Recently, new 3D maps of the Greenland Ice Sheet—the second largest in the world—have raised serious concerns among scientists worldwide. The findings suggest that the landmass is retreating faster than previously estimated. These cracks, known as crevasses, guide ice and meltwater into the ocean. However, this meltwater and heat can also be channelled inland, which is believed to accelerate melting and, eventually, contribute to sea level rise.
Thomas Chudley, a glaciologist at Durham University in the U.K. and lead author of a new study on Greenland’s crevasses, explained that melting causes the ice sheet’s glaciers to flow more rapidly down slopes and valleys. This stretches the ice so much that it begins to crack open. Chudley and his team analyzed more than 8,000 3D maps of Greenland’s surface, revealing that fissures in the ice sheet grew by up to 25% between 2016 and 2021, with the most significant increases seen in coastal regions.
Scientists are alarmed because these expanding cracks promote even more melting. Wider crevasses allow greater volumes of meltwater and heat to penetrate glaciers, increasing their flow rates and leading to more calving events—where large chunks of ice break off into the ocean as icebergs. Previous research suggested that the Greenland Ice Sheet holds enough water to raise global sea levels by up to 23 feet (7 meters). This new study highlights just how close we may be to a tipping point.
“If we continue along our current path […] we might see committed sea levels of 10 or even 20 meters [33 to 66 feet] of sea level rise from Greenland and Antarctica,” Chudley warned.