Subglacial plumbing mapped from space: water transfer, water volumes and implications for ice dynamics

Over the last two years, pivotal studies using satellite data have demonstrated that subglacial water can move rapidly and in large volumes beneath the Antarctic ice sheet. Movement is documented over long distances (10s of km), and persists under the fast-flowing ice streams all the way to the grounding line, where subglacial water reaches the Southern Ocean. It has been shown that subglacial lakes may have a role in initiating fast ice stream flow in the upper glacier catchments. The studies have provided a glimpse at a previously unidentified process occurring under the Antarctic ice sheet and point to a renewed appreciation of the importance of subglacial hydrology and how it relates to ice stream dynamics. Mapping subglacial water distribution and movement in Antarctica is of critical importance to the characterization of the ice sheet system and its potential for change. Monitoring subglacial outflows from the ice sheet margins is also important for quantifying freshwater flux to the ocean and understanding ice-ocean interactions. Such lakes have the potential to harbor unique life-forms. Discovery of lakes close to the grounding line, where there are no downstream lakes, provides an opportunity for exploration without the risk of contaminating other lakes.