Abstract
Current ice loss from the West Antarctic Ice Sheet (WAIS) accounts for about ten per cent of observed global sea-level rise1. Losses are dominated by dynamic thinning, in which forcings by oceanic or atmospheric perturbations to the ice margin lead to an accelerated thinning of ice along the coastline2,3,4,5. Although central to improving projections of future ice-sheet contributions to global sea-level rise, the incorporation of dynamic thinning into models has been restricted by lack of knowledge of basal topography and subglacial geology so that the rate and ultimate extent of potential WAIS retreat remains difficult to quantify. Here we report the discovery of a subglacial basin under Ferrigno Ice Stream up to 1.5 kilometres deep that connects the ice-sheet interior to the Bellingshausen Sea margin, and whose existence profoundly affects ice loss. We use a suite of ice-penetrating radar, magnetic and gravity measurements to propose a rift origin for the basin in association with the wider development of the West Antarctic rift system. The Ferrigno rift, overdeepened by glacial erosion, is a conduit which fed a major palaeo-ice stream on the adjacent continental shelf during glacial maxima6. The palaeo-ice stream, in turn, eroded the ‘Belgica’ trough, which today routes warm open-ocean water back to the ice front7 to reinforce dynamic thinning. We show that dynamic thinning from both the Bellingshausen and Amundsen Sea region is being steered back to the ice-sheet interior along rift basins. We conclude that rift basins that cut across the WAIS margin can rapidly transmit coastally perturbed change inland, thereby promoting ice-sheet instability.
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References
Meier, M. F. et al. Glaciers dominate eustatic sea-level rise in the 21st century. Science 317, 1064–1067 (2007)
Pritchard, H. D., Arthern, R. J., Vaughan, D. G. & Edwards, L. A. Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets. Nature 461, 971–975 (2009)
Wingham, D. J., Wallis, D. W. & Shepherd, A. Spatial and temporal evolution of Pine Island Glacier thinning, 1995–2006. Geophys. Res. Lett. 36, L17501 (2009)
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, L05503 (2011)
Jacobs, S. S., Jenkins, A., Giulivi, C. F. & Dutrieux, P. Stronger ocean circulation and increased melting under Pine Island Glacier ice shelf. Nature Geosci. 4, 519–523 (2011)
Ó Cofaigh, C. et al. Flow of the West Antarctic Ice Sheet on the continental margin of the Bellingshausen Sea at the Last Glacial Maximum. J. Geophys. Res. 110, B11103 (2005)
Holland, P. R., Jenkins, A. & Holland, D. M. Ice and ocean processes in the Bellingshausen Sea, Antarctica. J. Geophys. Res. 115, C05020 (2010)
Chen, J. L., Wilson, C. R., Blankenship, D. & Tapley, B. D. Accelerated Antarctic ice loss from satellite gravity measurements. Nature Geosci. 2, 859–862 (2009)
Schoof, C. Ice sheet grounding line dynamics: steady states, stability, and hysteresis. J. Geophys. Res. 112, F03S28 (2007)
Blankenship, D. D. et al. in The West Antarctic Ice Sheet: Behaviour and Environment (eds Alley, R. B. & Bindschadler, R. A. ) Antarct. Res. Ser. 77, 105–121 (AGU, 2001)
Winberry, J. P. & Anandakrishnan, S. Crustal structure of the West Antarctic Rift System and Marie Byrd Land hotpsot. Geology 32, 977–980 (2004)
Dalziel, I. W. D. On the extent of the active West Antarctic Rift System. Terra Antarctica Rep. 12, 193–202 (2006)
Anandakrishnan, S., Blankenship, D. D., Alley, R. B. & Stoffa, P. L. Influence of subglacial geology on the position of a West Antarctic ice stream from seismic observations. Nature 394, 62–65 (1998)
Studinger, M. et al. Subglacial sediments: a regional geological template for ice flow in West Antarctica. Geophys. Res. Lett. 28, 3493–3496 (2001)
Maule, C. F., Purucker, M. E., Olsen, N. & Mosegard, K. Heat flux anomalies in Antarctica revealed by satellite magnetic data. Science 309, 464–467 (2005)
Müller, R. D., Gohl, K., Cande, S. C., Goncharov, A. & Golynsky, A. V. Eocene to Miocene geometry of the West Antarctic Rift System. Aust. J. Earth Sci. 54, 1033–1045 (2007)
LeMasurier, W. E. Neogene extension and basin overdeepening in the West Antarctic rift inferred from comparisons with the East African rift and other analogs. Geology 36, 247–250 (2008)
Harbor, J. M. Numerical modeling of the development of U-shaped valleys by glacial erosion. Geol. Soc. Am. Bull. 104, 1364–1375 (1992)
Olsen, K. H. & Morgan, P. in Continental Rifts: Evolution, Structure, Tectonics (ed. Olsen, K. H. ) 3–26 (Elsevier, 2006)
Maslanyj, M. P. & Storey, B. C. Regional aeromagnetic anomalies in Ellsworth Land: crustal structure and Mesozoic microplate boundaries within West Antarctica. Tectonics 9, 1515–1532 (1990)
Siddoway, C. S. in Antarctica: a Keystone in a Changing World (eds Cooper, A. K. et al.), Proc. 10th Int. Symp. Ant. Sci. 91–114 (The National Academies Press, 2008)
Gohl, K. Basement control on past ice sheet dynamics in the Amundsen Sea Embayment, West Antarctica. Palaeogeogr. Palaeoclim. Palaeoecol. 335/6, 35–41 (2012)
Jordan, T. A. et al. Aerogravity evidence for major crustal thinning under the Pine Island Glacier region (West Antarctica). Geol. Soc. Am. Bull. 122, 714–726 (2010)
Granot, R., Cande, S. C., Stock, J. M., Davey, F. J. & Clayton, R. W. Postspreading rifting in the Adare Basin, Antarctica: regional tectonic consequences. Geochem. Geophys. Geosyst. 11, Q08005 (2010)
Schröder, H., Paulsen, T. & Wonik, T. Thermal properties of the AND-2A borehole in the southern Victoria Land Basin, McMurdo Sound, Antarctica. Geosphere 7, 1324–1330 (2011)
Taylor, J. et al. Topographic controls on post-Oligocene changes in ice-sheet dynamics, Prydz Bay region, East Antarctica. Geology 32, 197–200 (2004)
De Angelis, H. & Kleman, J. Palaeo-ice streams in the Foxe/Baffin sector of the Laurentide Ice Sheet. Quat. Sci. Rev. 26, 1313–1331 (2007)
Rignot, E. et al. Recent Antarctic ice mass loss from radar interferometry and regional climate modelling. Nature Geosci. 1, 106–110 (2008)
Vaughan, D. G. et al. New boundary conditions for the West Antarctic ice sheet: subglacial topography beneath Pine Island Glacier. Geophys. Res. Lett. 33, L09501 (2006)
Graham, A. G. C., Nitsche, F. O. & Larter, R. D. An improved bathymetry compilation for the Bellingshausen Sea, Antarctica, to inform ice-sheet and ocean models. Cryosphere 5, 95–106 (2011)
Acknowledgements
This study was supported by the Natural Environment Research Council (NERC/AFI/CGS/11/60) and British Antarctic Survey research programme Polar Science for Planet Earth. We acknowledge NASA Operation IceBridge for airborne ice-sounding data, A. G. C. Graham for bathymetry data and C. Griffiths for field assistance.
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All authors contributed to research design. R.G.B. performed the field research. R.G.B. and E.C.K. processed radar data. F.F. analysed and interpreted the aeromagnetic and aerogravity data; all authors participated in data discussion and interpretation; R.G.B. and F.F. wrote the manuscript; and all authors contributed substantial comments and editorial revisions.
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Bingham, R., Ferraccioli, F., King, E. et al. Inland thinning of West Antarctic Ice Sheet steered along subglacial rifts. Nature 487, 468–471 (2012). https://doi.org/10.1038/nature11292
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DOI: https://doi.org/10.1038/nature11292
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