地球上存在大型单体火山
文章来源:未知 文章作者:enread 发布时间:2013-09-06 08:22 字体: [ ]  进入论坛
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A University of Houston (UH) professor led a team of scientists to uncover the largest single volcano yet documented on Earth. Covering an area roughly equivalent to the British Isles1 or the state of New Mexico, this volcano, dubbed2 the Tamu Massif, is nearly as big as the giant volcanoes of Mars, placing it among the largest in the Solar System. William Sager3, a professor in the Department of Earth and Atmospheric4 Sciences at UH, first began studying the volcano about 20 years ago at Texas A&M's College of Geosciences. Sager and his team's findings appear in the Sept. 8 issue of Nature Geoscience, the monthly multi-disciplinary journal reflecting disciplines within the geosciences.
 
Located about 1,000 miles east of Japan, Tamu Massif is the largest feature of Shatsky Rise, an underwater mountain range formed 130 to 145 million years ago by the eruption5 of several underwater volcanoes. Until now, it was unclear whether Tamu Massif was a single volcano, or a composite of many eruption points. By integrating several sources of evidence, including core samples and data collected on board the JOIDES Resolution research ship, the authors have confirmed that the mass of basalt(玄武岩) that constitutes Tamu Massif did indeed erupt from a single source near the center.
 
"Tamu Massif is the biggest single shield volcano ever discovered on Earth," Sager said. "There may be larger volcanoes, because there are bigger igneous6 features out there such as the Ontong Java Plateau, but we don't know if these features are one volcano or complexes of volcanoes."
 
Tamu Massif stands out among underwater volcanoes not just for its size, but also its shape. It is low and broad, meaning that the erupted lava7 flows must have traveled long distances compared to most other volcanoes on Earth. The seafloor is dotted with thousands of underwater volcanoes, or seamounts(海底山), most of which are small and steep compared to the low, broad expanse of Tamu Massif.
 
"It's not high, but very wide, so the flank slopes are very gradual," Sager said. "In fact, if you were standing8 on its flank, you would have trouble telling which way is downhill. We know that it is a single immense volcano constructed from massive lava flows that emanated9 from the center of the volcano to form a broad, shield-like shape. Before now, we didn't know this because oceanic plateaus are huge features hidden beneath the sea. They have found a good place to hide."
 
Tamu Massif covers an area of about 120,000 square miles. By comparison, Hawaii's Mauna Loa -- the largest active volcano on Earth -- is approximately 2,000 square miles, or roughly 2 percent the size of Tamu Massif. To find a worthy10 comparison, one must look skyward to the planet Mars, home to Olympus Mons. That giant volcano, which is visible on a clear night with a good backyard telescope, is only about 25 percent larger by volume than Tamu Massif.


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1 isles 4c841d3b2d643e7e26f4a3932a4a886a     
岛( isle的名词复数 )
参考例句:
  • the geology of the British Isles 不列颠群岛的地质
  • The boat left for the isles. 小船驶向那些小岛。
2 dubbed dubbed     
v.给…起绰号( dub的过去式和过去分词 );把…称为;配音;复制
参考例句:
  • Mathematics was once dubbed the handmaiden of the sciences. 数学曾一度被视为各门科学的基础。
  • Is the movie dubbed or does it have subtitles? 这部电影是配音的还是打字幕的? 来自《简明英汉词典》
3 sager d66567f60a140c14f5ba87b995d3a5f7     
adj.贤明的,貌似聪明的( sage的比较级 )
参考例句:
  • Well, I want those yellow gators that Sager wore a few weeks ago. 好了,我想那些人认为是塞奇几个星期前穿的。 来自互联网
4 atmospheric 6eayR     
adj.大气的,空气的;大气层的;大气所引起的
参考例句:
  • Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
  • Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。
5 eruption UomxV     
n.火山爆发;(战争等)爆发;(疾病等)发作
参考例句:
  • The temple was destroyed in the violent eruption of 1470 BC.庙宇在公元前1470年猛烈的火山爆发中摧毁了。
  • The eruption of a volcano is spontaneous.火山的爆发是自发的。
6 igneous DyAyL     
adj.火的,火绒的
参考例句:
  • Igneous rocks do not contain fossils.火成岩不含化石。
  • The rocks here are igneous and do not fracture along predictable lines.这儿的石头都是火成岩,石头的裂缝极不规则。
7 lava v9Zz5     
n.熔岩,火山岩
参考例句:
  • The lava flowed down the sides of the volcano.熔岩沿火山坡面涌流而下。
  • His anger spilled out like lava.他的愤怒像火山爆发似的迸发出来。
8 standing 2hCzgo     
n.持续,地位;adj.永久的,不动的,直立的,不流动的
参考例句:
  • After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
  • They're standing out against any change in the law.他们坚决反对对法律做任何修改。
9 emanated dfae9223043918bb3d770e470186bcec     
v.从…处传出,传出( emanate的过去式和过去分词 );产生,表现,显示
参考例句:
  • Do you know where these rumours emanated from? 你知道谣言出自何处吗? 来自《简明英汉词典》
  • The rumor emanated from Chicago. 谣言来自芝加哥。 来自《现代英汉综合大词典》
10 worthy vftwB     
adj.(of)值得的,配得上的;有价值的
参考例句:
  • I did not esteem him to be worthy of trust.我认为他不值得信赖。
  • There occurred nothing that was worthy to be mentioned.没有值得一提的事发生。
TAG标签: earth single volcano
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