NORTHERN ILLINOIS UNIVERSITY INC

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 11-5). The RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic Ice Stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main varibles listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding aone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf vavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice oceanographic moorings. INTELLECTUAL MERIT: The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheetvulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. BROADER IMPACTS: "The complete abstract for this award is available in Research.gov at www.research.gov."

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