Thwaites Glacier is one of the largest ice sheets globally, and in the past, researchers said that it was in imminent danger of a sudden collapse. However, it turns out those researchers may not have been correct. According to a new study from researchers at the University of Michigan, the glacier may be more stable and in less danger of sudden collapse than previously predicted.
The study included simulating the demise of the Thwaites Glacier in the West Antarctic, which is one of the largest and most unstable glaciers in the entire world. For the study, researchers modeled the collapse of various heights of ice cliffs which are near vertical formations occurring where glaciers and ice shelves meet the ocean. The new study found instability doesn’t always lead to the rapid disintegration of the ice sheet.
Researcher Jeremy Bassis says that his team found over long time scales, ice behaves like a viscous fluid similar to a pancake spreading out in a frying pan. As the ice spreads and thins faster, it can stabilize the collapse. But when ice is unable to thin fast enough, there’s a possibility of rapid glacier collapse. The team of researchers combined variables including ice failure and ice flow rates for the first time and found that stretching of thinning of ice and buttressing from trapped chunks of ice could moderate the effects of fracture-induced marine ice cliff instability.
The team says the new findings add more nuance to the previous theory known as marine ice cliff instability. That theory suggested that if the height of an ice cliff reaches a certain threshold, it could suddenly disintegrate under its own weight leading to a chain reaction of ice fractures. Thwaites Glacier was moving closer to the threshold, and its collapse could reportedly lead to a nearly 3 feet rise in sea levels in the event of a sudden collapse.
Thwaites Glacier is massive at 74,000 square miles making it roughly the size of Florida. The team also found that iceberg calving could stave off catastrophic collapse where it was previously predicted to contribute to the collapse. In addition, the team notes if massive chunks of ice get stuck on outcroppings on the ocean floor, they exert back pressure on the glacier, helping to stabilize it.