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

主要目标是确定该地点冰盖推进的多个阶段的时间和持续时间。该学生将研究一组独特的不稳定鹅卵石，这些鹅卵石来自教皇冰川旁边的一个nunatak，它们的大小和岩性各不相同，尽管它们都沉积在相同的海拔高度，但它们的风化特征也各不相同。除了利用导师Johnson和Roberts在野外活动中对不稳定物的地貌环境进行的充分记录的观察外，学生还将应用使用多种宇宙形成核素进行暴露年龄测定的技术。该组中的22个样本保存在BAS的档案中。学生将首先确定其不同的岩性和风化特征，然后选择一部分样品进行宇宙成因分析。制备用于10Be AMS测量的纯石英和目标（如果需要，也可以制备26Al）将由学生在帝国理工学院的导师Rood实验室进行。然后，他们将选择多达10个样品进行原位宇宙成因14C测量，以确定该地点冰盖重新推进的持续时间和时间。第二个目标是使用遥感（World View 2和3卫星图像，加上主管Roberts获得的无人机图像）来探测教皇冰川附近冰峰上冰川不稳定的常见区域。菲利帕梅森（帝国）将监督这部分项目。在实地活动之前使用遥感有可能更有效地进行地表暴露测年取样，从而节省与南极偏远实地工作有关的时间和费用。

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.