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: DOROTHÉE VALLOT, RICKARD PETTERSSON, ADRIAN LUCKMAN, DOUGLAS I. BENN, THOMAS ZWINGER, WARD J. J. VAN PELT, JACK KOHLER, MARTINA SCHÄFER, BJÖRN CLAREMAR, NICHOLAS R. J. HULTON
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2017
• Subjects: Arctic glaciology; glacier modelling; ice dynamics; ice velocity; subglacial processes; Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Arctic; Svalbard; Kronebreen; glacier; Journal of Glaciology; Tidewater
• Online Access: https://doi.org/10.1017/jog.2017.69; https://doaj.org/article/0e26959c297e4d2684dea75cb6343a61

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.