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Antaretica

2006-7-23 00:07  

  Antarctica1 is the highest, driest and coldest continent.

  Its 5.4 million square miles make it larger than Europe. At its widest point, Antarctica is about 4,000 miles across. There are about 98% thick continental ice sheet and 2% barren2 rock. The average thickness of the ice sheet is 7,200 feet; this amounts up to 90% of all the ice and 70% of all the fresh water in the world. If the ice cap were to melt, the sea level would rise by an average of 230 feet. Mountain ranges up to 4897 meters high. Glaciers3 form ice shelves4 along about half of the coastline, and floating ice shelves constitute 11% of the area of the continent.

  Severe low temperatures vary with latitude5, elevation6, and distance from the ocean; East Antarctica is colder than West Antarctica because of its higher elevation. Antarctic Peninsula7 has the most moderate climate. Higher temperatures occur in January along the coast and average slightly below freezing. Average temperatures are never above 32 degrees Fahrenheit8, even in summer. In winter, the temperature averages minus 76 degrees.

  The Pole is actually a desert environment, averaging about the same amount of monthly rainfall as the Sahara Desert9.

  In October 1991 it was reported that the ozone shield, which protects the Earth's surface from harmful ultraviolet10 radiation, had dwindled11 to the lowest level recorded over Antarctica since 1975 when measurements were first taken.

  南极洲

  南极洲是最高、最干且最冷的大陆。

  540万平方英里的面积使其比欧洲还要大。其最宽阔处约4000英里。南极约98%覆盖着厚厚的大陆冰床,2%为光秃的岩石。冰床平均厚度是7200 英尺,占地球总冰量90%、淡水70%。若冰层融化,地球的海平面将平均上升230英尺。南极山脉最高达4897米。约半数的海岸沿线都有冰川形成的冰块,其中浮冰块占整个大陆面积的11%。

  严寒低温随纬度、海拔和距海洋远近的不同而不同。南极洲东部由于海拔较高,比南极洲西部寒冷。南极洲半岛气候最温和。1月份沿海地带的温度较高,温度稍低于零度。即使在夏季,平均气温也不会超过32华氏度。在冬天,平均气温为零下76度。

  极地实际上是一个沙漠环境,平均月降雨量约相当于撒哈拉沙漠。

  据报道,1991年10月,南极上空防止地球表面遭受有害紫外线辐射的臭氧层,萎缩至1975年开始有测量记录以来的最低点。

  注释:

  1.Antarctica 南极洲

  2.barren adj.不毛的,荒芜的

  3.glacier n.冰川,冰河

  4.ice shelves (极地海岸周围的)冰架

  5.latitude n.纬度

  6.elevation n.高度,海拔

  7.peninsula n.[地]半岛

  8.Fahrenheit adj.华氏温度计的,华氏的

  9.Sahara Desert撒哈拉沙漠

  10.ultraviolet adj.紫外线的

  11.dwindle vi.变小,减少

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