TCD The Cryosphere Discussions TCD The Cryosphere Discuss. 1994-0440 Göttingen, Germany 10.5194/tcd-8-3829-2014 GPS based surface displacements – a proxy for discharge and sediment transport from the Greenland Ice Sheet Hasholt B. 1 Khan S. A. https://orcid.org/0000-0002-2689-8563 2 Mikkelsen A. B. 1 Institute of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark DTU Space, Technical University of Denmark, Department of Geodesy, Kgs. Lyngby, Denmark 15 07 2014 8 4 3829 3850 Copyright: © 2014 B. Hasholt et al. 2014 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/8/3829/2014/tcd-8-3829-2014.html The full text article is available as a PDF file from https://tc.copernicus.org/preprints/8/3829/2014/tcd-8-3829-2014.pdf

The elastic respond of the Earth's surface to mass changes has been measured with Global Positioning System (GPS). Mass loss as accumulated runoff and sediment transport from a 10 000 km<sup>2</sup> segment of the Greenland Ice Sheet (GrIS) correlated very well (<i>R</i><sup>2</sup> = 0.83) with GPS measured uplift. Accumulated winter precipitation correlated fairly well with surface depression (<i>R</i><sup>2</sup> = 0.69). The relationships are based on seven years of runoff and sediment transport observations from the Watson River (2007–2013), winter precipitation from Kangerlussuaq Airport and GPS observations at Kellyville. GPS recordings of surface subsidence and uplift from 1996–2013 are used to calculate 18 years time series of annual runoff, sediment and solute transport and winter precipitation. Runoff and related transport of sediment and solutes increase over the period, while winter precipitation (land depression) tends to decrease. Based on the entire GPS record (1996–2013), it is shown that until 2005–2006 the mass balance of this segment of the GrIS was rather stable – since then there has been an increasing loss of mass, culminating in 2012.

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