Variations in upper water structure during MIS 3 from the western South China Sea  

作　　者：DU JiangHui HUANG BaoQi 

机构地区：[1]MOE Key Laboratory of Orogenic Belst and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871, China

出　　处：《Chinese Science Bulletin》2010年第3期301-307,共7页

基　　金：supported by the National Basic Re-search Program of China (Grant No. 2007CB 815901);National Natural Science Foundation of China (Grant No. 40306007);State Key Labora-tory of Paleobiology and Stratigraphy (Grant No. 033109)

摘　　要：Core 17954 is located in the modern summer upwelling area in western South China Sea, its sediments recorded the variations of upwelling generated by East Asia Summer Monsoon (EASM) during MIS 3. Based on the strict age model of AMS 14C dating, the paleo-Sea Surface Temperature (SST) and Salinity (SSS) are reconstructed by pairing Mg/Ca-Paleothermometer and δ 18o of planktonic foraminifera Globigerinoides ruber (white s.s.). Results show that in Core 17954, the δ 18O record of G.ruber has sig- nificant millennium fluctuations as the δ 18O records from NGRIP icecore and Hulu Cave stalagmites, this indicates that the cli- mate changes of western SCS contains both signals from High Latitude of Northern Hemisphere as well as EASM. In order to get more information on upwelling changes, previous records of thermocline and foraminiferal primary productivity in Core 17954 are collected, restudied and compared. Five distinct shallowing periods of thermocline (referred to as S1-S5) are identified in this study. In S1-S4, SST is lower and productivity is higher, these indicate to an enhanced upwelling and strengthened EASM during these periods. And the lower SSS, caused by increasing precipitation or fresh water input, also prove this standpoint.Core 17954 is located in the modem summer upwelling area in western South China Sea, its sediments recorded the variations of upwelling generated by East Asia Summer Monsoon （EASM） during MIS 3. Based on the strict age model of AMS ^14C dating, the paleo-Sea Surface Temperature （SST） and Salinity （SSS） are reconstructed by pairing Mg/Ca-Paleothermometer and δ^18o of planktonic foraminifera Globigerinoides ruber （white s.s.）. Results show that in Core 17954, the 6180 record of Gruber has significant millennium fluctuations as the δ^18O records from NGRIP icecore and Hulu Cave stalagmites, this indicates that the climate changes of western SCS contains both signals from High Latitude of Northem Hemisphere as well as EASM. In order to get more information on upwelling changes, previous records of thermocline and foraminiferal primary productivity in Core 17954 are collected, restudied and compared. Five distinct shallowing periods of thermocline （referred to as S 1-S5） are identified in this study. In S 1-S4, SST is lower and productivity is higher, these indicate to an enhanced upwelling and strengthened EASM during these periods. And the lower SSS, caused by increasing precipitation or fresh water input, also prove this standpoint.

关 键 词：南海西部海域 管理信息系统 中国 淡水 东亚夏季风 浮游有孔虫 结构 上层 

分 类 号：P618.13[天文地球—矿床学] TP399[天文地球—地质学]