Deploying an underwater robot beneath a rapidly melting ice shelf in Antarctica

 

Deploying an underwater robot beneath a rapidly melting ice shelf in Antarctica, scientists have uncovered new clues about how it is melting. The findings will help assess the threat it and other ice shelves pose for long-term sea-level rise.

The researchers said that overall melting of the underside of part of the Thwaites shelf in West Antarctica was less than expected from estimates derived from computer models. But they also discovered that rapid melting was occurring in unexpected places: a series of terraces and crevasses that extended up into the ice.

The findings do not alter the fact that the Thwaites is among the fastest receding and least stable ice shelves in Antarctica, and of the most concern when it comes to sea level rise. It also does not change forecasts that the collapse of the shelf and the glacier it is part of would lead to about two feet of rise over several centuries.

The research “is telling us a lot more about the processes that drive retreat on Thwaites,” said one of the scientists, Peter E.D. Davis, an oceanographer with the British Antarctic Survey. The findings, published Wednesday in the journal Nature, will be used to refine models that forecast Thwaites’s long-term future.