Stability of the Larsen C Ice Shelf

Project Overview

Swansea Glaciology Group has attracted four NERC grants for research into the stability of the Larsen C Ice Shelf (LCIS), Antarctic Peninsula, since 2008, and is currently expanding this research to pan-Antarctic ice shelves. Ice shelves matter because they are first-order controls on the sea level contribution and climate feedbacks from the Antarctic Ice Sheet, providing major physical restraint to the ice streams and glaciers that feed them from the continental interior. When an ice shelf collapses or retreats significantly then that buttressing restraint will decrease and feeder glacier flow speed and thus ice discharge into the ocean and sea level rise increase, and potentially so in the long term. Most notably, following four seasons of fieldwork on the LCIS combined with satellite remote sensing and ice shelf modelling, projects SOLIS (2008-11) and MIDAS (2014-17) asserted that LCIS’s internal structure is highly heterogeneous, and that this complex structure plays a fundamental role in controlling its response to atmospheric and ocean warming in a changing climate. Commencing with project AntShelf2000 (AXA-funded, 2017-18), the Glaciology Group is now striving to identify the pan-Antarctic significance of the many lessons learned at the LCIS since 2008.

Project Outcomes

Three highlight outcomes of our work so far include:

LCIS is stable at present due to suture zones that contain much ocean-derived ice with enhanced temperature and seawater content, which is able to inhibit or at least attenuate rift propagation across the ice shelf. If these zones were weakened, e.g. due to ocean warming and enhanced basal melting, especially near stabilising pinning points, then the LCIS may become susceptible to retreat akin to Larsen B before it rapidly disintegrated.

The LCIS has experienced two major periods of surface melting, including one in the 18th century and one that started in the 1960s and saw the onset of surface ponding in 1990s due to amplified foehn winds and sustained melting in the Antarctic winter, which creates massive internal bodies of refrozen ice that change the flow of the ice shelf and its susceptibility to fracturing.

The discovery of abundant basal crevasses in the LCIS that form when feeder glaciers flow across the grounding line, rendering the shelf units derived from these glaciers structurally much less intact than previously thought, with broader stability implications for many pan-Antarctic ice shelves.

Affiliated Staff

Current staff members involved are;

Steph Cornford (Swansea PI of NERC Urgency Project RACE68, led by the University of Leeds, 2017-19)

Bernd Kulessa (lead PI of NERC Standard Grant project SOLIS (2008-11) and budget holder of AntShelf2000 (2017-18))

Adrian Luckman / Suzanne Bevan (lead PI of / PDRA on NERC Standard Grant project MIDAS (2014-17) and NERC Small Grant project ‘Quantifying the role of marine ice in LCIS dynamics’ (2011-12)

Sarah Thompson (AXA postdoctoral fellow of project Antshelf (2000).

Collaborative / Industry Partners

Our main ongoing collaborators are Aberystwyth University, the British Antarctic Survey, the University of Leeds, the British Geological Survey, the Alfred Wegener Institute (Germany), the University of Utrecht (Netherlands) and the Colorado State University (USA).

Research Centres / Groups

Glaciology Group, College of Science

Publications

1) Bevan, S., L., A. J. Luckman, P. Kuipers Munneke, B. Hubbard, B. Kulessa and D. Ashmore. ASCAT scatterometer data reveal declines in Larsen C ice shelf surface melt accompany 21st century Antarctic Peninsula cooling. Earth and Space Science, in press.

(2) Kuipers Munneke, P., A. J. Luckman, S. L. Bevan, C. J. P. P. Smeets, E. Gilbert, M. R. van den Broeke, W. Wang, C. Zender, B. Hubbard, D. Ashmore, A. Orr, J. C. King, and B. Kulessa (2018). Intense winter surface melt on an Antarctic ice shelf. Geophysical Research Letters, 45, doi.org/10.1029/2018GL077899

(3) Bevan, S. L., A. J. Luckman, B. Hubbard, B. Kulessa, D. Ashmore, P. Kuipers Munneke, M. O’Leary, A. D. Booth, H. Sevestre and D. McGrath. 2017. Centuries of intense surface melt on Larsen C Ice Shelf. The Cryosphere, 11(6), 2743-2753, doi:10.5194/tc-11-2743-2017.

(4) Chester, M. L., B. Kulessa, A. J. Luckman, J. N. Bassis and P. Kuipers Munneke. 2017. Systems Analysis of complex glaciological processes and application to calving of Amery Ice Shelf, East Antarctica. Annals of Glaciology, 58(74), 60-71, doi:10.1017/aog.2017.1.

(5) Ashmore, D., B. Hubbard, A. J. Luckman, B. Kulessa, S. L. Bevan, A. D. Booth, P. Kuipers Munneke, M. O'Leary, H. Sevestre and P. R. Holland. 2017. Ice and firn heterogeneity within Larsen C Ice Shelf from borehole optical televiewing. Journal of Geophysical Research: Earth Surface, 122(5), 1139-1153, doi:10.1002/2016JF004047.

(6) Kuipers Munneke, P., D. McGrath, B. Medley, A. J. Luckman, S. L. Bevan, B. Kulessa, D. Jansen, A. D. Booth, P. Smeets, B. Hubbard, D. Ashmore, M. Van den Broeke, H. Sevestre, K. Steffen, A. Shepherd and N. Gourmelen. 2017. Observationally constrained surface mass balance of Larsen C ice shelf, Antarctica. The Cryosphere 11(6), 2411-2426, doi:10.5194/tc-11-2411-2017.

(7) Hubbard, B., A. Luckman, D. Ashmore, S. Bevan, B. Kulessa, P. Kuipers Munneke, D. Jansen, M. O’Leary and I. Rutt. 2016. Massive subsurface ice formed by refreezing of ice-shelf melt ponds. Nature Communications, 7, 11897, doi: 10.1038/ncomms11897.

(8) Jansen, D., A. J. Luckman, A. Cook, S. Bevan, B. Kulessa, B. Hubbard and P. R. Holland. 2015. Brief Communication: Newly developing rift in Larsen C Ice Shelf presents significant risk to stability. The Cryosphere, 9, 1223–1227, doi:10.5194/tc-9-1223-2015.

(9) Luckman, A., A. Elvidge, D. Jansen, B. Kulessa, P. Kuipers Munneke, J. King, and N. E. Barrand. Surface melt and ponding on Larsen C Ice Shelf and the impact of foehn winds. Antarctic Science, 26(6), 625-635, doi:10.1017/S0954102014000339.

(10) Kulessa, B., D. Jansen, A. J. Luckman, E. C. King, and P. R. Sammonds. 2014. Marine ice regulates the future stability of a large Antarctic ice shelf. Nature Communications, 5:3707, doi: 10.1038/ncomms4707.

(11) Jansen, D., A. J. Luckman, B. Kulessa, P. R. Holland, and E. C. King. 2013. Marine ice formation in a suture zone on the Larsen C Ice Shelf and its inﬂuence on ice shelf dynamics, Journal of Geophysical Research – Earth Surface, 118, 1–13, doi:10.1002/jgrf.20120.

(12) Luckman, A., D. Jansen, B. Kulessa, E. C. King, P. Sammonds and D. I. Benn. 2012. Basal crevasses in Larsen C Ice Shelf and implications for their global abundance. The Cryosphere, 6, 113-123, doi:10.5194/tc-6-113-2012.

(13) King, M. A., L. Padman, K. Nicholls, P. Clarke, H. Gudmundsson, B. Kulessa, A. Shepherd, and N. Gourmelen. 2011. Ocean tides in the Weddell Sea: new observations on the Filchner-Ronne and Larsen C ice shelves and model validation. Journal of Geophysical Research – Oceans, 116, C06006, doi: 10.1029/2011JC006949.

(14) Jansen, D., B. Kulessa, P. R. Sammonds, A. Luckman, E. C. King, and N. F. Glasser. Present stability of the Larsen C ice shelf, Antarctic Peninsula. Journal of Glaciology, 56(198), 593-600, doi:10.3189/002214310793146223 (October 2010).

Project Contact

Dr. Stephen Cornford (s.l.cornford@swansea.ac.uk)

Prof. Bernd Kulessa (b.kulessa@swansea.ac.uk)

Prof. Adrian Luckman (a.luckman@swansea.ac.uk)

External Project Websites

http://gotw.nerc.ac.uk/list_full.asp?pcode=NE%2FE012914%2F1

http://gotw.nerc.ac.uk/list_full.asp?pcode=NE%2FL005409%2F1

http://gotw.nerc.ac.uk/list_full.asp?pcode=NE%2FI016678%2F1

http://gotw.nerc.ac.uk/list_full.asp?pcode=NE%2FR012334%2F1