李青, 李铁刚, 常凤鸣, 曹奇原. 近7300 aBP以来冲绳海槽北部上升流的演化[J]. 海洋地质与第四纪地质, 2008, 28(2): 65-70.
引用本文: 李青, 李铁刚, 常凤鸣, 曹奇原. 近7300 aBP以来冲绳海槽北部上升流的演化[J]. 海洋地质与第四纪地质, 2008, 28(2): 65-70.
LI Qing, LI Tie-gang, CHANG Feng-ming, CAO Qi-yuan. EVOLUTION OF UPWELLING IN THE NORTH OF THE OKINAWA TROUGH SINCE ABOUT 7 300 aBP[J]. Marine Geology & Quaternary Geology, 2008, 28(2): 65-70.
Citation: LI Qing, LI Tie-gang, CHANG Feng-ming, CAO Qi-yuan. EVOLUTION OF UPWELLING IN THE NORTH OF THE OKINAWA TROUGH SINCE ABOUT 7 300 aBP[J]. Marine Geology & Quaternary Geology, 2008, 28(2): 65-70.

近7300 aBP以来冲绳海槽北部上升流的演化

EVOLUTION OF UPWELLING IN THE NORTH OF THE OKINAWA TROUGH SINCE ABOUT 7 300 aBP

  • 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 dutertrei δ18O的记录以及表层海水温度、温跃层深度的变化揭示了近7300 aBP以来日本九州西南海区上升流的演化过程。7300~7000 aBP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;7000~4800 aBP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4800~4200 aBP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。1900~1200 aBP期间上升流发育程度有所减弱,1200~400 aBP之间上升流的发育又逐渐增强,到约400aBP以后,N.dutertrei δ18O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400 aBP以来是区域上升流发育程度最强的时期。

     

    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 7 300~47 000 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; 7 000~44 800 aBP, the environment kept stable, but the upwelling began to develop; during 4 800~44 200 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 2004400 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.

     

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