In the present study published in Nature, researchers from the Grenoble Institute of Environmental Geosciences (IGE, France) developed an innovative approach combining satellite observations and numerical modelling to test how surface melt influences basal slipperiness over the entirety of western Greenland.

Surprisingly, the authors find that surface melt rates do not control basal slipperiness. Instead, they demonstrate that conditions at the ice edge, whether the ice flows directly into the ocean or terminates on land, has the largest difference on how melt influences basal slipperiness including far into the interior of Greenland. The authors suggest this different response is due to marine terminating glaciers having a different morphology than land terminating glaciers. They are consistently faster and steeper, which eases the removal of lubricating basal water compared to land terminating glaciers, which are slower and flatter.

This new insight suggests unforeseen dynamic changes which increase mass loss are likely to occur as marine terminating glaciers retreat into the future. Yet, the study suggests ways that the findings could be incorporated into ice sheet models, which will enable researchers to improve predictions of mass-loss and ice sheet evolution through the end of the century.