Articles | Volume 9, issue 2
The Cryosphere, 9, 603–611, 2015
https://doi.org/10.5194/tc-9-603-2015
The Cryosphere, 9, 603–611, 2015
https://doi.org/10.5194/tc-9-603-2015

Research article 01 Apr 2015

Research article | 01 Apr 2015

Self-regulation of ice flow varies across the ablation area in south-west Greenland

R. S. W. van de Wal1, C. J. P. P. Smeets1, W. Boot1, M. Stoffelen1, R. van Kampen1, S. H. Doyle2, F. Wilhelms3, M. R. van den Broeke1, C. H. Reijmer1, J. Oerlemans1, and A. Hubbard2 R. S. W. van de Wal et al.
  • 1Institute for Marine and Atmospheric research Utrecht, Utrecht University, the Netherlands
  • 2Centre for Glaciology, Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK
  • 3Alfred Wegener Institute, Bremerhaven, Germany

Abstract. The concept of a positive feedback between ice flow and enhanced melt rates in a warmer climate fuelled the debate regarding the temporal and spatial controls on seasonal ice acceleration. Here we combine melt, basal water pressure and ice velocity data. Using 20 years of data covering the whole ablation area, we show that there is not a strong positive correlation between annual ice velocities and melt rates. Annual velocities even slightly decreased with increasing melt. Results also indicate that melt variations are most important for velocity variations in the upper ablation zone up to the equilibrium line altitude. During the extreme melt in 2012, a large velocity response near the equilibrium line was observed, highlighting the possibility of meltwater to have an impact even high on the ice sheet. This may lead to an increase of the annual ice velocity in the region above S9 and requires further monitoring.

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Short summary
This paper addresses the feedback between ice flow and melt rates. Using 20 years of data covering the whole ablation area, we show that there is not a strong positive correlation between annual ice velocities and melt rates. Rapid variations around the equilibrium line indicate the possibility of rapid variations high on the ice sheet.