Global clustering of recent glacier surges from radar backscatter data, 2017–2022

• Published in: Journal of Glaciology
• Main Authors: Kääb, Andreas, Bazilova, Varvara, Leclercq, Paul Willem, Mannerfelt, Erik Schytt, Strozzi, Tazio
• Other Authors: Norges Forskningsråd, European Space Agency
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2023
• Subjects: Earth-Surface Processes; glacier; glaciers; Journal of Glaciology; Svalbard; Alaska; Yukon
• Online Access: http://dx.doi.org/10.1017/jog.2023.35; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143023000357

Abstract Using global Sentinel-1 radar backscatter data, we systematically map the locations of glaciers with surge-type activity during 2017–22. Patterns of pronounced increases or decreases in the strongest backscatter between two winter seasons often indicate large changes in glacier crevassing, which we treat here as a sign of surge-type activity. Validations against velocity time series, terminus advances and crevassing found in optical satellite images confirm the robustness of this approach. We find 115 surge-type events globally between 2017 and 2022, around 100 of which on glaciers already know as surge-type. Our data reveal a pronounced spatial clustering in three regions, (i) Karakoram, Pamirs and Western Kunlun Shan (~50 surges), (ii) Svalbard (~25) and (iii) Yukon/Alaska (~9), with only a few other scattered surges elsewhere. This spatial clustering is significantly more pronounced than the overall global clustering of known surge-type glaciers. The 2017–22 clustering may point to climatic forcing of surge initiation.