Deciphering 6 My of the Greenland Ice Sheet History using in situ 10-Be from marine sediment cores

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This research will explore a new method of deciphering the history of the Greenland Ice Sheet over the Pliocene and Pleistocene by measuring the cosmogenic isotope beryllium-10 in sediment cores previously collected off southern and eastern Greenland by the Ocean Drilling program. Beryllium-10 is produced by cosmic rays in exposed rock. The premise of this investigation is that Be-10 accumulates in surface rock during times of ice-sheet retreat and is eroded and deposited in marine sediment during times of ice-sheet growth. The isotopic time series will include Pleistocene and Pliocene sediment stretching back 4 to 6 million years, possibly beyond the onset of continental-scale glaciation in Greenland. The investigators hope to 1) constrain the time at which continental glaciation on Greenland began, 2) estimate the relative areal extent of the ice sheet through time, 3) determine the erosivity and sediment transport efficiency of the ice sheet, and 4) constrain the erosion rate of Greenland prior to the onset of glaciation. Understanding Greenland Ice Sheet dynamics in the past (particularly the extent of deglaciation and the timescale of regrowth) is key to understanding how the ice sheet might behave in the future. A central part of the project is the training of a young postdoctoral research associate, and two undergraduate students will work on the project as well.