Elastic deformation plays a non-negligible role in Greenland’s outlet glacier flow
Helm, Veit
Khan, Shfaqat Abbas
Kleiner, Thomas
Müller, Ralf
Morlighem, Mathieu
Neckel, Niklas
Rückamp, Martin
Steinhage, Daniel
Zeising, Ole
Humbert, Angelika
DOI: https://doi.org/10.1038/s43247-021-00296-3
Persistent URL: http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11133
Helm, Veit; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Khan, Shfaqat Abbas; Department of Geodesy and Earth Observations, National Space Institute, Technical University of Denmark, DTU Space, Copenhagen, Denmark
Kleiner, Thomas; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Müller, Ralf; Institute of Applied Mechanics, University of Kaiserslautern, Kaiserslautern, Germany
Morlighem, Mathieu; Department of Earth System Science, University of California, Irvine, USA
Neckel, Niklas; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Rückamp, Martin; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Steinhage, Daniel; Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
Zeising, Ole; Department of Geosciences, University of Bremen, Bremen, Germany
Humbert, Angelika; Department of Geosciences, University of Bremen, Bremen, Germany
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.
Ice flow dynamics in Greenland’s outlet glaciers are influenced by elastic deformation, both in the area of tidal influence up to 14 km inland from the grounding line and further upstream, suggest analyses of GPS observations and numerical simulations.