Late Holocene elemental and isotopic carbon and nitrogen records from the East China Sea inner shelf: Implications for monsoon and upwelling
Late Holocene elemental and isotopic carbon and nitrogen records from the East China Sea inner shelf: Implications for monsoon and upwelling
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东海内陆架全新世晚期元素和同位素碳氮记录：对季风和上升流的影响
DOI：
10.1016/j.marchem.2014.03.008
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发表时间：
2014-05-20
期刊：
影响因子：
3
通讯作者：
Sun, Rongtao
中科院分区：
文献类型：
--
作者：
Hu, Bangqi;Li, Jun;Sun, Rongtao
东海（ECS）的特点是与东亚季风系统相关的相对较高的河流军事输入。在这项研究中，我们研究了来自 ECS 内陆架的 272 厘米长的沉积物岩心 (THB-2)，进行了 AMS C-14 测年、粒度、总有机碳 (TOC)、总氮 (TN) 以及稳定碳和氮（δ C-13 和 δ N-15）同位素，以深入了解之前的季风气候变化和沿海上升流的强度。应用三端元（河流、三角洲和海洋）混合模型来确定沉积有机质来源的时间变化。东海内陆架长江沿岸有机碳的迁移和埋藏受到全新世晚期季风气候和人类活动共同影响的强烈控制。 THB-2 岩心的沉积三角洲 N-15 记录更为复杂，最好的解释可能是沿海地区地表水域养分利用的变化。海洋有机质三角洲N-15的地下变化与近3.6ka东亚夏季风的强度密切相关。较强的东亚夏季风可能有利于3.6-2.7ka和0.4-0ka期间沿海上升流的强烈和长江的额外排放，从而引发沿海地表水相对较高的硝酸盐利用率。 (C) 2014 Elsevier B.V. 保留所有权利。
The East China Sea (ECS) is characterized by a relatively high riverine martial input that is associated with East Asian monsoon systems. In this study, we investigated a 272 cm-long sediment core (THB-2) from the ECS inner shelf for the AMS C-14 dating, grain size, total organic carbon (TOC), total nitrogen (TN), and stable carbon and nitrogen (delta C-13 and delta N-15) isotopes to provide insights into previous changes in the monsoon-climate and the intensity of the coastal upwelling. A three end-member (riverine, deltaic, and marine) mixing model was applied to determine the temporal variations in sedimentary organic matter sources. The transport and burial of the Changjiang riverine organic carbon in the ECS inner shelf is strongly controlled by the combined effects of the monsoon-climate and human activities during the late Holocene. The sedimentary delta N-15 records of the THB-2 core are more complex and may be best explained by changes in the nutrient utilization in the coastal zone surface waters. The downcore variations of the marine organic matter-delta N-15 are closely related to the intensity of East Asian summer monsoon during the last 3.6 ka. The stronger East Asian summer monsoon likely favored the intensive coastal upwelling and additional Changjiang discharge during the 3.6-2.7 ka and 0.4-0 ka periods, which triggered the greater relative nitrate utilization in the coastal surface water. (C) 2014 Elsevier B.V. All rights reserved.