南海西部晚更新世以来表层海水剩余氧同位素及盐度变化  

VARIABILITY OF SEA SURFACE RESIDUAL OXYGEN ISOTOPIC AND SALINITY IN WESTERN SOUTH CHINA SEA OVER LATE PLEISTOCENE

作　　者：李丽[1] 王慧[1] 李建如[1] 赵美训[1] 汪品先[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399-406,共8页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:40403012);同济大学青年优秀人才培养行动基金项目(批准号:2006KJ055);国家重点基础研究发展规划项目(批准号:2007CB815904);国家自然科学基金创新研究群体科学基金项目(批准号:40621063)资助

摘　　要：根据南海西部越南岸外MD05—2901岩芯成对的有孔虫壳体氧同位素和U37^k-SST计算出过去450ka以来南海西部表层海水氧同位素艿。δ^18Owater和盐度Swater，二者的变化范围在冰期分别为0．2％0—0．6‰和34．2％0～35．1‰，间冰期分别为-0．6％0～0和32．4‰-33．7‰，表现为冰期高、间期低的特征。相反扣除冰盖影响后的剩余氧同位素δ^18Owater和剩余盐度Swater低、间冰期高的特征，在冰期分别平均为-0．5‰和32．7‰，间冰期分别平均为-0．3‰和33．1‰。研究认为该现象主要与赤道太平洋海域冰期纵向的ITCZ平均位置偏南导致的降雨增加有关，同时冰期温度低蒸发弱，间冰期温度高蒸发强以及冰期海平面下降，南海地理格局的改变、河流输入增多等因素也有一定影响。Records of δ^18Owater and Swater, in surface water of South China Sea over the past 450Ka was catcumteu irom paired δ^18O of foraminifera and U37^k - SST in core MD05 - 2901 off Vietnam. The results showed that δ^18O and Swater varied in the range of 0.2‰- 0.6‰ and 34.2‰ - 35.1‰ in glacial periods, - 0.6‰ - 0‰ and 32.4‰ 33.7‰ in interglacial periods, respectively. But δ^18O resid and Sresid estimated by subtracting the contribution from ice volume exhibited higher value in interglacials,lower value in glacials,averaged in -0.5‰ and 32.7‰ in glacial periods, -0.3‰ and 33.1‰ in interglacial periods, respectively. These may be related with higher precipitation by southern location of ITCZ during glacial periods. Decreasing evaporation by lower temperature,reduced sea level, increasing fluvial input, and geography change in SCS during glacial periods may also reduced the local oxygen isotopic and surface water salinity.

关 键 词：南海 表层海水氧同位素 表层海水盐度 表层海水剩余氧同位素 表层海水剩余盐度 

分 类 号：P534.631[天文地球—第四纪地质学] P736.4[天文地球—古生物学与地层学]