Researchers have found an unexpected river beneath the Antarctic ice sheet that affects the flow and melting of ice, potentially accelerating ice loss as the climate warms. Its discovery indicates the base of the ice sheet has more active water flow than previously thought.
Co-author Professor Martin Siegert said,”When we first discovered lakes beneath the Antarctic ice a couple of decades ago, we thought they were isolated from each other. Now we are starting to understand there are whole systems down there, interconnected by vast river networks, just as they might be if there weren’t thousands of meters of ice on top of them.”
Water can appear beneath ice sheets in two predominant ways: from surface meltwater running down through deep crevasses, or by melting at the base, caused by the natural heat of the Earth and friction as the ice moves over land.
However, the ice sheets around the north and south poles have different features. In Greenland, the surface experiences strong melting during the summer months, where vast amounts of water channel down through deep crevasses called moulins.
However, in Antarctica the surface doesn’t melt in sufficient quantities to create moulins, as the summers are still cold. It was believed this meant that there was relatively little water at the base of the Antarctic ice sheets.
This discovery negates that theory, showing there is sufficient water from basal melt alone to create huge river systems under kilometers of ice.
https://phys.org/news/2022-10-river-longer-thames-beneath-antarctic.html