Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Impacts of warm water on Antarctic ice shelf stability through basal channel formation

Nature Geoscience volume 9, pages 290–293 (2016)Cite this article

Subjects

Abstract

Antarctica’s ice shelves provide resistance to the flow of grounded ice towards the ocean. If this resistance is decreased as a result of ice shelf thinning or disintegration1, acceleration of grounded ice can occur, increasing rates of sea-level rise. Loss of ice shelf mass is accelerating, especially in West Antarctica, where warm seawater is reaching ocean cavities beneath ice shelves2. Here we use satellite imagery, airborne ice-penetrating radar and satellite laser altimetry spanning the period from 2002 to 2014 to map extensive basal channels in the ice shelves surrounding Antarctica. The highest density of basal channels is found in West Antarctic ice shelves. Within the channels, warm water flows northwards, eroding the ice shelf base and driving channel evolution on annual to decadal timescales. Our observations show that basal channels are associated with the development of new zones of crevassing, suggesting that these channels may cause ice fracture. We conclude that basal channels can form and grow quickly as a result of warm ocean water intrusion, and that they can structurally weaken ice shelves, potentially leading to rapid ice shelf loss in some areas.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

Buy

All prices are NET prices.

Figure 1: Distribution and examples of basal channel types around the Antarctic continent.
Figure 2: Growing channel on the Getz Ice Shelf.
Figure 3: Ice shelf fracture at the tip of the Scott Peninsula, Getz Ice Shelf.

References

  1. Scambos, T., Hulbe, C. & Fahnestock, M. Climate-induced ice shelf disintegration in the Antarctic Peninsula. Antarct. Res. Ser. 76, 335–347 (2003).

    Google Scholar 

  2. Paolo, F. S., Fricker, H. A. & Padman, L. Volume loss from Antarctic ice shelves is accelerating. Science 348, 899–903 (2015).

    Article  Google Scholar 

  3. Rignot, E. & Steffen, K. Channelized bottom melting and stability of floating ice shelves. Geophys. Res. Lett. 35, L02503 (2008).

    Google Scholar 

  4. Dutrieux, P. et al. Basal terraces on melting ice shelves. Geophys. Res. Lett. 41, 5506–5513 (2014).

    Article  Google Scholar 

  5. Bindschadler, R., Vaughan, D. G. & Vornberger, P. Variability of basal melt beneath the Pine Island Glacier Ice Shelf, West Antarctica. J. Glaciol. 57, 581–595 (2011).

    Article  Google Scholar 

  6. Mankoff, K. D., Jacobs, S. S., Tulaczyk, S. M. & Stammerjohn, S. E. The role of Pine Island Glacier Ice Shelf basal channels in deep-water upwelling, polynyas and ocean circulation in Pine Island Bay, Antarctica. Ann. Glaciol. 53, 123–128 (2012).

    Article  Google Scholar 

  7. Vaughan, D. G. et al. Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica. J. Geophys. Res. 117, F03012 (2012).

    Article  Google Scholar 

  8. Dutrieux, P. et al. Pine Island Glacier Ice Shelf melt distributed at kilometre scales. Cryosphere 7, 1543–1555 (2013).

    Article  Google Scholar 

  9. Drews, R. Evolution of ice-shelf channels in Antarctic ice shelves. Cryosphere 9, 1169–1181 (2015).

    Article  Google Scholar 

  10. Langley, K. et al. Complex network of channels beneath an Antarctic ice shelf. Geophys. Res. Lett. 41, 1209–1215 (2014).

    Article  Google Scholar 

  11. Le Brocq, A. M. et al. Evidence from ice shelves for channelized meltwater flow beneath the Antarctic Ice Sheet. Nature Geosci. 6, 945–948 (2013).

    Article  Google Scholar 

  12. Marsh, O. J. et al. High basal melt rates forming a channel at the grounding line of Ross Ice Shelf, Antarctica. Geophys. Res. Lett. 43, 250–255 (2015).

    Article  Google Scholar 

  13. Fricker, H. A. et al. Mapping the grounding zone of the Amery Ice Shelf, East Antarctica using InSAR, MODIS and ICESat. Antarct. Sci. 21, 515–532 (2009).

    Article  Google Scholar 

  14. Scambos, T. A., Haran, T. M. & Fahnestock, M. A. MODIS-based Mosaic of Antarctica (MOA) data sets: continent-wide surface morphology and snow grain size. Remote Sens. Cryosphere 111, 242–257 (2007).

    Google Scholar 

  15. Le Brocq, A., Payne, A. J., Siegert, M. J. & Alley, R. B. A subglacial water-flow model for West Antarctica. J. Glaciol. 55, 879–888 (2009).

    Article  Google Scholar 

  16. Sergienko, O. V. Basal channels on ice shelves. J. Geophys. Res. 118, 1342–1355 (2013).

    Article  Google Scholar 

  17. Rignot, E., Jacobs, S., Mouginot, J. & Scheuchl, B. Ice shelf melting around Antarctica. Science 341, 266–270 (2013).

    Article  Google Scholar 

  18. Pritchard, H. D. et al. Antarctic ice-sheet loss driven by basal melting of ice shelves. Nature 484, 502–505 (2012).

    Article  Google Scholar 

  19. Fretwell, P. et al. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica. Cryosphere 7, 375–393 (2013).

    Article  Google Scholar 

  20. Jacobs, S. et al. The Amundsen Sea and the Antarctic Ice Sheet. Oceanography 25, 154–163 (2012).

    Article  Google Scholar 

  21. Holland, P. R. A model of tidally dominated ocean processes near ice shelf grounding lines. J. Geophys. Res. 113, C11002 (2008).

    Article  Google Scholar 

  22. Griggs, J. A. & Bamber, J. L. Antarctic ice-shelf thickness from satellite radar altimetry. J. Glaciol. 57, 485–498 (2011).

    Article  Google Scholar 

  23. Gladish, C. V., Holland, D. M., Holland, P. R. & Price, S. F. Ice-shelf basal channels in a coupled ice/ocean model. J. Glaciol. 58, 1227–1244 (2012).

    Article  Google Scholar 

  24. Millgate, T., Holland, P. R. & Jenkins, A. The effect of basal channels on oceanic ice-shelf melting. J. Geophys. Res. 118, 6951–6964 (2013).

    Article  Google Scholar 

  25. Khazendar, E., Rignot, E. & Larour, E. Larsen B Ice Shelf rheology preceding its disintegration inferred by a control method. Geophys. Res. Lett. 34, L19503 (2007).

    Article  Google Scholar 

  26. Schmidtko, S., Heywood, K. J., Thompson, A. F. & Aoki, S. Multidecadal warming of Antarctic waters. Science 346, 1227–1231 (2014).

    Article  Google Scholar 

  27. Borsa, A. A., Moholdt, G., Fricker, H. A. & Brunt, K. M. A range correction for ICESat and its potential impact on ice-sheet mass balance studies. Cryosphere 8, 345–357 (2014).

    Article  Google Scholar 

  28. Fricker, H. A. & Padman, L. Ice shelf grounding zone structure from ICESat laser altimetry. Geophys. Res. Lett. 33, L15502 (2006).

    Article  Google Scholar 

  29. Padman, L., Fricker, H. A., Coleman, R., Howard, S. & Erofeeva, L. A new tide model for the Antarctic ice shelves and seas. Ann. Glaciol. 34, 247–254 (2002).

    Article  Google Scholar 

Download references

Acknowledgements

This study was supported by NASA through a NASA Earth Science Student Fellowship (NNX14AK82H) and grant NNX13AP60, and by USGS contract G12PC00066. We thank A. Le Brocq for providing subglacial hydrology data, and S. Schmidtko and L. Padman for ocean temperature data. We would also like to acknowledge assistance with figures from A. Pope, and helpful suggestions from O. Sergienko, R. Alley and C. Shuman.

Author information

Authors and Affiliations

  1. National Snow and Ice Data Center, University of Colorado Boulder, Boulder, Colorado 80309, USA

    Karen E. Alley & Ted A. Scambos

  2. Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, USA

    Matthew R. Siegfried & Helen Amanda Fricker

Authors
  1. Karen E. Alley
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Ted A. Scambos
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Matthew R. Siegfried
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Helen Amanda Fricker
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

K.E.A. led the writing, image analysis and compilation of graphics and tables, and with T.A.S., H.A.F. and M.R.S. conducted the ICESat-based elevation change analysis. All co-authors contributed to the writing of the paper.

Corresponding author

Correspondence to Karen E. Alley.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 7284 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Alley, K., Scambos, T., Siegfried, M. et al. Impacts of warm water on Antarctic ice shelf stability through basal channel formation. Nature Geosci 9, 290–293 (2016). https://doi.org/10.1038/ngeo2675

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ngeo2675

Further reading

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing