. m# r! x# A! l. T. |% P; k
Some volcanoes, such as Mount Etna in Italy, erupt almost constantlyfor years on end. Others, like Mount St. Helens,
4 [1 ~$ l; }1 ?6 F) Ywww3.tvboxnow.comerupt rarely andsometimes extremely destructively. Like Etna and Mount St. Helens, manyof the most dangerous www3.tvboxnow.com! v0 R6 P8 v0 F5 @$ p V
and explosive erupters are stratovolcanoes, whichare made of layers of ash and lava from previous eruptions. 1 R9 s+ a3 l. W3 f* L4 ^0 }% \ F
They tendto be steep-sided cone-shaped volcanoes and often rise strikingly abovethe surrounding landscape.
' b' S( q8 Q( ], L* btvb now,tvbnow,bttvb
0 w4 } I1 b L5 m; F0 v2 G0 Q
9 k u3 }4 g E9 u) j9 l' O! ewww3.tvboxnow.com
3 ^ D$ S( I- d/ A2 y0 T; ^) k1 {4 CMany of the stunning images of eruptions captured from space are ofviolent stratovolcanoes, such as the one above
& h. Y! L+ u9 N( @3 h! e. ?$ |: A: B- 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。of Kliuchevskoi, themost active volcano on Russia’s Kamchatka peninsula. The image abovewastvb now,tvbnow,bttvb. K3 ?. Z4 P" ]7 O: @
taken by astronauts on the space shuttle Endeavour in 1994, as an eruption was just getting underway. The ash 5 a& I2 q) H" n
plume reached as high as 50,000 feet.
0 |( j1 c# d' h3 T! `- _" YTVBNOW 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% K- d% K# ~+ I9 t7 B9 i公仔箱論壇公仔箱論壇; N5 q$ N$ D6 q+ I& @
$ R6 X9 [% o4 @3 V$ 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。Augustine Volcano is a 4,100-foot-tall, 7-mile-wide stratovolcano. This eruption was captured by NASA’s Terra
/ ?$ r7 [& ]/ w& l( E: dwww3.tvboxnow.comsatellite in 2006. Augustine’s dome collapsed in 1883, during its largest historical eruption. It has been erupting for at least 40,000
: c' G) K' o& o% i. `( Yyears. The island’s jagged edges were created by massive avalanches.公仔箱論壇( j5 R9 F" `0 K
& T( i% B# j3 c+ H! r公仔箱論壇Augustine lies in the Cook Inlet at the eastern end of the Aleutian trench which marks the northernmost portion of the Pacific Ring 公仔箱論壇9 S! {8 o" Q3 F* `- u6 L# g# c" E/ N" {
of Fire. Volcanic activity here is caused by the subduction of the Pacific plate beneath the North American plate. As the wet
7 b3 y3 F' \% V( a! ^ocean crust descends into the molten mantle below, superheated water is squeezed out and rises up to melt the bottom of
8 W0 |( H8 {! Z6 ^- U( n H8 Xthe continental crust, creating magma that drives the volcanic eruptions公仔箱論壇8 d! k) Y4 }- j7 g- A# F
5 g6 b6 T6 j- O1 s7 E ttvb now,tvbnow,bttvb
) ]% U. @) N% r: H2 \1 l! b* A, m$ @8 v5 a
Astronauts aboard the International Space Station caught a lucky glimpse of the start of this eruption of Sarychev Volcano
& C* Q% r, I- D( tin 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。! S6 C+ w' L* g+ W5 a2 \
+ X! A$ ]- N: p6 atvb now,tvbnow,bttvbThe smooth white cloud, known as a pileus cloud, topping the eruption column may be made of water condensation caused by rising
6 E7 g. W4 T5 ^, B4 P1 I& v0 G" z4 Ttvb now,tvbnow,bttvband 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* g' o# j0 D; m# a
as a pyroclastic flow.www3.tvboxnow.com$ a; }- R: [8 Y/ ~+ q; @! \3 f4 ^
: m& Z( J3 A% Q M/ x; Fwww3.tvboxnow.comThis photo sparked a debate among scientists about what caused the hole in the clouds above the eruption. Three possible options came up:tvb now,tvbnow,bttvb, e# O% I1 W; s% J" [
V) J6 Q* K5 y" o8 ?* o) M7 A s
* It could have nothing to do with the eruption and simply be caused by the contrast in temperatures between the ocean and the island.公仔箱論壇# V, s% F( ?( z8 |2 r( M$ w
* A shockwave from the eruption could have blown a hole in the cloud deck.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。& u* q4 ^ Z" g5 r
* As the plume rose, air flowed downward along the sides and became warmer and evaporated the clouds.8 z4 \2 a X3 s5 Q) d
www3.tvboxnow.com3 { B' Q4 A! p
) i; h9 j( E* l5 w, |, Y' h5 qTVBNOW 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。$ O9 O% L; _; |, y, k) g5 I- c
Alaska’s Redoubt Volcano erupted five times in one night this year after almost three decades of relative quiet.
; v( f8 c, ]! E3 {; \: 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。It continued erupting on and off for weeks afterward. This image was taken by the commercial satellite GeoEye-1 on March 30 when
/ A0 j, I" h/ F5 h5 j1 [! s8 [5 Gwww3.tvboxnow.com the ash reached heights of 27,000 feet. The volcano’s alert level is still “advisory,” and the aviation color code is yellow.& Q4 z0 ]$ o9 R7 k, o
- P2 z7 y, a$ o6 Ptvb now,tvbnow,bttvbRedoubt is a 10,200-foot tall stratovolcano 100 miles southwest of Anchorage in the Aleutian Range, west of the Cook Inlet.
1 ^) Y* o' R& `4 ]+ B+ C+ i% t2 p6 M- L4 K
9 ^2 M. p8 Z& s5 j" P* qtvb now,tvbnow,bttvbTVBNOW 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。! Z3 }/ u2 R8 v j# O- i
Mount Etna is the second tallest volcano in Europe, at almost 11,000 feet. It is one of the most active volcanoes in
# w H7 J5 m2 f8 jtvb now,tvbnow,bttvb the world and is erupting nearly continuously. It is no surprise that there are many great photos of this volcano erupting, including this one ( u; `6 i% Q5 x }' F9 L
captured by astronauts on the International Space Station in 2002. The lighter colored plumes of smoke on the slope of the volcano in
+ H" ^7 X4 M2 M' c! e" ?www3.tvboxnow.comthis picture are from forest fires ignited by lava.
* m9 B& a0 U; O4 n/ 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。www3.tvboxnow.com8 `. F. V0 ~2 p8 c; O8 U1 u
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( H4 _" b- V1 w* D, T9 `- I, l
also be the oldest-known active volcano.
. K8 b. l) p0 ]% L; E3 Y9 S3 M公仔箱論壇tvb now,tvbnow,bttvb. h, K$ `6 V# k" }9 @
tvb now,tvbnow,bttvb U# D* p1 O# l5 }0 w
+ B* }9 N% s! W* 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。A NASA astronaut spotted this eruption of Cleveland Volcano from the International Space Station in 2006. The volcano is 5,700 feet high
2 f/ @- L. a- H I* P; Y ZTVBNOW 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.
- v( P$ u4 @5 ?: K8 N6 K$ D9 Rtvb now,tvbnow,bttvb
- k/ D, E, _, e& i7 JTVBNOW 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。
) H2 f5 G# U2 ?, s5 U: R& P% w) e
3 ~* \. [. a/ e' ^7 H# zTVBNOW 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。Popoépetcatl, which means “smoking mountain” in the Aztec language, is a very active volcano just 44 miles outside Mexico City.
9 M# K& }, u9 T0 S `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 $ _$ u$ v) E+ u2 o- ^" }1 `
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
8 Q0 b- x! B' ?! etvb now,tvbnow,bttvbof frequent activity. The plume reached heights of around 30,000 feet.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 f# c6 K+ q& q
( [3 U5 W2 B, J$ A; D; ]/ @3 Zwww3.tvboxnow.com公仔箱論壇4 l) I1 w; S, W$ a
0 U$ A3 `" u. _, j2 j6 y0 itvb now,tvbnow,bttvb
2 g' V- j' |: t! K5 G& {+ v% ?公仔箱論壇5 A0 D V6 d% J. @8 B& V
This eruption of Chaitén caldera in Chile was photographed from the International Space Station in May 2008. Volcanism along the
! ~( e( D5 F. R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." m; i! C/ `# D4 X' N
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 {. U/ I Q8 v* N; d: a8 f
Chaitén was last active more than 9,000 years ago. The violent 2008 eruption inundated the small coastal town of Chaitén with ash, pyroclastic
3 S6 C" p7 r5 f. Q8 A: ETVBNOW 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.
: k; f) g1 U* s, S( P! }% J3 W+ a0 g! O6 p9 a6 T9 o" n
6 v1 l7 F! I6 JTVBNOW 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。tvb now,tvbnow,bttvb7 O; f/ s( q# L2 k
This image of the Sierra Negra volcano in the Galapagos Islands was taken by NASA’s Terra satellite in 2006. Sierra Negra + {" A' q- y) a% }2 c
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
6 V) Y% i1 n. f% N) wformed 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 tvb now,tvbnow,bttvb' h2 Z3 S' ]4 _: f
stationary hot spot, volcanoes are formed. The Hawaiian Islands were formed — and continue forming — the same way.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 X- @* g& j& o% a, k: ?
9 U. v1 Y$ [; H9 Z" q" G% J2 L; L
1 A7 Q. t5 p: d
$ j% N1 C7 O0 Z0 ]8 j! K- p$ s0 nwww3.tvboxnow.comNASA’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. 公仔箱論壇: `+ }: R3 {; U
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 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! p; A9 ]0 g6 y+ l
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,
, V3 A. q6 k2 }tvb now,tvbnow,bttvbcausing avalanches of debris into the crater. |