Ancient Ice Sheet Movements Studied

DURHAM, England, Sept. 17 (UPI) — British scientists say they have created a model of the British and Irish ice sheets that shows they moved in unexpected ways.

Durham University researchers said their model reveals for the first time how the glaciers reversed their flows and retreated back into upland regions from where they originated.

During the last glacial maximum, around 21,500 years ago, the ice sheets built up on the high land of the Lake District, north Pennines and Scottish Southern Uplands, the researchers said. As more snow fell and local ice caps thickened, glaciers flowed into surrounding lowlands as expected.

But the new model reveals an unusual twist. As the ice sheet evolved it flowed out towards the Irish Sea, eventually becoming so thick it reversed its flow back up the valleys, re-adjusting the landforms it had created during earlier stages of growth.

“The stereotypical image of Ice-age Britain is of ice rolling in from the Arctic,” said lead scientist David Evans. “But this is not an accurate description of what happened.”

Evans said the new model shows an ice sheet can reverse its flow in a hundred or so years and when that happens, it creates unique features in the landscape.

“Elongated drumlins and meltwater channels in northern England and southern Scotland provide evidence of this unique phenomenon,” he said.

The findings appear in the journal Quaternary Science Reviews.

Copyright 2009 by United Press International

Categorized | Nature & Ecosystems, Other
One Response to “Ancient Ice Sheet Movements Studied”
  1. Ian Marsden says:

    To most people this discovery may sound boring, but I find it quite exciting. I believe that the northern Icecap, in collecting precipitation moisture from the Atlantic, would progressively build up on its southern side. As accumulation reaches enough height to divert air currents around it, the deposition would occur progressively further south. The icecap would “advance” south, but by formation rather than glacial movement. Where this gets particularly interesting is that in so doing it could form a very deep barrier right across the North Atlantic, effectively damming off the Arctic Ocean. In the latter stages of the “meltdown” that occurred 11,000 years ago, the Arctic could build up as an upper glacial lake, and then release this as a catastrophic flood as the ice dam eventually collapses. My book on this can be found at
    if you are interested, or email me for more info at


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