|25 February 2011
New maps show how ice sheets shrank during Ice Age
Scientists from the University of Sheffield in England have for the first time brought to life through illustrated maps the shrinkage of the last British ice sheet as it shrunk during the last Ice Age, some 20,000 years ago.
Led by Professor Chris Clark, the team of experts created the maps which showed the ice sheet shrinking over a period of thousands of years, in an effort to understand what effect the current shrinking of ice sheets in parts of the Antarctic and Greenland will have on the speed of sea level rise. The ice sheet which covered most of Britain, Ireland and the North Sea, had a volume of ice sufficient enough to raise global sea levels by around 2.5 metres when it finally melted.
The maps are based on new information on glacial landforms, such as moraines and drumlins, which were discovered using new technology such as remote sensing data that is able to image the land surface and seafloor at unprecedented resolutions. Experts combined this new information with that from fieldwork, some of it dating back to the nineteenth century, to produce the final maps of retreat. These maps may reveal exactly when land became exposed from beneath the ice and was available for colonisation and use by plants, animals and humans. This provides the opportunity for viewers to pinpoint when their town/region emerged.
"It took us over 10 years to gather all the information in order to produce these maps, and we are delighted with the results," said Professor Clark. "It is great to be able to visualise the ice sheet and notice that retreat speeds up and slows down, and it is vital of course that we learn exactly why. With such understanding we will be able to better predict ice losses in Greenland and Antarctica. In our next phase of work we hope to really tighten up on the timing and rates of retreat in more detail, by dropping tethered corers from a ship to extract seafloor sediments that can be radiocarbon dated."
Edited from University of Sheffield Media Centre (11 February 2011), Reuters (17 February 2011), ScienceDaily (22 February 2011)
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