New Antarctic heat map reveals sub-ice hotspots

By Athena Dinar

An international team of scientists, led by British Antarctic Survey (BAS), has produced a new map showing how much heat from the Earth’s interior is reaching the base of the Antarctic Ice Sheet. The map is part of a new paper accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

The team has produced the most up to date, accurate and high-resolution map of the so called ‘geothermal heat flux’ at the base of the Antarctic Ice Sheet. Of the basic information that shapes and controls ice flow, the most poorly known about is this heat.

The data used  come from magnetic measurements mainly collected  by aircraft flying over the continent and the results reveal the ‘hot spots’ under West Antarctica and on the Antarctic Peninsula, the most rapidly changing areas of the Antarctic Ice Sheet.

“This new map of heat escaping from inside the Earth will help advance our understanding of the conditions at the base of the ice sheet, improving our ability to understand the past and to project future changes of the Antarctic Ice Sheet and its impact on global sea level,” said Yasmina Martos, a geophysicist who now works at NASA Goddard Space Flight Center and the University of Maryland. Martos completed the work at the British Antarctic Survey, and is the lead author of the new study. 

Heat flux map of Antarctica. More than 50 years of measurements were collected from thousands of hours flying over the continent. Warmer rocks lose their magnetic properties, and so the team was able to calculate the heat flux.
Credit: Martos et al.

“It is impossible to take direct measurements of heat from the Earth’s interior beneath 3-4 kilometers of ice in extremely cold and hostile conditions,” said Tom Jordan, a BAS geophysicist and co-author of the paper. “That’s why we have used magnetic data to infer the heat and we’re pleased that what we have is 30-50 percent more accurate than previous studies.”

The Antarctic Ice Sheet contains the largest reservoirs of fresh water on our planet – around 70 percent of the world’s fresh water – and is currently losing ice, which contributes to rising sea levels.

“If we are to predict with any certainty the future response of Antarctica in a warming world, scientists need to understand the role that heat from the Earth plays,” BAS Science Director and glaciologist David Vaughan said. “What we know is that over time, the heat flow into the ice is quite constant and so the ice sheet adjusts to it.  The ice loss we’ve seen in recent decades is actually the result of changes in air and ocean temperatures. How the ice sheet will respond to these recent changes is influenced by the pattern of geothermal heat, and that’s why this new map is so important.”

— Athena Dinar is a Senior PR & Communications Manager at the British Antarctic Survey. This blog post originally appeared as a press release on the BAS website. 


Leave a Reply

Your email address will not be published. Required fields are marked *