Complex evolving patterns of mass loss from Antarctica’s largest glacier

Abstract

Pine Island Glacier has contributed more to sea level rise over the past four decades than any other glacier in Antarctica. Model projections indicate that this will continue in the future but at conflicting rates. Some models suggest that mass loss could dramatically increase over the next few decades, resulting in a rapidly growing contribution to sea level and fast retreat of the grounding line, where the grounded ice meets the ocean. Other models indicate more moderate losses. Resolving this contrasting behaviour is important for sea level rise projections. Here, we use high-resolution satellite observations of elevation change since 2010 to show that thinning rates are now highest along the slow-flow margins of the glacier and that the present-day amplitude and pattern of elevation change is inconsistent with fast grounding-line migration and the associated rapid increase in mass loss over the next few decades. Instead, our results support model simulations that imply only modest changes in grounding-line location over that timescale. We demonstrate how the pattern of thinning is evolving in complex ways both in space and time and how rates in the fast-flowing central trunk have decreased by about a factor five since 2007.

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Fig. 1: PIG elevation, velocity and driving stress changes between 2005 and 2018.
Fig. 2: Elevation change over PIG between 2010 and 2018.
Fig. 3: Ice-shelf thinning rates for PIG, 1994–2017.
Fig. 4: Profile along a central flowline of PIG.

Data availability

The gridded swath-processed CryoSat datasets are available from the University of Bristol data portal at https://doi.org/10.5523/bris.xzwd95jqfpok2hi0tkxs5r6at. CryoSat-2 data were provided by the European Space Agency and are available from https://earth.esa.int/web/guest/-/how-to-access-cryosat-data-6842. ICESat-1 data, MEaSURES grounding lines and GoLIVE velocities are available from the National Snow and Ice Data Center, Boulder, Colorado, USA. Envisat data used in this study are available from https://doi.org/10.5270/EN1-ajb696a. The EIGEN-6C4 data are available from ref. 48, RACMO2.3 from https://www.projects.science.uu.nl/iceclimate/models/antarctica.php and Bedmap2 bedrock topography from https://www.bas.ac.uk/project/bedmap-2/.

References

  1. 1.

    Rignot, E. et al. Four decades of Antarctic Ice Sheet mass balance from 1979–2017. Proc. Natl Acad. Sci. USA 116, 1095–1103 (2019).

  2. 2.

    Hughes, T. West Antarctic Ice Sheet—instability, disintegration, and initiation of ice ages. Rev. Geophys. 13, 502–526 (1975).

  3. 3.

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

  4. 4.

    Rignot, E. J. Fast recession of a West Antarctic glacier. Science 281, 549–551 (1998).

  5. 5.

    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).

  6. 6.

    Joughin, I., Smith, B. E. & Holland, D. M. Sensitivity of 21st century sea level to ocean-induced thinning of Pine Island Glacier, Antarctica. Geophys. Res. Lett. 37, L20502 (2010).

  7. 7.

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

  8. 8.

    Seroussi, H. et al. Sensitivity of the dynamics of Pine Island Glacier, West Antarctica, to climate forcing for the next 50 years. Cryosphere 8, 1699–1710 (2014).

  9. 9.

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

  10. 10.

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

  11. 11.

    Johnson, J. S. et al. Rapid thinning of Pine Island Glacier in the early Holocene. Science 343, 999–1001 (2014).

  12. 12.

    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).

  13. 13.

    Joughin, I., Smith, B. E. & Schoof, C. G. Regularized coulomb friction laws for ice sheet sliding: application to Pine Island Glacier. Antarctica 46, 4764–4771 (2019).

  14. 14.

    Konrad, H. et al. Uneven onset and pace of ice-dynamical imbalance in the Amundsen Sea Embayment, West Antarctica. Geophys. Res. Lett. 44, 910–918 (2017).

  15. 15.

    Wouters, B. et al. Dynamic thinning of glaciers on the Southern Antarctic Peninsula. Science 348, 899–903 (2015).

  16. 16.

    Payne, A. J., Vieli, A., Shepherd, A. P., Wingham, D. J. & Rignot, E. Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans. Geophys. Res. Lett. 31, L23401 (2004).

  17. 17.

    Bamber, J. L. & Gomez-Dans, J. L. The accuracy of digital elevation models of the Antarctic continent. Earth Planet. Sci. Lett. 217, 516–523 (2005).

  18. 18.

    Wingham, D. J. et al. in Natural Hazards and Oceanographic Processes from Satellite Data Advances in Space Research Vol. 37 (eds R. P. Singh & M. A. Shea) 841–871 (Elsevier, 2006).

  19. 19.

    Gray, L. et al. Interferometric swath processing of Cryosat data for glacial ice topography. Cryosphere 7, 1857–1867 (2013).

  20. 20.

    Foresta, L. et al. Heterogeneous and rapid ice loss over the Patagonian ice fields revealed by CryoSat-2 swath radar altimetry. Remote Sens. Environ. 211, 441–455 (2018).

  21. 21.

    Felikson, D. et al. Comparison of elevation change detection methods from ICESat altimetry over the Greenland Ice Sheet. IEEE Trans. Geosci. Remote Sens. 55, 5494–5505 (2017).

  22. 22.

    Mouginot, J., Rignot, E., Scheuchl, B. & Millan, R. Comprehensive annual ice sheet velocity mapping using Landsat-8, Sentinel-1, and RADARSAT-2 data. Remote Sens. 9, 364 (2017).

  23. 23.

    Fahnestock, M. et al. Rapid large-area mapping of ice flow using Landsat 8. Remote Sens. Environ. 185, 84–94 (2016).

  24. 24.

    Christianson, K. et al. Sensitivity of Pine Island Glacier to observed ocean forcing. Geophys. Res. Lett. 43, 10817–10825 (2016).

  25. 25.

    Konrad, H. et al. Net retreat of Antarctic glacier grounding lines. Nat. Geosci. 11, 258–262 (2018).

  26. 26.

    Park, J. W. et al. Sustained retreat of the Pine Island Glacier. Geophys. Res. Lett. 40, 2137–2142 (2013).

  27. 27.

    Paolo, F. S. et al. Response of Pacific-sector Antarctic ice shelves to the El Niño/Southern Oscillation. Nat. Geosci. 11, 121–126 (2018).

  28. 28.

    Jenkins, A. et al. West Antarctic Ice Sheet retreat in the Amundsen Sea driven by decadal oceanic variability. Nat. Geosci. 11, 733–738 (2018).

  29. 29.

    Davis, P. E. D. et al. Variability in basal melting beneath Pine Island ice shelf on weekly to monthly timescales. J. Geophys. Res. Oceans 123, 8655–8669 (2018).

  30. 30.

    Donat-Magnin, M. et al. Ice-shelf melt response to changing winds and glacier dynamics in the Amundsen Sea sector, Antarctica. J. Geophys. Res. Oceans 122, 10206–10224 (2017).

  31. 31.

    Schodlok, M. P., Menemenlis, D., Rignot, E. & Studinger, M. Sensitivity of the ice-shelf/ocean system to the sub-ice-shelf cavity shape measured by NASA IceBridge in Pine Island Glacier, West Antarctica. Ann. Glaciol. 53, 156–162 (2012).

  32. 32.

    Milillo, P. et al. On the short-term grounding zone dynamics of Pine Island Glacier, West Antarctica, observed with COSMO-SkyMed interferometric data. Geophys. Res. Lett. 44, 10436–10444 (2017).

  33. 33.

    Argus, D. F., Peltier, W. R., Drummond, R. & Moore, A. W. The Antarctica component of postglacial rebound model ICE-6G_C (VM5a) based on GPS positioning, exposure age dating of ice thicknesses, and relative sea level histories. Geophys. J. Int. 198, 537–563 (2014).

  34. 34.

    Gunter, B. C. et al. Empirical estimation of present-day Antarctic glacial isostatic adjustment and ice mass change. Cryosphere 8, 743–760 (2014).

  35. 35.

    Ivins, E. R. et al. Antarctic contribution to sea level rise observed by GRACE with improved GIA correction. J. Geophys. Res. 118, 3126–3141 (2013).

  36. 36.

    Martín-Español, A. et al. An assessment of forward and inverse GIA solutions for Antarctica. J. Geophys. Res. 121, 6947–6965 (2016).

  37. 37.

    Barletta, V. R. et al. Observed rapid bedrock uplift in Amundsen Sea Embayment promotes ice-sheet stability. Science 360, 1335–1339 (2018).

  38. 38.

    Larour, E. et al. Slowdown in Antarctic mass loss from solid Earth and sea-level feedbacks. Science 364, eaav7908 (2019).

  39. 39.

    Helm, V., Humbert, A. & Miller, H. Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2. Cryosphere 8, 1539–1559 (2014).

  40. 40.

    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).

  41. 41.

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

  42. 42.

    Gray, L. et al. A revised calibration of the interferometric mode of the CryoSat-2 radar altimeter improves ice height and height change measurements in western Greenland. Cryosphere 11, 1041–1058 (2017).

  43. 43.

    Moholdt, G., Padman, L. & Fricker, H. A. Basal mass budget of Ross and Filchner‐Ronne ice shelves, Antarctica, derived from Lagrangian analysis of ICESat altimetry. J. Geophys. Res. Earth Surf. 119, 2361–2380 (2014).

  44. 44.

    Rignot, E., Mouginot, J. & Scheuchl, B. MEaSUREs Antarctic Grounding Line from Differential Satellite Radar Interferometry Version 2 (NASA National Snow and Ice Data Center Distributed Active Archive Center, 2016).

  45. 45.

    Scambos, T., Fahnestock, M., Moon, T., Gardner, A. & Klinger, M. Global Land Ice Velocity Extraction from Landsat 8 (GoLIVE) Version 1 (National Snow and Ice Data Center, 2016).

  46. 46.

    Sandwell, D. T. & Smith, W. H. F. Marine gravity anomaly from Geosat and ERS 1 satellite altimetry. J. Geophys. Res. 102, 10039–10054 (1997).

  47. 47.

    Flament, T. & Remy, F. Proc. IEEE International Geoscience and Remote Sensing Symposium 1848–1851 (IEEE, 2012).

  48. 48.

    Förste, C. et al. EIGEN-6C4 The latest combined global gravity field model including GOCE data up to degree and order 2190 of GFZ Potsdam and GRGS Toulouse (GFZ Data Services, 2014); https://doi.org/10.5880/icgem.2015.1

  49. 49.

    Van Wessem, J. et al. Improved representation of East Antarctic surface mass balance in a regional atmospheric climate model. J. Glaciol. 60, 761–770 (2014).

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Acknowledgements

We thank G.H. Gudmundsson and I. Joughin for comments on a draft of the manuscript. This work was supported by the UK Natural Environment Research Council (NERC) grant NE/N011511/1. J.L.B. was also supported by the European Research Council under grant agreement 694188 and a Royal Society Wolfson Merit Award.

Author information

J.L.B. conceived the study and wrote the paper. G.D. undertook the data analysis and developed the methods. Both authors commented on the manuscript.

Correspondence to Jonathan L. Bamber.

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The authors declare no competing interests.

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Peer review information Primary handling editor: Heike Langenberg.

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Extended data

Extended Data Fig. 1 Data density of CryoSat-2 observations for POCA and swath processing.

Number of observations per km plots for 1 year of CryoSat-2 swath (a) and POCA (b) data. With the mean surface elevation rate derived from swath (c) and POCA (d) data, for the period 2010-2018 for comparison.

Extended Data Fig. 2 Annual time series of elevation change over PIG.

Surface elevation rate derived from CryoSat-2 POCA and swath data for three-year moving window centred on the years between 2012-2017 at 4 km postings. The dark red lines are mean velocity contours for the period 2005-2017and the star is the location of the INMN GPS station. The dashed black box is the area shown in Fig. 1 and the solid black line is a composite of the 2011 and 2015 grounding line position.

Extended Data Fig. 3 Standard errors of the elevation change observations.

Standard error to the model fit for ICESat-1 and CryoSat-2, with ICESat-1 tracks overlain on the CryoSat-2 grid. The black dashed line is the grounding line recorded in 2011 and contours are mean velocities for the period 2005-2017.

Extended Data Fig. 4 Change in ice velocity between 2013 and 2017.

Ice velocity change calculated between 2013 and 2017 (with white directional arrows) using GoLIVE Landsat 8 ice velocities. Contours are mean velocities for the period 2011 to 2017 and the black dashed line is the grounding line recorded in 2011.

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Supplementary Information

Supplementary Table 1.

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Bamber, J.L., Dawson, G.J. Complex evolving patterns of mass loss from Antarctica’s largest glacier. Nat. Geosci. 13, 127–131 (2020). https://doi.org/10.1038/s41561-019-0527-z

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