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

主要目的是确定冰盖在现场推进的多个阶段的时间和持续时间。学生将与一套独特的不稳定的鹅卵石从一个冰原岛峰旁边的教皇冰川是广泛变化的大小和岩性，以及具有不同的风化特征，尽管所有已沉积在同一海拔。学生将应用暴露年龄测年技术，使用多种宇宙成因核素，除了绘制在由主管约翰逊和罗伯茨实地活动期间所做的地形地貌背景的充分记录的观察。该套件中的22份样本保存在BAS的档案室中。学生将首先确定其不同的岩性和风化特征，然后选择一个样本子集进行宇宙成因分析。在伦敦帝国理工学院的鲁德实验室，学生将负责制备10 Be AMS测量（和26 Al，如果需要）所需的纯石英和靶。然后，他们将选择最多10个样本进行原位宇宙成因14 C测量，以确定冰盖在现场重新前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，以及监督员罗伯茨获得的无人机图像）来检测教皇冰川附近的冰原岛峰上常见的冰川不规则区域。菲利帕梅森（帝国）将监督该项目的这一部分。在实地考察之前使用遥感技术有可能提高表面暴露年代测定的采样效率，从而节省与南极远程实地考察有关的时间和费用。

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.