2026-09-01 北海道大学,名古屋大学国立極地研究所
カナック氷河で実施した観測（左）と氷河上を激しく流れる融解水（右）の様子。
＜関連情報＞
- https://www.hokudai.ac.jp/news/2026/09/13-19.html
- https://www.cambridge.org/core/journals/journal-of-glaciology/article/surface-mass-balance-and-ice-dynamics-of-qaanaaq-ice-cap-northwestern-greenland-kalaallit-nunaat-from-2012-to-2025/AC6708216C0E86BF3E7587BE0140C825
2012年から2025年におけるグリーンランド北西部カナック氷帽の表面質量収支と氷流動 Surface mass balance and ice dynamics of Qaanaaq Ice Cap, northwestern Greenland (Kalaallit Nunaat), from 2012 to 2025
Takuro Imazu,Shin Sugiyama,Kaho Watanabe,Ken Kondo and Shun Tsutaki
Journal of Glaciology Published:18 June 2026
DOI:https://doi.org/10.1017/jog.2026.10178
Abstract
To investigate glacier mass loss and ice dynamics in northwestern Greenland, we measured surface mass balance (SMB), ice velocity and surface elevation from 2012 to 2025 on Qaanaaq Glacier, an outlet glacier of Qaanaaq Ice Cap. Stake measurements at six locations along the central flowline suggested an ice-cap-wide mass loss of −8.01 ± 0.22 m w.e. over the 13-year period. Horizontal ice velocities decreased by 8–64% in the ablation area, whereas the change was insignificant in the upper reaches. The emergence velocity varied from −0.35 ± 0.10 m a−1 above the equilibrium line altitude to 0.94 ± 0.12 m a−1 near the terminus. Along the flowline, the glacier surface elevation decreased by 8.7 m on average. Ice thinning accelerated from 2012–2019 to 2019–2025 in the lower reaches (<500 m a.s.l.). Approximately 50% of this change was due to a decrease in the emergence velocity, and the remainder was attributed to a more negative SMB. In contrast, the thinning rate showed little change in the upper reaches (>800 m a.s.l.), where an increase in the emergence velocity compensated for the increasingly negative SMB. This study highlights the essential role of ice dynamics in surface elevation change.
