Evolution of the dynamics of Airdrop Glacier, western Axel Heiberg Island, over a seven-decade-long advance

• Published in: Arctic Science
• Main Authors: Benoît Lauzon, Luke Copland, Wesley Van Wychen, William Kochtitzky, Robert McNabb
• Format: Article in Journal/Newspaper
• Language: English; French
• Published: Canadian Science Publishing 2024
• Subjects: glacier dynamics; glacier surging; remote sensing; Axel Heiberg Island; Canadian Arctic; Environmental sciences; GE1-350; Environmental engineering; TA170-171; Arctic; Iceberg*; Nunavut
• Online Access: https://doi.org/10.1139/as-2022-0045; https://doaj.org/article/a8d607200c4c48b781e8bbaa5f3a6e04

Various remotely sensed data, including historical aerial photographs, declassified intelligence satellite photographs, optical satellite imagery, and synthetic aperture radar data, were used to undertake the first comprehensive reconstruction of the dynamics of Airdrop Glacier on Axel Heiberg Island, Nunavut. Observations show a continuous terminus advance totalling ∼6 km since 1950 and notably less variability in its surface velocities in comparison to adjacent Iceberg Glacier. This advance is concurrent with relatively high flow rates over its entire surface, resulting in significant thickening near the terminus and thinning at higher elevations. Velocities have more than halved from the mid-2000s to 2021, but without any definitive evidence of previous flow instabilities, we cannot confirm whether Airdrop's behaviour is cyclic in nature and therefore characteristic of a surge. Instead, Airdrop Glacier could be experiencing a delayed response to the positive mass balance conditions of the Little Ice Age, which could also explain the advance of other nearby glaciers. Its recent slowdown could then be indicative of a gradual adjustment to recent climatic conditions. This study highlights the need for comprehensive studies of glacier dynamics in the Canadian Arctic to improve our understanding of the factors triggering dynamic instabilities and causing the observed variety of behaviours.