Robotic "dolphins" are being used to examine ice in the Antarctic, to study how the formations are affected by rising global temperatures. The subsea drones, also called ocean gliders, have no motors, being propelled by pumps, which bring water in and out of the automated vehicles.

Two studies released in 2014 each presented evidence that melting of the West Antarctic ice sheet on the southern-most continent may now be irreversible. If this vast quantity of ice were to completely turn to liquid water, sea levels would rise by an estimated ten feet.

Rising temperatures of ocean water off the coast of Antarctica may be melting the undersides of ice shelves, making them more fragile, and apt to break apart, reducing ice cover in the region.

Ocean eddies, described as storms underwater, are carried to coastal areas of Antarctica, potentially compounding the problem of disappearing ice sheets. These formations cause conditions where mid-ocean depths are warmer than areas above or below, contributing to the loss of ice. Researchers are uncertain what may be the underlying cause of warmer ocean temperatures, but man-made global warming is among the possibilities being explored by researchers.

"We are working on exactly this question. With the current study we now know that these small-scale feature, the eddies, will be an integral part of understanding why these changes are occurring," Andrew Thompson oceanographer at CalTech, said.

The robotic dolphins dive more than half a mile under the Weddell Sea, controlled by researchers in Norwich, England. The six-foot-long autonomous vehicles send data back to controllers each time the vehicles surface. This includes information on water temperature and density, as well as salinity. Salt water freezes at a lower temperature than fresh water, making ice less likely to form in regions with higher concentrations of the material.

"Using gliders as part of our future ocean and climate observing systems will save tax-payers' money since some ocean observations can be done much more efficiently by remotely controlled gliders. Gliders can also observe the ocean when we'd really rather not be there with ships, such as in winter or in strong winds and heavy seas," CalTech researchers who helped develop the vehicle, wrote.

The Drake Passage, an area of the Southern Ocean known for rough currents, will be visited by the team in December, utilizing the robotic dolphins. Deep water is carried from great depths to the surface, making the region a valuable location to study, in order to investigate the exchange of gases within the ocean.

Study of melting ice in the Antarctic utilizing robotic dolphins was profiled in the journal Nature Geoscience.