Thermodynamics of a fast-moving Greenlandic outlet glacier revealed by fiber-optic distributed temperature sensing.
Robert Law, Poul Christoffersen, Bryn Hubbard, Samuel H Doyle, Thomas R Chudley, Charlotte M Schoonman, Marion Bougamont, Bas des Tombe, Bart Schilperoort, Cedric Kechavarzi, Adam Booth, Tun Jan Young
Author Information
Robert Law: Scott Polar Research Institute, University of Cambridge, Cambridge, UK. rl491@cam.ac.uk. ORCID
Poul Christoffersen: Scott Polar Research Institute, University of Cambridge, Cambridge, UK. ORCID
Bryn Hubbard: Centre for Glaciology, Aberystwyth University, Aberystwyth, UK. ORCID
Samuel H Doyle: Centre for Glaciology, Aberystwyth University, Aberystwyth, UK. ORCID
Thomas R Chudley: Scott Polar Research Institute, University of Cambridge, Cambridge, UK. ORCID
Charlotte M Schoonman: Scott Polar Research Institute, University of Cambridge, Cambridge, UK. ORCID
Marion Bougamont: Scott Polar Research Institute, University of Cambridge, Cambridge, UK. ORCID
Bas des Tombe: Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands. ORCID
Bart Schilperoort: Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands. ORCID
Cedric Kechavarzi: Centre for Smart Infrastructure and Construction, Department of Engineering, University of Cambridge, Cambridge, UK.
Adam Booth: School of Earth and Environment, University of Leeds, Leeds, UK. ORCID
Tun Jan Young: Scott Polar Research Institute, University of Cambridge, Cambridge, UK. ORCID
Measurements of ice temperature provide crucial constraints on ice viscosity and the thermodynamic processes occurring within a glacier. However, such measurements are presently limited by a small number of relatively coarse-spatial-resolution borehole records, especially for ice sheets. Here, we advance our understanding of glacier thermodynamics with an exceptionally high-vertical-resolution (~0.65 m), distributed-fiber-optic temperature-sensing profile from a 1043-m borehole drilled to the base of Sermeq Kujalleq (Store Glacier), Greenland. We report substantial but isolated strain heating within interglacial-phase ice at 208 to 242 m depth together with strongly heterogeneous ice deformation in glacial-phase ice below 889 m. We also observe a high-strain interface between glacial- and interglacial-phase ice and a 73-m-thick temperate basal layer, interpreted as locally formed and important for the glacier's fast motion. These findings demonstrate notable spatial heterogeneity, both vertically and at the catchment scale, in the conditions facilitating the fast motion of marine-terminating glaciers in Greenland.
