Researchers Discover a Cause of Rapid Ice Melting in Greenland
Published:28 May2023 Source:University of California - Irvine
While conducting a study of Petermann Glacier in northwest Greenland, researchers at the University of California, Irvine and NASA's Jet Propulsion Laboratory uncovered a previously unseen way in which the ice and ocean interact. The glaciologists said their findings could mean that the climate community has been vastly underestimating the magnitude of future sea level rise caused by polar ice deterioration.
Using satellite radar data from three European missions, the UCI/NASA team learned that Petermann Glacier's grounding line -- where ice detaches from the land bed and begins floating in the ocean -- shifts substantially during tidal cycles, allowing warm seawater to intrude and melt ice at an accelerated rate. The group's results are the subject of a paper published in Proceedings of the National Academy of Sciences.
The researchers found that as Petermann Glacier's grounding line retreated nearly 4 kilometers -- 2½ miles -- between 2016 and 2022, warm water carved a 670-foot-tall cavity in the underside of the glacier, and that abscess remained there for all of 2022.The Greenland ice sheet has lost billions of tons of ice to the ocean in the past few decades, the PNAS paper stresses, with most of the loss caused by warming of subsurface ocean waters, a product of Earth's changing climate. Exposure to ocean water melts the ice vigorously at the glacier front and erodes resistance to the movement of glaciers over the ground, causing the ice to slide more quickly to the sea, according to Rignot.