Shear margins in upper half of Northeast Greenland Ice Stream were established two millennia ago

• Published in: Nature Communications
• Main Authors: Jansen, Daniela, Franke, Steven, Bauer, Catherine C, Binder, Tobias, Dahl-Jensen, Dorthe, Eichler, Jan, Eisen, Olaf, Hu, Yuanbang, Kerch, Johanna, Llorens, Maria-Gema, Miller, Heinrich, Neckel, Niklas, Paden, John, de Riese, Tamara, Sachau, Till, Stoll, Nicolas, Weikusat, Ilka, Wilhelms, Frank, Zhang, Yu, Bons, Paul D
• Other Authors: Ministerio de Ciencia, Innovación y Universidades (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2024
• Subjects: Northeast Greenland Ice Stream; Structural geology; Cryospheric science; Arctic; Bergen; Greenland; Norway; Paul-Emile Victor; East Greenland; East Greenland Ice-core Project; Greenland ice core; Greenland Ice core Project; ice core; Ice Sheet; National Institute of Polar Research; National Science Foundation Office of Polar Programs
• Online Access: http://hdl.handle.net/10261/357880; https://doi.org/10.1038/s41467-024-45021-8; https://api.elsevier.com/content/abstract/scopus_id/85187153737

Only a few localised ice streams drain most of the ice from the Greenland Ice Sheet. Thus, understanding ice stream behaviour and its temporal variability is crucially important to predict future sea-level change. The interior trunk of the 700 km-long North-East Greenland Ice Stream (NEGIS) is remarkable due to the lack of any clear bedrock channel to explain its presence. Here, we present a 3-dimensional analysis of the folding and advection of its stratigraphic horizons, which shows that the localised flow and shear margins in the upper NEGIS were fully developed only ca 2000 years ago. Our results contradict the assumption that the ice stream has been stable throughout the Holocene in its current form and show that upper NEGIS-type development of ice streaming, with distinct shear margins and no bed topography relationship, can be established on time scales of hundreds of years, which is a major challenge for realistic mass-balance and sea-level rise projections. We thank the Kenn Borek crew of the research aircraft Polar 6 and system engineer Lukas Kandora. Logistical support in the field was provided by the East Greenland Ice-Core Project (EGRIP). EGRIP is directed and organised by the Center of Ice and Climate at the Niels Bohr Institute. It is supported by funding agencies and institutions in Denmark (A. P. Møller Foundation, University of Copenhagen), USA (US National Science Foundation, Office of Polar Programs), Germany (Alfred Wegener Insti- tute, Helmholtz Centre for Polar and Marine Research), Japan (National Institute of Polar Research and Arctic Challenge for Sustainability), Norway (University of Bergen and Bergen Research Foundation), Swit- zerland (Swiss National Science Foundation), France (French Polar Institute Paul-Emile Victor, Institute for Geosciences and Environmental research) and China (Chinese Academy of Sciences and Beijing Normal University). We acknowledge the use of the CReSIS toolbox from CReSIS generated with support from the University of Kansas, NASA Operation IceBridge ...