Collaborative Research: The Influence of Hydrofracture and Surface Melt Variability on Greenland Ice Sheet Flow

与格陵兰湖排水相关的水力压裂事件产生了表面到床的管道，通过该管道，表面熔体以从夏季长的熔体流排放到突然的湖泊排水期间的大的瞬时脉冲的速率到达床。虽然最近的研究表明，增强的季节性润滑作用对格陵兰冰盖的不稳定影响可能比以前担心的要小，但表面融化和冰流之间的相互作用仍然没有受到很好的约束，其影响在目前的冰盖模型中没有得到很好的体现。该项目旨在通过对冰盖水力压裂的坚实的、基于物理的理解，以及通过表征表面融化对季节性和年际时间尺度上的冰盖流动的影响，为改善未来海平面上升评估做出贡献。获得这方面的知识是一个重要的步骤，整合增加的表面融化的影响，在模型推导的海平面预测。研究人员将使用综合地面和卫星观测的实验设计，再加上数值模型，以确定管理水力压裂的过程，并利用这种理解来确定格陵兰冰盖的面积是否？在气候变暖的情况下，暴露在表面融水中的海床将大大增加。这项研究的结果将通过这些研究人员的广泛持续努力向公众传播，包括K-12活动和公开讲座。一个作家-作家小组的直接参与还将使人们从当地角度了解和宣传气候变化对格陵兰社区的影响。我们的研究结果也将立即引起致力于了解格陵兰冰盖过去和未来变化的科学家的兴趣，包括理论和建模研究。该项目还将包括研究生直接参与WHOI和UW的实地和研究活动。

Hydrofracture events associated with lake drainages in Greenland create surface-to-bed conduits through which surface melt reaches the bed at rates ranging from that of summer-long melt-stream discharge to that of large, transient pulses during sudden lake drainages. While recent work suggests that enhanced seasonal lubrication may have less of a destabilizing effect on the Greenland Ice Sheet than once feared, the interaction between surface melt and ice flow remains poorly constrained and its influence is not well represented in current ice-sheet models. This project aims to contribute toward improving future sea-level rise assessments by achieving a firm, physically based understanding of ice-sheet hydrofracture, and by characterizing the influence of surface melt on ice-sheet flow over seasonal and inter-annual time scales. Acquisition of this knowledge is an important step toward integrating the influence of increased surface melt in model-derived sea level projections. The investigators will use an experimental design of integrated ground- and satellite-based observations coupled to numerical models to determine the processes that govern hydrofracturing and use this understanding to determine whether the area of the Greenland Ice Sheet?s bed exposed to surface meltwater will increase substantially in a warming climate. The results of this research will be disseminated to the public through extensive ongoing efforts of these investigators including K-12 activities and public lectures. The direct involvement of a photographer-writer team will also bring a local dimension to understanding and communicating the impact of climate change on Greenland communities. Our results will also be of immediate interest to scientists working to understand past and future changes to the Greenland Ice Sheet, including theoretical and modeling studies. This project will also include direct graduate student involvement in field and research activities at both WHOI and UW.