Feb 26, 2007

Secrets contained within polar ice

Recently, a science news feed on on my blog about Antarctic ice melts caught my eye. Due to global warming, some polar ice shelves melted and scientists have discovered some unique and exotic species trapped within the ice. From CNN.com...
Spindly orange sea stars, fan-finned ice fish and herds of roving sea cucumbers are among the exotic creatures spied off the Antarctic coast in an area formerly covered by ice, scientists reported Sunday. This is the first time explorers have been able to catalog wildlife where two mammoth ice shelves used to extend for some 3,900 square miles over the Weddell Sea. At least 5,000 years old, the ice shelves collapsed in two stages over the last dozen years. One crumbled 12 years ago and the other followed in 2002.
This is quite cool on its own, but it reminded me of another interesting study I had read about earlier. In that study, scientists studying climate change, (Climatologists) would search for trapped air bubbles within polar ice. They would then examine the contents of the polar ice and examine its composition. This would subsequently give them an accurate and preserved snapshot of the atmosphere hundreds of years ago. This is ideal for studying climate change and apparently has been instrumental in advising and informing scientists about global warming. Apparently this technique been around for about 50 years now.

Another blog I browsed through comments that sometimes they drill up to 2 miles deep and find air bubbles that are more than 400,000 years old!
For example, ice cores from Greenland tell us that Earth's atmosphere has undergone rapid global changes many times in the past 110,000 years. But since the time that people have developed agriculture and industry, the climate has been the most stable and at least Greenland has been far warmer.

Ice cores from the Andes Mountains of South America and the Himalayan Mountains of Asia suggest that the climate drastically cooled about 5,000 years ago but is now reversing to a warming trend within the last 50 years...and that most of the world's high-elevation glaciers may melt in the near future.

Ice cores from Antarctica have been drilled to over 2.2 miles deep. Studies revealed that greenhouse gases (CO2, methane, and other gases) trapped in the ice correspond with temperature variations, over a 420,000 year history...perhaps warning us of current influences from our own activities that produce such gases. But it's unclear if the greenhouse gases caused the temperature increases or vice versa.
Very cool!

Some additional links...
Link1, Link2

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