Closing the mass budget of a tidewater glacier : the example of Kronebreen, Svalbard

• Published in: Journal of Glaciology
• Main Authors: Deschamps-Berger, Cesar, Nuth, Christopher, Van Pelt, Ward, Berthier, Etienne, Kohler, Jack, Altena, Bas
• Format: Article in Journal/Newspaper
• Language: English
• Published: Uppsala universitet, Luft-, vatten- och landskapslära 2019
• Subjects: glaciological instruments and methods; glacier mass balance; remote sensing; Physical Geography; Naturgeografi; Kronebreen; Svalbard; glacier; Journal of Glaciology; Tidewater
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-379123; https://doi.org/10.1017/jog.2018.98

In this study, we combine remote sensing, in situ and model-derived datasets from 1966 to 2014 to calculate the mass-balance components of Kronebreen, a fast-flowing tidewater glacier in Svalbard. For the well-surveyed period 2009-2014, we are able to close the glacier mass budget within the prescribed errors. During these 5 years, the glacier geodetic mass balance was -0.69 +/- 0.12 m w.e. a(-1), while the mass budget method led to a total mass balance of -0.92 +/- 0.16 m w.e. a(-1), as a consequence of a strong frontal ablation (-0.78 +/- 0.11 m w.e. a(-1) ), and a slightly negative climatic mass balance (-0.14 +/- 0.11 m w.e. a(-1) ). The trend towards more negative climatic mass balance between 1966-1990 (+0.20 +/- 0.05 m w.e. a(-1) ) and 2009-2014 is not reflected in the geodetic mass balance trend. Therefore, we suspect a reduction in ice-discharge in the most recent period. Yet, these multidecadal changes in ice-discharge cannot be measured from the available observations and thus are only estimated with relatively large errors as a residual of the mass continuity equation. Our study presents the multidecadal evolution of the dynamics and mass balance of a tidewater glacier and illustrates the errors introduced by inferring one unmeasured mass-balance component from the others.