Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 10, 1381-1393, 2016
https://doi.org/10.5194/tc-10-1381-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
08 Jul 2016
Modeling Antarctic subglacial lake filling and drainage cycles
Christine F. Dow1,a, Mauro A. Werder2, Sophie Nowicki1, and Ryan T. Walker1,3 1Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA
2Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland
3Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
anow at: Department of Geography and Environmental Management, University of Waterloo, Waterloo, ON, Canada
Abstract. The growth and drainage of active subglacial lakes in Antarctica has previously been inferred from analysis of ice surface altimetry data. We use a subglacial hydrology model applied to a synthetic Antarctic ice stream to examine internal controls on the filling and drainage of subglacial lakes. Our model outputs suggest that the highly constricted subglacial environment of our idealized ice stream, combined with relatively high rates of water flow funneled from a large catchment, can combine to create a system exhibiting slow-moving pressure waves. Over a period of years, the accumulation of water in the ice stream onset region results in a buildup of pressure creating temporary channels, which then evacuate the excess water. This increased flux of water beneath the ice stream drives lake growth. As the water body builds up, it steepens the hydraulic gradient out of the overdeepened lake basin and allows greater flux. Eventually this flux is large enough to melt channels that cause the lake to drain. Lake drainage also depends on the internal hydrological development in the wider system and therefore does not directly correspond to a particular water volume or depth. This creates a highly temporally and spatially variable system, which is of interest for assessing the importance of subglacial lakes in ice stream hydrology and dynamics.

Citation: Dow, C. F., Werder, M. A., Nowicki, S., and Walker, R. T.: Modeling Antarctic subglacial lake filling and drainage cycles, The Cryosphere, 10, 1381-1393, https://doi.org/10.5194/tc-10-1381-2016, 2016.
Publications Copernicus
Download
Short summary
We examine the development and drainage of subglacial lakes in the Antarctic using a finite element hydrology model. Model outputs show development of slow-moving pressure waves initiated from water funneled from a large catchment into the ice stream. Lake drainage occurs due to downstream channel formation and changing system hydraulic gradients. These model outputs have implications for understanding controls on ice stream dynamics.
We examine the development and drainage of subglacial lakes in the Antarctic using a finite...
Share