Abstract

An Active Subglacial Water System in West Antarctica Mapped from Space

Helen A. Fricker
Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0225, USA.

T. Scambos
National Snow and Ice Data Center, University of Colorado, Boulder, CO 80302, USA.

R. Bindschadler
NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.

Laurie Padman
Earth & Space Research, Corvallis, OR 97333, USA.




Satellite laser altimeter elevation profiles from 2003 to 2006 collected over the lower parts of Whillans and Mercer ice streams, West Antarctica, reveal 14 regions of temporally varying elevation, which we interpret as the surface expression of subglacial water movement. Vertical motion and spatial extent of two of the largest regions are confirmed by satellite image differencing. A major, previously unknown subglacial lake near the grounding line of Whillans Ice Stream is observed to drain 2.0 km3 cubic kilometers of water over ~3 years, while elsewhere a similar volume of water is being stored subglacially. These observations reveal a widespread, dynamic subglacial water system which that may exert an important control on ice flow and mass balance.






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