The Cryosphere Discuss., 7, 841-871, 2013
www.the-cryosphere-discuss.net/7/841/2013/
doi:10.5194/tcd-7-841-2013
© Author(s) 2013. This work is distributed
under the Creative Commons Attribution 3.0 License.
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This discussion paper has been under review for the journal The Cryosphere (TC). Please refer to the corresponding final paper in TC.
Cascading water underneath Wilkes Land, East Antarctic Ice Sheet, observed using altimetry and digital elevation models
T. Flament, E. Berthier, and F. Rémy
1CNRS, LEGOS, UMR5566 CNRS-CNES-IRD-Université de Toulouse III, 14 Avenue Edouard Belin, 31400 Toulouse, France

Abstract. We describe a major subglacial lake drainage close to the ice divide in Wilkes Land, East Antarctica, and the subsequent cascading of water underneath the ice sheet toward the coast. To analyze the event, we combined altimetry data from several sources and bedrock data. We estimated the total volume of water that drained from Lake CookE2 by differencing digital elevation models (DEM) derived from ASTER and SPOT5 stereo-imagery. With 5.2 ± 0.5 km3, this is the largest single subglacial drainage event reported so far in Antarctica. Elevation differences between ICESat laser altimetry and the SPOT5 DEM indicate that the discharge lasted approximately 2 yr. A 13-m uplift of the surface, corresponding to a refilling of about 0.64 ± 0.32 km3, was observed between the end of the discharge in October 2008 and February 2012. Using Envisat radar altimetry, with its high 35-day temporal resolution, we monitored the subsequent filling and drainage of connected subglacial lakes located downstream. In particular, a transient temporal signal can be detected within the theoretical 500-km long flow paths computed with the BEDMAP2 data set. The volume of water traveling in this wave is in agreement with the volume that drained from Lake CookE2. These observations contribute to a better understanding of the water transport beneath the East Antarctic ice sheet.

Citation: Flament, T., Berthier, E., and Rémy, F.: Cascading water underneath Wilkes Land, East Antarctic Ice Sheet, observed using altimetry and digital elevation models, The Cryosphere Discuss., 7, 841-871, doi:10.5194/tcd-7-841-2013, 2013.
 
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