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

为了应对气候变化，世界各地的许多温带冰川正在消退，包括冰岛东南部的Skeidarjokull冰川。与这种退缩相关的是冰川湖泊的出现和扩张。这些冰川湖泊导致外溢平原(桑达尔)与冰川断开或脱钩。因此，原本应该沉积在桑达河上的沉积物反而被困在这些湖泊中，导致桑达河远端的沉积物被剥夺，进而影响河流和海岸系统。最近冰川湖泊的形成也给约库拉普风险评估带来了新的挑战。尽管它们很重要，但还没有对经历主动脱钩的大规模冰川沉积系统进行详细研究，而且这一过程对沉积物通量和景观发展的作用尚不清楚。2021年12月，格里姆斯沃顿冰下湖泊从Skeidarjokull排出0.9千米的水。这提供了一次难得的机会来捕捉水下环境中的约库拉隆湖的地貌和沉积特征，并评估冰川湖泊在改变下游河流和海岸系统的响应方面所起的作用。该项目的总体目标是增进对乔库勒劳普湖对前冰川湖泊内地貌和沉积组合的影响的了解，并评估这些湖泊对斯凯达达桑杜尔冰川河流和海岸系统的影响。冰岛东南部。收集和分析2021年12月JOKULHLAUP的数据将使我们能够准确预测和模拟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.