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Nearly all of Antarctica is covered by a sheet of ice that is, on average, at least 1,500 m (5,000 ft) thick. Antarctica contains 90% of the world's ice and more than 70% of its fresh water. If all the land-ice covering Antarctica were to melt — around 30 × 10 ^ 6 km 3 (7.2 × 10 ^ 6 cu mi) of ice — the seas would rise by over 60 m (200 ft ...
The weather in Antarctica can be highly variable, and weather conditions will oftentimes change dramatically in a short period of time. Weather conditions on the continent are classified in a number of ways, and restrictions placed upon workers and other staffs vary both by stations and by nations.
Antarctica is a polar desert with little precipitation; the continent receives an average equivalent to about 150 mm (6 in) of water per year, mostly in the form of snow. The interior is dryer and receives less than 50 mm (2 in) per year, whereas the coastal regions typically receive more than 200 mm (8 in). [ 73 ]
Alpine tundra in the North Cascades of Washington, United States. Alpine tundra does not contain trees because the climate and soils at high altitude block tree growth. [26]: 51 The cold climate of the alpine tundra is caused by the low air temperatures, and is similar to polar climate. Alpine tundra is generally better drained than arctic ...
McMurdo Dry Valleys, Landsat 7 imagery acquired on December 18, 1999 The Dry Valleys are so named because of their extremely low humidity and lack of snow or ice cover. They are also dry because, in this location, the mountains are sufficiently high that they block seaward-flowing ice from the East Antarctic Ice Sheet from reaching the Ross
Most of the interior of Antarctica is polar desert, despite the thick ice cover. Conversely, the McMurdo Dry Valleys of Antarctica , although they have had no ice for thousands of years due to katabatic wind but contain ephemeral streams and hypersaline lakes characteristic of extreme non-polar deserts, are not necessarily polar desert.
By middle Miocene, 16–11.6 Ma, a tundra landscape completely replaced any remaining woodlands. At this time, woodlands became completely extirpated from the Antarctic Peninsula and all of Antarctica. A tundra landscape probably persisted until about 12.8 Ma when the transition from a temperate, alpine glaciation to a dynamic ice sheet occurred.
Antarctica is the largest ice desert in the world. Some 98% of Antarctica is covered by the Antarctic ice sheet , the world's largest ice sheet and also its largest reservoir of fresh water . Averaging at least 1.6 km thick, the ice is so massive that it has depressed the continental bedrock in some areas more than 2.5 km below sea level ...