Seasonal velocities of eight major marine-terminating outlet glaciers of the Greenland ice sheet from continuous in situ GPS instruments 1Geological Survey of Denmark and Greenland, Øster Voldgade 10, 1350 Copenhagen, Denmark
2Laboratoire de Glaciologie, Université libre de Bruxelles, Brussels, Belgium
3Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, the Netherlands
4Applied Physics Laboratory, University of Washington, Seattle, USA
5National Space Institute, Danish Technical University, Kgs. Lyngby, Denmark
6Byrd Polar Research Center and Department of Geography, The Ohio State University, Columbus, USA
7Institute of Geography & Earth Sciences, Aberystwyth University, Aberystwyth, UK
Received: 01 August 2012 – Published in Earth Syst. Sci. Data Discuss.: 23 January 2013 Abstract. We present 17 velocity records derived from in situ stand-alone
single-frequency Global Positioning System (GPS) receivers placed on eight
marine-terminating ice sheet outlet glaciers in South, West and North
Greenland, covering varying parts of the period summer 2009 to summer 2012.
Common to all the observed glacier velocity records is a pronounced seasonal
variation, with an early melt season maximum generally followed by a rapid
mid-melt season deceleration. The GPS-derived velocities are compared to
velocities derived from radar satellite imagery over six of the glaciers to
illustrate the potential of the GPS data for validation purposes. Three
different velocity map products are evaluated, based on ALOS/PALSAR data,
TerraSAR-X/Tandem-X data and an aggregate winter TerraSAR-X data set. The
velocity maps derived from TerraSAR-X/Tandem-X data have a mean difference
of 1.5% compared to the mean GPS velocity over the corresponding period,
while velocity maps derived from ALOS/PALSAR data have a mean difference of
9.7%. The velocity maps derived from the aggregate winter TerraSAR-X data
set have a mean difference of 9.5% to the corresponding GPS velocities.
The data are available from the GEUS repository at doi:10.5280/GEUS000001.
Revised: 16 June 2013 – Accepted: 18 June 2013 – Published: 30 July 2013
Citation: Ahlstrøm, A. P., Andersen, S. B., Andersen, M. L., Machguth, H., Nick, F. M., Joughin, I., Reijmer, C. H., van de Wal, R. S. W., Merryman Boncori, J. P., Box, J. E., Citterio, M., van As, D., Fausto, R. S., and Hubbard, A.: Seasonal velocities of eight major marine-terminating outlet glaciers of the Greenland ice sheet from continuous in situ GPS instruments, Earth Syst. Sci. Data, 5, 277-287, doi:10.5194/essd-5-277-2013, 2013.