Satellite images have shown that two of the fastest-changing glaciers in Antarctica are cracking and weakening faster than ever. Using observations from the ESA, NASA and USGS satellites, scientists examined the Pine Island and Thwaites Glaciers, also known as the Doomsday Glacier, in the Amundsen Sea Bay. These two glaciers are some of the most dynamic on the Antarctic continent and they are responsible for the significant rise in sea levels.
Together, the two glaciers form an area of floating ice the size of Norway and contain enough water to raise global sea levels by more than a meter. Both massifs have noticeably changed in their morphology over the past decades under the influence of atmospheric and oceanic conditions – global warming has led to the melting, thinning and retreat of ice shelves.
Predictions of how these vital glaciers will develop in the coming years are critical to understanding the future of the planet and sea level. However, they remain uncertain because computer models cannot fully account for the processes and properties of glaciers.
As a result, scientists found structural damage at the “shear boundaries” of the ice shelves: large cracks and open faults, which indicate that these glaciers are slowly breaking apart. These types of glaciers are like a slow-moving car: they cause everything behind them to slow down. Once they are removed, ice farther from land can accelerate, which in turn will lead to even greater sea-level rise.
New breaks are causing the ice shelves to collapse, explains co-author Thomas Nagler of ENVEO in Innsbruck, Austria. “As glaciers break down at their weakest points, damage accelerates, spreads and more and more ice shelves weaken, increasing the likelihood that the shelves will begin to fall apart even faster,” concludes Nagler.