Evidence for Pathways of Concentrated Submarine Groundwater Discharge in East Antarctica from Helicopter-Borne Electrical Resistivity Measurements
Evidence for Pathways of Concentrated Submarine Groundwater Discharge in East Antarctica from Helicopter-Borne Electrical Resistivity Measurements
复制标题
DOI：
10.3390/hydrology6020054
复制
发表时间：
2019-06-01
期刊：
影响因子：
3.2
通讯作者：
Virginia, Ross
中科院分区：
文献类型：
--
作者：
Foley, Neil;Tulaczyk, Slawek M.;Virginia, Ross
南大洋从南极大陆接收有限的液态地表水输入。然而，据推测，大量的液态水可能从南极冰盖下流出，这种冰下水流将水与溶解的营养物质一起沿着到海岸。向南大洋输送溶质，特别是限制营养物质，如生物可利用铁，可能有助于生态系统进程，包括初级生产力。使用一个机载时域电磁测量沿着南维多利亚地，南极洲的麦克默多干谷地区的沿海边缘，我们发现内陆湖泊，含水层，冰下沃茨之间的地下连接。这些沃茨表现为导电异常，是盐水，可能含有高浓度的生物重要离子，包括铁和二氧化硅。当地的水力梯度可能会驱使这些沃茨到海岸，在那里我们假设他们出现海底地下水排放。这个高纬度地下水系统，在麦克默多干旱山谷区域成像，可能是一个更广泛的南极海底地下水排放系统，肥沃南大洋的代表。总的来说，它有可能向沿海地区提供数十千兆克的生物可利用的铁和硅。
The Southern Ocean receives limited liquid surface water input from the Antarctic continent. It has been speculated, however, that significant liquid water may flow from beneath the Antarctic Ice Sheet, and that this subglacial flow carries that water along with dissolved nutrients to the coast. The delivery of solutes, particularly limiting nutrients like bioavailable iron, to the Southern Ocean may contribute to ecosystem processes including primary productivity. Using a helicopter-borne time domain electromagnetic survey along the coastal margins of the McMurdo Dry Valleys region of Southern Victoria Land, Antarctica, we detected subsurface connections between inland lakes, aquifers, and subglacial waters. These waters, which appear as electrically conductive anomalies, are saline and may contain high concentrations of biologically important ions, including iron and silica. Local hydraulic gradients may drive these waters to the coast, where we postulate they emerge as submarine groundwater discharge. This high latitude groundwater system, imaged regionally in the McMurdo Dry Valleys, may be representative of a broader system of Antarctic submarine groundwater discharge that fertilizes the Southern Ocean. In total, it has the potential to deliver tens of gigagrams of bioavailable Fe and Si to the coastal zone.