TCD The Cryosphere Discussions TCD The Cryosphere Discuss. 1994-0440 Göttingen, Germany 10.5194/tcd-6-4387-2012 Thinning and slowdown of Greenland's Mittivakkat Gletscher Mernild S. H. 1 Knudsen N. T. 2 Hoffman M. J. 3 Yde J. C. 4 Lipscomb W. H. 2 Hanna E. 5 Malmros J. K. 6 Fausto R. S. 7 Climate, Ocean, and Sea Ice Modeling Group, Computational Physics and Methods, Los Alamos National Laboratory, New Mexico, USA Department of Geoscience, Aarhus University, Aarhus, Denmark Climate, Ocean, and Sea Ice Modeling Group, Fluid Dynamics and Solid Mechanics, Los Alamos National Laboratory, New Mexico, USA Sogn og Fjordane University College, Sogndal, Norway Department of Geography, University of Sheffield, UK Centro de Estudios Científicos, Valdivia, Chile Geological Survey of Denmark and Greenland, Denmark 12 10 2012 6 5 4387 4415 Copyright: © 2012 S. H. Mernild et al. 2012 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://tc.copernicus.org/preprints/6/4387/2012/tcd-6-4387-2012.html The full text article is available as a PDF file from https://tc.copernicus.org/preprints/6/4387/2012/tcd-6-4387-2012.pdf

Here, we document changes for the Mittivakkat Gletscher, the glacier in Greenland (disconnected to the Greenland Ice Sheet, GrIS) having the longest observed mass balance and surface velocity time series (since 1995). Between 1986 and 2011, this glacier decreased by 15% in mean ice thickness and 30% in volume. We attribute these changes to summer warming and less winter snowfall. The vertical strain was able to compensate about 60% of the elevation change due to surface mass balance (SMB) in the lower part, and about 25% in the upper part. The annual mean ice surface velocity decreased by 30%, likely as a dynamic effect of ice thinning. Mittivakkat Gletscher summer surface velocities were on average 50–60% above winter background values, and up to 160% higher during peak velocity events.

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