Immediate jokulhlaup (glacier outburst flood) impacts in a recently decoupled proglacial meltwater system, Skeidararjokull, SE Iceland.

作为对气候变化的回应，世界上许多温带冰川，包括冰岛东南部的斯基达拉冰川，正在退缩。与这种退缩相关的是前冰期湖泊的出现和扩张。这些前冰期湖泊导致冲积平原（砂砂）与冰川分离或分离。因此，原本会沉积在砂砂上的沉积物被困在这些湖泊中，导致远端砂砂的沉积物被剥夺，进而影响河流和海岸系统。最近形成的前冰期湖泊也为冰川灾害评估提供了新的挑战。尽管它们很重要，但目前还没有对大尺度前冰期沉积体系进行主动解耦的详细研究，并且这一过程对沉积物通量和景观发育的作用尚不清楚。2021年12月，Grimsvotn冰下湖从Skeidararjokull喷出0.9立方公里的水。这为在水下环境中捕捉冰川的地貌和沉积特征提供了难得的机会，并评估了前冰期湖泊在改变下游河流和海岸系统响应方面的作用。该项目的总体目标是提高对jokulhlaups对前冰川湖内地貌和沉积组合的影响的认识，并评估这些湖泊对斯基达尔桑德尔冰川河流和海岸系统的影响。SE冰岛。收集和分析2021年12月jokulhlaup的数据将能够对未来更大事件的影响进行准确预测和建模，这将有助于我们的项目合作伙伴冰岛气象局提供更好的洪水预警。

In response to climate change many temperate glaciers worldwide, including Skeidararjokull in SE Iceland, are retreating. Associated with this retreat is the appearance and expansion of proglacial lakes. These proglacial lakes lead to the outwash plains (sandar) being disconnected or decoupled from the glacier. Consequently, the sediment that would otherwise be deposited on the sandar is instead trapped within these lakes, leading to sediment deprivation of the distal sandar which in-turn impacts the fluvial and coastal systems. The recent formation of proglacial lakes also provides new challenges jokulhlaup hazard assessment. Despite their importance, there have been no detailed studies of large-scale proglacial sedimentary systems undergoing active decoupling, and the role of this process for sediment flux and landscape development remains unclear. In December 2021 Grimsvotn subglacial lake drain 0.9 km3 of water as a jokulhlaup from Skeidararjokull. This provides a rare opportunity to capture the geomorphological and sedimentary signature of a jokulhlaup within a subaqueous setting and assess the role that proglacial lakes have in altering the response of the downstream fluvial and coastal system.The overall aim of the project is to improve understanding of the impact of jokulhlaups on landform and sedimentary assemblages within proglacial lakes and assess the impact of these lakes on the glacifluvial and coastal system of Skeidararsandur. SE Iceland. The collection and analysis of data from the 2021 December jokulhlaup will enable accurate prediction and modeling of the impacts of larger future events that will assist our project partners, the Icelandic Meteorological Office, to provide better early warning of floods.