Elastic deformation plays a non-negligible role in Greenland’s outlet glacier flow

• Published in: Communications Earth & Environment
• Main Authors: Christmann, Julia, Helm, Veit, Khan, Shfaqat Abbas, Kleiner, Thomas, Müller, Ralf, Morlighem, Mathieu, Neckel, Niklas, Rückamp, Martin, Steinhage, Daniel, Zeising, Ole, Humbert, Angelika
• Other Authors: Bundesministerium für Bildung und Forschung, European Union’s Horizon 2020 Research and Innovation Programme
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: General Earth and Planetary Sciences; General Environmental Science; Greenland; glacier
• Online Access: http://dx.doi.org/10.1038/s43247-021-00296-3; https://www.nature.com/articles/s43247-021-00296-3.pdf; https://www.nature.com/articles/s43247-021-00296-3

Abstract Future projections of global mean sea level change are uncertain, partly because of our limited understanding of the dynamics of Greenland’s outlet glaciers. Here we study Nioghalvfjerdsbræ, an outlet glacier of the Northeast Greenland Ice Stream that holds 1.1 m sea-level equivalent of ice. We use GPS observations and numerical modelling to investigate the role of tides as well as the elastic contribution to glacier flow. We find that ocean tides alter the basal lubrication of the glacier up to 10 km inland of the grounding line, and that their influence is best described by a viscoelastic rather than a viscous model. Further inland, sliding is the dominant mechanism of fast glacier motion, and the ice flow induces persistent elastic strain. We conclude that elastic deformation plays a role in glacier flow, particularly in areas of steep topographic changes and fast ice velocities.