Letter | Published:

Sub-ice-shelf sediments record history of twentieth-century retreat of Pine Island Glacier

Nature volume 541, pages 7780 (05 January 2017) | Download Citation

  • A Corrigendum to this article was published on 13 September 2017


The West Antarctic Ice Sheet is one of the largest potential sources of rising sea levels1. Over the past 40 years, glaciers flowing into the Amundsen Sea sector of the ice sheet have thinned at an accelerating rate2, and several numerical models suggest that unstable and irreversible retreat of the grounding line—which marks the boundary between grounded ice and floating ice shelf—is underway3. Understanding this recent retreat requires a detailed knowledge of grounding-line history4, but the locations of the grounding line before the advent of satellite monitoring in the 1990s are poorly dated. In particular, a history of grounding-line retreat is required to understand the relative roles of contemporaneous ocean-forced change and of ongoing glacier response to an earlier perturbation in driving ice-sheet loss. Here we show that the present thinning and retreat of Pine Island Glacier in West Antarctica is part of a climatically forced trend that was triggered in the 1940s. Our conclusions arise from analysis of sediment cores recovered beneath the floating Pine Island Glacier ice shelf, and constrain the date at which the grounding line retreated from a prominent seafloor ridge. We find that incursion of marine water beyond the crest of this ridge, forming an ocean cavity beneath the ice shelf, occurred in 1945 (±12 years); final ungrounding of the ice shelf from the ridge occurred in 1970 (±4 years). The initial opening of this ocean cavity followed a period of strong warming of West Antarctica, associated with El Niño activity. Thus our results suggest that, even when climate forcing weakened, ice-sheet retreat continued.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. in Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (eds et al. .) Ch. 13, 1137–1216 (Cambridge Univ. Press, 2013)

  2. 2.

    , & Sustained increase in ice discharge from the Amundsen Sea Embayment, West Antarctica, from 1973 to 2013. Geophys. Res. Lett. 41, 1576–1584 (2014)

  3. 3.

    et al. Retreat of Pine Island Glacier controlled by marine ice-sheet instability. Nat. Clim. Chang. 4, 117–121 (2014)

  4. 4.

    , & Sensitivity of 21st century sea level to ocean-induced thinning of Pine Island Glacier, Antarctica. Geophys. Res. Lett. 37, L20502 (2010)

  5. 5.

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

  6. 6.

    , , & Stronger ocean circulation and increased melting under Pine Island Glacier ice shelf. Nat. Geosci . 4, 519–523 (2011)

  7. 7.

    , & Warm ocean is eroding West Antarctic Ice Sheet. Geophys. Res. Lett. 31, L23402 (2004)

  8. 8.

    , , , & Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans. Geophys. Res. Lett. 31, L23401 (2004)

  9. 9.

    et al. Observations beneath Pine Island Glacier in West Antarctica and implications for its retreat. Nat. Geosci . 3, 468–472 (2010)

  10. 10.

    et al. Coastal-Change and Glaciological Map of the Eights Coast Area, Antarctica, 1972–2001: Geological Investigation Series Map I-2600-E (US Department of the Interior, US Geological Survey, 2004)

  11. 11.

    et al. Grounding-line retreat of the West Antarctic Ice Sheet inner Pine Island Bay. Geology 41, 35–38 (2013)

  12. 12.

    , , & Modelling circumpolar deep water intrusions on the Amundsen Sea continental shelf, Antarctica. Geophys. Res. Lett. 35, L18602 (2008)

  13. 13.

    , , & Tropical forcing of circumpolar deep water Inflow and outlet glacier thinning in the Amundsen Sea Embayment, West Antarctica. Ann. Glaciol. 53, 19–28 (2012)

  14. 14.

    & Ice cores record significant 1940s Antarctic warmth related to tropical climate variability. Proc. Natl Acad. Sci. USA 105, 12154–12158 (2008)

  15. 15.

    et al. Strong sensitivity of Pine Island ice-shelf melting to climatic variability. Science 343, 174–178 (2014)

  16. 16.

    et al. Channelized ice melting in the ocean boundary layer beneath Pine Island Glacier. Antarct. Sci. 341, 1236–1239 (2013)

  17. 17.

    et al. Stability of the Larsen B ice shelf on the Antarctic Peninsula during the Holocene epoch. Nature 436, 681–685 (2005)

  18. 18.

    & A new depositional model for ice shelves, based upon sediment cores from the Ross Sea and the Mac. Robertson shelf. Ann. Glaciol. 27, 281–284 (1998)

  19. 19.

    & Microfossil distribution in modern Amundsen Sea sediments. Mar. Micropaleontol. 12, 203–222 (1987)

  20. 20.

    , , & Distinguishing subglacial till and glacial marine diamictons in the western Ross Sea, Antarctica: implications for a last glacial maximum grounding line. Geol. Soc. Am. Bull. 111, 91–103 (1999)

  21. 21.

    , , & Observations of the grounding-line area at a floating glacier terminus. Ann. Glaciol. 22, 217–223 (1996)

  22. 22.

    et al. Meltwater intensive glacial retreat in polar environments and investigation of associated sediments: example from Pine Island Bay, West Antarctica. Quat. Sci. Rev. 85, 99–118 (2014)

  23. 23.

    et al. Seabed corrugations beneath an Antarctic ice shelf revealed by autonomous underwater vehicle survey: origin and implications for the history of Pine Island Glacier. J. Geophys. Res. Earth Surf . 118, 1356–1366 (2013)

  24. 24.

    & , , & Bromine counts from XRF scanning as an estimate of the marine organic carbon content of sediment cores. Geochem. Geophys. Geosyst. 9, Q05009 (2008)

  25. 25.

    et al. Provenance changes between recent and glacial-time sediments in the Amundsen Sea embayment, West Antarctica: clay mineral assemblage evidence. Antarct. Sci. 23, 471–486 (2011)

  26. 26.

    , , , & Distribution of clay minerals and proxies for productivity in surface sediments of the Bellingshausen and Amundsen seas (West Antarctica)—relation to modern environmental conditions. Mar. Geol. 193, 253–271 (2003)

  27. 27.

    Ice-shelf changes in Pine Island Bay, Antarctica, 1947–2000. J. Glaciol. 48, 247–256 (2002)

  28. 28.

    , & Marine ice sheet collapse potentially under way for the Thwaites Glacier Basin, West Antarctica. Science 344, 735–738 (2014)

  29. 29.

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

  30. 30.

    et al. A consistent dataset of Antarctic ice sheet topography, cavity geometry, and global bathymetry. Earth Syst. Sci. Data 2, 261–273 (2010)

  31. 31.

    , , , & Marine vs. terrigenous organic matter in Louisiana coastal sediments: the uses of bromine:organic carbon ratios. Mar. Chem. 107, 244–254 (2007)

  32. 32.

    Organic geochemical proxies of paleoceanographic, paleolimnologic, and paleoclimatic processes. Org. Geochem. 27, 213–250 (1997)

  33. 33.

    et al. New constraints on the timing of West Antarctic Ice Sheet retreat in the eastern Amundsen Sea since the Last Glacial Maximum. Global Planet. Change 122, 224–237 (2014)

  34. 34.

    & Flow behaviour of the submarine glacigenic debris flows on the Bear Island Trough Mouth Fan, western Barents Sea. Sedimentology 47, 1105–1117 (2000)

  35. 35.

    , , & Comparisons of 210Pb and pollen methods for determining rates of estuarine sediment accumulation. Quat. Res. 18, 196–217 (1982)

  36. 36.

    & The assessment of 210Pb data from sites with varying sediment accumulation rates. Hydrobiologia 103, 29–35 (1983)

  37. 37.

    , & Radiometric dating of lake-sediments from Signy Island (maritime Antarctic)—evidence of recent climatic-change. J. Paleolimnol. 13, 179–191 (1995)

  38. 38.

    in Tracking Environmental Change Using Lake Sediments Volume 1: Basin Analysis, Coring, and Chronological Techniques (eds & ) 171–203 (Kluwer, 2001)

  39. 39.

    & X-ray fluorescence core scanning of wet marine sediments: methods to improve quality and reproducibility of high-resolution paleoenvironmental records. Limnol. Oceanogr. Methods 10, 991–1003 (2012)

  40. 40.

    & Environmental magnetism—past, present and future. J. Geophys. Res. Solid Earth 100, 2175–2192 (1995)

  41. 41.

    , & Global distribution of Pu isotopes and 237Np. Sci. Total Environ. 237–238, 483–500 (1999)

  42. 42.

    , , & The Pu-240 Pu-239 ratio, a potential geochronometer. Earth Planet. Sci. Lett. 72, 1–8 (1985)

  43. 43.

    et al. A method for continuous (PU)-P-239 determinations in Arctic and Antarctic ice cores. Environ. Sci. Technol. 50, 7066–7073 (2016)

  44. 44.

    , , & Plutonium isotopes as tracers for ocean processes: a review. Mar. Environ. Res. 69, 73–84 (2010)

  45. 45.

    , , & in Plutonium in the Environment. Radioactivity in the Environment Vol. 1 (ed. ) 267–292 (Elsevier, 2001)

Download references


We thank D. Pomraning for help with designing and manning the hot-water drill equipment. Logistic and safety support was provided by K. Gibbon, D. Einerson, E. Steinarsson, F. McCarthy, S. Consalvi, S. King, the PIG support camp personnel, and the National Science Foundation (NSF) Antarctic support team. We particularly thank E. Steinarsson for his help with sediment coring. This research project was supported by NSF’s Office of Polar Programs under NSF grants including ANT-0732926 and ANT 0732730; by funding from NASA’s Cryospheric Sciences Program; by New York University Abhu Dabi grant 1204; and by the Natural Environment Research Council–British Antarctic Survey Polar Science for Planet Earth Programme. Work at the Lawrence Livermore National Laboratory (LLNL) was performed under contract DE-AC52-07NA27344; LLNL-JRNL-697878.

Author information


  1. British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK

    • J. A. Smith
    • , M. Shortt
    • , A. Jenkins
    • , C.-D. Hillenbrand
    • , H. F. J. Corr
    • , N. Farley
    •  & D. G. Vaughan
  2. Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen K, Denmark

    • T. J. Andersen
  3. Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, California 94550, USA

    • A. M. Gaffney
  4. Geophysical Institute, University of Alaska, Fairbanks, Alaska 99775-7320, USA

    • M. Truffer
  5. Department of Oceanography, Naval Postgraduate School, Monterey, California 93943, USA

    • T. P. Stanton
  6. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA

    • R. Bindschadler
  7. Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA

    • P. Dutrieux
  8. Institute for Geophysics and Geology, University of Leipzig, Talstrasse 35, D-04103 Leipzig, Germany

    • W. Ehrmann
  9. Department of Earth Sciences, University of Geneva, 13 Rue des Maraîchers, CH-1205 Geneva, Switzerland

    • N. Farley
    •  & S. Crowhurst
  10. Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK


  1. Search for J. A. Smith in:

  2. Search for T. J. Andersen in:

  3. Search for M. Shortt in:

  4. Search for A. M. Gaffney in:

  5. Search for M. Truffer in:

  6. Search for T. P. Stanton in:

  7. Search for R. Bindschadler in:

  8. Search for P. Dutrieux in:

  9. Search for A. Jenkins in:

  10. Search for C.-D. Hillenbrand in:

  11. Search for W. Ehrmann in:

  12. Search for H. F. J. Corr in:

  13. Search for N. Farley in:

  14. Search for S. Crowhurst in:

  15. Search for D. G. Vaughan in:


J.A.S., R.B., D.G.V. and H.F.J.C. conceived the study, and M.S., M.T. and T.P.S. conducted the fieldwork. J.A.S. and N.F. were responsible for sediment-core analysis and J.A.S. led the writing of the paper. T.J.A. measured 210Pb and 137Cs levels and developed the age models. A.M.G. measured plutonium isotopes on the PIG B core. P.D. and A.J. provided the bathymetric compilation, multibeam imagery and knowledge of the seafloor beneath Pine Island Glacier, and C-.D.H. contributed expertise on glacial sedimentology and data interpretation. W.E. is responsible for analysis of clay minerals, organic carbon and total nitrogen, and S.C. performed the X-ray fluorescence (XRF) scanning. All authors contributed to data interpretation and writing of the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to J. A. Smith.

Reviewer Information Nature thanks M. Baskaran, M. Jakobsson and J. Wellner for their contribution to the peer review of this work.

Extended data

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.