A vast reservoir of water has been detected in the mud and sediment underlying a part of the West Antarctic ice sheet. It is estimated to be several hundred metres deep, or about the size of two Empire State buildings.
The ice cap that covers Antarctica is not rigid and researchers have discovered in recent years hundreds of interconnected liquid lakes and rivers cradled within the ice itself. This is the first time, however, the presence of large amounts of liquid water in below-ice sediments has been found.
The current discovery is under the Whillans Ice Stream but it is estimated that water is also present elsewhere in the Antarctic.The research was led by a team from the Scripps Institution of Oceanography in San Diego, California.
Water at the base of glaciers and ice streams works to facilitate the movement of the ice above.
Therefore, transfer of water into or from this reservoir could either slow down or speed up ice flow.
The presence of water below the glaciers could be an important influence on how Antarctica reacts to a warmer world, researchers claim.
It is estimated that the groundwater discovered was potentially relatively warm because of the heat of the underlying rocks. When the warm water meets the ice-bed, it could accelerate the flow of the ice.
The Scripps-led team that discovered the Whillans reservoir are intending to replicate its work at the very much larger Thwaites Glacier, which about the size of Great Britain. Thwaites is currently the subject of intense study by US and UK researchers because of its melt rate.
Thwaites' outflow speed has doubled in the past 30 years and there is concern that future ice losses could add significantly to global-sea level rise.