| 摘要: |
| 为了解自末次间冰期以来这一地区的古海水表层温度变化,应用气相色谱技术对取自冲绳海槽东侧的Z14-6孔的长链(C37)不饱和烯酮进行了分析。结果发现,该孔U37k在0.83—0.95之间,其变化趋势与两种浮游有孔虫N.dutertrei和G.sacculifer的氧同位素组成一致。根据U37k重建的SST在24.0—27.5°C之间变化,最高值27.5°C出现在MIS-5,最低值24°C出现在MIS-2(LGM)。从LGM到全新世SST增加约2°C。这与早期在附近地区根据U37k重建的SST变化趋势一致。根据重建的SST自LGM以来的变化,作者认为现代黑潮洋流系统最晚在约10kaB.P.后已在冲绳海槽重新建立。许多早期研究揭示的黑潮在7.5—7kaB.P.的加强可能与全新世大暖期有关。 |
| 关键词: SST 不饱和烯酮 冲绳海槽 黑潮 |
| DOI： |
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| 基金项目:中国科学院知识创新工程项目,KZCX2-SW-133号;中国科学院有机地球化学国家重点实验室开放基金项目,OGL-200308号;黄土与第四纪地质国家重点实验室开放基金项目,SKLLQG0408号;中国科学院广州地化所创新项目,GIGCX-04-01号。 |
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| SEA SURFACE TEMPERATURE RECONSTRUCTION WITH LONG CHAIN UNSATURATED ALKENONES FOR THE MIDDLE OKINAWA TROUGH DURING THE LAST GLACIAL-INTERGLACIAL CYCLE |
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ZHOU Hou-Yun1,2,3, LI Tie-Gang4, JIA Guo-Dong1, ZHU Zhao-Yu2, CHI Bao-Quan2, CAO Qi-yuan4, SUN Rong-Tao4
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1.State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences,Guangzhou,510640;2.Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences,Guangzhou,510640;3.State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences,Xi’an,710075;4.Institute of Oceanology, Chinese Academy of Sciences,Qingdao,266071
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| Abstract: |
| Okinawa Trough is an important area for investigation on the past climate, environment, and oceanography. To investigate sea surface temperature (SST) variation in this area during the last glacial-interglacial cycle, gas chromatography was used to determine long chain (C37) unsaturated alkenones in the sediments in Core Z14-6 on the east side of the middle trough. It was found that U37k for Core Z14-6; varies between 0.83 and 0.95 with a trend parallel to those of the oxygen isotopic composition in two planktonic foraminifera, N. dutertrei and G. sacculifer. The U37k-derived SST varies between 24.0 and 27.5°C with its highest value 27.5°C occurring in MIS-5 and the lowest value 24.0°C in MIS-2 [Last Glacial Maximum (LGM)]. The U37k-derived SST displays an increase of ~2°C from the LGM to the Holocene, which is consistent with previous studies carried out in this area. Based on the U37k-derived SST variation since the LGM, it is suggested that modern Kuroshio Current was established in the Okinawa Trough no later than l0 ka B.P. The strengthening of the Kuroshio Current during 7.5 - 7 ka B.P. indicated by many other researchers, may be related to the Holocene Optimum. |
| Key words: SST, Unsaturated Alkenone, Okinawa Trough, Kuroshio Current |
