Variability in iron (II) oxidation kinetics across diverse hydrothermal sites on the northern Mid Atlantic Ridge
Variability in iron (II) oxidation kinetics across diverse hydrothermal sites on the northern Mid Atlantic Ridge
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DOI：
10.1016/j.gca.2021.01.013
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发表时间：
2021-02-04
影响因子：
5
通讯作者：
Santana-Casiano, J. Magdalena
中科院分区：
文献类型：
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作者：
Gonzalez-Santana, David;Gonzalez-Davila, Melchor;Santana-Casiano, J. Magdalena
最近确认的深海清单铁的主要来源之一是大洋中脊的热液活动。很少有人知道铁（II）在这些环境中的氧化动力学，特别是对物理化学参数，如温度（T），pH值，粒度分级和有机物的影响的依赖。在GA 13号段航行期间采集样本后，对沿着大西洋中脊的六个热液喷口地点（Menez Gwen、Lucky Strike、Rainbow、迷城、Broken Spur和TAG）的铁（II）氧化情况进行了调查，结果显示变化很大。在两个站点（彩虹和TAG）的多个站点的Fe（II）氧化速率常数分析显示，除T和pH值外，其他因素控制氧化过程。在不同pH值下对颗粒尺寸分级和有机物的影响的实验表明，有机配体和胶体尺寸颗粒的存在延迟了氧化过程，同时不影响整体pH依赖性。将我们的分析扩展到一组选定热液样本在温度（2至25摄氏度）和pH值（7至8之间）范围内的Fe（II）氧化速率常数之间更广泛的关系，使我们能够推导出一个多参数方程来模拟铁（II）海洋中的氧化速率常数。该方程比以前发表的方程覆盖了更大的温度范围，提高了其对全球地球化学模型的适用性。(C)2021由Elsevier Ltd.出版
One of the recently recognized main sources of iron to the deep ocean inventory is the hydrothermal activity associated with mid-ocean ridges. Little is known about the oxidation kinetics of iron(II) within these environments, especially the dependence on physico-chemical parameters such as temperature (T), pH, particle size-fractionation and the effect of organic matter. Following sample collection during the GA13 section cruise, the iron(II) oxidation at six hydrothermal vent sites (Menez Gwen, Lucky Strike, Rainbow, Lost City, Broken Spur and TAG) along the Mid-Atlantic Ridge were investigated, revealing high variability. The Fe(II) oxidation rate constant analysis from multiple stations at two sites (Rainbow and TAG), revealed that factors, other than T and pH, controlled the oxidation process. Experiments on the effect of particle size-fractionation and organic matter at different pH showed that the presence of organic ligands and colloidal size particles delayed the oxidation process, while not affecting the overall pH dependency. Extending our analysis to the broader relationship between the Fe(II) oxidation rate constants across a range of temperatures (between 2 and 25 degrees C) and pH (between 7 and 8) on a set of selected hydrothermal samples allowed us to derive a multiparametric equation to model the iron(II) oxidation rate constants in the ocean. This equation covers a larger range of temperatures than previous published equations, improving its applicability for global biogeochemical models. (C) 2021 Published by Elsevier Ltd.