Multi-million-year evolution of the Greenland Ice Sheet in Inglefield Land, North Greenland

Information on past sensitivity of the Greenland Ice Sheet to climate change is of importance for optimizing models simulating the future evolution of ice mass loss. While the ice-sheet change during the Lateglacial and Holocene is relatively well constrained, the long-term (multi-million-year) evolution of the Greenland Ice Sheet remains poorly known. In this study, we use in situ cosmogenic ¹⁰Be, ²⁶Al, and ¹⁴C nuclide concentrations from bedrock in Inglefield Land, western North Greenland, together with Markov chain Monte Carlo inversion to constrain the multi-million-year ice sheet history of this area. Our results indicate that the area became ice-covered for the first time at the beginning of the Quaternary and was glaciated for extensive periods during the Pleistocene. We cannot resolve whether the ice cover was confined to local ice caps or part of a larger ice sheet but only conclude that the ice cover was likely persistent with short interglacials. Further, our results show that the area has been characterized by low erosion rates (<1 m/Myr) during the past million years, suggesting cold-based ice similar to today's conditions.