春季长江口及邻近海域水体Eh和pH的分布  

The States of Eh,pH of Water From Yangtze River Estuary and Its Adjacent Areas and Their Implications

作　　者：孙学诗[1,2] 范德江[1,2] 刘鹏飞[3] 逄悦[1,2] 田元[1,2] SUN Xue-shi FAN De-liang LIU Peng-fei PANG Yue TIAN Yuan(Ocean University of China, Qingdao 266100,China Key Lab of Submarine Geoscience and Prospecting Techniques ,Minstry of Education, Qingdao 266100,China College of Marine Geosciences ,Shanghai Ocean University ,Shanghai 200062 ,China)

机构地区：[1]中国海洋大学,山东青岛266100 [2]海底科学与探测技术教育部重点实验室,山东青岛266100 [3]上海海洋大学海洋科学学院,上海200062

出　　处：《海洋科学进展》2017年第1期96-106,共11页Advances in Marine Science

基　　金：国家自然科学基金项目--东海内陆架250年来海洋温盐和生产力重建及其对年代际气候波动的响应(41376055);国家重大基础研究发展计划项目--气候变化影响下典型海岸冲淤过程及演变趋势(2010CB951202)

摘　　要：依据2015年春季对长江口及邻近海域水体Eh和pH的现场调查数据,分析研究区海域水体Eh和pH的空间分布特征,结合同航次现场测得的温度、盐度数据,系统探讨了Eh和pH对水团发育特征的指示作用及对自生矿物形成的影响。结果显示:研究区水体为弱氧化环境,Eh变化范围为202.3~317.2mV,空间分布上具有分带性和不均一的特点,表现为近岸高、离岸越远越低,北部垂向混合均匀、南部层化作用明显。该海区水体总体上为中性-弱碱性环境,pH变化范围为7.05~8.19,空间分布上具有分带性,表现为近岸低、外海高,北部层化明显、南部混合均匀。依据pH-Eh判别图解,判定存在3个水团:长江冲淡水团以低pH和高Eh为特征,台湾暖流为高pH和低Eh,而沿岸流水团以快速变化的pH为特征。pH-Eh特征表明研究区水体中有利于铁、锰氧化物(Fe2O3和Mn2O3)等自生矿物的形成,水体中出现的少量胶黄铁矿(FeS2)与微环境有关。Based on the in-situ investigation for Eh and pH of water samples, and the simultaneous temper- ature and salinity data from the Yangtze river estuary and its adjacent areas,we study illustrated the spatial distribution characteristics of Eh,pH and further discussed their implications for water-masses and authi- genic mineral.The results show that water in the area is weak oxidizing,and its Eh values range from 202.3 to 317.2 mV.The distribution of Eh in the area takes on zonality and heterogeneity.From coastal areas out- wards,the Eh gradually reduce.The pH data show vertical mixing phenomena in the northern part and ob- vious stratification effect in the southern part.The sea water in the area is neutral-slightly alkaline environ- ment,and its pH range from 7.10 to 8.19.The distribution of pH also takes on zonality.From coastal areas outwards,the pH values gradually increase.The Eh data show obvious stratification effect in the northern part and homogeneous mixed phenomena in the southern part.The discrimination diagrams of pH-Eh reveal that there exist three types of water masses,i.e. ,Yangtze Diluted Water with low pH and high Eh,Taiwan Warm Current with high pH and low Eh,and coastal current with rapid variations in pH.The pH-Eh phase discrimination diagrams reveal that in the Yangtze River estuary and adjacent waters there exist authigenic mineral including dominant Fe-Mn oxide （Fe2O3 and Mn2O3） ,and minor pyrite （FeS2）.

关 键 词：EH PH 水团 自生矿物 长江口及邻近海域 

分 类 号：P736.4[天文地球—海洋地质]