Fast-flowing ice streams transport ice from the interior of West Antarctica to the ocean, and fluctuations in their activity control the mass balance of the ice sheet. The mass balance of the Ross Sea sector of the West Antarctic ice sheet is now positive—that is, it is growing—mainly because one of the ice streams (ice stream C) slowed down about 150 years ago1. Here we present evidence from both surface measurements and remote sensing that demonstrates the highly dynamic nature of the Ross drainage system. We show that the flow in an area that once discharged into ice stream C has changed direction, now draining into the Whillans ice stream (formerly ice stream B). This switch in flow direction is a result of continuing thinning of the Whillans ice stream and recent thickening of ice stream C. Further abrupt reorganization of the activity and configuration of the ice streams over short timescales is to be expected in the future as the surface topography of the ice sheet responds to the combined effects of internal dynamics and long-term climate change. We suggest that caution is needed when using observations of short-term mass changes to draw conclusions about the large-scale mass balance of the ice sheet.
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Joughin, I. & Tulaczk, S. Positive mass balance of the Ross Ice Streams, West Antarctica. Science 295, 476–480 (2002)
Denton, G. H. & Hughes, T. J. Reconstructing the Antarctic Ice Sheet at the Last Glacial Maximum. Quat. Sci. Rev. 21, 193–202 (2002)
Shipp, S., Anderson, J. & Domack, E. Late Pleistocene-Holocene retreat of the West Antarctic ice-sheet system in the Ross Sea: Part 1 – Geophysical results. Geol. Soc. Am. Bull. 111, 1486–1516 (1999)
Conway, H., Hall, B. L., Denton, G. H., Gades, A. M. & Waddington, E. D. Past and future grounding-line retreat of the West Antarctic Ice Sheet. Science 286, 280–283 (1999)
Bentley, C. R. West Antarctic Ice Sheet collapse? Science 276, 663–664 (1997)
Oppenheimer, M. Global warming and the stability of the West Antarctic Ice Sheet. Nature 393, 325–332 (1998)
Bindschadler, R. A. Future of the West Antarctic Ice Sheet. Science 282, 428–429 (1998)
Kamb, B. in The West Antarctic Ice Sheet: Behavior and Environment (eds Alley, R. B. & Bindschadler, R. A.) Antarctic Research Series 77 157–199 (American Geophysical Union, Washington DC, 2001)
Tulaczyk, S., Kamb, B. & Engelhardt, H. Basal mechanics of Ice Stream B, West Antarctica 2. Undrained plastic bed model. J. Geophys. Res. 105, 483–494 (2000)
Raymond, C. F. Energy balance of ice streams. J. Glaciol. 46, 665–674 (2000)
Whillans, I. M., Bentley, C. R. & van der Veen, C. J. in The West Antarctic Ice Sheet: Behavior and Environment (eds Alley, R. B. & Bindschadler, R. A.) Antarctic Research Series 77 257–281 (American Geophysical Union, Washington DC, 2001)
Vaughan, D. G. Relating the occurrence of crevasses to surface strain rates. J. Glaciol. 39, 255–266 (1993)
Jacobel, R. W., Scambos, T. A., Nereson, N. A. & Raymond, C. F. Changes in the margin of Ice Stream C, Antarctica. J. Glaciol. 46, 102–110 (2000)
Retzlaff, R. & Bentley, C. R. Timing of stagnation of Ice Stream C, West Antarctica from short-pulse-radar studies of buried crevasses. J. Glaciol. 39, 553–561 (1993)
Fahnestock, M. A., Scambos, T. A., Bindschadler, R. A. & Kvaran, G. A millennium of variable ice-flow recorded by the Ross Ice Shelf, Antarctica. J. Glaciol. 46, 652–664 (2000)
Bindschadler, R. & Vornberger, P. Changes in the West Antarctic Ice Sheet since 1963 from declassified satellite photography. Science 279, 689–692 (1998)
Clarke, T. S., Liu, C., Lord, N. E. & Bentley, C. R. Evidence for a recently abandoned shear margin adjacent to Ice Stream B2, Antarctica, from ice-penetrating radar measurements. J. Geophys. Res. 105, 13409–13422 (2000)
Catania, G. & Paola, C. Braiding under glass. Geology 29, 259–262 (2001)
Murray, A. B. & Paola, C. A cellular model of braided rivers. Nature 371, 54–57 (1994)
Alley, R. B. & Bentley, C. R. Ice-core analysis on the Siple Coast of West Antarctica. Ann. Glaciol. 11, 1–7 (1988)
Nereson, N. A. & Raymond, C. F. The elevation history of ice streams and the spatial accumulation pattern along the Siple Coast of West Antarctica inferred from ground-based radar data from three inter-ice-stream ridges. J. Glaciol. 47, 303–313 (2001)
Shabtaie, S., Bentley, C. R., Bindschadler, R. A. & MacAyeal, D. R. Mass-balance studies of Ice Streams A, B and C, West Antarctica, and possible surging behavior of Ice Stream B. Ann. Glaciol. 11, 165–172 (1988)
Price, S. F., Bindschadler, R. A., Hulbe, C. L. & Joughin, I. R. Post-stagnation behavior in the upstream regions of Ice Stream C, West Antarctica. J. Glaciol. 47, 283–294 (2001)
Weertman, J. General theory of water flow at the base of a glacier or ice sheet. Rev. Geophys. Space Phys. 10, 287–333 (1972)
Rose, K. E. Characteristics of ice flow in Marie Byrd Land, Antarctica. J. Glaciol. 24, 63–74 (1979)
Anandakrishnan, S. & Alley, R. B. Stagnation of Ice Stream C, West Antarctica by water piracy. Geophys. Res. Lett. 24, 265–268 (1997)
Paterson, W. S. B. The Physics of Glaciers (Pergamon, Oxford, 1994)
Jezek, K. C. Glaciological properties of the Antarctic ice sheet from RADARSAT-1 synthetic aperture imagery. Ann. Glaciol. 27, 33–40 (1999)
Scambos, T. A. & Fahnestock, M. A. Improving digital elevation models over ice sheets using AVHRR-based photoclinometry. J. Glaciol. 44, 97–103 (1998)
We thank Raytheon Polar Services for logistical support in Antarctica, and C. R. Bentley, M. Conway, N. Lord and B. Smith for contributions. This work was supported by the US National Science Foundation.
The authors declare that they have no competing financial interests.
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Conway, H., Catania, G., Raymond, C. et al. Switch of flow direction in an Antarctic ice stream. Nature 419, 465–467 (2002). https://doi.org/10.1038/nature01081
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