Permafrost alone holds back Arctic rivers—and a lot of carbon

New research from Dartmouth College provides the first evidence that the Arctic's frozen soil is the dominant force shaping Earth's northernmost rivers. Permafrost, the thick layer of soil that stays frozen for two or more years at a time, is the reason that Arctic rivers are uniformly confined to smaller areas and shallower valleys than rivers to the south, according to a study in the Proceedings of the National Academy of Sciences.