In 2020, Australian CSIRO scientists launched the small Argo robot near East Antarctica’s Totten Glacier, expecting to routinely collect data on ocean temperature and salinity. Instead, strong Antarctic currents carried it far south, where it disappeared under the Denman Ice Sheet. The team almost gave up, but after nine months the robot surfaced with data recorded for the first time from a completely unexplored environment under the ice.
During its eight-month stay under the ice, the robot measured temperature and salinity every five days, all the way from the seabed to the base of the ice sheet.
An unplanned mission that brought invaluable data to science
In total, he collected 195 profiles during two and a half years of work, including the first ever direct measurements under the Denman and Shackleton ice sheets. Using the robot’s impacts on the ice, the scientists were able to reconstruct its underwater route by comparing it with satellite data on the thickness of the ice.
The results confirm the large differences between the two regions: while the northern part of the Shackleton Ice Sheet has yet to meet warmer water, the Denman is already showing signs of accelerated melting. The collected data reveal a complex thermal system that currently keeps these ice structures stable, but also their vulnerability to rising ocean temperatures.
The surprising durability of the robot and the scientific value of its “mistake” mission, opened the door to a new generation of autonomous instruments for exploring areas under the ice sheets, which are otherwise almost inaccessible. Although these devices cannot directly penetrate thick ice masses, their measurements are crucial for improving models that predict future sea level rise, writes Gizmodo.