AbstractThe direct sampling of deep ice is an invaluable tool for environmental research, however the logistical, technical and financial difficulties associated with many direct sampling approaches renders them unfeasible for all but the largest research collaborations. This thesis considers two alternative sampling approaches, both of which utilise deep ice that has been exposed for surface sampling by the natural flow of glaciers. Namely, it presents the biogeochemical analysis of terminal blue ice from the Marble Hills Blue Ice Area (Antarctica) and calved icebergs from Lago Steffen (Chilean Patagonia). These samples were collected and analysed using straightforward, low-cost methodologies, available to a large number of glaciological researchers. These approaches are evaluated in terms of the usefulness of the data that can be obtained and the availability of potential sample sites for future investigation. In doing so, this thesis sheds light on new methodologies that could be employed to answer questions concerning glacial processes.
As well as exploring novel research approaches, this thesis offers original contributions to the knowledge of natural processes occurring within the vicinity of Horseshoe Valley Glacier (West Antarctic Ice Sheet) and Steffen Glacier (North Patagonian Icefield). The discussion of the Antarctic samples centres on the subglacial origin of the ice, which is indicated by the non-meteoric relationship between δ2H and δ18O and the high concentrations of certain nutrients (CaCO3, SO42–, DOC) corresponding with subglacial environments. This also reveals the dominant chemical processes occurring at the bed. The discussion of iceberg samples employs similar techniques with a different focus: augmented by samples of local rivers and precipitation, it considers the impact of Steffen Glacier on downstream freshwater systems. This thesis therefore emphasises how readily-available deposits of deep ice can be utilised for a wide range of contemporary research questions.
|Date of Award||23 Jan 2019|
|Supervisor||Jemma L Wadham (Supervisor)|