解放军文职招聘考试海洋升温 冰架消退1

 The study is the first comprehensive survey of all the Antarctic ice shelves - that's the 1.5 million square kilometers that fringe much of the frozen continent. Lead author Eric Rignot is a professor of Earth System Science at the University of California, Irvine. He says ice melt from below accounted for 55% of the shelf loss from 2003 to 2008, a rate much higher than previously thought. "We find that the melting of the underside of the ice shelves is even larger than the production of icebergs. So it is the dominant process of mass removal in the Antarctica." Rignot and colleagues used satellite observations, radar and computer models to measure features above the ice to calculate what was going on below. "So that includes the velocity of the ice, the thickness of the ice, how fast the freeboard of the ice shelf is changing with time and also how much snowfall there is on the top of the ice shelves." The measurements showed regional differences around the continent. The giant ice shelves - Ross, Filchner and Ronne - make up 2/3 of Antarctica's ice shelves, yet accounted for only 15% of the melting.

这是首个对南极冰架进行综合勘测的研究。这些冰架给这片150万平方公里的冰封大陆画了个圈。第一作者埃里克•里格诺特是加州大学尔湾分校的地球系统科学教授。他说自2003到2008年，从深海融化的冰占了冰架总消失量的55%，这比预期高出很多。“我们发现从底部流失的冰架比冰山的产生量都大。因此这是南极冰雪转移的主要过程 “里格诺特和同事运用卫星观测、雷达以及电脑模型，通过测量冰层上的特征来推断冰层下的玄机。“所以这包含了冰层的移动速度，冰层的厚度，冰架的出水高度随时间变化的频率以及冰架顶端的降雪量如何。“此次测量显示出南极大陆各地区之间的差异。三个巨大的冰架：罗斯、菲尔希纳和龙尼，构成南极洲冰架的三分之二，然而其融雪量只占全部的15%。