Collaborative Research: Initiation, Propagation, and Termination: Understanding coupled hydrologic and glacier dynamic instabilities from the surge of Turner Glacier

冰川和冰盖正在迅速缩小，对当地水资源、溪流、河流、峡湾和海洋的地球化学性质以及全球海平面上升都有影响。随着气温变暖，冰川融化的水可以被输送到冰川底部，在那里冰与下面的基岩相遇。这些水的加入导致一些冰川的冰流急剧加速，另一些冰川的冰流变化很小，甚至其他冰川的冰流减速。冰流的变化可能是戏剧性的和不稳定的，导致冰川的快速损失，无法使用目前的冰流模型预测。该项目旨在通过研究一种称为冰川激增的事件，更好地了解冰川水文学和冰流之间的联系，在这种事件中，冰流在几年内急剧增加。该项目将对阿拉斯加东南部特纳冰川的冰川激增进行综合实地、遥感和建模研究。在这里获得的科学见解将广泛适用于北极和南极许多地区的冰川和冰盖条件，减少未来几十年全球冰川损失预测的不确定性。该项目将通过跨学科的包容性研究、外展和社区建设，加强爱达荷州两所最大大学的冰川研究项目。该项目将收集现场地震，雷达，大地测量，气象和时间推移的水文和冰川动力学不稳定性发生在整个即将到来的特纳冰川激增的图像。该小组将结合联合收割机现场观测与卫星派生的冰川速度，海拔，终点位置和冰下羽流数据，以绘制冰川下的融水路线在启动，传播和终止的激增。这些数据将与最先进的水文数值模拟相结合，以研究整个涌浪期间水文和动态冰川不稳定性控制的演变。前所未有的数据集，加上现代模型，将产生改进的，基于过程的理解一个基本的，50多年的，在冰川学的一阶问题：是什么控制着冰川潮的开始，传播和终止？鉴于冰川水文学、基底过程和冰川流动之间的相互作用仍然是冰川学中最基本的问题之一，该项目的结果具有广泛的社会影响。对气候引发的冰川流动快速不稳定性的任何见解将大大提高我们对冰川变化的预测能力，以及我们了解冰质量损失对地球系统影响的能力。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Glaciers and ice sheets are rapidly shrinking, with implications for local water resources, biogeochemical properties of streams, rivers, fjords, and oceans, and global sea level rise. As air temperatures warm, melting water from glaciers can be transported to the base of the glaciers where the ice meets the bedrock below. The addition of this water has caused dramatic acceleration of ice flow for some glaciers, small flow changes in others, and even deceleration for other glaciers. Changes in ice flow can be dramatic and unstable, leading to rapid glacier loss that cannot be predicted using current ice flow models. This project aims to better understand the links between glacier hydrology and ice flow by studying an event called a glacier surge during which the ice flow increases dramatically for a period of a few years. The project will conduct an integrated field, remote sensing, and modeling study of a glacier surge at Turner Glacier in Southeast Alaska. The scientific insights gained here will have broad applicability across glacier and ice sheet conditions in many parts of the Arctic and Antarctic, reducing uncertainties in predictions of global glacier loss in the coming decades. The project will strengthen the glacier research programs at Idaho’s two largest universities through interdisciplinary inclusive research, outreach, and community building. The project will collect in-situ seismic, radar, geodetic, meteorological, and time-lapse imagery of hydrologic and glacier dynamics instabilities occurring throughout the upcoming surge of Turner Glacier. The team will combine in-situ observations with satellite-derived glacier velocity, elevation, terminus position, and subglacial plume data to map meltwater routing beneath the glacier during the initiation, propagation, and termination of the surge. These data will be paired with a state-of-the-art hydrologic numerical modeling to investigate the evolution of the controls on the hydrologic and dynamic glacier instabilities throughout the full surge. The unprecedented dataset, coupled with modern models, will yield improved, process-based understanding of a fundamental, 50-plus year-old, first-order question in glaciology: What controls the initiation, propagation, and termination of glacier surges? Given that the interplay between glacier hydrology, basal processes, and glacier flow remains one of the most fundamental questions in glaciology, the results of this project have broad societal impacts. Any insights into rapid instabilities in glacier flow triggered by climate will considerably advance our predictive capabilities of glacier change, and our ability to understand the impacts of ice mass loss on the Earth system.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.