近岸强海流切变锋作用下悬浮沉积物的输送和沉积——以山东半岛东端外海为例  

Suspended Sediment Transport and Deposition due to Strong Regional Shear Current Front: an example from the shelf waters off eastern Shandong Peninsula

作　　者：王勇智[1,2] 乔璐璐[3] 杨作升[3] 鲍献文[3] 赵美训[3] 王关锁[1,4] 

机构地区：[1]国家海洋局第一海洋研究所,山东青岛266061 [2]国土资源部海洋油气资源与环境地质重点实验室,山东青岛266071 [3]中国海洋大学,山东青岛266100 [4]海洋环境科学和数值模拟国家海洋局重点实验室,山东青岛266061

出　　处：《沉积学报》2013年第3期486-496,共11页Acta Sedimentologica Sinica

基　　金：我国陆架海生态环境演变过程;机制及未来变化趋势预测(编号:2010CB428901);国家自然科学基金项目(批准号:40906025);"海陆相互作用和海岸带地质灾害研究"项目(编号:GZH201100203);我国近海海洋综合调查与评价专项(编号:908-01-ST02);山东优秀中青年奖励基金(编号:BS2012HZ022)联合资助

摘　　要：利用2007年国家908专项ST02区块(渤海海峡及北黄海)水体专项夏季和冬季两个航次调查的温度、浊度和悬浮体浓度数据,选取了跨越山东半岛东端外海泥质沉积体的B1和B2两个断面,结合该区浅地层剖面资料,辅以研究海域的冬季环流数值模拟,着重分析了山东半岛东端外海强海流切变锋作用下的悬浮体输送和沉积特征。结果表明山东半岛东端外海悬浮体向外海输送存在类似"夏储冬输"的规律:夏季,北黄海海水浊度普遍小,不仅北黄海温跃层抑制了底层悬浮体向中上层水体扩散,而且北黄海冷水团在中底层与山东半岛东部沿岸水也形成了显著的温度和悬浮体锋面,阻碍了悬浮物的纬向输送,故夏季应是悬浮体沉积的主要时节;冬季,温跃层消亡,在强风的作用下,山东半岛东部悬浮体浓度高且垂向混合较好,然而在泥质沉积体顶积层两侧,山东半岛东部沿岸中下层北上的逆风补偿流和北上的黄海暖流与位于顶积层上方表中层南下的沿岸流构成了两道显著的强海流切变锋,使得底积层上大量的再悬浮沉积物不能越过山东半岛东部陆架末梢,从而有助于形成山东半岛东端外海特有的Ω状泥质沉积体。Based on field data of temperature, turbidity and suspended matter concentration in summer and winter de- rived from the project named National Coastal Sea Comprehensive Investigation and Evaluation （908-ST02）, the sus- pended sediment transport and deposition due to strong regional shear current front off eastern Shandong Peninsula were studied, combined with observation from B1 and B2 sections, circulation simulation in winter by POM model and shallow seismic profile. The results show that the transportation mechanism of suspended matter off eastern Shandong Peninsula is similar to the existing rule in East China Sea： deposition in summer and transport in winter. In summer, not only suspended matter was restricted near bottom by thermocline, but also restricted by the front formed by coastal currents off eastern Shandong Peninsula and northern Yellow Sea cold water mass. Therefore suspended matter mainly deposited in summer. In winter, with the help of strong northeastly wind and the thermocline, the turbidity was high vertical mixing was better off eastern Shandong Peninsula. However, two strong shear current fronts could be found on both sides of the top-set of mud wedge, which was respectively generated by northward upwind compensation current along eastern Shandong Peninsula in the middle and lower water, northward Yellow Sea warm currents and southward coastal wind currents above topset of mud wedge. The two strong shear current fronts prevented suspended sediments from bottom-set of the mud wedge getting cross eastern Shandong Peninsula continental shelf peripheral, which was helpful to omega-shaped （ Ω ） mud wedge formation off eastern Shandong Peninsula.

关 键 词：悬浮体 北黄海冷水团 海流切变锋 黄海暖流 泥质沉积体 

分 类 号：P512.2[天文地球—地质学] P736.21