Camp Century Northwestern Greenland, n-alkanoic acids and glycerol dialkyl glycerol tetraethers, Early and Mid-Pleistocene, 2025

Determining the ancient climatic conditions under which the Greenland Ice Sheet (GrIS) was smaller than present is an important piece to solving the puzzle of GrIS sensitivity to ongoing climate change. Sediments retrieved in the 1960s below the Greenland Ice Sheet at Camp Century, northwestern Greenland, contain five stratigraphic units indicating different depositional environments (from bottom to top): Unit 1 is a till; Unit 2 is dominated by ice with few dispersed fine sediments; and the upper Units 3-5 are fluvial sediments. At the University at Buffalo Organic and Stable Isotope Biogeochemistry Laboratory and the University of Massachusetts Amherst Biogeochemistry Laboratory, we analyzed biomarkers in separate samples throughout all five units: leaf wax distributions, leaf wax hydrogen isotopes, and branched glycerol dialkyl glycerol tetraether (brGDGT) distributions. These will be used to reconstruct summer temperature and atmospheric circulation when the Greenland Ice Sheet was smaller than present.