Lakes under glaciers a key to sea level rise
Submerged Lakes Vostok, 90˚E, and Sovetskaya under the side of the Gambertsev Mountains. (Credit: NASA, Christopher Shuman UMBC-GEST, Vijay Suchdeo Sigma Space, and Mark Fahnestock UNH)
Earth scientist Chris Shuman studies liquid lakes beneath ice sheets in Antarctica. They stay liquid due to geothermal heat from Earth’s interior. Shuman said these hidden Antarctic lakes affect the way glaciers move toward the sea.
Chris Shuman: In the long run, it is the ice sheets and the contribution of their water mass into the global ocean that is going to be the biggest contributor to future sea level rise. Basically, we want to be able to understand how sea level is changing today and how it may change in the future.
He spoke of improved GPS data, radar measurements, and better images taken from space, all of which have revealed these subglacial lakes in more detail than ever before.
Chris Shuman: And so it’s pretty clear that these lakes are helping to help the ice sheet begin to flow faster. And the thing that we really don’t know is exactly why are those lakes there, and are they stable or are they changing? And consequently, then, is the ice stream system stable or changing?
He said the lakes aren’t thought to be directly affected by the ongoing global warming. But if the lakes are changing through factors outside the climate system, scientists want to learn more to predict how melting polar ice sheets might raise sea level in this century.
Christopher Shuman: It is how lakes influence ice sheet motion that’s the thing that is most interesting to me right now. We know that there are these places in the underlying bedrock where water can accumulate. What we don’t really know is whether that water level can change, and if so, what are the factors controlling how that water level can change. Where does that water then go if the lakes levels are rising?
He spoke of the lakes triggering ice stream flow as “a completely new factor” in scientists’ ability to predict the behavior of Antarctic’s glaciers, as Earth warms.
Christopher Shuman: And so subglacial lakes are just one part of that overall study on how ice sheets are changing
Thanks today to NASA, in celebration of the International Polar Year.
Chris Shuman studies liquid lakes under Antarctic ice
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What is interesting is, in spite of all of the gnashing of teeth and wailing about sea level rise, it is not happening. Not at all. I think there are things much more pressing to worry about.
When I first started working in Corpus Christi, I drove down Laguna Shores Rd. This road is literally inches above sea level. During extreme high tide this road is under water, but above the sea level. I drove down this road many times. When I last drove drove down this road, during the sea level rising talk, well Laguna Shores Rd. is still under water during extreme tide and above water most of the time.