Enhanced terrigenous organic matter input and productivity on the western margin of the Western Pacific Warm Pool during the Quaternary sea-level lowstands: Forcing mechanisms and implications for the global carbon cycle
Enhanced terrigenous organic matter input and productivity on the western margin of the Western Pacific Warm Pool during the Quaternary sea-level lowstands: Forcing mechanisms and implications for the global carbon cycle
复制标题
第四纪海平面低位期间西太平洋暖池西缘陆源有机质输入和生产力增强：强迫机制及其对全球碳循环的影响
DOI：
10.1016/j.quascirev.2020.106211
复制
发表时间：
2020
影响因子：
4
通讯作者：
Dhongil Lim
中科院分区：
文献类型：
--
作者：
Zhaokai Xu;Shiming Wan;Christophe Colin;Tiegang Li;Peter D. Clift;Fengming Chang;Rongtao Sun;Zhaojie Yu;Dhongil Lim
第四纪西太平洋暖池（WPWP）西缘陆源有机质（OM）输入、生产力和相关底水氧化还原条件的变化，以及这些变化的强迫机制和全球碳循环意义仍然存在争议。在这项研究中，我们利用菲律宾海大陆斜坡的一个岩心重建了水文动力学、陆源OM输入、生产力和深海氧化还原条件。新数据与来自同一岩心和来自菲律宾深海的另外两个岩心的已发布代理数据相结合。结果显示上述指标有明显的变化，与陆源物质供应的变化相对应。在第四纪海平面低洼期，陆坡沉积表现出暴露陆架松散沉积物强烈的物理侵蚀和化学风化信号，显著增加了陆源有机质输入和生产力，降低了底水氧合和大气co2浓度。在深海菲律宾海，增加的亚洲沙尘驱动的有机质输入和生产力也在海平面低水位期间充当了大气co2的汇。分析表明，陆源有机质输入和生物泵的增加，导致西洼带西缘底水溶解氧水平的降低，在海平面低洼期对全球碳循环的调节中发挥了重要作用。相比之下，第四纪水文动态对陆源有机质输入、生产力和氧化还原条件的影响有限。
Changes in terrigenous organic matter (OM) input, productivity and the associated bottom-water redox conditions, together with forcing mechanisms and global carbon cycle implications of such variations, on the western margin of the Western Pacific Warm Pool (WPWP) during the Quaternary remain controversial. In this study, we reconstructed the hydrological dynamics, terrigenous OM input, productivity, and deep-sea redox conditions using one core from the continental slope of the Philippine Sea. The new data were integrated with published proxies from the same core and two additional cores from the abyssal Philippine Sea. The results exhibited noticeable variations in the abovementioned indicators, in correspondence to changes in the supply of terrigenous material. The continental slope deposition featured signals of strong physical erosion and chemical weathering of unconsolidated sediments on the exposed continental shelf during the Quaternary sea-level lowstands, which significantly contributed to increased terrigenous OM input and productivity and, in turn, decreased bottom-water oxygenation and atmospheric CO2concentrations. In the abyssal Philippine Sea, increased Asian dust-driven OM input and productivity also acted as a sink of atmospheric CO2during sea-level lowstands. Analysis of the data suggested that the enhanced terrigenous OM input and biological pump and thus the decreased dissolved oxygen level of the bottom water on the western margin of the WPWP played important roles in modifying the global carbon cycle during sea-level lowstands. In contrast, the influence of hydrological dynamics on terrigenous OM input, productivity, and redox conditions therein during the Quaternary was limited.