Monthly Archives: February 2008

More on glaciers Pt 1- Intro to glaciology

Roughly 10% of the land area on Earth is covered by glaciers– most of this number comes from the Antarctic and Greenland ice sheets. Other areas of permanent ice are scattered around in places like the Rockies, Alps, Andes, Himalayas, etc. Ice also covers roughly 7% of the oceans in the annual mean, though both hemispheres experience sea ice loss in their respective summers, and regrowth in their winters. Around 75% of the freshwater on Earth is stored in glaciers, and they provide water for millions of people worldwide. Glaciers form when more snow falls each year than can melt or evaporate. The snow piles up, is squeezed into ice under the weight of more snow (with an intermediate form called ‘firn’), and begins to flow under gravity. Such conditions are generally a function of both temperature and precipitation and are dominant at low latitudes and high altitudes, or high latitudes.

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