【摘要】 对取自冲绳海槽北部的DOC024岩心进行了浮游有孔虫氧同位素和统计分析,依据浮游有孔虫群落组合和Neogloboquadrina dutertreiδ18O的记录以及表层海水温度、温跃层深度的变化揭示了近7300aBP以来日本九州西南海区上升流的演化过程。7300~7000aBP期间,较轻的δ18O值、较高的年平均表层海水温度以及典型上升流种Globigerina bulloides的低含量和较大的温跃层深度指示这一时期该海区上升流尚不发育,其环境主要受黑潮暖流的控制;7000~4800aBP期间,区域环境略有变化,上升流开始出现,但发育程度不高;在4800~4200aBP期间,各环境参数的变化都说明该时期为上升流的迅速发育期,并逐渐取代黑潮成为该区环境的主要控制因素。1900~1200aBP期间上升流发育程度有所减弱,1200~400aBP之间上升流的发育又逐渐增强,到约400aBP以后,N.dutertreiδ18O的明显加重、年平均表层海水温度的显著下降、Globigerina bulloides含量的快速增加和温跃层的明显变浅指示近400aBP以来是区域上升流发育程度最强的时期。更多还原

【Abstract】 Cores DOC024,retrieved from the northern Okinawa Trough in the East China Sea,are used to reconstruct the upwelling evolution over the last 7 300 years based on a multi-proxy approach including the combination of planktonic foraminifer fauna,Neogloboquadrina dutertrei δ18O,sea surface temperature(SST)and depth of thermocline.At about 7 300~7 000 aBP,light δ18O,high SST,low Globigerina bulloides % and deep thermocline show that the region was controlled by the warm Kuroshio current and there was no upwelling;7 000~4 800 aBP,the environment kept stable,but the upwelling began to develop;during 4 800~4 200 aBP,all proxies changed quickly,which indicates that the upwelling developed rapidly and gradually and controlled the environment;from 1 900 to 1 200 aBP,the upwelling declined slightly;around 1 200~400 aBP,the upwelling gradually increased;since 400 aBP,δ18O of N.dutertrei increased quickly,SST declined rapidly,Globigerina bulloides% increased fast and depth of thermocline declined obviously,all varieties of proxies point out that the upwelling developed strongly.更多还原