西菲律宾海26万年来古生产力变化的颗石藻证据  

Variations of primary productivity in the western Philippine Sea in the past 260000 years:evidence from coccolith

作　　者：安佰正 李铁刚[3,4] 刘健 孙晗杰[2,3] 徐兆凯 唐正[3,4] 赵京涛 AN Baizheng;LI Tiegang;LIU Jian;SUN Hanjie;XU Zhaokai;TANG Zheng;ZHAO Jingtao(Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology,Qingdao Institute of Marine Geology,Qingdao 266071,China;Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;Laboratory for Marine Geology,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266061,China;Key Laboratory of Marine Sedimentology and Environmental Geology,First Institute of Oceanography,SOA,Qingdao 266061,China)

机构地区：[1]中国地质调查局青岛海洋地质研究所,青岛266071 [2]中国科学院海洋研究所海洋地质与环境重点实验室,青岛266071 [3]青岛海洋科学与技术国家实验室海洋地质过程与环境功能实验室,青岛266061 [4]自然资源部第一海洋研究所海洋沉积与环境地质重点实验室,青岛266061

出　　处：《海洋地质与第四纪地质》2019年第3期113-121,共9页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目“15万年以来热带西太平洋颗石藻碳酸钙输出通量演变及其影响因素”(41706070),“中更新世以来热带西太平洋颗石藻钙化作用研究”(41876041),“80万年来热带西太平洋上层水体pH和pCO2演变及影响机理”(41230959);青岛海洋科学与技术国家实验室鳌山科技创新计划项目(2016ASKJ13);中国科学院海洋地质与环境重点实验室开放基金“西太平洋上层水体现代颗石藻碳酸钙分布特征”(MGE2017KG03);山东省自然科学基金面上项目“山东半岛东部近岸中、晚全新世高分辨率环境演化过程研究”(ZR2016DM12)

摘　　要：基于国际海洋古全球变化研究项目(IMAGES)在西菲律宾海本哈姆海台获取的高质量柱状沉积物岩芯MD06-3047(17°00.44′N、124°47.93′E),利用颗石藻下透光带属种Florisphaera profunda的相对丰度以及初级生产力转换函数,恢复了260 ka以来西菲律宾海上部水体营养跃层以及初级生产力的变化历史。发现该区域26万年以来初级生产力冰期-间冰期变化特征较不明显,冰期生产力平均值略高于间冰期。通过与前人已发表的指示东亚冬季风强弱的伊利石/蒙脱石记录和热带太平洋纬向表层海水温度梯度记录的对比,提出MIS 8期以来,热带西菲律宾海古生产力变化的主要受控因素在MIS 5a左右发生明显转变。在MIS 8后期至MIS 5a之间,初级生产力受到长期类ENSO过程的影响较为显著,当热带东西太平洋海水表层温度梯度较小的时期,认为热带太平洋处于类El Niňo状态,此时西菲律宾海营养跃层相对较浅,生产力较高,反之则相反。而在MIS 5末期至末次冰消期时段,生产力受东亚冬季风的影响相对于长期ENSO过程更强,可能掩盖了后者的古生产力信号。冰期东亚冬季风加强,一方面,可以引起上部水体混合加强,增加下部营养物质向上的输送,另一方面大量风尘物质的输入可以刺激颗石藻的生长;反之在冰消期,水体混合较弱,风尘输入显著减少,生产力也随之降低。Primary productivity data of the Core MD06-3047(17°00.44′N,124°47.93′E,2510 m water depth)from the International Marine Global Change Study Program(IMAGES)is presented in this paper.The core is taken from the Benham Rise of West Philippine Sea.Coccolith records revealed considerable glacial-interglacial changes of paleoproductivity in the west Philippine Sea over the past 260 ka.The recently published research data of the core made this study possible to reveal the forcing mechanisms of the glacial-interglacial variations in primary productivity.During the period of 260~80 ka,the abundance of F.profunda and primary productivity shows a similar variation trend with the tropical eastern-western Pacific sea surface temperature gradient(ΔSST).The lowerΔSST in the glacial intervals indicate that tropical Pacific was suffered a long term El Niňo-like condition,which produced relatively shallow thermocline/nutricline and high primary productivity in the western Pacific.On the contrary,the higherΔSST in the interglacial intervals indicates a La Niňa-like state in the tropical Pacific,which deepened the thermocline/nutricline and suppressed the primary productivity.From the late MIS5 to the last deglacial,we attribute the high values of productivity in the glacial interval and low values in the interglacial intervals to the Eastern Asian winter monsoon,due to the similar trend between illite/smectite ratio and primary productivity in the core MD06-3047.

关 键 词：初级生产力 颗石藻 东亚冬季风 晚第四纪 西菲律宾海 

分 类 号：P736[天文地球—海洋地质]