Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean.
Glacial lake drainage in Patagonia (13-8 kyr) and response of the adjacent Pacific Ocean.
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DOI：
10.1038/srep21064
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发表时间：
2016-02-12
影响因子：
4.6
通讯作者：
Harrison S
中科院分区：
文献类型：
--
作者：
Glasser NF;Jansson KN;Duller GA;Singarayer J;Holloway M;Harrison S
在末次冰盛期后的冰川消退期间，北美和欧洲形成了大型淡水湖。这些湖泊迅速排入海洋导致了气候的突然扰动，包括新仙女木事件和8.2 kyr冷却事件。在南半球的中纬度地区，主要的冰川湖泊也在冰消期形成和排水，但对这些排水事件的规模、组织和时间及其对区域气候的影响知之甚少。我们使用16个新的单颗粒光释光（OSL）的日期来定义三个阶段的快速冰川湖排水在湖一般卡雷拉/湖布宜诺斯艾利斯和湖Cohrane/Pueyrredón盆地的巴塔哥尼亚，并提供第一次评估湖泊排水对太平洋的影响。湖泊排水发生在13和8 kyr前，最初是逐渐向东进入大西洋，然后重组向西进入太平洋的巴塔哥尼亚冰盖冰消期间开辟了新的排水路线。耦合的海洋-大气模型实验，采用HadCM 3与强加的淡水表面“软管”，以模拟冰川湖排水表明，负盐度异常平流南方周围的合恩角，导致沿海海洋垂直混合和区域气候的短暂但显着的影响。
Large freshwater lakes formed in North America and Europe during deglaciation following the Last Glacial Maximum. Rapid drainage of these lakes into the Oceans resulted in abrupt perturbations in climate, including the Younger Dryas and 8.2 kyr cooling events. In the mid-latitudes of the Southern Hemisphere major glacial lakes also formed and drained during deglaciation but little is known about the magnitude, organization and timing of these drainage events and their effect on regional climate. We use 16 new single-grain optically stimulated luminescence (OSL) dates to define three stages of rapid glacial lake drainage in the Lago General Carrera/Lago Buenos Aires and Lago Cohrane/Pueyrredón basins of Patagonia and provide the first assessment of the effects of lake drainage on the Pacific Ocean. Lake drainage occurred between 13 and 8 kyr ago and was initially gradual eastward into the Atlantic, then subsequently reorganized westward into the Pacific as new drainage routes opened up during Patagonian Ice Sheet deglaciation. Coupled ocean-atmosphere model experiments using HadCM3 with an imposed freshwater surface “hosing” to simulate glacial lake drainage suggest that a negative salinity anomaly was advected south around Cape Horn, resulting in brief but significant impacts on coastal ocean vertical mixing and regional climate.