Millan R, Jager E, Mouginot J, Wood M H, Larsen S H, Mathiot P, Jourdain N C, Bjørk A
Université Grenoble Alpes, CNRS, IRD, INP, 38400, Grenoble, Isère, France.
Moss Landing Marine Laboratories, San José State University, San Jose, CA, 95192, USA.
Nat Commun. 2023 Nov 7;14(1):6914. doi: 10.1038/s41467-023-42198-2.
The glaciers of North Greenland are hosting enough ice to raise sea level by 2.1 m, and have long considered to be stable. This part of Greenland is buttressed by the last remaining ice shelves of the ice sheet. Here, we show that since 1978, ice shelves in North Greenland have lost more than 35% of their total volume, three of them collapsing completely. For the floating ice shelves that remain we observe a widespread increase in ice shelf mass losses, that are dominated by enhanced basal melting rates. Between 2000 and 2020, there was a widespread increase in basal melt rates that closely follows a rise in the ocean temperature. These glaciers are showing a direct dynamical response to ice shelf changes with retreating grounding lines and increased ice discharge. These results suggest that, under future projections of ocean thermal forcing, basal melting rates will continue to rise or remain at high level, which may have dramatic consequences for the stability of Greenlandic glaciers.
北格陵兰的冰川蕴含着足以使海平面上升2.1米的冰量，长期以来一直被认为是稳定的。格陵兰的这一区域由冰盖中仅存的冰架支撑。在此，我们表明，自1978年以来，北格陵兰的冰架已损失了其总体积的35%以上，其中三个已完全崩塌。对于剩余的漂浮冰架，我们观察到冰架质量损失普遍增加，这主要是由基底融化速率加快所致。在2000年至2020年期间，基底融化速率普遍增加，这与海洋温度的上升密切相关。这些冰川正表现出对冰架变化的直接动力响应，其接地线后退，冰流量增加。这些结果表明，在未来海洋热强迫的预测下，基底融化速率将继续上升或保持在高水平，这可能会对格陵兰冰川的稳定性产生巨大影响。
