West Antarctic Ice Sheet Underpinned By High Geothermal Heat Flows

A new study conducted on the West Antarctic Ice Sheet suggests that one factor that may lead to its melting is the heat flow beneath it.

Geothermal sources are the underpinning of the unusually high amounts of heat flows at the base of the West Antarctic Ice Sheet. The study, conducted by scientists at UC Santa Cruz brings a new body of data for analyzing the rapid decline of the Ice Sheet during the past ten years.

Of course, there is a multitude of studies dealing with the advanced melting of the West Antarctic Ice Sheet, yet the UC Santa Cruz research, led by Andrew Fisher – Professor of Earth and Planetary Sciences at the same University, does not pitch geothermal heating as a cause of ice loss.

Rather, it looks at geothermal heating as a pre-existent slow-working factor which, combined with a multitude of others may lead to further ice loss in the West Antarctic Ice Sheet.

As Professor Fisher explained:

“The ice sheet developed and evolved with the geothermal heat flux coming up from below-it’s part of the system. But this could help explain why the ice sheet is so unstable. When you add the effects of global warming, things can start to change quickly”.

Looking into geothermal sources that spark the high heat flow underneath the West Antarctic Ice Sheet may provide insight on the development of lakes also underpinning the ice sheet. Lakes and streams forming beneath the West Antarctic are lubricating the ice streams’ motion, carrying them to the onto the ice shelves. But too much water is detrimental to the West Antarctic Ice Sheet.

Collapsing and melting are incumbent if the volume of heat flows beneath the West Antarctic Ice sheet surpasses certain levels. Nonetheless, the measurements on which the UC Santa Cruz study is based are representative of only one location. Thus, the team warned that it is possible the values of the high heat flow varies from other locations across the West Antarctic Ice Sheet.

“This is the first geothermal heat flux measurement made below the west Antarctic ice sheet, so we don’t know how localized these warm geothermal conditions might be. This is a region where there is volcanic activity, so this measurement may be due to a local heat source in the crust”,

added Professor Andrew Fischer.

The UC Santa Cruz study was conducted as part of the Antarctic drilling project titled WISSARD and financially supported by the National Science Foundation.

The specific location referred to in the study is the Subglacial Lake Whillans, found underneath the ice, at half a mile depth. A thermal probe, designed at the UC Santa Cruz laboratories, was lowered in the sediments beneath Lake Whillans.

Here, different depth measurements held different temperatures, representative for a change rate five times that of continental temperature change. Thus, the geothermal sparked high heat flows came to the attention of the team.

The UC Santa Cruz study is complementary to other recent studies that have looked at the warm ocean currents flowing beneath the ice sheet and accelerating the loss of ice in the West Antarctic Ice sheet, known to be more unstable.

The results of the study have been published in the July 10th issue of Science Advances journal.

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