Publié le 18 juin 2019
Jakobshavn Glacier in western Greenland is notorious for being the world’s fastest-moving glacier. It is also one of the most active, discharging a tremendous amount of ice from the Greenland Ice Sheet into Ilulissat Icefjord and adjacent Disko Bay—with implications for sea level rise. The image below, acquired on June 6, 2019, by the Operational Land Imager (OLI) on Landsat 8, shows a natural-color view of the glacier.
Jakobshavn has spent decades in retreat—that is, until scientists observed an unexpected advance between 2016 and 2017. In addition to growing toward the ocean, the glacier was found to be slowing and thickening. New data collected in March 2019 confirm that the glacier has grown for the third year in a row, and scientists attribute the change to cool ocean waters.
“The third straight year of thickening of Greenland’s biggest glacier supports our conclusion that the ocean is the culprit,” said Josh Willis, an ocean scientist at NASA’s Jet Propulsion Laboratory and principal investigator of the Oceans Melting Greenland (OMG) mission.
The maps above show how the glacier’s height changed between March 2016 and 2017 (top); March 2017 and 2018 (middle); and March 2018 and 2019 (bottom). The elevation data come from a radar altimeter that has been flown on research airplanes each spring as part of OMG. Blue areas represent where the glacier’s height has increased, in some areas by as much as 30 meters per year.