Cracks herald the calving of a large iceberg from Petermann Glacier

Cracks in the floating ice tongue of Petermann Glacier in the far northwest reaches of Greenland indicate the pending loss of another large iceberg. As glaciologists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) report in a new study, the glacier’s flow rate has increased by an average of 10 percent since the calving event in 2012, during which time new cracks have also formed—a quite natural process. However, the experts’ model simulations also show that, if these ice masses truly break off, Petermann Glacier’s flow rate will likely accelerate further and transport more ice out to sea, with corresponding effects on the global sea level. The study was recently released in the Journal of Geophysical Research: Earth Surface and is freely available.