A 10Be chronology of early Holocene local glacier moraines in central West Greenland

Abstract

New cosmogenic 10Be exposure ages constrain Greenland Ice Sheet (GrIS) deglaciation and the culmination of a local glacier advance on the southern shore of Nuussuaq (peninsula) in central West Greenland. Mean ages of GrIS deglaciation and local glacier moraine deposition are 10.5±0.1 ka (n = 2) and 10.4±0.2 ka (n = 5), respectively. The similar ages suggest an advance/stillstand of local glaciers soon after the local retreat of the GrIS. The moraines dated in this study may be correlative to the nearby Disko Stade moraines. Moraine chronologies for both GrIS moraines and our local glacier moraines in central West Greenland correspond to detrital carbonate peaks in a Labrador shelf marine sediment core that records Laurentide Ice Sheet (LIS) discharge from Hudson Strait. Large freshwater discharge events into the North Atlantic sub‐polar gyre have been linked to abrupt cooling events in the Northern Hemisphere during the early Holocene. We propose LIS freshwater input to the sub‐polar gyre and associated regional cooling as the main driver for advance/stillstand of both local glaciers and the GrIS in central West Greenland during the early Holocene.