Thermodynamics of a fast-moving Greenlandic outlet glacier revealed by fiber-optic distributed temperature sensing

• Published in: Science Advances
• Main Authors: Law, Robert, Christoffersen, Poul, Hubbard, Bryn, Doyle, Samuel H, Chudley, Thomas R, Schoonman, Charlotte M, Bougamont, Marion, des Tombe, Bas, Schilperoort, Bart, Kechavarzi, Cedric, Booth, Adam, Young, Tun Jan
• Other Authors: University of St Andrews.Bell-Edwards Geographic Data Institute, University of St Andrews.School of Geography & Sustainable Development
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2023
• Subjects: GB Physical geography; GE Environmental Sciences; DAS; SDG 14 - Life Below Water; MCC; GB; GE; Greenland; Kujalleq; glacier; greenlandic; Sermeq Kujalleq
• Online Access: https://hdl.handle.net/10023/27372; https://doi.org/10.1126/sciadv.abe7136

Funding: This research was funded by the European Research Council as part of the RESPONDER project under the European Union’s Horizon 2020 research and innovation program (grant 683043). R.L. and T.R.C. were supported by Natural Environment Research Council Doctoral Training Partnership studentships (grant NE/ L002507/1). B.H. was supported by a HEFCW/Aberystwyth University Capital Equipment Grant. 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. Peer reviewed