Accelerated Volume Loss in Glacier Ablation Zones of NE Greenland, Little Ice Age to Present

Mountain glaciers at the periphery of the Greenland ice sheet are a crucial freshwater and sediment source to the North Atlantic and strongly impact Arctic terrestrial, fjord, and coastal biogeochemical cycles. In this study we mapped the extent of 1,848 mountain glaciers in NE Greenland at the Little Ice Age. We determined area and volume changes for the time periods Little Ice Age to 1980s and 1980s to 2014 and equilibrium line altitudes. There was at least 172.76 +/- 34.55-km(3) volume lost between 1910 and 1980s, that is, a rate of 2.61 +/- 0.52 km(3)/year. Between 1980s and 2014 the volume lost was 90.55 +/- 18.11 km(3), that is, a rate of 3.22 +/- 0.64 km(3)/year, implying an increase of similar to 23% in the rate of ice volume loss. Overall, at least similar to 7% of mass loss from Greenland mountain glaciers and ice caps has come from the NE sector. Plain Language Summary Mountain glaciers are especially important sources of freshwater and sediment to the oceans. They are known to be diminishing globally, but there is a lack of information on how present rates of ice mass loss compare to those in the past. In this study we have for the first timemapped the extent of mountain glaciers in NE Greenland at the Little Ice Age, which was approximately year 1910, and we have determined the glacier area and volume changes fromthen to the present day. Overall, we find an acceleration in the rate of ice volume loss toward the present day of similar to 23% but we note considerable differences in that rate between individual glaciers. We suggest that the NE Greenland mountain glaciers contribute similar to 7% of the entire mass loss from Greenland as a whole. These findings are important because the resultant meltwater and sediment efflux affects North Atlantic and Arctic Ocean circulation and the associated conveyance of mineral, nutrient, and carbon also strongly impacts terrestrial, fjord, and coastal flora and fauna.