Glaciers are generally considered to be important indicators of climate, but the variability in glacier behaviour observed across the Canadian Arctic Archipelago (CAA) indicates that not all ice masses respond in the same way to external forcing. This thesis presents detailed studies on the contrasting behaviour of two ice masses with widely different characteristics: Good Friday Glacier on western Axel Heiberg Island, a large marine-terminating outlet glacier which has undergone an uninterrupted advance over the last seven decades, and Bowman Glacier in Tanquary Fiord, northern Ellesmere Island, a small mountain glacier destined to disappear within a few decades.
Changes of these glaciers are determined from field and remote sensing observations, with a particular focus on digital photogrammetry techniques applied to recent and historical aerial photography for generating topographic datasets. Strategies are presented for the flexible acquisition of high-resolution topographic data in challenging field conditions, typical of high arctic glacier environments, and a workflow is described for deriving detailed surface reconstructions, yielding centimetre-scale digital elevation models and orthomosaics of a small ice mass in the CAA. This work also demonstrates the application of current digital photogrammetry processing for deriving surface elevation information from historical aerial photography from the 1950s, enabling direct comparison with recent topographic products to calculate glacier volume change and geodetic mass balance over decadal timescales.
Observations on Good Friday Glacier show a continuous advance totalling >9 km since the late 1940s, representing a 5% increase in glacier area over a total basin size of 800 km², and ice flow rates higher than on most other marine-terminating glaciers in the CAA. In contrast, since 1959, Bowman Glacier lost 78% of its area and 60% of its volume and currently covers only 0.61 km². Projecting the trend in ice extent and surface thinning observed over the last decade indicates that Bowman Glacier will likely disappear entirely between 2030-60. While the ongoing advance of Good Friday Glacier is out of sync with current climatic conditions, changes at Bowman Glacier are in agreement with the dominant regional trend of accelerated mass loss and glacier retreat.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/43981 |
| Date | 30 August 2022 |
| Creators | Medrzycka, Dorota |
| Contributors | Copland, Luke |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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