Scientists have seen once again just how dynamic a place the underside of the Antarctic ice sheet can be. Survey data collected from the middle of the White Continent shows liquid water is being frozen on to the bottom of the sheet in huge quantities.
In places, this deeply buried add-on layer is hundreds of metres thick and represents about half of the entire ice column, researchers say. The discovery is reported online in the journal Science.
Project leaders confess to being astonished by the findings. “It’s jaw-dropping, I have to say,” said Professor Robin Bell from Columbia University’s Lamont-Doherty Earth Observatory.
“The first time I showed the data to colleagues, there was an audible gasp,” she told BBC News.
The new data will add to the understanding of how the ice sheet expands and moves, which in turn will inform researchers as they try to grasp how Antarctica might change in a warmer world. The observations come from a major expedition to survey the Gamburtsev mountain range in the polar summer of 2008-2009.
Although similar to the European Alps in scale, the Gamburtsevs are hidden under kilometres of ice deep in the Antarctic interior.
An expeditionary team used instrumented planes to gather a wealth of new information about the peaks and their ice shroud. Equipment included radar to see through the ice, showing its many layers, right down to the rock bed.
