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首页> 外文期刊>Journal of oceanography >239,240Pu and137Cs in the East China and the Yellow Seas
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239,240Pu and137Cs in the East China and the Yellow Seas

机译：中国东部和黄海中的239,240 Pu和137 Cs

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摘要

The distribution and inventory of artificial radionuclides,239,240Pu and137Cs were determined in the East China and the Yellow Seas in 1987. Almost all of239,240Pu and 50 to 80% of137Cs in the continental shelf area are retained in the sediment column.239,240Pu sediment inventory in the sea area is larger than the fallout input and tends to increase southwardly. This excess239,240Pu and the lateral distribution are attributable to the supply of239,240Pu by the Yangtze River discharge. On the contrary,137Cs sediment inventory shows a decrease to the south, and the fact can be accounted for by the southward dispersion of fine silt particles discharged from the Yellow River. Total137Cs inventory is smaller than the estimated fallout input, and the fact seems to indicate dispersion of137Cs out of the shelf region. Vertical profiles of239,240Pu and137Cs contents in sediments differ from that of natural210Pb, implying the effect of varied accumulation rates of the artificial radionuclides over the sediment particle mixing by benthic organisms. Apparent maximum sediment particle mixing coefficient (DB) calculated from the excess210Pb profiles in stations located between the inner and outer shelves ranged from 1.4 to 8.3 cm2y?1. ThisDB value is higher than that in the Okinawa Trough (1.0 cm2y?1), but lower than previously estimatedDB value (≈26 cm2y?1) in the outer shelf mud.
机译：1987年在中国东部和黄海确定了人工放射性核素239,240Pu和137Cs的分布和清单。大陆架区域几乎所有的239,240Pu和137Cs都保留在了沉积物柱中。239,240Pu沉积物海域的库存量大于沉降物输入量，并且倾向于向南增加。多余的239,240Pu和横向分布可归因于长江流域的239,240Pu的供应。相反，137 Cs的沉积物存量向南减少，这可以由黄河排放的细粉尘颗粒向南扩散来解释。 137Cs的总库存量小于估计的辐射输入，并且事实似乎表明137Cs分散在货架区域之外。沉积物中239,240Pu和137Cs含量的垂直分布与天然210Pb的垂直分布不同，这意味着底栖生物在沉积物颗粒混合过程中人工放射性核素的累积速率发生变化。根据内，外层架之间站点中多余的210Pb剖面计算得出的表观最大沉积物颗粒混合系数（DB）为1.4至8.3 cm2y？1。该DB值高于冲绳海槽的值（1.0 cm2y？1），但比外架子泥中的先前估算的DB值（≈26cm2y？1）低。

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