Remote sensing of avalanches on mountain glaciers
| Autor: | Kneib, Marin, Dehecq, Amaury, Karbou, Fatima, Karas, Anna, Leinss, Silvan, Brun, Fanny, Wagnon, Patrick, Maussion, Fabien |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| Popis: | Avalanches are important contributors to the mass balance of glaciers located in mountain ranges with steep topographies. They result in localized accumulation that is seldom accounted for in glacier models, due to the difficulty to quantify this contribution, let alone the occurrence of avalanches in these remote regions. Here, we apply an automated mapping approach developed to map snow avalanches from Sentinel-1 SAR images to characterize the avalanche activity in the Mt. Blanc massif (European Alps) and the Khumbu region (High Mountain Asia) for the period 2017-2021. These two regions are characterized by steep topographies, but also present contrasting climatic characteristics, with most of the solid precipitation falling during the winter in the Alps and during the summer monsoon in Nepal. Our validation efforts with Pléiades and Venus optical satellite images show the limitations of the detection with Sentinel-1 imagery when it comes to small frequent avalanche events or when the snow water content is high. Beyond these limitations, the results highlight the variety in avalanche events, from small and frequent avalanches from steep headwalls to occasional large events from hanging glaciers. in this regard, linking the size-frequency of avalanche events with the characteristics of their source area enables us to highlight the topo-climatic controls of these events at the catchment scale. This study is part of the recently started research project CAIRN (contribution of avalanches to glacier mass balance), which aims at improving the representation of avalanches in large-scale glacier models based on detailed remote sensing and field observations. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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