The effects of continental margins and water mass circulation on the distribution of dissolved aluminum and manganese in Drake Passage
The effects of continental margins and water mass circulation on the distribution of dissolved aluminum and manganese in Drake Passage
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DOI：
10.1029/2011jc007434
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发表时间：
2012
影响因子：
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通讯作者：
R. Middag;D. Baar;P. Laan;O. Huhn
中科院分区：
文献类型：
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作者：
R. Middag;D. Baar;P. Laan;O. Huhn
共232个样品进行了分析溶解铝（[Al]）和锰（[Mn]）在德雷克通道的浓度。[Al]和[Mn]在中间德雷克通道的表层都极低（分别为0.3和0.1 nM），最有可能是由于有限的输入和生物吸收/清除。在南美洲大陆架，[Al]（>14 nM）和[Mn]（>2 nM）升高与陆地径流有关，而南极半岛附近浓度升高（分别>1 nM和>2 nM）最有可能与沉积物重新悬浮有关。沉积颗粒和孔隙沃茨的再悬浮作用影响了德雷克海峡两侧陆坡上[Al]和[Mn]的分布。大陆边缘的影响和积累的灰尘输入可能解释了较高的[Al]东观察到在南大洋的大西洋部分。在北方德雷克海峡，海底附近的[Al]（类似于0.8 nM）和[Mn]（类似于0.3 nM）升高很可能是相对较强的海流使海底沉积物重新悬浮的结果。在德雷克海峡南部深处，与威德尔海深水流入相关的沉积物再悬浮似乎导致[Al]（>1 nM）和[Mn]（类似于0.4 nM）升高。在北方德雷克海峡深处，北大西洋深水带来了升高的[Al]，东南太平洋深水斜坡水带来了太平洋热液喷口的特征。高[Mn]和三角洲的He-3相关的这一水层，最有可能起源于火山活动的洋脊在太平洋。
A total of 232 samples were analyzed for concentrations of dissolved aluminum ([Al]) and manganese ([Mn]) in Drake Passage. Both [Al] and [Mn] were extremely low (similar to 0.3 and 0.1 nM, respectively) in the surface layer of the middle Drake Passage, most likely due to limited input and biological uptake/scavenging. Elevated [Al] (>14 nM) and [Mn] (>2 nM) over the South American continental shelf are related to land run-off, whereas elevated concentrations (>1 nM and >2 nM, respectively) near the Antarctic Peninsula are most likely related to sediment re-suspension. Re-suspension of sedimentary particles and pore waters influences the distribution of [Al] and [Mn] over the continental slopes on both sides of Drake Passage. The influence of the continental margins and accumulated dust input potentially explains the higher [Al] observed eastward in the Atlantic section of the Southern Ocean. In the northern Drake Passage, elevated [Al] (similar to 0.8 nM) and [Mn] (similar to 0.3 nM) near the seafloor are most likely the result of bottom sediment re-suspension by the relatively strong currents. In the deep southern Drake Passage sediment re-suspension associated with the inflow of Weddell Sea Deep Water appears to cause elevated [Al] (>1 nM) and [Mn] (similar to 0.4 nM). In the deep northern Drake Passage, North Atlantic Deep Water brings in elevated [Al] and Southeast Pacific Deep Slope Water brings in the signature of Pacific hydrothermal vents. Elevated [Mn] and delta He-3 were correlated in this water layer and are most likely originating from the volcanically active ridges in the Pacific Ocean.