Lakes with floating ice cover in the summer of 2000. Public Deposited
Description of this collection of datasets: Moulins are important conduits for surface meltwater to reach the bed of the Greenland Ice Sheet. It has been proposed that in a warming climate, newly formed moulins associated with the inland migration of supraglacial lakes could introduce surface melt to new regions of the bed, introducing or enhancing sliding there. By examining surface strain rates, we found that the upper limit to where crevasses, and therefore moulins, are likely to form is ~1600 m. This is also roughly the elevation above which lakes do not drain completely. Thus, meltwater above this elevation will largely flow tens of kilometers through surface streams into existing moulins downstream. Furthermore, results from a thermal ice-sheet model indicate that the ~1600-m crevassing limit is below the wet–frozen basal transition (~2000 m). Together, these datasets suggest that new supraglacial lakes will have a limited effect on the inland expansion of melt-induced seasonal acceleration.
Supraglacial lakes with floating ice covers on the western Greenland Ice Sheet were identified using Landsat and Radarsat imagery. These shape files give the locations and approximate boundaries of all such lakes (570) in the year 2000.