Research published recently in Nature Geoscience details the findings of the most accurate topographical map of Antarctica that we have to date. The map has been dubbed BedMachine and holds critical information regarding the vulnerability of specific regions of the continent under predicted climate conditions.
The study comes from a team of glaciologists at the University of California, Irvine that was interested in improving the scientific community’s understanding of Antarctica’s ice sheet. UCI associate professor of Earth system science Mathieu Morlighem led the team and commented, "There were lots of surprises around the continent, especially in regions that had not been previously mapped in great detail with radar. Ultimately, BedMachine Antarctica presents a mixed picture: Ice streams in some areas are relatively well-protected by their underlying ground features, while others on retrograde beds are shown to be more at risk from potential marine ice sheet instability."
Indeed, the variability that the project discovered showed several noteworthy areas that are particularly vulnerable to rapid ice melting and retreat, such as a bed in the Thwaites and Pine Island glaciers sector of West Antarctica and a bed under the Recovery and Support Force glaciers. BedMachine also discovered the deepest land canyon in the world beneath Denman Glacier in East Antarctica as well as stabilizing ridges that actually act to shelter the ice flowing across the Transantarctic Mountains.
How did the team get such precise data, you ask? The project of creating BedMachine was ambitious, to say the least, combining ice thickness data from radar soundings from 19 research institutes going back to 1967. They also took into consideration ice shelf bathymetry measurements from NASA's Operation IceBridge campaigns, ice flow velocity, and seismic information.
Although past analyses have yielded somewhat similar topographical maps, there have been some discrepancies due to technical limitations. For example, Morlighem says, "Older maps suggested a shallower canyon, but that wasn't possible; something was missing.” He says the analyses to develop BedMachine depend on the fundamental physics-based method of mass conservation.
“With conservation of mass, by combining existing radar survey and ice motion data, we know how much ice fills the canyon -- which, by our calculations, is 3,500 meters below sea level, the deepest point on land. Since it's relatively narrow, it has to be deep to allow that much ice mass to reach the coast."
You might be wondering why this matters exactly. You know, you might be thinking, just how important is it to know the depth of every nook and cranny of this huge ice continent to our south? According to the researchers, this information is key because it gives us a better idea of what we can expect (and therefore how we should prepare) in the coming decades. "Using BedMachine to zoom into particular sectors of Antarctica, you find essential details such as bumps and hollows beneath the ice that may accelerate, slow down or even stop the retreat of glaciers," Morlighem explained. “BedMachine will help reduce the uncertainty in sea level rise projections from numerical models,” he added.