Hidden beneath the biggest ice mass on Earth, hundreds of subglacial lakes form a crucial part of Antarctica’s icy structure, affecting the movement and stability of glaciers, and consequentially influencing global sea level rise.

Thanks to a decade of data from the European Space Agency’s CryoSat satellite, researchers have identified 85 previously unknown lakes several kilometres under the frozen surface surrounding the South Pole. This increases the number of known active subglacial lakes below Antarctica by more than half to 231.