Using a decade of observations from CryoSat, researchers detected localised changes in the height of Antarctica's icy surface, which rises and falls as the lakes fill and drain at the base of the ice sheet. They could then detect and map subglacial lakes and monitor their filling and draining cycles over time.

Anna Hogg, a co-author on the study and Professor at the University of Leeds, said, "It was fascinating to discover that the subglacial lake areas can change during different filling or draining cycles. This shows that Antarctic subglacial hydrology is much more dynamic than previously thought, so we must continue to monitor these lakes as they evolve in the future."

Sally explained that observations like these are vital to understanding the structural dynamics of ice sheets and how they affect the ocean around them. "The numerical models we currently use to project the contribution of entire ice sheets to sea level rise do not include subglacial hydrology. These new datasets of subglacial lake locations, extents, and timeseries of change, will be used to develop our understanding of the processes driving water flow beneath Antarctica."

Martin Wearing, ESA Polar Science Cluster Coordinator, noted, "This research again demonstrates the importance of data from the CryoSat mission to improve our understanding of polar regions and particularly the dynamics of ice sheets. The more we understand about the complex processes affecting the Antarctic Ice Sheet, including the flow of meltwater at the base of the ice sheet, the more accurately we will be able to project the extent of future sea level rise."