EAR-Climate: Acquisition of hydrometric equipment to support undergraduate training and research on glacier lake outburst floods in southeast Alaska

随着每年夏天冰川融化，并由于气候变暖而随着时间的推移而消退，冰川融化的水的化学性质发生了变化。研究冰川释放出的融化水的物理和化学特性非常重要，因为它直接影响下游湖泊、溪流和沿海海域的质量。阿拉斯加东南部的海岸山脉正在经历地球上一些最高的冰川融化速度。随着冰川的缩小，它们留下了新形成的景观和水体，如在冰川前面集水的湖泊(前冰川湖泊)，以及被冰川冰筑坝的冰川边缘的湖泊(冰川筑坝湖泊)。这样的湖泊可以捕获沉积物、营养物质、碳和其他元素，阻止它们向下游移动。此外，冰川筑坝的湖泊如果冰坝坍塌，可能会突然释放大量的水，造成洪水危险，并向下游输送大量泥沙和溶解的化学物质。随着阿拉斯加数以千计的冰川目前正在消退，至关重要的是确定冰川集水区正在发生的变化的特征和数量，并更好地了解其生态影响。我们将使用声学多普勒测速仪和通过该项目获得的其他设备来跟踪流经和流出阿拉斯加东南部冰川堰塞湖和冰川湖的水和沉积物的数量和质量。为此，我们将让阿拉斯加东南大学和当地高中的本科生参与并培训他们，帮助下一代地球科学家掌握应对冰川变化、水文动力学、地球表面过程和自然灾害所需的技能和工具。气候变化导致阿拉斯加海岸山脉的冰川以地球上最快的速度消退。冰川质量损失的增加正在导致(1)冰川湖泊的增长，这些湖泊可以极大地改变流域的沉积物和化学物质的输出，以及(2)冰川堤坝湖泊的增长，这可能会产生危险的冰川湖泊暴发洪水，并向下游生态系统释放大量生物地球化学元素和沉积物。了解碳、水、沉积物和汞等金属在这些与冰川相关的湖泊中和通过这些湖泊的储存和释放对于解释冰川退缩和随之而来的景观变化将如何影响当前和未来的化学和沉积物通量非常重要。随着全球变暖的持续和冰川的进一步减少，冰川集水区不断变化的物理和化学输出将对接受影响的水生生态系统产生影响，包括食物网结构和生产力、污染物的可用性、沿海沉积物中的有机碳埋藏、向大气中排放二氧化碳以及沿海海洋酸化的季节性时间和强度。在这个项目中，我们将通过购买声学多普勒测速仪、水质探测仪和多探头水质测定仪来监测阿拉斯加东南部冰川变化的水文影响，以便在阿拉斯加朱诺的冰川门登霍尔分水岭使用。这些水文仪器将用于通过阿拉斯加东南大学的课堂实验室和研究助学金来培训本科生，这是一所阿拉斯加本土的本科生服务的小型大学，并将用于吸引当地高中生。这些仪器将使我们能够进一步开发一个研究计划，旨在了解冰川融化和GLOF对向阿拉斯加东南部高产沿海流域的沉积物和化学品出口的动态和后果。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

As glaciers melt each summer and recede over the years due to the warming climate, the chemical nature of their meltwater changes. Studying the physical and chemical characteristics of the meltwater released from glaciers is important because it directly affects the quality of downstream lakes, streams, and coastal marine zones. The Coastal Mountains of southeast Alaska are experiencing some of the highest glacial melt rates on Earth. As the glaciers shrink, they leave behind newly formed landscapes and waterbodies such as lakes collecting water in front of the glacier (proglacial lakes) and lakes on the edges of glaciers that are dammed by the glacier ice (glacially dammed lakes). Such lakes can trap sediment, nutrients, carbon, and other elements, preventing them from moving downstream. Additionally, glacially dammed lakes can suddenly release massive outbursts of water if their ice dam fails, creating flooding hazards and sending a surge of sediment and dissolved chemicals downstream. With thousands of glaciers currently receding in Alaska, it is critical to characterize and quantify the ongoing changes in glacierized watersheds and to better understand their ecological impacts. We will track the quantity and quality of water and sediment moving through and out of a glacially dammed lake and a proglacial lake in southeast Alaska using the acoustic doppler velocimeter and other equipment acquired through this project. In doing so, we will involve and train undergraduate students from the University of Alaska Southeast and the local high school, helping to equip the next generation of earth scientists with the skills and tools they need to address glacier change, hydrologic dynamics, Earth surface processes, and natural hazards.Climate change has triggered glaciers in the Coastal Mountain of Alaska to recede at some of the highest rates on Earth. Increased glacier mass loss is causing the growth of (1) proglacial lakes that can dramatically alter sediment and chemical export from watersheds and of (2) glacially-dammed lakes, which can produce hazardous glacial lake outburst floods (GLOFs) and release a large pulse of biogeochemical elements and sediment to downstream ecosystems. Understanding the storage and release of carbon, water, sediment, and metals such as mercury in and through these glacier-associated lakes is important for explaining how glacier retreat and ensuing landscape change will affect current and future chemical and sediment fluxes. As warming continues and glaciers further diminish, the changing physical and chemical outputs from glaciated watersheds will have implications for recipient aquatic ecosystems, including food web structure and productivity, availability of contaminants, organic carbon burial in coastal sediments, CO2 outgassing to the atmosphere, and the seasonal timing and intensity of coastal ocean acidification. In this project, we will monitor the hydrometric impacts of glacial change in southeast Alaska by acquiring an Accoustic Doppler Velocity meter, water quality sondes, and a multi-probe water quality meter for use in the glacierized Mendenhall watershed in Juneau, Alaska. The hydrometric instruments will be used to train undergraduate students through class labs and research assistantships at the University of Alaska Southeast, which is a small, Alaska-native serving, undergraduate university, and to engage local high school students. The instruments will allow us to further develop a research program aimed at understanding the dynamics and consequences of glacier melt and GLOFs on sediment and chemical export to the highly productive coastal watersheds of southeast Alaska.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.