Antarctica’s Eastern Thwaites Ice Shelf Moving Close to Collapse

American Geophysical Union, December 13

Rising global temperatures appear to be accelerating the spread of deep and fast-moving cracks across the Thwaites Eastern Ice Shelf. This ice shelf plays a pivotal role in slowing the flow of ice from the massive Thwaites Glacier, one of the largest and fastest-melting glaciers on the continent. Thwaites currently loses 50 billion tons of ice each year, producing 4% of global sea-level rise. If this ice shelf breaks apart, which these observations indicate might occur within the next five years, the eastern portion of Thwaites Glacier would release a stream of icebergs and begin flowing faster in the ocean. Such ice loss would increase the contribution of Thwaites to global sea level rise. The warming waters around this region are also loosening the ice shelf’s grip on the underwater ridge that helps it brace against the ice flow. Even if the fractures do not cause the shelf to disintegrate, it is likely to become completely detached from the seafloor within the next decade, which also might hasten its collapse. Authors warn that the total loss of Thwaites Glacier alone would result in nearly a meter of sea-level rise. Loss of the surrounding glaciers making up the West Antarctic Ice Sheet, which might be destabilized by the loss of Thwaites, would result in 3-4 meters SLR globally; endangering many major cities and millions of people living in coastal areas.