New Global Estimate of Rock-Debris Cover on Glaciers Helps Improve Projections of Glacier Melt and Sea Level Rise

Nature Geoscience, August 3

An updated approach is required to estimate the melting of global glaciers due to rock debris partially insulating the glaciers’ surface. As glaciers shrink, eroded rock from surrounding mountain slopes becomes exposed and slides down, forming a layer on the surface of glaciers which, if thick enough, reduces the rate at which the ice below melts. This work reveals that 44% of the world’s glaciers are covered in debris, with Alaska, the Southwestern Himalayas, and Greenland having the greatest absolute cover. Rock debris cover has been long omitted from global-scale glacier models, and models neglecting debris cover and its evolution might be overestimating glacier melt in these regions, the authors suggest, underscoring the complexity of individual glacier dynamics.

Compiled by Amy Imdieke