Using Coastal Ice Cap Records to Investigate Maritime Climate and Ice Sheet Processes in West Greenland

Monday, 15 December 2014
Sarah B Das1, Matthew Jared Evans2, Karen E Frey3, Matthew B Osman1,4, Benjamin Eaton Smith5, Laura A Stevens1,4, Luke D Trusel3, Ashley York3 and Matthew Bingham6, (1)WHOI, Woods Hole, MA, United States, (2)Wheaton College, Norton, MA, United States, (3)Clark University, Graduate School of Geography, Worcester, MA, United States, (4)Massachusetts Institute of Technology, Cambridge, MA, United States, (5)University of Washington, Seattle, WA, United States, (6)Milton Academy, Milton, MA, United States
Recent changes, including outlet glacier retreat and speedup, and increased rates of surface melting, have dramatically increased the Greenland ice sheet contribution to sea-level rise over the past few decades. Increasingly studies point towards the influence of coupled ocean-ice processes in modulating Greenland ice sheet mass balance and glacier behavior in response to climate change, but many of these studies are limited to the past few years to decades, restricting our ability to understand these ocean-ice relationships over longer time periods. Ice core records have the potential to provide unique, high-resolution records of interest (e.g. accumulation and melt variability, as well as contemporaneous proxy records of regional air temperature and sea surface conditions), but suitable Greenland ice sheet coring regions are often located far inland (>200 km) from many maritime regions of interest. In this study we focus on new records from previously unstudied maritime ice caps (10-30 km from the coast) to reconstruct past environmental conditions in the Disko, Ummannaq and Baffin Bay regions. Here we present results from our recent 2014 field investigation of three high altitude ice caps (1300-2000 m) on Disko Island and the Nuussuaq Peninsula, as well as complementary results from two sites in the western ice sheet accumulation zone. Geophysical observations provide constraints on ice thickness, layering, and ice flow. Physical and chemical stratigraphic observations from snow pits and shallow firn cores are used to reconstruct recent accumulation rate and melt variability, as well as to develop and test environmental proxy relationships over the satellite era. Multi-century records from longer coastal ice cores, to be drilled in 2015, will contribute a key missing component to the existing observational record documenting ice, ocean and atmospheric changes in this region over a time period of dramatic change in Greenland ice sheet behavior (retreat and thinning) and regional climate warming