U.S. and British science agencies Thursday announced a multimillion-dollar research mission to study an enormous and remote Antarctic glacier that is already showing accelerating ice loss and could trigger a major rise in sea levels before the end of the century.
The move reflects the growing sense of urgency about understanding one of the biggest consequences of a warming globe – the melting of polar ice and its impact on the oceans.
The glacier in question, named Thwaites, acts as a kind of lynchpin to the West Antarctic ice sheet. It is larger than Pennsylvania and presents a 75-mile-long front to the ocean, in this case the Amundsen Sea, where recent studies have suggested that warm waters at extreme depths are causing a major glacial retreat that NASA once described as “unstoppable.”
Such a retreat could lead to a significant increase in sea levels.
“The evidence is amassing that we really need to understand this better, so that we know where we’ll be in people’s lifetimes, basically,” said Paul Cutler, the program director for Antarctic Integrated System Science at the NSF’s Division of Polar Programs.
Investigating the pace of that breakup is a complex undertaking; the closest permanent research station is 1,000 miles away and the approach to the glacier by sea is often blocked by floating sea ice.
The mission is expected to take several years to unfold. In a statement, the National Science Foundation suggested the cost of the research itself will be $20 million to $25 million, but that “allocation of logistics support for field work would increase that commitment significantly.”
The final tally will depend on how scientists propose to tackle the problem.
“I can envisage ships, I can envisage camps on the glacier itself, there’s going to be aircraft flying missions over, and possibly helicopters,” Cutler said “From the ships, there will probably be autonomous underwater vehicles, underneath the ice shelf. It’s up to the imagination of the scientists to make the best case, and we’ll work, to the extent we can, to make that happen.”
Setting up shop is just part of the logistical challenge. Conducting research on the glacier itself poses its own complications.
Like many or most Antarctic glaciers, Thwaites consists of both a large ice “shelf,” or a floating part of the glacier that sits on top of the ocean, and then a far larger area where the glacier rests firmly on the seafloor. The glacier’s “grounding line,” where it first touches the seafloor, is currently at 300 and 700 meters below sea level, or just under half a mile at most, according to Robin E. Bell, an Antarctic researcher at Columbia University’s Lamont-Doherty Earth Observatory, but if it continues to retreat it could enter far, far deeper waters.
Warming waters are weakening the glacier, causing portions to break off. A retreat has already begun. Between 1992 and 2011, the Thwaites grounding line retreated inland 8 miles, a 2014 study found.
Vast additional volumes of the glacier and the West Antarctic Ice Sheet rest above sea level, and this is where the major contribution to sea level rise would come from. According to the foundation, Thwaites is already contributing an astonishing 10 percent of all global sea level rise. The fear is just how much this could increase.
Thwaites itself could ultimately contribute around two feet to the global sea level if it were to be lost entirely. But it also connects with the interior of the West Antarctic ice sheet. The entirety of West Antarctica could contribute more than 3 meters, or more than 10 feet, of sea level rise if it were to melt entirely into the ocean.
