Researchers from the Institute for Marine and Antarctic Studies, the Australian Maritime College, the Antarctic Climate and Ecosystems Cooperative Research Centre and the Australian Antarctic Division are using the $5 million AUV to gather data from difficult to reach underwater areas.

The study's lead researcher David Gwyther said ice shelves such as the Sorsdal were a floating extension of Antarctic glaciers which played an important role in curbing the flow of the ice sheet toward the ocean.

"nupiri muka is one of the few AUVs in the world capable of operating autonomously under the ice, and our results show the value of this capability," Dr Gwyther said.

"Last year's deployment was the first time a vehicle of this type has explored beneath the Sorsdal ice shelf.

"When combined with data from a range of more traditional sampling methods, our results have allowed us to build a more complete picture of the processes controlling melting of the ice shelf.

"Although previous studies have documented the presence of a reservoir of ocean heat less than 50 kilometres from the Sorsdal, we found that cold and salty water may be blocking the warm water from reaching it, maintaining relatively weak rates of melting.

"The deep trough that we identified is a potential pathway for warm water that could see the Sorsdal melt more quickly if ocean processes in the region change."

Dr Gwyther said the melting of ice shelves threatened their role as a buttress which block the progress of ice sheets draining from the Antarctic.

"Ocean-driven melting at the base of ice shelves is already the main contributor to mass loss from the Antarctic ice sheet," he said.

"A reduction in the buttressing effect of ice shelves is a negative feedback that can lead to glacial acceleration and a further increase in their contribution to mean sea level.

"It is therefore vital that scientists continue to monitor and better understand the changes taking place underneath the Antarctic ice."

In February, the AUV also completed a 60-kilometre journey beneath the sea ice adjacent to the Thwaites Glacier in the Amundsen region of West Antarctica.

The AUV is housed and maintained at the AMC site in Launceston.