Relative summer temperature changes from glacial fluctuations in the Scoresby Sund region, Central East Greenland, during late-glacial time

Abstract

Understanding climate conditions in the mid-to-high-latitude North Atlantic region during late-glacial time can provide valuable information to test hypotheses concerning the mechanisms of climate change that ended the last glacial period. Glaciers (particularly mountain glaciers) are sensitive recorders of summer temperature change because of its influence on the ablation season, snowline elevation and, hence, glacier length. Here, we develop a record of glacial fluctuations in the Scoresby Sund region in Central East Greenland and use these data to infer the timing and pattern of summer temperature changes in the mid-to-high-latitude North Atlantic region. We present 64 new ¹⁰Be ages of glacial landforms and remap and recalculate an additional 65 ¹⁰Be ages from prior work in the region. Even with boulders with inherited nuclides in some of the datasets, a two-step pattern of glacial fluctuations is apparent, with an outer moraine dating to ∼14.0–12.8 ka, an inner moraine dating to ∼11.7–11.3 ka, and ice retreat in the time between moraine deposition. A comparison of these data with ¹⁰Be chronologies of mountain glacier fluctuations in Northeast Greenland, Svalbard, Norway and Scotland, shows a consistent pattern throughout the mid-to-high-latitude North Atlantic region of summer cooling and warming during late-glacial time.