Robot survives months in never-seen Antarctic cavity, finds heat beneath glaciers

A robotic Argo float has successfully completed a groundbreaking 300-kilometre journey beneath East Antarctica’s Denman and Shackleton ice shelves, drifting for two-and-a-half years in one of the planet’s most inaccessible regions. Equipped with temperature and salinity sensors, the autonomous probe collected nearly 200 ocean profiles from the seafloor to the ice base, including an unprecedented eight-month period beneath the ice where it lost satellite communication. Scientists reconstructed its path by matching ice-draft measurements recorded by the float with satellite data, enabling the first-ever ocean transect beneath an East Antarctic ice shelf. The data revealed contrasting conditions under the two ice shelves: Shackleton appears relatively stable with no warm water detected, while Denman Glacier—capable of raising global sea levels by 1.5 meters—is already influenced by warm water that could accelerate melting and trigger unstable retreat. The float’s ability to measure the critical 10-meter boundary layer beneath the ice shelf, which controls melt rates, provides valuable