A high-resolution environmental and climate record of change in the Holocene sediments of Windermere, UK

• Main Author: Fielding, John, James
• Format: Thesis
• Language: English
• Published: University of Southampton 2018
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: https://eprints.soton.ac.uk/427040/; https://eprints.soton.ac.uk/427040/1/Fielding_James_PhD_Thesis_Nov_18.pdf

The Holocene (11,750 Yrs. B.P. – present day) provides valuable examples of climate change in response to natural and anthropogenic forcing, by which future forecasting models can be validated. However, reliable climate and environmental observations rarely extend beyond the past 200 years. In this case proxy-based reconstructions can extend the record further. The sediments and water of Windermere, NW England, have been studied since the 1930s. These studies show the potential of the sediments to create a record of environment and climate change which extends from the Pleistocene to the present day. It’s location in the NE Atlantic region means it is ideally suited to record changes in climate and environment which are affected by globally important systems such as the North Atlantic Oscillation, Atlantic sea surface temperatures and the North Atlantic Currents. This thesis aims to firstly provide preliminary results of a multiproxy study of the whole Holocene sediment sequence from Windermere’s North Basin. A combination of organic, geochemical, and sediment microfabric analysis complemented by a chironomid inferred mean July temperature and pollen community reconstruction show the potential for the Holocene sediments of Windermere to record major climate events such as the 4.2 k. Yrs. B.P. cooling event. More detailed analysis has identified mass transport deposits (MTDs) in the early Holocene, likely caused by seismic instability induced by isostatic readjustment following deglaciation. The sediments of Windermere have also been impacted by anthropogenic activities since at least the beginning of the industrial revolution. However, the full impact of this activity is as yet unknown. With this in mind this thesis aims to provide a detailed history of anthropogenic impacts on the water column and sediments. Using gravity cores collected from Windermere in 2014 this thesis presents a novel combination of techniques to relate microscopic sediment fabric features to lake-basin scale processes. Together ...