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Abstract：
90Sr is useful for tracing water mass movement in oceans. We collected a suit of seawater samples from the East China Sea (ECS) in the May 2011 to investigate the spatial and vertical distribution of 90Sr and to understand its transportation and fate. To understand the sources and transportation of 90Sr more clearly, published 137Cs data from the same cruise were used to obtain the 90Sr/137Cs activity ratios. The results showed that 90Sr activities were controlled by the circulation system of the ECS, with high values in coastal regions and low values in oceanic waters. The plume with a high 90Sr/137Cs ratio showed that in late spring, the Changjiang Diluted Water could flow southeastward and extend to 126-127° E, which is farther than the previously known value of 124° E. The high 90Sr/137Cs ratios (1.35 ± 0.62) and a long effective half-life of 90Sr (20.0 ± 0.3 y) in the ECS surface water revealed that 90Sr is surplus in comparison with 137Cs. However, historical variations in the 90Sr/137Cs ratio seem to preclude the simple explanation that riverine input causes a 90Sr surplus in the ECS. Groundwater discharge with a high 90Sr but very low 137Cs may be a new potential source. However, it is difficult to quantify the contribution of groundwater discharge at present, and more detailed studies are required in this regard. Additionally, we compiled 90Sr and 137Cs water column inventory data in the western North Pacific and found that the cumulative fallout onto the ocean was different from that on land in the 20-40° N band.
摘要：
90Sr可用于追踪海洋中的水团运动。我们于2011年5月从东海（ECS）收集了一套海水样品，以调查90Sr的空间和垂直分布，并了解其运输和命运。为了更清楚地了解90Sr的来源和运输，来自同一巡航的已发布的137Cs数据用于获得90Sr/137Cs活性比。结果表明，90Sr活性受ECS循环系统控制，在沿海地区价值高，在海洋水域价值低。具有高90Sr/137Cs比率的羽流表明，在春末，长江稀释水可以向东南流动，延伸到126-127°E，比先前已知的124°E值远。ECS地表水中90Sr/137Cs的高比率（1.35±0.62）和90Sr的长有效半衰期（20.0±0.3y）表明90Sr与137Cs相比过剩。然而,90Sr/137Cs比率的历史变化似乎排除了河流输入导致ECS中90Sr过剩的简单解释。高90Sr但低137Cs的地下水排放可能是新的潜在来源。然而,目前很难量化地下水排放的贡献，在这方面需要更详细的研究。此外,我们编制了北太平洋西部的90Sr和137Cs水柱清单数据，发现海洋上的累积沉降量与20-40°N波段的陆地上的累积沉降量不同。
