It’s commonly known that Antarctica is home to lots and lots of ice, but what may surprise some is that the most important aspect of that ice is the so-called ‘safety band’ of floating ice shelves that follow the perimeter of the continent. That band serves an important purpose: to hold back Antarctica’s ice floes from wandering off into the surrounding ocean. Now, the European Space Agency (ESA) reports that the ice band has reached a crucial point – possibly the point of no return.
Over the past several decades, ESA has been collecting radar data that reflects Antarctic ice loss with the help of its Envisat satellite. Scientists from the University of Erlangen-Nuremberg Institute of Geography and from the Laboratoire de Glaciologie et Géophysique de l’Environnement (LGGE) in Grenoble have used the ESA’s data, as well as other data sets, to measure just how bad the situation is. Verdict? It’s quite bad. Their research warns that if enough of these floating ice shelves collapse, the rate of inland ice loss would be expected to accelerate, causing widespread impacts around the globe.
Make no mistake; ice all across Antarctica is slowly but surely melting. But since the safety band of floating ice shelves that prevent inland glaciers and ice streams from flowing out to sea, scientists studying the effects of climate change are keeping those key areas under the microscope, so to speak. Some 13 percent of the total ice-shelf area is comprised of ‘passive’ ice shelves, which provide a slight buffer between the safety band and the open water, but those are rapidly waning.
Dr Johannes Fürst from the University of Erlangen-Nuremberg’s Institute of Geography offers a further explanation. “Once ice loss through the calving of icebergs goes beyond the passive shelf ice and cuts into the safety band,” he said, “ice flow towards the ocean will accelerate, which might well entail an elevated contribution to sea-level rise for decades and centuries to come.”
The most recent findings were published this week in Nature Climate Change.