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| 利用谷歌“延时摄影”近30年数据发现加拿大北极滑坡加剧 |
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论文标题：Extremes of summer climate trigger thousands of thermokarst landslides in a High Arctic environment
期刊：Nature Communications
作者：Antoni G. Lewkowicz, Robert G. Way
发表时间：2019/04/02
数字识别码： 10.1038/s41467-019-09314-7
原文链接：https://www.nature.com/articles/s41467-019-09314-7
微信链接：https://mp.weixin.qq.com/s/KyBDI29rL0_KjoEstb1pww
本周《自然-通讯》发表的一篇论文Extremes of summer climate trigger thousands of thermokarst landslides in a High Arctic environment显示，在加拿大北极群岛的班克斯岛上，热融滑塌的数量在1984-2015年期间增加了60倍——热融滑塌是由多年冻土中的地下冰融化导致的滑坡。研究指出，滑塌数量从1984年的63个增加至2013年的最大值4077个。这项研究和越来越多的证据表明，寒冷的连续多年冻土可能对夏季的极端气候非常敏感。
图1: 热融滑塌的地图和卫星图。图源：Antoni G. Lewkowicz 和 Robert G. Way等
近来，热融滑塌在北极有增多趋势，但是这种趋势的开始时间以及与气候变化之间的联系尚未完全建立。
加拿大渥太华大学的Antoni Lewkowicz和Robert Way利用谷歌“延时摄影”（Timelapse）1984-2015年的数据集，发现整个班克斯岛30年里一共出现过4000多个热融滑塌。作者指出，85%以上的热融滑塌都集中在四个尤为炎热的夏季之后（分别在1998年、2010年、2011年和2012年），而半数左右的热融滑塌在30多年里一直保持活跃。此外，作者利用卫星成像发现，由于水体沉积物浓度会随热融滑塌增加，岛上285个湖泊的颜色从深蓝色变成了蓝绿色或米黄色。
图2：班克斯岛1984-2014年间活跃热融滑塌的观察资料。
图源：Antoni G. Lewkowicz 和 Robert G. Way等
根据热融滑塌的活动情况，作者估计班克斯岛上已融化的冰量有1亿吨。
摘要：Retrogressive thaw slumps (RTS) – landslides caused by the melt of ground ice in permafrost – have become more common in the Arctic, but the timing of this recent increase and its links to climate have not been fully established. Here we annually resolve RTS formation and longevity for Banks Island, Canada (70,000 km2) using the Google Earth Engine Timelapse dataset. We describe a 60-fold increase in numbers between 1984 and 2015 as more than 4000 RTS were initiated, primarily following four particularly warm summers. Colour change due to increased turbidity occurred in 288 lakes affected by RTS outflows and sediment accumulated in many valley floors. Modelled RTS initiation rates increased by an order of magnitude between 1906–1985 and 2006–2015, and are projected under RCP4.5 to rise to >10,000 decade−1after 2075. These results provide additional evidence that ice-rich continuous permafrost terrain can be highly vulnerable to changing summer climate.
阅读论文全文请访问：https://www.nature.com/articles/s41467-019-09314-7
期刊介绍：Nature Communications(https://www.nature.com/ncomms/) is an open access journal that publishes high-quality research from all areas of the natural sciences. Papers published by the journal represent important advances of significance to specialists within each field.
The 2017 journal metrics for Nature Communications are as follows:
•2-year impact factor: 12.353
•5-year impact factor: 13.691
•Immediacy index: 1.829
•Eigenfactor® score: 0.92656
•Article Influence Score: 5.684
（来源：科学网）
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