Geological history constraints on grounding line retreat in the Thwaites Glacier Systems

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The primary objective is to determine the timing and duration of multiple phases of ice sheet advance over the site. The student will work with a unique suite of erratic cobbles from a nunatak next to Pope Glacier that are of widely varying size and lithology, as well as having differing weathering characteristics despite all having been deposited at the same elevation. The student will apply the technique of exposure age dating using multiple cosmogenic nuclides, in addition to drawing on the well-documented observations of geomorphological context of the erratics made during a field campaign by supervisors Johnson and Roberts. 22 samples from this suite are held in the archive at BAS. The student will initially work on identifying their different lithological and weathering characteristics before choosing a subset of samples for cosmogenic analysis. Preparation of pure quartz and targets for 10Be AMS measurement (and 26Al if required) will be undertaken by the student in supervisor Rood's laboratory at Imperial College London. They will then select up to 10 samples for in situ cosmogenic 14C measurement, to determine the duration and timing of ice sheet re-advances over the site.A secondary objective is to use remote sensing (World View 2 and 3 satellite imagery, plus drone imagery obtained by supervisor Roberts) to detect areas where glacial erratics are common on nunataks near Pope Glacier. Philippa Mason (Imperial) will supervise this part of the project. Using remote sensing in advance of field campaigns has the potential to enable more efficient sampling for surface exposure dating and thus save time and expenses associated with remote Antarctic fieldwork.