Investigating marine-terminating glacier behaviour in Greenland

• Main Author: Bunce, Charlotte
• Other Authors: Nienow, Peter, Gourmelen, Noel, Newton, Anthony, Natural Environment Research Council (NERC)
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: The University of Edinburgh 2022
• Subjects: Greenland ice sheet; glaciology; ice-ocean interaction; climate change; Greenland; glacier; Ice Sheet; Journal of Glaciology
• Online Access: https://hdl.handle.net/1842/38616; https://doi.org/10.7488/era/1879

Recent changes at marine-terminating glaciers in Greenland have suggested a dynamic and sensitive response to climate via atmospheric and oceanic warming. Ice loss from marine-terminating glaciers has already contributed significantly to global sea level rise and this is likely to continue with future warming. However, understanding the processes connecting this warming to ice loss from marine-terminating glaciers remains confounded. This is in part due to the complex and dynamic interactions between various potential forcing mechanisms and also due to limited observations of marine-terminating glacier behaviour at sufficiently high spatial and temporal resolutions. This thesis combines remote sensing techniques and field-based observations to investigate ice loss at marine-terminating glaciers at a range of spatial and temporal scales. Here, the overarching aim is to better elucidate the dominant controls on ice loss at marine-terminating glaciers and thus the role they play in the sensitivity of the Greenland Ice Sheet to future environmental change. This thesis first aimed to address one of the primary gaps in observations regarding how key regions of the ice sheet have responded to environmental change, by deriving a detailed record of marine-terminating glacier terminus positions in southeast and northwest Greenland between 2000 and 2015. Through analysing these two key regions of ice loss alongside potential controls on retreat, the ambition was to better constrain the mechanisms driving region-wide change. The results revealed that irrespective of individual spatial or temporal variations in glacier terminus behaviour within or between these two regions, there was an overriding signal of marine-terminating glacier retreat (and thus ice loss) during the 21st Century. Overall, 97% of glaciers experienced terminus retreat, with mean annual retreat rates of -90 m a−1 and -70 m a−1 in the northwest and south-east respectively. This work also showed that changes in bed and fjord geometry were key controls on ...