Kääb Andreas, Røste Julie
Department of Geosciences, University of Oslo, Oslo, Norway.
Nat Commun. 2024 Aug 31;15(1):7581. doi: 10.1038/s41467-024-52093-z.
Despite their extensive global presence and the importance of variations in their speed as an essential climate variable, only about a dozen global time series document long-term changes in the velocity of rock glaciers - large tongue-shaped flows of frozen mountain debris. By analysing historical aerial photographs, we reconstruct here 16 new time series, a type of data that has not previously existed for the North American continent. We observe substantial accelerations, as much as 2-3 fold, in the surface displacement rates of rock glaciers across the mountains of the western contiguous United States over the past six to seven decades, most consistent with strongly increasing air temperatures in that region. Variations between individual time series suggest that different local and internal conditions of the frozen debris bodies modulate this overall climate response. Our observations indicate fundamental long-term environmental changes associated with frozen ground in the study region.
尽管它们在全球广泛存在，且其速度变化作为一个关键气候变量具有重要意义，但仅有大约十几个全球时间序列记录了岩石冰川（由冻结的山间碎屑形成的大型舌状流）速度的长期变化。通过分析历史航空照片，我们在此重建了16个新的时间序列，这类数据在北美大陆此前并不存在。我们观察到，在过去六到七十年间，美国西部毗邻山区的岩石冰川表面位移速率大幅加速，高达2至3倍，这与该地区气温的急剧上升最为相符。各个时间序列之间的差异表明，冻结碎屑体不同的局部和内部条件调节了这种整体气候响应。我们的观测结果表明，研究区域内与冻土相关的长期基本环境发生了变化。
