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Article: According to Georaphical's Antarctica map, no rain or snow has fallen in the Dry Valleys near McMurdo Sound for two million years. Why not, and how can scientists be sure of this remarkable length of time?(Quizzical)(Brief Article)
- Article from:
- Geographical
- Article date:
- April 1, 2004
- Author:
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According to Georaphical's Antarctica map, no rain or snow has fallen in the Dry Valleys near McMurdo Sound for two million years. Why not, and how can scientists be sure of this remarkable length of time?
ANSWER: The ice that covers almost all of Antarctica has been there for a long time Across the continent, it's generally too cold for rain, but it rarely snows either, particularly in the interior. Antarctic blizzards are largely made up of ice crystals from the surface whipped up by the strong winds. The annual average precipitation is just 150 millimetres--in the form of snow--so much of the continent is classed as desert (for an area to qualify as a desert, ...