IAP-26-082

Novel applications of remotely-sensed radar data for understanding Antarctic ice sheet flow

The Antarctic Ice Sheet contains enough freshwater to raise global sea level by 58 metres and is losing mass at an accelerating rate. More than 90% of the ice mass lost to the oceans from Antarctica comes from ice streams and outlet glaciers – dynamic corridors of fast-flowing ice. Quantification and characterisation of the form, structure, and rheology of ice streams is needed to derive robust projections of future ice-stream behaviour and, thus, global sea-level rise.

Present-day ice flow in Palmer and Ellsworth Lands is a diverse patchwork of varied ice dynamics, including narrow topographically-constrained glaciers (Antarctic Peninsula), wide fast-flowing West Antarctic ice streams (e.g. Evans, Rutford ice streams), and slow-flowing ice islands (e.g. Thurston Island). Satellite observations demonstrate ice surface thinning, speed-up and grounding-line retreat in this region (Wouters et al., 2015; Christie et al. 2016). Despite this, little is known about the controls on ice flow, nor how the pattern and rate of ice flow has changed over time, and why some areas may be bucking the regional trend of ice surface lowering (e.g. Thurston Island). Over millennial timescales, evidence exists for ice-stream flow-switching and water piracy in the region (Vaughan et al, 2008; King et al., 2011). However, the timing of glaciological change, the ice sheet structures and processes controlling and driving it, are poorly understood or constrained. This uncertainty has implications for the flux of grounded ice into the Bellinghausen and Weddell seas, and therefore global sea level rise.

To address these knowledge gaps, this PhD project will integrate novel satellite remote sensing (i.e. Synthetic Aperture Radar – SAR – observations) with airborne and ground-based geophysics to evaluate how factors such as topography (Carter et al., 2025), ice structure and rheology, and basal hydrology influence the pattern and discharge of ice flow at the boundary between West Antarctica and the Antarctic Peninsula. We will use these data to: (i) characterise the present-day ice sheet, including how it flows; (ii) investigate how ice flow has changed in the past; and (iii) assess future ice sheet change.

The key research questions, all critical for understanding ongoing change to the Antarctic Ice Sheet, are:

1. What do new and innovative datasets (e.g. satellite based synthetic aperture radar (SAR)) and recently acquired ice-penetrating radar (IPR) reveal about the structures (e.g. crevassing, locations of shear margins etc.) and rheology of present-day and past ice flow in Palmer and Ellsworth Lands, Antarctica?

2. What do novel SAR observations reveal about the present-day ice flow in the study region? What are the glaciological factors and processes that control modern and recent ice flow? What new insights into the ice surface and near subsurface do new L- and P-band SAR datasets provide?

3. What was the nature of past ice flow in Palmer and Ellsworth Lands? From integrating SAR and IPR data, can past fast-flowing corridors of ice be located, and what is revealed from this about the ice sheet history of the region?

This project and its goals align closely with multiple ongoing international scientific efforts (e.g. the Scientific Committee for Antarctic Research RINGS ice sheet margin and AntArchitecture Expert Groups). This presents opportunities for networking, wider scientific collaboration, and potentially for fieldwork.

The project will utilise and integrate existing freely-available satellite and airborne geophysical datasets, including:

• New L- and P-band SAR satellite observations (e.g. from the Biomass and NISAR satellites) will be integrated with Digital Elevation Models and existing ice velocity datasets to: (i) classify and quantify the glaciers and ice streams of Palmer and Ellsworth Lands; (ii) identify localities where past ice-flow changes may have occurred; and (iii) reveal recent changes in glaciological processes.

• High-resolution (0.5-1 km line spacing) ground-based ice-penetrating radar data acquired through the Durham University-led Interglacial Collapse of Ice Sheets revealed by Subglacial Drilling of Bedrock (INCISED) project will be used to calibrate the surface and near-surface signatures of ice flow and sub-ice features observed in satellite imagery, for both existing C-band SAR (e.g. RADARSAT, Sentinel-1) and P- and L-band SAR datasets (e.g. Biomass, NISAR, ROSE-L).

• Existing airborne ice-penetrating radar (e.g. acquired by the British Antarctic Survey (BAS)) will be integrated with the SAR data and analysed to: (i) reveal the glaciological/geomorphic setting of the study region; (ii) test hypotheses of past ice-flow changes; and (iii) characterise englacial features such as crevasses, internal layering, and Raymond Arches.

Year 1

Systematic synoptic ‘mapping’ and physical characterisation of features diagnostic of the controls on ice flow and from which ice rheology can be inferred (e.g. shear margins, flow stripes and zones of crevassing) across the study region. Present-day ice flow and dynamics will be compared to knowledge of past ice flow. Exploration of, and gaining experience of handling, SAR and IPR data.

Year 2

Comparison between and/or integration of new and novel satellite remote sensing datasets (e.g. NISAR/Biomass), the glaciological product from year 1, and airborne and ground-based geophysical datasets (e.g. INCISED radar data). Exploration of what the backscatter in data acquired using the new satellite datasets represents will be undertaken, with the goal of establishing the innovative potential of the Biomass and NISAR satellites. 1-2 week visit to either BAS in Cambridge to work with Dr Jordan, or the University of Stirling to work with Dr Marino.

Year 3

Year 3 is deliberately left open to enable the research student to choose the avenue they wish to explore during the latter parts of their PhD. The research at this stage will be dedicated to a specific geographical area or a process within the study region that has been identified as important during years 1-2. 1-2 week visit to either BAS in Cambridge to work with Dr Jordan, or the University of Stirling to work with Dr Marino.

Year 3.5

Write-up and submit PhD thesis.

There will be opportunities for the successful candidate to develop skills and to undergo training throughout the course of the PhD. This training can be ‘in-house’ at Newcastle University, as well as via external training (e.g. NERC-funded training courses for PhD researchers, and/or glaciology summer schools and European Space Agency SAR training). There will be opportunities for developing ‘big data’ skills, i.e. remote sensing, coding, geophysics and numerical modelling, highly sought after in both academia and industry. For example, the University of Stirling supervisor (Dr Marino) has developed his own Python codes (PyPolSARPro) for handling, analysing and interpreting SAR data, and the student will be encouraged to develop appropriate skills in this area. Opportunities for the student to use innovative AI Earth Observation tools and approaches will also be explored, where appropriate, throughout the PhD. The supervisory team have substantial experience in supporting their PhD researchers to undertake training additional to PhD projects (e.g. industrial placements, overseas placements, civil service placements). We will happily support any future PhD researchers to also explore such opportunities.