Earlier this month, teams from the UK and the US started to arrive in Antarctica to begin work on one of the largest international scientific missions to the ‘White Continent’ ever conceived. Over the next five years, they will seek to understand recent changes in the Thwaites Glacier in West Antarctica and what they mean for future global sea levels.
Antarctica is losing ice at unprecedented speed and the challenge facing scientists is to understand how quickly and why. The fastest ice-loss is happening in West Antarctica, where ten glaciers that help pin back the West Antarctic Ice Sheet are accelerating towards the sea. If these glaciers continue to accelerate, and the ‘buttressing’ they provide the inland ice is lost, the Ice Sheet itself is expected to collapse, with global repercussions, potentially affecting hundreds of millions of people. Currently ice loss from the West Antarctic Ice Sheet is contributes 10% of measured global sea level rise, but that could increase substantially in coming decades. This part of the West Antarctic Ice Sheet, contains enough ice to raise global sea level by 1.1 meters.
Recently, scientists discovered the flow of the Thwaites Glacier, one of the biggest in West Antarctica, is accelerating for the first time since measurements began in 1973. The reason appears to be that warming water near Antarctica is getting under the ice shelf (the part of the glacier that extends out over the sea). The water melts the ice shelf from below, and as it thins, it is less able to prevent the rest of the glacier flowing more rapidly into the sea. This process is repeating itself at glaciers all along this part of the West Antarctic Ice Sheet. Unlike in East Antarctica, where the base of the main ice sheet is high above sea level, the base of the West Antarctic Ice Sheet is bowl-shaped, stretching 1.7 miles below sea level. As more water gets underneath the ice shelves, the Ice Sheet itself will start to lift up, eventually allowing the bowl to fill. If that happens, runaway melt is expected to ensue. While the earth below the Ice Sheet is likely to rebound as the immense weight is of the ice is reduced, this is unlikely be rapid enough to protect the West Antarctic Ice Sheet from collapse.
The International Thwaites Glacier Collaboration (ITGC) formally began in April 2018 and this month the team of UK and US polar scientists arrived for their first field season. The £20 million project will take five years and is funded by the UK Natural Environment Research Council
(NERC) and the US National Science Foundation (NSF). More than 100 scientists and support staff will take part. One of the biggest challenges facing the project is that the Thwaites Glacier is extremely remote and difficult to reach, sitting roughly equidistant from the US McMurdo Station and the UK’s British Antarctic Survey Rothera Station (the study sites are almost 1,000 miles away from both research bases).
This winter, the UK is mobilising large tracked vehicles, snow mobiles, sledges, and cabooses, deployed from the British Antarctic Survey’s logistics ship RRS Ernest Shackleton, with support from the Royal Navy’s only ice patrol ship, HMS Protector. Over 20 researchers will follow in late January, onboard the US icebreaker Nathaniel B Palmer. They will begin by mapping the sea floor around the front of the Thwaites Glacier and collecting sediment cores from the seabed. Ocean gliders and autonomous vehicles will collect data on how the glacier interacts with the ocean.
Weddell and Elephant seals will be studied to learn more about their behaviour and the ocean conditions where they dive. Rocks, penguin bones, algae and shells from nearby islands will be carbon dated to see how sea level has changed over the past 5,000 years. BAS Twin Otter aircraft will collect data on ice thickness from above. All of this data will help improve the reliability of the ice sheet models used to predict future changes.
The scale of the UK-US collaboration is such that the project will be one the largest field programmes ever undertaken in the 70 years of modern research. The mission serves as a reminder of the importance of international cooperation when it comes to operating in one of the most extreme, remote, and hostile environments in the world, and reaffirms the spirit of the Antarctic Treaty, which reaches its 60th anniversary next year, and the commitment undertaken by the signatories to maintain Antarctica as “a natural reserve, devoted to peace and science”. The project also has a particular significance to the UK because in the years ahead, the RSS Sir David Attenborough – the UK’s new £200 million research ship – will take over as the principal research vessel supporting the mission.