Links between iron supply from Asian dust and marine productivity in the Japan Sea since four million years ago
Links between iron supply from Asian dust and marine productivity in the Japan Sea since four million years ago
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四百万年前亚洲尘埃的铁供应与日本海海洋生产力之间的联系
DOI：
10.1017/s0016756819000554
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发表时间：
2019
影响因子：
2.3
通讯作者：
Li Anchun
中科院分区：
文献类型：
--
作者：
Zhai Lina;Wan Shiming;Tada Ruyji;Zhao Debo;Shi Xuefa;Yin Xuebo;Tang Yang;Li Anchun
摘要沙尘输入对海洋生态地球化学循环有重要影响，并可能控制大气CO2浓度。然而，在西北太平洋长期风尘供应和初级生产力之间的可能联系仍然知之甚少。在这里，我们提出了一个全面的研究，主要和微量元素和总有机碳（TOC）的浓度从综合大洋钻探计划（IODP）网站U1430在日本海南部的沉积物，以重建海洋古生产力的演变，并测试其可能的联系，亚洲尘埃输入自4马。古生产力指标表明，1.3 -2 Ma期间生产力显著增加，1.2Ma以来生产力出现高频振荡。我们认为，更高的尘埃衍生铁供应从中亚在3-2 Ma，这可能是由北方冰盖的增长，可以解释提高初级生产力和出口生产在日本海。这种海洋古生产力的增加可以增强有机碳的埋藏，这可能有助于降低大气CO2浓度，并对全球变冷提供积极的反馈。然而，对马暖流（TSWC）通过对马海峡南部的入侵，这是由冰川海平面变化控制的，一直是初级生产力和底栖生物氧化还原条件的快速变化的主要原因，自1.2 Ma以来，无论是不断增加的亚洲粉尘输入。
Abstract Aeolian dust input exerts significant influence on oceanic biogeochemical cycles and further potentially controls atmospheric CO2 concentrations. However, the possible link between long-term aeolian dust supply and primary productivity in the western North Pacific remains poorly understood. Here, we present a comprehensive study of major and trace elements and total organic carbon (TOC) concentrations of sediments from Integrated Ocean Drilling Program (IODP) Site U1430 in the southern Japan Sea, in order to reconstruct oceanic palaeoproductivity evolution and test its possible link to Asian dust input since 4 Ma. Palaeoproductivity proxies indicate remarkable increases in productivity at ∼3–2 Ma followed by high-frequency oscillations in productivity since 1.2 Ma. We suggest that higher dust-derived iron supply from Central Asia at 3–2 Ma, which was likely driven by the growth of the Northern Hemisphere ice sheets, could account for enhanced primary productivity and export production in the Japan Sea. Such increased oceanic palaeoproductivity could enhance organic carbon burial, which might contribute to the decrease in atmospheric CO2 concentrations, and provide a positive feedback to the global cooling. However, the Tsushima Warm Current (TSWC) intrusion via the southern Tsushima Strait, which was controlled by glacioeustatic sea level changes, has been the principal cause of the rapid changes in primary productivity and benthic redox condition since 1.2 Ma, regardless of continuously increased Asian dust input.