Nicknamed the “doomsday glacier”, the Thwaites glacier in western Antarctica has the potential to devastate the globe. About the size of Britain, NASA estimates state that if it melted it would increase sea levels by 0.5 meters (1.6 feet). More worrying, however, is the cascade of ice melt it would likely unleash, as the glaciers currently protected from the warming ocean by Thwaites' presence would be exposed, causing a sea level rise that would sink New York City, Miami, and the Netherlands. It's already retreating at an alarming rate, but new research published in the journal Proceedings of the National Academy of Sciences fears this rate could speed up as increasing damage was found to weaken the ice shelf's integrity.
The study used multisource satellite imagery to map how increasing damage to the ice shelf affected its strength, monitoring how sections would crack and fragment from the glacier’s edge. The research focused on the rapid development of damaged areas in the shear zones of Pine Island and Thwaites ice shelves, where the glacier meets the ocean. These damaged areas are made up of open fractures and crevasses where moving ice meets rock and are often the first indicators of catastrophic weakening for ice shelves.
Their modeling revealed that as the ice shelf becomes more damaged, it initiates a feedback process that further weakens the ice shelf, speeding up the development of thinning areas and cracks until sections of ice break away. The discovery brings a fresh perspective for scientists working with sea ice, demonstrating the importance of considering these feedback processes when making sea level rise projections and assessing the stability of surviving ice shelves.
The importance of the Thwaites glacier goes beyond its own survival, as it acts as a barrier between the ever-warming ocean and other glaciers. If it were to melt completely, it could have a cascading effect and bring down ice masses throughout western Antarctica. The resulting release of water into our oceans could see sea levels rise to almost 3 meters (10 feet), devastating coastal settlements across the globe.
“The results of this study suggest that damage feedback processes are key to future ice shelf stability, grounding line retreat, and sea level contributions from Antarctica,” the authors wrote. “Moreover, they underline the need for incorporating these feedback processes, which are currently not accounted for in most ice sheet models, to improve sea level rise projections.”