Scientists have produced the most detailed map yet of the landscape beneath Antarctica’s ice sheet, providing new insight into the continent’s future. A team led by the British Antarctic Survey (BAS) used data collected over six decades by planes, satellites, ships and even dog-drawn sleds. The resulting map reveals what lies beneath 27 million cubic km of ice, including hidden locations of the tallest mountains and deepest canyons.
The map, known as Bedmap3, provides valuable and worrying new insight into how Antarctica might respond to the warming climate. Study leader Dr Hamish Pritchard, a glaciologist at BAS, said: “This is the fundamental information that underpins the computer models we use to investigate how the ice will flow across the continent as temperatures rise. Imagine pouring syrup over a rock cake – all the lumps, all the bumps, will determine where the syrup goes and how fast.
“And so it is with Antarctica: some ridges will hold up the flowing ice; the hollows and smooth bits are where that ice could accelerate.”
The average thickness of Antarctic ice, including ice shelves, is 1,948m. If all the ice melted, this could trigger a global sea-level rise of 58m.
Peter Fretwell, mapping specialist and co-author at BAS, said it had become clear that the Antarctic Ice Sheet is thicker than scientists originally thought and has a larger volume of ice that is grounded on a rock bed sitting below sea-level.
He added: “This puts the ice at greater risk of melting due to the incursion of warm ocean water that’s occurring at the fringes of the continent. What Bedmap3 is showing us is that we have got a slightly more vulnerable Antarctica than we previously thought.”
Bedmap3 is the third such view of Antarctica’s rock bed that has been created since 2001, and includes 82 million data points — double the number previously used.
Revisions to the map include the discovery that the thickest overlying ice is found at an unnamed canyon at 76.052°S, 118.378°E in Wilkes Land.
The ice there is 4,757m thick, or more than 15 times the height of the Shard, the UK’s tallest skyscraper.
Techniques including radar, seismic reflection with sounds waves and gravity measurements were used. The findings were published in the journal Scientific Data.