Dedicated to the balanced discussion of global warming
BBC News – February 15, 2007
I am constantly amazed that we discover so much about our planet almost every day. It appears that we really don’t understand all of the influences of water, ice, wind, snow, etc. and we are constantly learning more. This is why there may be realism to the argument that we simply do not know if the current warming trend is man-made or caused by other combinations of influences.
Giant “blisters” containing water that rapidly expand and contract have been mapped beneath the Antarctic ice sheet. Fed by a complex network of rivers, the subglacial reservoirs force the overlying ice to rise and fall. By tracking these changes with Nasa’s Ice Cloud and land Elevation Satellite (ICESat) scientists were able to map the extent of the subglacial plumbing. The results, published in the journal Science, show that some areas fell by up to 9m (30ft) over just two years. “We didn’t realise that the water under these ice streams was moving in such large quantities, and on such short time scales,” said Dr Helen Fricker of the Scripps Institution of Oceanography, University of California, and one of the authors of the paper.
The results are important for understanding how the Antarctic Ice sheet, which contains nearly 90% of the world’s ice, may respond to global warming and how much it may contribute to sea level rise.
Nearly 150 subglacial lakes have been identified beneath the vast Antarctic ice sheet.
As atmospheric temperatures rise, melting the ice shelves, their ability to hold back the ice streams on land would be reduced.
We aren’t yet able to predict what these ice streams are going to do.
The study revealed a complex network of ponds and rivers, the largest of which occurred under the Whillans ice stream and covered an area of 500 sq km (190 sq miles).
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