Skip to main content Accessibility help

Localized uplift of Vatnajökull, Iceland: subglacial water accumulation deduced from InSAR and GPS observations

  • Eyjólfur Magnússon (a1) (a2), Helgi Björnsson (a1), Helmut Rott (a2), Matthew J. Roberts (a3), Finnur Pálsson (a1), Sverrir Guđmundsson (a1), Richard A. Bennett (a4), Halldór Geirsson (a3) and Erik Sturkell (a5)...

We report on satellite and ground-based observations that link glacier motion with subglacial hydrology beneath Skeiðarárjökull, an outlet glacier of Vatnajökull, Iceland. We have developed a technique that uses interferometric synthetic aperture radar (InSAR) data, from the European Remote-sensing Satellite (ERS-1/-2) tandem mission (1995–2000), to detect localized anomalies in vertical ice motion. Applying this technique we identify an area of the glacier where these anomalies are frequent: above the subglacial course of the river Skeiðará, where we observed uplift of 0.15–0.20 m d−1 during a rainstorm and a jökulhlaup, and subsidence at a slower rate subsequent to rainstorms. A similar pattern of motion is apparent from continuous GPS measurements obtained at this location in 2006/07. We argue that transient uplift of the ice surface is caused by water accumulating at the glacier base upstream of an adverse bed slope where the overburden pressure decreases significantly over a short distance. Most of the frictional energy of the flowing water is therefore needed to maintain water temperature at the pressure-melting point. Hence, little energy is available to enlarge water channels sufficiently by melting to accommodate sudden influxes of water to the base. This causes water pressure to exceed the overburden pressure, enabling uplift to occur.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the or variations. ‘’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Localized uplift of Vatnajökull, Iceland: subglacial water accumulation deduced from InSAR and GPS observations
      Available formats
      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Localized uplift of Vatnajökull, Iceland: subglacial water accumulation deduced from InSAR and GPS observations
      Available formats
      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Localized uplift of Vatnajökull, Iceland: subglacial water accumulation deduced from InSAR and GPS observations
      Available formats
Hide All
Alley, R.B., Lawson, D.E., Larson, G.J., Evenson, E.B. and Baker, G.S.. 2003. Stabilizing feedbacks in glacier-bed erosion. Nature, 424(6950), 758760.
Anderson, R.S. and 6 others. 2004. Strong feedbacks between hydrology and sliding of a small alpine glacier. J. Geophys. Res., 109(F3), F03005. (10.1029/2004JF000120.)
Bacher, U., Bludovsky, S., Dorrer, E. and Münzer, U.. 2001. Precision aerial survey of Vatnajökull, Iceland by digital photogrammetry. In Oltan, M.O. and Gründig, L., eds. Proceedings of 3rd Turkish– German Joint Geodetic Days: Towards a Digital Age. Istanbul, Istanbul Technical University, 110.
Bartholomaus, T.C., Anderson, R.S. and Anderson, S.P.. 2008. Response of glacier basal motion to transient water storage. Nature Geosci., 1(1), 3337.
Bartholomew, I., Nienow, P., Mair, D., Hubbard, A., King, M.A. and Sole, A.. 2010. Seasonal evolution of subglacial drainage and acceleration in a Greenland outlet glacier. Nature Geosci., 3(6), 408411.
Bell, R.E. 2008. The role of subglacial water in ice-sheet mass balance. Nature Geosci., 1(5), 297304.
Berthier, E. 2005. Dynamique et bilan de masse des glaciers de montagne (Alpes, Islande, Himalaya): contribution de l’imagerie satellitaire. (PhD thesis, Université Paul Sabatier.)
Björnsson, H. 1998. Hydrological characteristics of the drainage system beneath a surging glacier. Nature, 395(6704), 771774.
Björnsson, H. and Pálsson, F.. 2008. Icelandic glaciers. Jökull, 58, 365386.
Björnsson, H., Pálsson, F., Sigurðsson, O. and Flowers, G.E.. 2003. Surges of glaciers in Iceland. Ann. Glaciol., 36, 8290.
Clarke, G.K.C. 2005. Subglacial processes. Annu. Rev. Earth Planet. Sci., 33, 247276.
Defense Mapping Agency (DMA) and Iceland Geodetic Survey (IGS). 1990. Skeiðarárjökull, Island – Iceland. Map no. 2013/II. Ser. C761. Washington, DC, Defense Mapping Agency. Hydrographic/Topographic Center.
Fatland, D.R. and Lingle, C.S.. 2002. InSAR observations of the 1993–95 Bering Glacier (Alaska, U.S.A.) surge and a surge hypothesis. J. Glaciol., 48(162), 439451.
Flowers, G.E. 2008. Subglacial modulation of the hydrograph from glacierized basins. Hydrol. Process., 22(19), 39033918.
Fricker, H.A., Scambos, T., Bindschadler, R. and Padman, L.. 2007. An active subglacial water system in West Antarctica mapped from space. Science, 315(5818), 15441548.
Fudge, T.J., Harper, J.T., Humphrey, N.F. and Pfeffer, W.T.. 2009. Rapid glacier sliding, reverse ice motion and subglacial water pressure during an autumn rainstorm. Ann. Glaciol., 50(52), 101108.
Generalstabens topografiske Afdeling. 1905. Öræfajökull. Copenhagen, Generalstabens topografiske Afdeling. (Kvartblade 87.)
Gray, L., Joughin, I., Tulaczyk, S., Spikes, V.B., Bindschadler, R. and Jezek, K.. 2005. Evidence for subglacial water transport in the West Antarctic Ice Sheet through three-dimensional satellite radar interferometry. Geophys. Res. Lett., 32(3), L03501. (10.1029/2004GL021387.)
Guðmundsson, S., Björnsson, H., Pálsson, F. and Haraldsson, H.H.. 2003. Comparison of physical and regression models of summer ablation on ice caps in Iceland. Reykjavík, University of Iceland. Science Institute/Reykjavík, National Power Company of Iceland. (Tech. Rep. RH-15-2003.)
Guðmundsson, S., Björnsson, H., Pálsson, F. and Haraldsson, H.H.. 2009. Comparison of energy balance and degree-day models of summer ablation on the Langjökull ice cap, SW-Iceland. Jökull, 59, 118.
Hanssen, R.F. 2001. Radar interferometry: data interpretation and error analysis. Dordrecht, etc., Kluwer Academic Publishers.
Hooke, R.LeB., Calla, P., Holmlund, P., Nilsson, M. and Stroeven, A.. 1989. A 3 year record of seasonal variations in surface velocity, Storglaciären, Sweden. J. Glaciol., 35(120), 235247.
Iken, A. and Bindschadler, R.A.. 1986. Combined measurements of subglacial water pressure and surface velocity of Findelengletscher, Switzerland: conclusions about drainage system and sliding mechanism. J. Glaciol., 32(110), 101119.
Iken, A., Röthlisberger, H., Flotron, A. and Haeberli, W.. 1983. The uplift of Unteraargletscher at the beginning of the melt season – a consequence of water storage at the bed? J. Glaciol., 29(101), 2847.
Kamb, B. 1987. Glacier surge mechanism based on linked cavity configuration of the basal water conduit system. J. Geophys. Res., 92(B9), 90839100.
Magnússon, E. 2008. Glacier hydraulics explored by means of SARinterferometry. (PhD thesis, University of Innsbruck.)
Magnússon, E., Rott, H., Björnsson, H., Roberts, M.J., Berthier, E. and Pálsson, F.. 2006. The effects of basal water beneath Vatnajökull, Iceland, observed by SAR interferometry. In Lacoste, H., ed. Proceedings of Fringe 2005 Workshop, 28 November–2 December 2005, Frascati, Italy. Noordwijk, European Space Agency. CD-ROM. (ESA SP-610.)
Magnússon, E., Rott, H., Björnsson, H. and Pálsson, F.. 2007. The impact of jökulhlaups on basal sliding observed by SAR interferometry on Vatnajökull, Iceland. J. Glaciol., 53(181), 232240.
Magnússon, E., Björnsson, H., Rott, H. and Pálsson, F.. 2010. Reduced glacier sliding caused by persistent drainage from a subglacial lake. Cryosphere, 4(1), 1320.
Nye, J.F. 1976. Water flow in glaciers: jökulhlaups, tunnels and veins. J. Glaciol., 17(76), 181207.
Paterson, W.S.B. 1994. The physics of glaciers. Third edition. Oxford, etc., Elsevier.
Reeh, N., Mohr, J.J., Madsen, S.N., Oerter, H. and Gundestrup, N.S.. 2003. Three-dimensional surface velocities of Storstrømmen glacier, Greenland, derived from radar interferometry and ice-sounding radar measurements. J. Glaciol., 49(165), 201209.
Rignot, E. and Kanagaratnam, P.. 2006. Changes in the velocity structure of the Greenland Ice Sheet. Science, 311(5673), 986990
Roberts, M.J. and 7 others. 2002. Glaciohydraulic supercooling in Iceland. Geology, 30(5), 439442.
Röthlisberger, H. 1972. Water pressure in intra- and subglacial channels. J. Glaciol., 11(62), 177203.
Schoof, C. 2010. Ice-sheet acceleration driven by melt supply variability. Nature, 468(7325), 803806.
Shepherd, A., Hubbard, A., Nienow, P., McMillan, M. and Joughin, I.. 2009. Greenland ice sheet motion coupled with daily melting in late summer. Geophys. Res. Lett., 36(1), L01501. (10.1029/ 2008GL035758.)
Spring, U. and Hutter, K.. 1981. Numerical studies of jökulhlaups. Cold Reg. Sci. Technol., 4(3), 227244.
Sugiyama, S. and Gudmundsson, G.H.. 2004. Short-term variations in glacier flow controlled by subglacial water pressure at Lauteraargletscher, Bernese Alps, Switzerland. J. Glaciol., 50(170), 353362.
Truffer, M., Motyka, R.J., Harrison, W.D., Echelmeyer, K.A., Fisk, B. and Tulaczyk, S.. 1999. Subglacial drilling at Black Rapids Glacier, Alaska, U.S.A.: drilling method and sample descriptions. J. Glaciol., 45(151), 495505.
Truffer, M., Echelmeyer, K.A. and Harrison, W.D.. 2001. Implications of till deformation on glacier dynamics. J. Glaciol., 47(156), 123134.
Van de Wal, R.S.W. and 6 others. 2008. Large and rapid melt-induced velocity changes in the ablation zone of the Greenland Ice Sheet. Science, 321(5885), 111113.
Walder, J.S. 1986. Hydraulics of subglacial cavities. J. Glaciol., 32(112), 439445.
Waller, R.I., van Dijk, T.A.G.P. and Knudsen, Ó.. 2008. Subglacial bedforms and conditions associated with the 1991 surge of Skeiðarárjökull, Iceland. Boreas, 37(2), 179194.
Weertman, J. 1957. On the sliding of glaciers. J. Glaciol., 3(21), 3338.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Glaciology
  • ISSN: 0022-1430
  • EISSN: 1727-5652
  • URL: /core/journals/journal-of-glaciology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed