The biogeochemical impact of glacial meltwater from Southwest Greenland
The biogeochemical impact of glacial meltwater from Southwest Greenland
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DOI：
10.1016/j.pocean.2019.102126
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发表时间：
2019-09-01
影响因子：
4.1
通讯作者：
Woodward, E. Malcolm S.
中科院分区：
文献类型：
--
作者：
Hendry, Katharine R.;Huvenne, Veerle A. I.;Woodward, E. Malcolm S.
高纬度地区的生物地球化学循环对全球养分收支有着不成比例的影响。在这里，我们介绍了一个整体的，多学科的框架，阐明冰川融水，陆架流和生物生产对高纬度大陆边缘的地球化学循环的影响，重点是硅循环。我们的研究结果突出了显着的冰川排放营养供应的影响，货架和斜坡沃茨，以及在这些地区的表面和底栖生物生产，在一系列的时间尺度从几天到几千年。虽然生物吸收在峡湾和沿海沃茨的硅藻活性强，保持低溶解硅浓度的表面沃茨，我们发现重要的，但空间异质添加到系统中的颗粒，这是迅速远离海岸。我们预计，冰川衍生的颗粒-与生物硅测试-将通过浅层沉积物快速循环，导致溶解硅的强底栖通量。夹带到边界流的这种底栖硅可能会提供一个重要的来源，这一关键的营养物质进入拉布拉多海，也有可能再循环回深峡湾近岸。这项研究说明了如何地球化学和海洋学分析可以一起使用，以进一步探讨现代养分循环在这一地区，以及古气候学的方法来调查冰川融水排放的变化，通过时间，特别是在晚第四纪气候变化迅速的时期。
Biogeochemical cycling in high-latitude regions has a disproportionate impact on global nutrient budgets. Here, we introduce a holistic, multi-disciplinary framework for elucidating the influence of glacial meltwaters, shelf currents, and biological production on biogeochemical cycling in high-latitude continental margins, with a focus on the silica cycle. Our findings highlight the impact of significant glacial discharge on nutrient supply to shelf and slope waters, as well as surface and benthic production in these regions, over a range of timescales from days to thousands of years. Whilst biological uptake in fjords and strong diatom activity in coastal waters maintains low dissolved silicon concentrations in surface waters, we find important but spatially heterogeneous additions of particulates into the system, which are transported rapidly away from the shore. We expect the glacially-derived particles - together with biogenic silica tests - to be cycled rapidly through shallow sediments, resulting in a strong benthic flux of dissolved silicon. Entrainment of this benthic silicon into boundary currents may supply an important source of this key nutrient into the Labrador Sea, and is also likely to recirculate back into the deep fjords inshore. This study illustrates how geochemical and oceanographic analyses can be used together to probe further into modern nutrient cycling in this region, as well as the palaeoclimatological approaches to investigating changes in glacial meltwater discharge through time, especially during periods of rapid climatic change in the Late Quaternary.