Science Advances, 1 January 2022
Warm water from the Atlantic Ocean fills the bottom of Greenland’s deepest fjords, where its major outlet glaciers meet the ocean. During the summer, this dense layer of ocean water mixes with glacial meltwater, sending a plume of warmer water to the surface. This process, known as “undercutting,” accelerates melting at the base of the glacier and creates an overhanging layer of ice that breaks off to form icebergs. Seventy-four glaciers situated in these deep fjords, which are more subject to undercutting, produced nearly half of Greenland’s total ice loss between 1992 and 2017. As global temperatures have risen, the amount of meltwater flowing into these fjords has increased, intensifying the effects of undercutting and accelerating ice loss and sea-level rise from the Greenland Ice Sheet. Developing stronger climate models that include how a warming ocean affects these glaciers will help communities better project future sea-level rise, prepare for flooding and mitigate coastal ecosystem damage.