Bathymetry data reveal glaciers vulnerable to ice‐ocean interaction in Uummannaq and Vaigat glacial fjords, west Greenland
Bathymetry data reveal glaciers vulnerable to ice‐ocean interaction in Uummannaq and Vaigat glacial fjords, west Greenland
复制标题
测深数据显示格陵兰岛西部乌玛纳克和瓦伊加特冰川峡湾的冰川容易受到冰海相互作用的影响
DOI：
10.1002/2016gl067832
复制
发表时间：
2016
影响因子：
5.2
通讯作者：
D. Duncan
中科院分区：
文献类型：
--
作者：
E. Rignot;I. Fenty;Yun Xu;C. Cai;I. Velicogna;C. Ó. Cofaigh;J. Dowdeswell;W. Weinrebe;G. Catania;D. Duncan
海洋终止冰川在控制格陵兰冰盖质量平衡方面发挥着关键作用。它们的锋面边缘与海洋相互作用，但我们对这种相互作用的理解有限，部分原因是缺乏测深数据。本文对格陵兰岛西部Uummannaq和Vaigat峡湾的14个冰川峡湾进行了多波束回声测深，这些峡湾从大陆架延伸到冰川前缘。数据显示了浅岩谷、冰川侵蚀造成的过深（约1300米）和比现有图表深100-1000米的海底深度。在峡湾足够深的地方，我们发现普遍存在温暖的、含盐的大西洋水（AW）（>2.5°C），具有高融化电位，但我们也发现许多冰川建立在浅（<200米）的基板上，站在寒冷（<1°C）的水域中，否则是深的峡湾，即融化电位降低。延伸到冰川锋面的水深观测对了解冰川演化至关重要。
Marine‐terminating glaciers play a critical role in controlling Greenland's ice sheet mass balance. Their frontal margins interact vigorously with the ocean, but our understanding of this interaction is limited, in part, by a lack of bathymetry data. Here we present a multibeam echo sounding survey of 14 glacial fjords in the Uummannaq and Vaigat fjords, west Greenland, which extends from the continental shelf to the glacier fronts. The data reveal valleys with shallow sills, overdeepenings (>1300 m) from glacial erosion, and seafloor depths 100–1000 m deeper than in existing charts. Where fjords are deep enough, we detect the pervasive presence of warm, salty Atlantic Water (AW) (>2.5°C) with high melt potential, but we also find numerous glaciers grounded on shallow (<200 m) sills, standing in cold (<1°C) waters in otherwise deep fjords, i.e., with reduced melt potential. Bathymetric observations extending to the glacier fronts are critical to understand the glacier evolution.