夏季南黄海悬浮体粒度分布及其影响因素  

Grain size distribution pattern and influencing factors of suspended matters in the Southern Yellow Sea during summer season

作　　者：李文建 王珍岩[1,2,3,4] 黄海军 LI Wenjian;WANG Zhenyan;HUANG Haijun(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Laboratory for Marine Mineral Resources,Pilot National Laboratory for Marine Science and Technology,Qingdao 266071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao,266071,China)

机构地区：[1]中国科学院海洋研究所海洋地质与环境重点实验室,青岛266071 [2]青岛海洋科学与技术试点国家实验室,海洋矿产资源评价与探测技术功能实验室,青岛266071 [3]中国科学院大学,北京100049 [4]中国科学院海洋大科学研究中心,青岛266071

出　　处：《海洋地质与第四纪地质》2020年第6期49-60,共12页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金面上项目“黄海冷水团沉积动力过程及其沉积环境效应”(41476045);中国科学院战略性先导科技专项“地球大数据科学工程”(XDA19060401);“美丽中国生态文明建设科技工程”(XDA23050502)。

摘　　要：南黄海是东亚海区陆源物质向西太平洋扩散的重要通道,阐明该海区悬浮体粒度特征及其分布规律对于深入揭示中国东部陆架海区源汇沉积体系形成机制具有重要意义。利用2012年夏季在南黄海调查获取的水文环境资料和悬浮体现场粒度(LISST)观测数据,分析悬浮体粒度分布特征及其影响因素,探讨其在南黄海中部泥质区成因机制中的作用。结果表明:夏季,南黄海悬浮颗粒中≤128μm的细颗粒主要是由无机矿物颗粒组成,而>128μm的粗颗粒则由有机颗粒主导。无机颗粒主要分布在混合作用较强的近岸浅水区以及远岸的近底水层,有机颗粒在水体层化较强海域的密度跃层处占据主导地位。再悬浮的海底表层沉积物是海水中无机颗粒的主要来源,潮混合过程是引起再悬浮作用的主要动力因素。潮混合锋阻挡了近岸高浓度无机悬浮颗粒物沿近底层向远岸扩散,但跨锋面的表层离岸流可以将近岸区的部分无机细颗粒物输运至南黄海中部。密度跃层阻碍了冷水团内营养盐进一步向海表扩散,导致浮游植物在密度跃层处富集;大量浮游生物及其分泌物与细小的无机颗粒相结合形成絮集体是海水中>128μm粗颗粒的主要来源。絮集体的形成促进了表层无机细颗粒向海底沉降,促进了泥质区的形成。The Southern Yellow Sea is an important passage for transporting terrigenous materials from the East Asian continent to the western Pacific Ocean.It is of great significance to clarify the size and distribution patterns of the particles transported through the Southern Yellow Sea for further understanding the source to sink system of the region.In this paper,we analyzed the grain size distribution and its influencing factors based on the hydrological and LISST data measured in the Southern Yellow Sea during the summer season of 2012.The results show that fine particles(≤128μm)are mainly composed of inorganic particles,while the coarse(>128μm)dominated by organic particles during the summer season.The inorganic particles are mainly distributed in the well-mixed coastal shallow area and the bottom layer offshore,while organic particles mainly occupy the pycnocline where the water is highly stratified.The resuspended surface sediment is the main source of inorganic particles,and the tidal mixing process is the main driving force of resuspension.The tidal mixing front prevents the coastal inorganic particles from spreading to the offshore area in bottom layer,but some finer particles(<16μm)can be transported to the central Southern Yellow Sea by surface cross-front currents.The pycnocline obstructs the upward diffusion of nutrients inside the Yellow Sea Cold Water Mass,which leads to the accumulation of phytoplankton in the pycnocline.The coarse particles(>128μm)are mainly from the plankton or aggregates formed by organic secretion mixed with fine inorganic particles.The formation of aggregates enhances the sedimentation of surface fine inorganic particles and promotes the formation of mud deposits.

关 键 词：悬浮体 粒度分布 泥质沉积 黄海冷水团 南黄海 

分 类 号：P736.21[天文地球—海洋地质]