A large section of the mighty West Antarctica ice sheet is melting and it appears to be irreversible.  That’s the conclusion from two separate groups of scientists studying the collapse of the ice sheet using two different methods.  Global warming caused by human activity is among the causes. 

“This is really happening,” said Thomas P. Wagner, who runs NASA’s programs on polar ice.  “There’s nothing to stop it now.  But you are still limited by the physics of how fast the ice can flow.”

One of the studies comes from the University of California, Irvine.  Scientists used satellite and air measurements to document an accelerating retreat over the past several decades of six glaciers draining into the Amundsen Sea region.

A separate team from the University of Washington put highly detailed data about a key glacier into a sophisticated modeling program.  Using the glacier’s own history, they ran the model forward to find that a slow-motion collapse was inevitable. 

“There is now little doubt that this sector of West Antarctica is in a state of rapid retreat, and the burning question is whether and how soon this retreat might escalate into irreversible collapse,” said Professor Andy Shepherd, from Leeds University.  “Thankfully, we now have an array of satellites capable of detecting the tell-tale signs, and their observations will allow us to monitor the progress and establish which particular scenario Thwaites Glacier will follow.”