Science & Environment

Antarctica's warm underbelly revealed

Geothermal heat flux Image copyright BAS
Image caption Hotspots are located under West Antarctica; in contrast, the East is broadly relatively cold


This "geothermal heat flux" is key data required by scientists in order to model how the White Continent is going to react to climate change.

If the rock bed's temperature is raised, it makes it easier for the ice above to move.



"The heat coming from the Earth's interior is important to understand the overall conditions that control the dynamics at the base of the ice sheet and hence the ice flow,” explained Yasmina Martos, currently affiliated to the US space agency.



"Even a little melting at the base helps the ice sheet to slide faster. We also identified areas of low heat flux, which will help stabilise the ice sheet," she told BBC News.

Image copyright M.BRANDON/OU
Image caption The West contributes most to sea level rise currently, but this is a consequence of warm ocean water eroding glacier fronts - not from the interior ice sheet being melted by underlying warm rock




What happens next is a smart calculation.

Scientists know the temperature (580C) at which hot minerals lose their magnetism, so if they can gauge how close to the rock-ice interface this is occurring then they have a means of estimating the heat flux.


It supports - but with far more detail - the established idea that East and West Antarctica are very different provinces.


"This rifting has thinned the crust and brought hot material from deep down in the Earth - from hundreds of km down - to within 100km or so, or even maybe less, of the rock surface," said co-author Tom Jordan.

"It confirms what you would expect from the sparse, exposed geology in West Antarctica where we have volcanoes."

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Media captionTom Jordan: "Just the ice being warm means it's more plastic and deformable"




One research project that will see an immediate benefit from the map's data is the quest to drill the oldest ice on the continent.


This information - about historic atmospheric conditions including carbon dioxide levels - can be deciphered from tiny air bubbles trapped in the ice.


"It is very exciting to see the implications this new heat map has for many communities, including new generations of ice sheet and sea level models," said Dr Martos.

"I am very glad we are contributing an important aspect at unprecedented detail. The Earth’s interior has a lot to tell us in terms on how the ice behaves." and follow me on Twitter: @BBCAmos