Dr Gareth Roberts; Dr Chris Lloyd
Rationale:
The subglacial hydrological system modulates ice dynamics and is a vital component in understanding how glaciers respond to climate change [1]. Recent work has suggested that soft-bedded glacier (such as the unstable West Antarctic Ice streams) have a braided subglacial hydrology [2], whilst traditional models argue for a channelized hydrology. The difference in hydrology is important as it is part of the understanding of the rate of glacier velocity and hence sea-level rise. If soft-bedded glaciers have a braided hydrology, what would this look like in terms of glacial sedimentology from both modern and Quaternary environments? This project would investigate sites from Iceland and UK Quaternary sites to develop a model of subglacial braided system sedimentology. This models will be developed in Iceland and the UK using a variety of techniques These will be tested by using a variety of techniques including the use of ‘Planet Lab’ images and UAV survey to carry out offset (or intensity) tracking, a well-established method for deriving displacements from repeat imagery to calculate velocity, to map the glacial geomorphology, as well as sedimentological logging.
Methodology:
There will be number of techniques used to develop geomorphological and sedimentological model soft-bed hydrology: 1) Daily Planet optical imagery and Sentinel 1 and 2 imagery will be used to assess short-term changes in glacier velocity in order to identify subglacial hydrology. Velocity data will be generated using the intensity tracking algorithm within the European Space Agency (ESA) Sentinel Application Platform (SNAP). We will also assess changes in the surface elevation of the glaciers and compute geodetic mass balances. This will be done by comparing multi-temporal DEMs, both pre-processed (such as the Arctic DEM, and the national LiDAR DEMs of Iceland); 2) use Planet and UAV data to map the glacier forelands of selected modern glaciers; 3) use oblique UAV survey to map Quaternary sections. Carry out sedimentological sediment logging on these mapped sections, including grainsize, facies identification and till fabric analysis; 4) This data will be entered into a GIS system for spatial analysis.
Location:
University of Southampton, Highfield Campus
Training:
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at the School of Geography and Environmental Science. Specific training will
include: Specific training will include: glaciology, glacial geomorphology and sedimentology, remote sensing, GIS and UAV survey. The student will have the opportunity to acquire a UAV pilot license, learn to use the Metashape photogrammetry processing, as well as the grain size laboratory equipment. The student will also carry out much of the RS and photogrammetry analysis on the SoGES high specification workstations.
Eligibility & Funding Details:
Please see https://inspire-dtp.ac.uk/how-apply for details.
Background Reading:
- Hart, J.K., Martinez, K., Basford, P.J., Clayton, A.I., Robson, B.A. and Young, D.S., 2019. Surface melt driven summer diurnal and winter multi-day stick-slip motion and till sedimentology. Nature communications, 10(1), p.1599.
- Hart, J.K., Young, D.S., Baurley, N.R., Robson, B.A. and Martinez, K., 2022. The seasonal evolution of subglacial drainage pathways beneath a soft-bedded glacier. Nature Communications Earth & Environment, 3(1), pp.1-13.
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