南海南部晚第四纪表层海水温度的变化及其与极地冰芯古气候记录的比较  

LATE QUATERNARY CHANGES OF SEA SURFACE TEMPERATURE IN THE SOUTHERN SOUTH CHINA SEA AND THEIR COMPARISON WITH THE PALEOCLIMATIC RECORDS OF POLAR ICE CORES

作　　者：翦知湣[1] 王博士[1] 乔培军[1] 

机构地区：[1]同济大学海洋地质国家重点实验室,上海200092

出　　处：《第四纪研究》2008年第3期391-398,共8页Quaternary Sciences

基　　金：国家重点基础研究发展规划项目(批准号:2007CB815900);国家自然科学基金项目(批准号:40621063);大洋协会“十一五”项目(批准号:DY115-01-2-3)联合资助

摘　　要：本次研究选取南海南部"太阳号"95航次17961-2柱状样(8°30.4′N,112°19.9′E,水深1795m,柱长10.3m)的175块样品进行浮游(Globigerinoides ruber)和底栖有孔虫(Cibicidoides wuellerstorfi)的氧碳稳定同位素及浮游有孔虫G.ruber壳体的Mg/Ca比值测定,再造了距今约140ka以来时间分辨率约800年的表层海水温度(SST)变化,揭示末次冰期南海南部的SST曾降温达约5℃,且存在类似Dansgaard-Oeschger(D/O)事件的千年尺度波动。将南海南部的研究结果与极地冰芯古气候记录进行对比,发现在千年时间尺度上南海南部SST的变化特征与南极冰芯的古气候变化相一致,而与格陵兰冰芯δ18O所展示的锯齿状形态D/O事件的变化不一样,且最近的两个末次冰消期南海南部SST与代表高纬冰盖体积大小的底栖有孔虫δ18O几乎同步变化,反映南海南部热带海区古气候变化的特殊性,为进一步研究低纬热带海区在全球古气候变化中的作用提供了新证据。A total of 175 sediment samples of core 17961 - 2 （ 8°30.4＇N, 112° 19.9＇E, water depth 1795m, core length 10.3m） ,taken from the southern South China Sea（SCS） during the SONNE Cruise 95 ,were analyzed for the oxygezl and carbon stable isotopes of planktonic （ Globigerinoides ruber） and benthic （ Cibicidoides wueUerstorfi） foraminifers and the measurements of Mg/Ca ratios of G. ruber shells,in order to reconstruct the sea surface temperature（SST） changes at a general time resolution of average ca. 800a over the past ca. 140ka. It has been revealed that the SST of the southern SCS had ever dropped about 5℃ and displayed Dansgaard-Oeschger（ D/O）-like millennial-scale fluctuations. The comparison of the paleoclimatic records between the southern SCS and polar region shows that on millennial time-scale the SST change of the southern SCS was consistent with the paleoclimatic changes in the Antarctic region,but different from the sawteeth-like D/O events recorded in the Greenland ice-core δ^18O. During the last two deglaciations,the SST change of the southern SCS was found parallel to that of benthic δ^18O which is indicative of high-latitude ice volume,reflecting the particularity of the paleoclimatic changes in tropical sea of the southern SCS,and providing new evidence for the study on the role of the lower latitude tropical sea in the global climatic changes.

关 键 词：南海南部 表层海水温度 Mg/ca比值测定 高低纬度气候联系 晚第四纪 

分 类 号：P534.63[天文地球—第四纪地质学] P736.22[天文地球—古生物学与地层学]