Abstract
Over the next century, one of the largest contributions to sea level rise will come from ice sheets and glaciers calving ice into the ocean1. Factors controlling the rapid and nonlinear variations in calving fluxes are poorly understood, and therefore difficult to include in prognostic climate-forced land-ice models. Here we analyse globally distributed calving data sets from Svalbard, Alaska (USA), Greenland and Antarctica in combination with simulations from a first-principles, particle-based numerical calving model to investigate the size and inter-event time of calving events. We find that calving events triggered by the brittle fracture of glacier ice are governed by the same power-law distributions as avalanches in the canonical Abelian sandpile model2. This similarity suggests that calving termini behave as self-organized critical systems that readily flip between states of sub-critical advance and super-critical retreat in response to changes in climate and geometric conditions. Observations of sudden ice-shelf collapse and tidewater glacier retreat in response to gradual warming of their environment3 are consistent with a system fluctuating around its critical point in response to changing external forcing. We propose that self-organized criticality provides a yet unexplored framework for investigations into calving and projections of sea level rise.
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Change history
18 November 2014
In the version of this Letter originally published online, the following sentence should have appeared in the Acknowledgements section: "The simulated graphics have been rendered by J. Hokkanen (CSC-IT Centre for Science)". This error has been corrected in all versions of the Letter.
References
Moore, J. C., Grinsted, A., Zwinger, T. & Jevrejeva, S. Semi-empirical and process-based global sea level projections. Rev. Geophys. 51, 484–522 (2013).
Bak, P., Tang, C. & Wiesenfeld, K. Self-organized criticality: An explanation of the 1/f noise. Phys. Rev. Lett. 59, 381–384 (1987).
Luckman, A., Murray, T., de Lange, R. & Hanna, E. Rapid and synchronous ice-dynamic changes in East Greenland. Geophys. Res. Lett. 33, L03503 (2006).
Anthoff, D., Nicholls, R. J., Tol, R. S. J. & Vafeidis, A. T. Global and Regional Exposure to Large Rises in Sea-Level: A Sensitivity Analysis (Tyndall Centre for Climate Change Research, 2006).
Rignot, E., Velicogna, I., van den Broeke, M. R., Monaghan, A. & Lenaerts, J. Acceleration of the contribution of the Greenland and Antarctic ice sheets to sea level rise. Geophys. Res. Lett. 38, 1–5 (2011).
Rignot, E., Jacobs, S., Mouginot, J. & Scheuchl, B. Ice-shelf melting around Antarctica. Science 341, 266–270 (2013).
Bindschadler, R. A. et al. Ice-sheet model sensitivities to environmental forcing and their use in projecting future sea level (the SeaRISE project). J. Glaciol. 59, 195–224 (2013).
Main, I. Is the reliable prediction of individual earthquakes a realistic scientific goal? Nature Debateshttp://www.nature.com/nature/debates/earthquake (1999).
Fineberg, J. & Marder, M. Instability in dynamic fracture. Phys. Rep. 313, 2–108 (1999).
Åström, J. A. Statistical models of brittle fragmentation. Adv. Phys. 55, 247–278 (2006).
Kekäläinen, P., Åström, J. A. & Timonen, J. Solution for the fragment-size distribution in a crack-branching model of fragmentation. Phys. Rev. E 76, 026112 (2007).
Bak, P. How Nature Works: The Science of Self-Organized Criticality (Springer, 1996).
Jensen, H. J. Self-Organized Criticality (Cambridge Univ. Press, 1998).
Dhar, D. The Abelian sandpile and related models. Physica A 263, 4–25 (1999).
Dhar, D. Theoretical studies of self-organized criticality. Physica A 369, 29–70 (2006).
Paczuski, M., Boettcher, S. & Baiesi, M. Interoccurrence times in the Bak–Tang–Wiesenfeld sandpile model: A comparison with the observed statistics of solar flares. Phys. Rev. Lett. 95, 181102–181105 (2005).
Åström, J. A. et al. A particle based simulation model for glacier dynamics. Cryosphere 7, 1591–1602 (2013).
Crocker, G. B. Size distributions of bergy bits and growlers calved from deteriorating icebergs. Cold Reg. Sci. Technol. 22, 113–119 (1993).
Savage, S. B., Crocker, G. B., Sayed, M. & Carriers, T. Size distribution of small ice pieces calved from icebergs. Cold Reg. Sci. Technol. 31, 163–172 (2000).
Scambos, T. A., Hulbe, C. L. & Fahnestock, M. A. Climate-induced ice shelf disintegration in the Antarctic Peninsula. Antarct. Res. Ser. 79, 79–92 (2003).
Bassis, J. N. & Jacobs, S. Diverse calving patterns linked to glacier geometry. Nature Geosci. 6, 833–836 (2013).
Amundson, J. A. & Truffer, M. A unifying framework for iceberg-calving models. J. Glaciol. 56, 822–830 (2010).
Bassis, J. N. The statistical physics of iceberg calving and the emergence of universal calving laws. J. Glaciol. 57, 3–16 (2011).
Gagliardini, O. et al. Capabilities and performance of Elmer/Ice, a new-generation ice sheet model. Geosci. Model Dev. 6, 1299–1318 (2013).
Chapuis, A. & Tetzlaff, T. The variability of tidewater-glacier calving: Origin of event-size and interval distributions. J. Glaciol. 60, 622–634 (2014).
Padman, L. & Erofeeva, S. A. Barotropic inverse tidal model for the Arctic Ocean. Geophys. Res. Lett. 31, L02303 (2004).
Acknowledgements
We thank J. A. Jania, D. Ignatiuk, M. Laska, B. Luks, M. Ciepły, J. Halat, A. Piechota, M. Sund and crews from the Polish Polar Station in Hornsund (Institute of Geophysics, Polish Academy of Sciences) for their help collecting data at Paierlbreen; A. Hodson and D. Benn for their help at Tunabreen; and G. Hamilton for suggesting the Greenland data. Kronebreen geometry was provided by the Norwegian Polar Institute. The European Space Agency provided ENVISAT ASAR imagery for the Antarctic ice shelves. Support provided by: SvalGlac (Paierlbreen); SVALI (Tunabreen); US Geological Survey Climate and Land Use Change, Department of Interior Climate Science Center, and Prince William Sound Regional Citizens’ Advisory Council (Columbia Glacier); NSF-EAR-0810313 (Yahtse Glacier); National Basic Research Program of China (2012CB957704 and 2015CB953600) and Fundamental Research Funds for the Central Universities of China (2013NT5) (Antarctic ice shelves). This publication is contribution number 33 of the Nordic Centre of Excellence SVALI, ‘Stability and Variations of Arctic Land Ice’, funded by the Nordic Top-level Research Initiative (TRI). The simulated graphics have been rendered by J. Hokkanen (CSC–IT Centre for Science).
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Contributions
J.A.Å. and T.I.R. constructed the calving model. J.A.Å. assembled and interpreted the calving observations. Co-authors collected, processed or interpreted the calving observations, as follows: Columbia (E.Z.W. and S.O’.N.), Yahtse (T.C.B. and S.O’.N.), Tunabreen (D.V.), Paierlbreen (M.S. and E.Z.W.), Helheim and Kangerdlugssuaq (M.S.), and Antarctic ice shelves (Y.L. and J.C.M.). T.Z. performed the ice-flow model simulations. E.Z.W. compiled the Calving Event Catalogue. All authors have contributed to, seen and approved the manuscript.
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Supplementary information
Supplementary Information
Supplementary Information (Methods 1, Methods 2 and Discussion) (PDF 12013 kb)
Supplementary Movie 1
2D Glacier in Deep Water (MOV 5049 kb)
Supplementary Movie 2
2D Glacier in Shallow Water (MOV 1971 kb)
Supplementary Movie 3
3D Glacier in Critical State (MOV 21643 kb)
Supplementary Movie 4
3D Glacier in Super-critical State (MOV 26149 kb)
Supplementary Information
Calving Event Catalogue (PDF 555 kb)
Supplementary Information
Supplementary Data (described in the Calving Event Catalogue) (ZIP 2364 kb)
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Åström, J., Vallot, D., Schäfer, M. et al. Termini of calving glaciers as self-organized critical systems. Nature Geosci 7, 874–878 (2014). https://doi.org/10.1038/ngeo2290
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DOI: https://doi.org/10.1038/ngeo2290