Drainage networks, lakes and water fluxes beneath the Antarctic ice sheet

Antarctica Bedmap2 datasets are used to calculate subglacial hydraulic potential and the area, depth and volume of hydraulic potential sinks. There are over 32,000 contiguous sinks, which can be thought of as predicted lakes. Patterns of subglacial melt are modelled with a balanced ice flux flow model, and water fluxes are cumulated along predicted flow pathways to quantify steady state fluxes from the main basin outlets and from known subglacial lakes. The total flux from the continent is ~21 km³ a⁻¹. Byrd Glacier has the greatest basin flux of ~2.7 km³ a⁻¹. Fluxes from subglacial lakes range from 1.05 x 10⁻⁴ to 1.49 km³ a⁻¹. Lake turnover times are calculated from their volumes and fluxes, and have median values of ~100 years for known ‘active’ lakes and ~ 500 years for other lakes. Recurrence intervals of a 0.25km³ 26 flood range from ~ 2 months to ~ 2,000 years (median ≈ 130 years) for known ‘active’ lakes and from ~ 2 years to ~ 2,400 years (median ≈ 360 years) for other lakes. Thus, several lakes which have not, so far, been observed to fill and drain have the potential to do so, even at annual to decadal timescales.Funding for the ice flow modelling work associated with this paper was provided by the U.K. Natural Environment Research Council grant NER/A/S/2001/01011 and we thank Richard Hindmarsh for his early involvement with this aspect of the work. G. Leysinger Vieli was funded by a Royal Society BP Dorothy Hodgkin Fellowship. We thank two anonymous referees and the scientific editor, Joel Harper, for their very thorough and constructively helpful reviews which led to substantial improvements to the paper. All gridded data files referred to in this paper will be made available following an e‐mail request to the corresponding author.This is the final version of the article. It first appeared from Cambridge University Press via https://doi.org/10.1017/aog.2016.1