The first detailed, high-resolution 3D maps of Antarctic sea ice have been developed using an underwater robot. Scientists from the UK, US, and Australia say the new technology provides accurate ice thickness measurements from areas that were previously too difficult to access.
The yellow SeaBED robot, which is approximately two meters long and weighs nearly 200 kilograms, has a twin-hull design that gives the robot enhanced stability for low-speed photographic surveys.
While most oceanographic survey instruments look down at the seafloor, SeaBED was fitted with an upward-looking sonar in order to measure and map the underside of sea ice floes. The AUV operated at a depth of 20 to 30 meters and was driven in a lawnmower pattern. The lines of data were merged to form high-resolution 3D bathymetric surveys of the underside of the ice.
The next steps are for the scientists to do large-scale surveys that can be compared to large-scale observations from aircraft and satellites.
"What this effort does is show that observations from AUVs under the ice are possible and there is a very rich data set that you can get from them," says Ted Maksym, a WHOI scientist. "This work is an important step toward making the kinds of routine measurements we need in order to really monitor and understand what's happening with the ice and the large scale changes that are occurring."