Slashdot Mirror
Geothermal Heat Contributing To West Antarctic Ice Sheet Melting
bricko sends this news from The University of Texas at Austin:
Thwaites Glacier, the large, rapidly changing outlet of the West Antarctic Ice Sheet, is not only being eroded by the ocean, it's being melted from below by geothermal heat, researchers at the Institute for Geophysics at The University of Texas at Austin (UTIG) report in the current edition of the Proceedings of the National Academy of Sciences. The findings significantly change the understanding of conditions beneath the West Antarctic Ice Sheet, where accurate information has previously been unobtainable. The Thwaites Glacier has been the focus of considerable attention in recent weeks as other groups of researchers found the glacier is on the way to collapse, but more data and computer modeling are needed to determine when the collapse will begin in earnest and at what rate the sea level will increase as it proceeds. The new observations by UTIG will greatly inform these ice sheet modeling efforts.
The Thwaites Glacier is melting because of Geothermal heat rather than AGW?
No. It isn't. Read the paper instead of making inferences from a summary that is significantly lacking in details.
Scientists knew there was geothermal heat contributing to base melting of the glacier. Most places on Earth have a tiny amount of geothermal heat flux so underneath most glaciers there some small amount of melting due to this heat. On average, the geothermal flux on Earth is about 65 milliwatts/square meter.
This paper was looking to quantify the geothermal flux under the glacier so that they could model the behavior more accurately. It turns out the the average geothermal flux under the glacier is around 120 milliwatts/square meter with some areas going as high as 200 milliwatts/square meter. This adds a little bit more base melt and thus allows the glacier to move a little bit faster.
Keep in mind, these are milliwatts we're talking about, so it certainly isn't melting a lot. But since it is base melt it is contributing to glacier movement speed. This contributes to the ice loss already occurring due to warmer temperatures.
~X~