What Lies Beneath: Digitally Denuded Antarctic Shows Land Mass Stripped of Ice

[node:summary]Digital modeling shows Antarctic without its ice sheet.

The sprawling land mass that is Antarctica—under all that ice, that is—has been unveiled, at least digitally.

The Arctic and the far north have commanded much attention of late because of sovereignty battles over its plentiful resources as they become exposed due to melting ice. (Related: Canada Takes Helm of Arctic Council With First Indigenous Leader)

However its counterpart down south is even more enigmatic, improbable as that may seem. British scientists have created a detailed image of the bedrock underlying the sometimes two-mile-thick layer of frozen water that blankets it. Pulling together decades of geophysical measurements, a team at the British Antarctic Survey created a map that enables forecasters to better predict changes in the ice sheets and the effect of those changes on sea level rise.

"It will be an important resource for the next generation of ice sheet modelers, physical oceanographers and structural geologists," said Peter Fretwell, one of the agency’s scientists and the survey’s lead author, in a statement from the survey. "The new Bedmap shows, with unprecedented detail, the bedrock beneath the ice sheets of Antarctica. Before we had a regional overview of the topography, but this new map, with its much higher resolution, shows the landscape itself; a complex landscape of mountains, hills and rolling plains, dissected by valleys troughs and deep gorges."

The work is important because of the key role Antarctica plays in the global climate system, the Antarctic Survey said. This includes everything from ocean currents to sea-level increases. The work, published in the journal The Cryosphere, gives a detailed map of the terrain underneath the ice continent.

Among statistics that the new map revealed, the scientists said, was that there is 4.6 percent more ice in Antarctica than was previously believed; the mean depth of underlying terrain is 200 feet lower than had been thought. In addition, the amount of ice whose bed is below sea level is 23 percent higher than originally estimated, which increases the amount of ice known to be susceptible to melting rapidly, given its vulnerability to warming ocean currents.

“The Bedmap2 project is about more than making a map of the landscape,” said Hamish Pritchard, co-lead author of the study, in the statement. “The data we've put together on the height and thickness of the ice and the shape of the landscape below are fundamental to modeling the behavior of the ice sheet in the future. This matters because in some places, ice along the edges of Antarctica is being lost rapidly to the sea, driving up sea level. Knowing how much the sea will rise is of global importance, and these maps are a step toward that goal."

Below, a graphic explanation of the differences and a visual of the terrain from NASA Goddard's Scientific Visualization Studio.