Scientists predict the contribution of the West Antartic Ice Sheet’s (WAIS) to sea-level rise by the boulders collected from the glaciers.
Scientists have collected boulders the size of footballs at WAIS witch has the potential to raise sea-level by 1.5 meters.
The boulders analysis has enabled the scientists to construct a long-term picture about the glacier behavior in the region. The idea is to determine if the retreat of the ice has been natural or not since the end of the last glaciation (20 thousand years ago).
Lead author Dr. Joanne Johnson of BAS says: “Until now we didn’t know much about the long-term history of this part of the West Antarctic Ice Sheet because the region is incredibly remote and inaccessible. Our geological findings add a new piece to the jigsaw and will be used for improving computer models – the most important tools we have for predicting future change.”
When the results are compared, they show that the ice has thinned 20 times faster than its natural evolution.
Scientists reached these conclusions by investigating for how long the boulders have been exposed to cosmic radiation instead of shielded by the ice.
Co-author Dr Mike Bentley from the University of Durham said:
“When rocks are left high and dry by thinning glaciers they are exposed to high energy cosmic rays which bombard the rock. This creates atoms of particular elements that we can extract and measure in the laboratory - the longer they have been exposed the greater the build-up of these elements. The discovery that we can place a fix on when rocks were left behind by the ice has revolutionized our understanding of how the Antarctic ice sheet has behaved in the past. “
