Mar 25, 2019

Interruption of two decades of Jakobshavn Isbrae acceleration and thinning as regional ocean cools

by
Ala Khazendar, Ian G. Fenty, Dustin Carroll, Alex Gardner, Craig M. Lee, Ichiro Fukumori, Ou Wang, Hong Zhang, Hélène Seroussi, Delwyn Moller, Brice P. Y. Noël, Michiel R. van den Broeke, Steven Dinardo, Josh Willis
,
Nature Geoscience
  • States that Jakobshavn Isbrae has been the single largest source of mass loss from the Greenland Ice Sheet over the last 20 years
  • During that time, it has been retreating, accelerating and thinning. Here we use airborne altimetry and satellite imagery to show that since 2016 Jakobshavn has been re-advancing, slowing and thickening
  • Links these changes to concurrent cooling of ocean waters in Disko Bay's upper 250 m, which have cooled to levels not seen since the mid 1980s and spill over into Ilulissat Icefjord
  • Concludes that projections of Jakobshavn’s future contribution to sea-level rise that are based on glacier geometry are insufficient, and that accounting for external forcing is indispensable