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Albany, NY – In today's Academic Minute, Dr. Robin Bell of Columbia University explains the strange behavior of water beneath the glaciers or Antarctica.
Robin Bell is a research professor and lecturer in marine geology and geophysics at Columbia University's Lamont-Doherty Earth Observatory. She has led many expeditions to study the ice sheets of Antarctica. She holds a Ph.D. from Columbia University.
Dr. Robin Bell - Subglacial Lakes of Antarctica
If you stand on top of the Antarctic ice sheet, it's cold minus 40 in the summer. The ice is about 2 miles thick, but at the bottom, there is a whole other world a hidden landscape, where the weather is nicer in a way. But also weirder.
That thick ice acts as an insulating blanket, capturing heat coming out of the rocks at the base of the ice enough to melt the ice, and form lakes. Some of these are really just small ponds, but others are huge. Lake Vostok, the largest lake under the ice sheets today, is the size of New Jersey, and in places the water in it is more than 3,000 feet deep. Scientists have also discovered that water can move between one lake and another. We know this because from space, we can see the ice surface bulge when a lake fills, and sag when one drains.
It gets stranger. I and colleagues have spent quite a bit of time flying over the top of the ice sheet in East Antarctica. From the surface, it looks pretty flat but far below the ice is a giant mountain range, the Gamburtsev Mountains. Showing up clearly in radar images, these invisible mountains are similar in shape to the Rocky Mountains.
Recently, radar images showed us that there is water lining the deep valleys in the Gamburtsevs. A bigger surprise came when we found that this water was flowing, and we calculated its direction. It turns out that the ice sheet is squeezing water up the valleys. It ascends until it reaches the mountain peaks, where it's colder. Here, the water freezes back onto the bottom of the ice. So, water does flow uphill at least in this parallel subglacial universe.