Basal dynamics of Kronebreen, a fast-flowing tidewater glacier in Svalbard : non-local spatio-temporal response to water input

• Published in: Journal of Glaciology
• Main Authors: Vallot, Dorothée, Pettersson, Rickard, Luckman, Adrian, Benn, Douglas I., Zwinger, Thomas, van Pelt, Ward J. J., Kohler, Jack, Schäfer, Martina, Claremar, Björn, Hulton, Nicholas R. J.
• Other Authors: University of St Andrews. School of Geography & Sustainable Development, University of St Andrews. Bell-Edwards Geographic Data Institute
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Arctic glaciology; Glacier modelling; Ice dynamics; Ice velocity; Subglacial processes; GE Environmental Sciences; QE Geology; Earth-Surface Processes; NDAS; GE; QE; Arctic; Greenland; Kronebreen; Svalbard; Climate change; glacier; Journal of Glaciology; Tidewater
• Online Access: http://hdl.handle.net/10023/12282; https://doi.org/10.1017/jog.2017.69

This project was financially supported by the Greenland Analogue Project (GAP) and the Nordic Centre of Excellence SVALI. Acquisition of the TerraSAR-X imagery was funded by the ConocoPhillips Northern Area Program, via the CRIOS project (Calving Rates and Impact on Sea Level). The leading author received an Arctic Field Grant from the Svalbard Science Forum to acquire radar lines for the basal topography in 2014. Thomas Zwinger was supported by the Nordic Center of Excellence eSTICC (eScience Tools for Investigating Climate Change in Northern High Latitudes) funded by Nordforsk (grant 57001). We evaluate the variability in basal friction for Kronebreen, Svalbard, a fast-flowing tidewater glacier. We invert 3 years (2013–15) of surface velocities at high temporal resolution (generally 11 days), to estimate the changing basal properties of the glacier. Our results suggest that sliding behaviour of Kronebreen within a year is primarily influenced by changes in water input patterns during the meltwater season and basal friction is highly variable from a year to another. At present, models usually employ parameterisations to encompass the complex physics of glacier sliding by mathematically simulate their net effect. For such ice masses with strong seasonal variations of surface melt, the spatio-temporal patterns of basal friction imply that it is neither possible nor appropriate to use a parameterisation for bed friction that is fixed in space and/or time, at least in a timescale of a few years. Basal sliding may not only be governed by local processes such as basal topography or summer melt, but also be mediated by factors that vary over a larger distance and over a longer time period such as subglacial hydrology organisation, ice-thickness changes or calving front geometry. Publisher PDF Peer reviewed