Improving geological constraints on Holocene ice sheet change in Antarctica using cosmogenic nuclides and remote sensing
File(s)
Author(s)
Adams, Jonathan
Type
Thesis
Abstract
The implementation of effective policy-based solutions to mitigate the global impact of sea-level rise is hampered by large uncertainty surrounding how the Antarctic Ice Sheet will evolve beyond the 21st century in response to climate change. Much of this uncertainty is because models used for predicting ice sheet evolution lack realistic representations of underlying physical processes that take place over timescales spanning centuries or longer. Geological records provide the constraints required to validate model simulations on such timescales (centuries to millennia) but must be precise enough to adequately resolve past ice sheet change at the centennial-scale. Such records have been made possible by the application of cosmogenic nuclides to measure the exposure of rock outcrops and glacial deposits above the ice surface. Here, I apply the cosmogenic nuclide technique in the Amundsen Sea sector of Antarctica, a region currently experiencing extremely high rates of ice mass loss. Firstly, I show how the ice sheet thinned by at least 560 metres between 8.1 – 6.3 ka, with demonstrable centennial-scale precision. Such precision enables me to infer this area deglaciated over 1000 years earlier than previously thought. Secondly, I conduct a thorough analysis of the 14C-10Be paired nuclide technique. My results demonstrate further work is required to improve measurement precision of in situ 14C, so that its pairing with other nuclides can be applied to generate sub-millennial scale deglacial records with high confidence...
Version
Open Access
Date Issued
2024-05-03
Date Awarded
01/08/2024
License URL
Advisor
Johnson, Joanne
Rood, Dylan
Mason, Philippa
Roberts, Stephen
Sponsor
Natural Environment Research Council (Great Britain)
Grant Number
NE/S006710/1
NE/S006753/1
Publisher Department
Earth Science & Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)