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Buoyant flexure and basal crevassing in dynamic mass loss at Helheim Glacier

Abstract

Iceberg calving accounts for a significant proportion of annual mass loss from marine-terminating glaciers1,2 and may have been a factor in the rapid demise of ancient ice sheets3. The largest contributions from the main outlet glaciers of the Greenland ice sheet to sea-level rise over the next two centuries have been projected to be dynamic in origin, that is, driven by glacier flow and calving4. However, present physical models remain a coarse approximation of real calving mechanisms because models are poorly constrained by sparse glacier geometry observations5. Here we present a record of daily digital elevation models from the calving margin of Greenland’s Helheim Glacier at a high spatial resolution. Our digital elevation models are derived from stereo terrestrial photography taken over the summers of 2010 and 2011. We find that during these two summers dynamic mass loss at Helheim Glacier was dominated by calving events exceeding 1 km3 that were the result of buoyant flexure and the propagation of basal crevasses. We suggest that this buoyancy-driven mechanism for calving may be common elsewhere in Greenland and could be a first-order control on the ice sheet’s future contribution to sea-level rise.

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Figure 1: Camera locations with differenced DEMs.
Figure 2: Elevation profiles along Helheim’s central flowline.
Figure 3: Image feature tracking before 12 July 2010 18:30 UTC calving event.
Figure 4: Surface profiles and bed topography.

References

  1. Hagen, J. O., Kohler, J., Melvold, K. & Winther, J. G. Glaciers in Svalbard: Mass balance, runoff and freshwater flux. Polar Res. 22, 145–159 (2003).

    Article  Google Scholar 

  2. Rignot, E. & Kanagaratnam, P. Changes in the velocity structure of the Greenland ice sheet. Science 311, 986–990 (2006).

    Article  Google Scholar 

  3. Van der Veen, C. J. Calving glaciers. Prog. Phys. Geogr. 26, 96–122 (2002).

    Article  Google Scholar 

  4. Nick, F. M. et al. Future sea-level rise from Greenland’s main outlet glaciers in a warming climate. Nature 497, 235–238 (2013).

    Article  Google Scholar 

  5. Nick, F. M., Van der Veen, C. J., Vieli, A. & Benn, D. I. A physically based calving model applied to marine outlet glaciers and implications for the glacier dynamics. J. Glaciol. 56, 781–794 (2010).

    Article  Google Scholar 

  6. Meier, M. F. & Post, A. Fast tidewater glaciers. J. Geophys. Res. 92, 9051–9058 (1987).

    Article  Google Scholar 

  7. Van der Veen, C. J. Tidewater calving. J. Glaciol. 42, 375–385 (1996).

    Article  Google Scholar 

  8. Benn, D. I., Hulton, N. R. J. & Mottram, R. H. ‘Calving laws’, ‘sliding laws’ and the stability of tidewater glaciers. Ann. Glaciol. 46, 123–130 (2007).

    Article  Google Scholar 

  9. Vieli, A. & Nick, F. M. Understanding and modelling rapid dynamic changes of tidewater outlet glaciers: Issues and implications. Surv. Geophys. 32, 437–458 (2011).

    Article  Google Scholar 

  10. Cook, S., Zwinger, T., Rutt, I. C., O’Neel, S. & Murray, T. Testing the effect of water in crevasses on a physically based calving model. Ann. Glaciol. 53, 90–96 (2012).

    Article  Google Scholar 

  11. Vieli, A., Jania, J. & Kolondra, L. The retreat of a tidewater glacier: Observations and model calculations on Hansbreen, Spitsbergen. J. Glaciol. 48, 592–600 (2002).

    Article  Google Scholar 

  12. Joughin, I. et al. Ice-front variation and tidewater behavior on Helheim and Kangerdlugssuaq Glaciers, Greenland. J. Geophys. Res. 113, F01004 (2008).

    Google Scholar 

  13. De Juan Verger, J. Tidewater Glacier Flow of Helheim Glacier, Greenland, 2006–2008, Using High-Rate GPS PhD thesis, Univ. Barcelona (2011)

  14. Benn, D. I., Warren, C. R. & Mottram, R. H. Calving processes and the dynamics of calving glaciers. Earth Sci. Rev. 82, 143–179 (2007).

    Article  Google Scholar 

  15. Boyce, E. S., Motyka, R. J. & Truffer, M. Flotation and retreat of a lake-calving terminus, Mendenhall Glacier, southeast Alaska, USA. J. Glaciol. 53, 211–224 (2007).

    Article  Google Scholar 

  16. Andersen, M. L. et al. Spatial and temporal melt variability at Helheim Glacier, East Greenland, and its effect on ice dynamics. J. Geophys. Res. 115, F04041 (2010).

    Article  Google Scholar 

  17. Bevan, S. L., Luckman, A. J. & Murray, T. Glacier dynamics over the last quarter of a century at Helheim, Kangerdlugssuaq and 14 other major Greenland outlet glaciers. Cryosphere 6, 923–937 (2012).

    Article  Google Scholar 

  18. Schild, K. M. & Hamilton, G. S. Seasonal variations of outlet glacier terminus position in Greenland. J. Glaciol. 59, 759–770 (2013).

    Article  Google Scholar 

  19. Vaughan, D. G. Tidal flexure at ice shelf margins. J. Geophys. Res. 100, 6213–6224 (1995).

    Article  Google Scholar 

  20. Durand, G., Gagliardini, O., de Fleurian, B., Zwinger, T. & Le Meur, E. Marine ice sheet dynamics: Hysteresis and neutral equilibrium. J. Geophys. Res. 114, F03009 (2009).

    Google Scholar 

  21. Van der Veen, C. J. Fracture mechanics approach to penetration of bottom crevasses on glaciers. Cold Reg. Sci. Technol. 27, 213–223 (1998).

    Article  Google Scholar 

  22. Amundson, J. M. et al. Ice mélange dynamics and implications for terminus stability, Jakobshavn Isbrae Greenland. J. Geophys. Res. 115, F01005 (2010).

    Article  Google Scholar 

  23. O’Leary, M. & Christoffersen, P. Calving on tidewater glaciers amplified by submarine frontal melting. Cryosphere 7, 119–128 (2012).

    Google Scholar 

  24. James, T. D., Murray, T., Barrand, N. E. & Barr, S. L. Extracting photogrammetric ground control from lidar DEMs for change detection. Photogramm. Rec. 21, 310–326 (2006).

    Google Scholar 

  25. James, T. D. et al. Observations of enhanced thinning in the upper reaches of Svalbard glaciers. Cryosphere 6, 1369–1381 (2012).

    Article  Google Scholar 

  26. Ayoub, F., Leprince, S. & Avouac, J. P. Co-registration and correlation of aerial photographs for ground deformation measurements. ISPRS J. Photogramm. 64, 551–560 (2009).

    Article  Google Scholar 

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Acknowledgements

T.D.J. was supported by The Leverhulme Trust Research Leadership Award GLIMPSE Project (F/00391/J) and the Climate Consortium for Wales (C3W). N.S. is supported by NERC (NE/I007148/1). N.S. and K.S. were also supported by The Leverhulme Trust. M.O. was supported by the Welsh Institute for Sustainable Environments (WISE). Field work was funded by The Leverhulme Trust, a Royal Geographical Society-Institute of British Geographers EPSRC Geographical Research Grant (20IGC 01/10), NERC (NE/I007148/1) and the European Union Seventh Framework Programme [FP7/2007–2013] under grant agreement number 262693 [INTERACT]. ASTER imagery were acquired through NASA’s Land Processes Distributed Active Archive Center (LP DAAC) with thanks to Operation IceBridge and B. Krabill. The authors would also like to acknowledge software support from TerraDat Geophysics (ImageMaster) and F. Ayoub (COSI-Corr). We acknowledge the use of bed data from CReSIS generated with support from NSF grant ANT-0424589 and NASA grant NNX10AT68G and their assistance with data analysis.

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T.D.J. developed the methodology, undertook the analysis and interpretation and prepared the manuscript. T.M. was the grant-holder and contributed to data collection and interpretation. N.S. and K.S. contributed to methodological development and data collection. M.O. contributed to the interpretation. All authors contributed to the manuscript preparation.

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Correspondence to Timothy D. James.

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The authors declare no competing financial interests.

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James, T., Murray, T., Selmes, N. et al. Buoyant flexure and basal crevassing in dynamic mass loss at Helheim Glacier. Nature Geosci 7, 593–596 (2014). https://doi.org/10.1038/ngeo2204

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