Program
 
Special Session 4: Biogeochemical cycling of trace elements in the ocean: GEOTRACES and beyond
 

 
 
1035
Contribution of East China Sea shelf water to the Sea of Japan and the Northwestern Pacific using neodymium isotope
Monday 9th @ 1035-1055
Room 4
Hong Che* , Ocean University of China
Jing Zhang, 1 University of Toyama, Japan 2 Ocean University of China
Huijun He, Ocean University of China
Presenter Email: chexinyao19880201@163.com
East China Sea, as a marginal sea adjacent to the continent and Pacific Ocean, plays a very important role in the biogeochemical cycle of the Northwest Pacific Ocean. The neodymium (Nd) isotope composition as a reliable tracer is poorly documented in this area. This is the first study that employed Nd isotopic compositions to explore the contribution of East China Sea to the open sea and the Sea of Japan. The isotopic composition (¦ÅNd) and the concentration of Nd were treated using NOBIAS and LN Resins, after measured by MC-ICP-MS (un plasma) and ICP-MS (ICAP-Q SRD=¡À5%), respectively. The isotopic ratios measured for the standards JNdi-1(Geological Survey of Japan), were 0.512110¡À0.000006. Our results indicate that the study area had the most highly un-radiogenic Nd (¦ÅNd = -12.8~-7.7), which is generally lower than other water masses. Measured ¦ÅNd values in the surface water shows an increase trend from Changjiang Estuary to the outer shelf, suggesting the terrestrial material is a controlling factor for Nd isotopic composition in the estuary area. Three end-member box models (Changjiang Diluted Water, Yellow Sea and Kuroshio Water) indicates that, during the summer about 7.8% of CDW, 37% Yellow Sea Water and 55% Kuroshio Water will enter into the south end of the Sea of Japan, and about 10% of East China Sea shelf water was discharged into the adjacent area of Northwest Pacific. Our study documents that the East China Sea plays a significant contribution of neodymium to the Northwest Pacific.Acknowledgments: This work was supported in part by JSPS KAKENHI Grant (Numbers JP26241009 and JP15H00973) and National Nature Science Foundation of China (NSFC-41276071; 41530965).