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

为了应对气候变化，全球许多温带冰川，包括冰岛东南部的Skeidarjokull，正在退缩。与这种退缩相关的是冰前湖的出现和扩张。这些冰前湖导致冰水平原（sandar）与冰川分离或分离。因此，原本会沉积在桑达尔上的沉积物反而被困在这些湖泊中，导致远端桑达尔的沉积物匮乏，这反过来又影响了河流和海岸系统。最近形成的冰前湖也提供了新的挑战jokulhlaup灾害评估。尽管它们的重要性，一直没有详细的研究大规模的冰川前沉积系统进行主动脱钩，沉积物通量和景观发展的这一过程的作用仍然不清楚。2021年12月，格里姆火山冰下湖从Skeidarjokull排出0.9 km3的水作为jokulhlaup。这提供了一个难得的机会，捕捉地貌和沉积特征的jokulhlaup在水下设置和评估的作用，冰前湖在改变下游河流和海岸系统的响应。该项目的总体目标是提高认识的地形和沉积组合的jokulhlaup在冰前湖，并评估这些湖泊的影响，对冰川冲积和Skeidararsandur海岸系统。冰岛东南部。收集和分析2021年12月jokulhlaup的数据将能够准确预测和建模未来更大事件的影响，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.