日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

WORLD> Global General
Alp-sized peaks found entombed in Antarctic ice
(Agencies)
Updated: 2009-02-25 09:19

OSLO  – Jagged mountains the size of the Alps have been found entombed in Antarctica's ice, giving new clues about the vast ice sheet that will raise world sea levels if even a fraction of it melts, scientists said on Tuesday.


A November 9, 2007 file photo shows melting icebergs in Antarctica. [Agencies] 

Related readings:
 Antarctica is warming, not cooling, says study
 First inland Antarctica station opens
 China opens 1st research station in inland Antarctica
 Cruise ship carrying 105 aground in Antarctica

Using radar and gravity sensors, the experts made the first detailed maps of the Gamburtsev subglacial mountains, originally detected by Russian scientists 50 years ago at the heart of the East Antarctic ice sheet.

"The surprising thing was that not only is this mountain range the size of the Alps, but it looks quite similar to the (European) Alps, with high peaks and valleys," said Fausto Ferraccioli, a geophysicist at the British Antarctic Survey who took part in the research.

He told Reuters that the mountains would probably have been ground down almost flat if the ice sheet had formed slowly. But the presence of jagged peaks might mean the ice formed quickly, burying a landscape under up to 4 km (2.5 miles) of ice.

Ferraccioli said the maps were "the first page of a new book" of understanding how ice sheets behave, which in turn could help predict how the ice will react to global warming.

Antarctica, bigger than the United States, has been swathed in ice for about 35 million years, and contains enough of it to raise world sea levels by about 57 metres (187 feet) if it ever all melted. So even a fractional melt would affect coasts around the globe.

"Unless we have a basic understanding of how ice sheets work, any sort of predictive model won't match reality," Ferraccioli said.

The UN panel on climate change says that greenhouse gases, mainly emitted by burning fossil fuels, will bring more heatwaves, floods and droughts, and raise sea levels.

The team of experts from Australia, Britain, Canada, China, Germany, Japan and the United States also found water below the ice, using survey aircraft that flew 120,000 km (75,000 miles).

"The temperatures at our camps hovered around minus 30 Celsius (minus 22 Fahrenheit), but 3 km (2 miles) beneath us at the bottom of the ice sheet we saw liquid water in the valleys," Robin Bell, of the Lamont-Doherty Earth Observatory at Columbia University, said in a statement.

Many sub-glacial lakes have been found in Antarctica in recent years.

Geologists say that mountain ranges such as the Alps or the Himalayas form in collisions between continents. The last time Antarctica was exposed to such forces was 500 million years ago.

"The mystery here is that the Alps are only 50 to 60 million years old, while here we have a mountain range that may perhaps be as old as 500 million years," Ferraccioli said.

主站蜘蛛池模板: 久久中文字 | 91精品免费 | 91精品在线看 | 久久视频一区 | 亚洲午夜18毛片在线看 | 夜夜爽av福利精品导航 | 日韩欧美视频在线 | 一级黄色免费 | 日韩有码在线播放 | 国产精品777| 男人天堂综合 | 日批视频在线播放 | 黄色草逼视频 | 午夜视频网 | 亚洲免费精品视频 | 亚洲小视频在线播放 | 大桥未久一区 | 久久久久久黄色 | 黄色成人免费视频 | 国产成人麻豆精品午夜在线 | 国产在线123| 欧美网站在线 | 日韩精品一区不卡 | 亚洲第一视频在线观看 | 开心激情综合 | 免费欧美视频 | 91插插插插 | 国产成人精品a视频一区 | 亚洲欧美日本在线观看 | 中文字幕一区二区不卡 | 2020av| 国内精品久久久久久久 | 日韩免费中文字幕 | 在线欧美成人 | 欧美精品第一页 | 男女涩涩| 亚洲欧美一区二区三区久久 | 日韩欧美网址 | 黄色网址在线免费 | 久久久视频在线观看 | 亚洲成人看片 |