Direct geological, glaciological, biological and oceanographic

advertisement

Frontiers and Opportunities in Antarctic Geosciences * Certosa di Pontignano * 29-31 July 2004

Direct Geological, Glaciological, Biological and Oceanographic Observations at Ice Sheet Grounding Lines

R. Scherer*,

Northern Illinois University

R. Powell,

Northern Illinois University

S. Tulaczyk,

University of California, Santa Cruz

S. Anandakrishnan,

Pennsylvania State University

S. Vogel,

Ohio State University

B. Lanoil,

University of California, Riverside

M. Lencziewski,

Northern Illinois University

* Corresponding author (reed@geol.niu.edu)

The physical conditions at the zone where ice sheets decouple from a submarine bed and go afloat as ice shelves are poorly understood, and have only been remotely observed and measured along the Ross ice streams. A new multidisciplinary initiative to access and directly measure ice stream and interstream grounding zones has recently been proposed. The program proposes transects of hot-water drilled access holes along several ice streams and an interstream ridge, from the southern portion of the floating Ross Ice Shelf to fully grounded ice. These access holes will permit a diverse array of measurements, including piston coring and hard rock drilling, high resolution imaging, oceanographic observations, sub-ice geophysical surveys, and biological sampling of sediments, water, and basal ice.

We will observe the physical affects of ice flow across full tidal cycles and test existing glacial facies models, as well as contribute to sub-ice shelf oceanographic data. One of the key tools to be deployed beneath the ice shelf is a slim-line remote operated vehicle (ROV)/tethered automated underwater vehicle (AUV). The vehicle will include integrated sampling, imaging and measurement tools and will be used to deploy a geophone array for high-resolution seismic imaging. We anticipate significant advancement in our understanding of the interaction between glacier ice and the bed, thereby contributing to the next wave of ice sheet mass balance, stability, and predictive models.

Download