Antarctica's warm underbelly revealed

[nitpicker]

http://www.bbc.com/news/science-environment-41972297

Antarctica's warm underbelly revealed

By Jonathan Amos
BBC Science Correspondent

13 November 2017

From the section Science & Environment

This is the best map yet produced of the warmth coming up from the rocks underneath the Antarctic ice sheet. 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 rockbed's temperature is raised, it makes it easier for the ice above to move. And if global warming is already forcing change on the ice sheet, a higher flux could accelerate matters. The map was made by researchers at the British Antarctic survey and is published in the journal Geophysical Research Letters.
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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

No-one has actually drilled through the kilometres of ice in Antarctica to take the temperature of the bed. Instead, the BAS team inferred the likely warmth of rocks from their magnetism. This property can be sensed by instruments flown across the surface of the ice sheet by planes.

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 occurring then they have a means of estimating the heat flux. The new map is said to represent a 30-50% improvement on previous efforts. It supports - but with far more detail - the established idea that East and West Antarctica are very different provinces.

The East is a giant chunk of old, cold continental crust. The West, however, underwent recent rifting in the Cretaceous (100 million years ago) that has pulled it apart.
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