NSFGEO-NERC: Chemistry and biology under low flow hydrologic conditions beneath the Greenland Ice Sheet from naturally emerging subglacial water

The Earth's atmosphere gradually weathers the rocks and minerals on the Earth's surface. These weathering processes control the Earth's climate on long timescales, and the break down of weathered minerals forms nutrients that are essential for life. We seek to understand the effect of large glaciers on these weathering processes and their consequences for life. The chemical weathering products washing out of the Greenland Ice Sheet have been previously sampled and measured at several locations, but these measurements are usually collected in summer when the glacier is flush with water from melting ice. Here we seek to understand how these processes change over winter and will sample the seasonal ice that forms in front of Greenland's glacial outlets during the freezing months. The chemistry and microbiology of this ice will reflect the wintertime conditions under the glacier when input of fresh meltwater is minimal. This in turn will inform us not only about winter conditions under the Greenland Ice Sheet but allow us to extrapolate to the inaccessible interior portions of the ice sheet and to past colder conditions when meltwater input was minimal. These analyses will inform our understanding of the role of glaciers on earth: presently, under past ice age conditions, and in a future deglaciating world.