Subglacial Access and Fast Ice Research Experiment (SAFIRE): Resolving the Basal Control on Ice Flow and Calving in Greenland

以海洋为终点的出水口冰川消耗了格陵兰冰盖88%的冰，造成了至少一半的冰盖年净质量损失，目前约为200立方千米/年。了解驱动这些冰川快速流动的过程是至关重要的，因为越来越多的证据表明，对海洋和大气强迫的反应是强烈的，但在空间上是不同的，而且往往是复杂的。虽然已知其他地方的冰川床对冰的流动有强烈的影响，但从未在格陵兰岛的海洋冰川下进行过观测；在目前的海平面上升预测中，一个潜在的和可能的重大错误的原因。该项目将通过进入西格陵兰岛主要的海洋终端出口冰川（Store Gletscher）的底部来纠正这种观测限制的缺乏，以便观察和描述基底界面。通过在冰川床、冰川表面和前场部署仪器，该项目将全面解决对冰流的基础控制和冰川对冰山崩解的反应，包括融水输入到冰川床的影响。观测结果将为冰川对大气和海洋强迫的敏感性提供信息，同时也使冰流数值模拟具有前所未有的细节和精度。

Marine-terminating outlet glaciers drain 88% of the Greenland Ice Sheet and are responsible for at least half of the ice sheet's net annual mass loss, which at present is around 200 km3/year. Understanding the processes that drive the fast flow of these glaciers is crucial because a growing body of evidence points to a strong, but spatially varied and often complex, response to both oceanographic and atmospheric forcing. While the bed of glaciers elsewhere is known to strongly influence the flow of ice, no observations have ever been made from beneath a marine-terminating glacier in Greenland; a potential and likely cause of significant error in current predictions of sea level rise. This project will correct this paucity of observational constraint by gaining access to the bed of a major marine-terminating outlet glacier (Store Gletscher) in West Greenland, in order to observe and characterise the basal interface. With instruments deployed at the bed and on the glacier's surface and forefield, the project will fully resolve the basal control on ice flow and the glacier's response to iceberg calving, including the effects of meltwater input to the bed. The observational outcome will inform the glacier's sensitivity to atmospheric as well as oceanographic forcing while also enabling numerical ice flow modelling of unprecedented detail and accuracy.