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Amazing Antarctica
Factfile |
 Amazing Antarctica |
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The Highest Continent |
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Antarctica is the highest continent in the world, with an average height of 2,400 m above sea level – compare this with Australia’s average of 340 m. However in some places, the weight of Antarctica’s ice sheet has pushed the bedrock 2500 m below sea level.
Mount Erebus
Some of the rocks forming the Antarctic continent are amongst the oldest in the world. The rocks of West Antarctica are mostly less than 300 million years old while the ancient rocks of East Antarctica are at least 3000 million years old!
Many scientists still argue about the reality of global warming. But if all the ice in Antarctica were to melt, apart from the predicted rise in the level of the world's oceans, the underlying rock in Antarctica would rise on average by 1000 m due to the weight of the ice being removed. This process is called isostatic uplift, but it would take many thousands of years to happen.
However, while research on global warming continues, a finding from Antarctica that brought the scientific community together was the research into the ozone layer and the international cooperation that would be needed to address the problem now.
Ozone hole - NASA
The formation of an `Ozone Hole' above Antarctica each spring has been a major concern for scientists. Ozone is formed naturally in the upper atmosphere, where it blocks harmful UV rays from reaching the Earth's surface. Chlorofluorocarbons (CFCs), which are artificial compounds used in fridges, air conditioners and aerosols, cause chlorine atoms to accumulate on ice crystals in the atmosphere of Antarctica during winter. In spring when the ice crystals melt, this chlorine is released, whereupon it reacts with and destroys ozone in a chain reaction. A large hole in the ozone is formed, which drifts north and breaks up in late spring.
Although there are now international agreements that have helped to phase out the use of chemicals that affect the ozone layer, it will be a long time before improvements are noticed and more than 50 years before the hole will disappear.
Meanwhile, the long term scientific monitoring of Antarctica's atmosphere will continue, but it should be mentioned that the very existence of the ozone hole, should serve as a warning to everyone that it is very easy for humans to significantly alter the Earth's atmosphere.
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