The first detailed, high-resolution 3-D maps of Antarctic sea ice have been developed using an underwater robot. Scientists from the UK, USA and Australia say the new technology provides accurate ice thickness measurements from areas that were previously too difficult to access.
Scientists have used a wide range of technologies and techniques to measure sea ice thickness, but difficulties in getting access to thicker areas of sea ice leaves gaps in vital data. Now, with the Autonomous Underwater Vehicle (AUV) known as SeaBED, a new way of mapping sea ice is provided. 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. “Putting an AUV together to map the underside of sea ice is challenging from a software, navigation and acoustic communications standpoint,” says Hanumant Singh, an engineering scientist at the Woods Hole Oceanographic Institution (WHOI), in Massachusetts, USA, whose lab designed, built and operated the AUV.
The data from SeaBED, combined with airborne measurements of sea-ice surface elevation, ice coring surveys, and satellite observations, improves scientists’ estimates of thickness and total sea ice volume. In some areas, the team found ice up to 56ft thick, much thicker than that measured by previous techniques. The mapping by the submarine was undertaken in two expeditions during 2010 and 2012 and now routine surveys will allow monitoring of changes over long periods of time.
Sea ice thickness is normally measured using ‘point-based’ method of drilling hundreds of holes, which is labor intensive and season dependent endeavour. The SeaBED AUV has made this entire method easier. This is a big leap forward in the ability to understand why and how the ice is changing on both small and large scales.