French scientists have found that the ice shelves of North Greenland are receding rapidly, and the total volume has decreased by more than 30% since 1978. These ice shelves have always been considered stable, but since the 2000s, three have completely collapsed. The authors point out that of the remaining five ice shelves, the mass loss of ice shelves near glaciers that will recede further with ocean warming is becoming unstable and will have serious consequences of sea level rise. The study was recently published in Nature Communications.
Ice loss from the Greenland Ice Sheet led to 17.3% of the observed sea level rise between 2006 and 2018. The only remaining Greenland floating ice shelf, located on the northern edge of the Greenland ice sheet, stabilizes the ice sheet by regulating the flow of ice discharged into the ocean. The northern Greenland glaciers have only begun to become unstable in the last 20 years, meaning that more ice is lost than the ice formed, due to the weakening and collapse of some of the floating extensions of these glaciers. In order to better predict this impact on sea level rise, it is necessary to determine the timing and drivers of changes in the remaining ice shelves, as well as the response of glaciers. However, there is a lack of complete description of the evolution of these ice shelves and the complex processes that affect them.
Romain Millan and colleagues at France’s National Center for Scientific Research (CNRS) analyzed glacier-climate-ocean interactions in North Greenland using thousands of satellite imagery and climate modelling. They observed a significant and widespread increase in ice shelf mass loss. Since 2000, they have found that ocean warming is mainly responsible for ice loss at the bottom of the Greenland ice shelf. In addition, they found that Greenland’s glaciers have begun to recede, and the flow of ice into the ocean is increasing, which coincides with the loss of ice shelves.
The results of the study suggest that the rate of basal melting will continue to rise or remain high according to future projections of ocean thermal stress, which may destabilize Greenland’s glaciers. The authors believe that if the ice shelves collapse completely, the glaciers of northern Greenland could greatly contribute to the rise in sea levels caused by the ice sheets. (Source: China Science News Jin Nan)
From Zachari? The huge iceberg that broke away in front of the Isstrom glacier, whose floating glacier tongue collapsed in 2003. Since then, the amount of ice discharged into the ocean by the glacier has increased dramatically. Photo by Anders Bjork
Related Paper Information:https://doi.org/10.1038/s41467-023-42198-2