Antartica glaciers melting at a great speed
Two new studies by researchers at the University of California, Irvine and NASA have found the glaciers in Antartica are melting at a great speed. This is the fastest rate of glacier retreat ever observed in West Antarctica.
The results highlight how the interaction between ocean conditions and the bedrock beneath a glacier can influence the frozen mass and it will help scientists predict future ice loss in Antartica as also the rise in global sea level in a much better way.
The studies examined three neighboring glaciers that are melting and retreating at different rates. The Smith, Pope and Kohler glaciers flow into the Dotson and Crosson ice shelves in the Amundsen Sea embayment in West Antarctica, the part of the continent with the largest decline in ice.
“Our primary question is how the Amundsen Sea sector of West Antarctica will contribute to a rise in sea level in the future, particularly following our observations of massive changes in the area over the last two decades,” said UCI’s Bernd Scheuchl, lead author on the first of the two studies, published in the journal Geophysical Research Letters in August.
“Using satellite data, we continue to measure the evolution of the grounding line of these glaciers, which helps us determine their stability and how much mass the glacier is gaining or losing,” he said. “Our results show that the observed glaciers continue to lose mass and thus contribute to global sea level rise,” he added.
Scheuchl’s team compared radar measurements from the European Space Agency’s Sentinel-1 mission and data from the earlier ERS-1 and ERS-2 satellites to identify changes in each glacier’s grounding line – the boundary where it loses contact with bedrock and begins to float on the ocean.
The grounding line is important because nearly all glacier melting takes place on the underside of this floating portion, called the ice shelf. If a glacier loses mass from enhanced melting, it may start floating farther inland from its former grounding line, just as a boat stuck on a sandbar may be able to float again if a heavy cargo is removed. This is called grounding line retreat.