The glaciology and sub-ice landscape of the Weddell Sea region of Antarctica: implications for past ice sheet behaviour.

Overview

The Weddell Sea region of Antarctica currently hosts a multitude of very large outlet glaciers that originate from both East and West Antarctica. These outlets converge at the Ronne Filchner Ice shelf which is currently helping to maintain the stability of these glaciers through the influence of buttressing (Reese et al., 2018). Although this region is thought to be relatively robust to ongoing climate change, there is evidence that in the past the ice flow has changed dynamically over glacial-interglacial cycles (Siegert et al., 2018). Upcoming release of British Antarctic Survey Radio Echo Sounding (RES) survey data in this region will provide new detail on the subglacial landscape in the Weddell Sea region. Given that subglacial topography inherently acts as a record of past ice sheet behaviour, and potentially of past ice extent (Paxman et al., 2018), there is a significant opportunity to investigate the long-term stability of both Antarctic ice sheets in this region. Initial investigation of the RES data suggests the presence of flat surfaces at low elevation which may reflect glacial erosion and solid-earth feedbacks (e.g. erosion and isostasy) under different ice sheet conditions.
The aim of this project is therefore to investigate the subglacial landscape of the Weddell Sea region in respect of the interactions between the ice sheet, the landscape and the solid earth. We will address a number of objectives:
1) We will use newly released RES data to develop more detailed subglacial topography maps of the Weddell Sea region.
2) We will geomorphologically interpret the topography in respect of past ice flow behaviour.
3) We will investigate potential interactions between glacial erosion, ice flow behaviour, solid earth response and tectonics to understand how the topography evolved.
4) Compare the subglacial landscapes to other potentially flat coastal regions around Antarctica.
We expect the outcome will help us more clearly understand the past stability of the Weddell Sea region in the context of wider Antarctic Ice Sheet behaviour.

Methodology

RES data from surveys ranging back to 2004 has is being made available via BAS. The student will investigate that data using geophysical software and will produce more detailed bed-picks of the region before gridding the outcome up as a new topographic dataset. Morphometric analysis using Matlab and QGIS/ArcGIS will be undertaken to understand both the detailed shapes of any valleys, ridges or plateaus identified as well as the regional morphological signature. This analysis will be supplemented by analysis of ice surface satellite data that may also record the positions of subglacial valleys and ridges in a more continuous manner (Ross et al., Jamieson et al). We will use geophysical modelling techniques in Matlab in order to understand the isostatic response of the topography in relation to glacial erosion and to explore whether faulting also needs to be invoked to understand the regional elevations of the landscape. Finally, other previously available RES data from other regions of Antarctica will be compared in order to understand whether the patterns in the landscape are more widespread than just the Weddell Sea region.

Project Timeline

Year 1

Access and process the data, checking automated bed topography picks, learning how to use geophysical software, and reading to become familiar with previous work of this type in Antarctica (and elsewhere).

Year 2

Background reading and technical training on geomorphometry and conducting geomorphometric analysis of detailed and regional-scale data. Geophysical modelling – reading and application to the region. Drafting of related research paper.

Year 3

Wider RES and morphometric data comparison. Drafting of further research papers.

Year 3.5

Complete write-up of papers and package as thesis.

Training
& Skills

The student will gain experience of a wide range of research methods relating to remote sensing, geophysical data analysis (optionally on numerical modelling) and Antarctic science in general. The supervisory team covers the wide breadth of methods to be applied and can provide hands-on training in all aspects of the project at Durham and Newcastle Universities The student will be supported to attend international training opportunities (e.g. Karthaus summer school on ‘ice and climate dynamics’) and appropriate national and international conferences. The student will be a member of the Sea Level, Ice and Climate Research Cluster in Geography at Durham (https://www.dur.ac.uk/geography/slic/).

Broader transferable skills (e.g. communicating science, thesis writing, writing for publication, presentation skills) will be developed through various training events at Durham University offered by IAPETUS as well as through Durham’s award winning Career and Research Development (CAROD) group. At all stages the students writing skills will be developed and supported and they will be encouraged to lead papers outlining the project results. The project and supervisory team is designed to give the student broad, multi-disciplinary training including quantitative skills to ensure they have a range of applicable and transferable skills.

Students will also be encouraged to engage with Scientific Committee on Antarctic Research (SCAR) activities which involve wider international collaboration and discussion and will be supported in doing so by the project supervisors who are active in this area.

References & further reading

Neil Ross, Tom A. Jordan, Robert G. Bingham, Hugh F.J. Corr, Fausto Ferraccioli, Anne Le Brocq, David M. Rippin, Andrew P. Wright, Martin J. Siegert; The Ellsworth Subglacial Highlands: Inception and retreat of the West Antarctic Ice Sheet. GSA Bulletin 2014; 126 (1-2): 3–15. doi: https://doi.org/10.1130/B30794.1

Paxman, G. J. G., Jamieson, S. S. R., Ferraccioli, F., Bentley, M. J., Ross, N., Armadillo, E., Gasson, E. G. W., Leitchenkov, G. & DeConto, R. M. (2018). Bedrock erosion surfaces record former East Antarctic Ice Sheet extent. Geophysical Research Letters 45(9): 4114-4123. https://doi.org/10.1029/2018GL077268

Reese, R., Gudmundsson, G.H., Levermann, A. et al. The far reach of ice-shelf thinning in Antarctica. Nature Clim Change 8, 53–57 (2018). https://doi.org/10.1038/s41558-017-0020-x

Siegert, Martin J. and Kingslake, Jonny and Ross, Neil and Whitehouse, Pippa L. and Woodward, John and Jamieson, Stewart S.R. and Bentley, Michael J. and Winter, Kate and Wearing, Martin and Hein, Andrew S. and Jeofry, Hafeez and Sugden, David E. (2019) Major ice‐sheet change in the Weddell Sector of West Antarctica over the last 5000 years, Reviews of geophysics., 57 (4). pp. 1197-1223. https://doi.org/10.1029/2019RG000651

Stewart S.R. Jamieson, Neil Ross, Jamin S. Greenbaum, Duncan A. Young, Alan R.A. Aitken, Jason L. Roberts, Donald D. Blankenship, Sun Bo, Martin J. Siegert; An extensive subglacial lake and canyon system in Princess Elizabeth Land, East Antarctica. Geology 2016; 44 (2): 87–90. doi: https://doi.org/10.1130/G37220.1

Further Information

Dr Stewart Jamieson
Department of Geography
Durham University
Email: Stewart.Jamieson@durham.ac.uk
Tel: +44 (0) 191 3341990
https://www.durham.ac.uk/staff/stewart-jamieson/

Apply Now