Sedimentation and lateral transport of 210Pb over the East China Sea Shelf
Sedimentation and lateral transport of 210Pb over the East China Sea Shelf
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东海陆架210Pb的沉积与横向运移
DOI：
10.1007/s10967-013-2561-4
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发表时间：
2013-11-01
影响因子：
1.6
通讯作者：
Qiu, Yusheng
中科院分区：
文献类型：
--
作者：
Fang, Ziming;Yang, Weifeng;Qiu, Yusheng
摘要pb是一种有效的抑制陆架区域颗粒迁移和沉积的示踪剂。为揭示东海陆架（即ECS）表层沉积物中210Pb的空间分布规律，对11个站点的表层沉积物和4个站点的水柱中210Pb进行了检测。总体而言，沿岸线的长江羽流带是外陆架210Pb的源区，至少输出0.46 dpm cm−2 year−1，约占该区域210Pb输入量的25%。在台湾海峡以北的ECS架南部，聚焦因子(f)值大于1，表明沉降面积为210Pb。根据质量平衡模式评估，210Pb的边界清除对该汇面积的贡献为0.36 dpm cm−2 year−1。水柱中234和210Pb向该地区的横向输送变化范围为3.34 ~ 6.39 dpm cm−2年−1，平均为4.83 dpm cm−2年−1，也支持其汇特征。济州岛西南部f值小于1，显示为210Pb源区。该地区210Pb的平均输出通量为1.64 dpm cm−2 year−1。因此，210Pb沉积/沉降显示出ECS陆架上颗粒物的显著非均质沉降。
Abstract210Pb is an effective tracer of constraining particle transport and sedimentation in shelf regions. To reveal the spatial pattern of 210Pb over the East China Sea (i.e. ECS) Shelf, 210Pb in the surface sediments were examined at 11 stations, as well as 234Th and 210Pb in the water column at four stations. Overall, the plume zone of the Yangtze River along the coastline is a source area of 210Pb for the outer shelf, exporting 0.46 dpm cm−2 year−1 at least, which accounts for about 25 % of 210Pb input into this region. In the southern ECS Shelf to the north of the Taiwan Strait, the focusing factor (f) values are higher than unity, indicating a sink area of 210Pb. Boundary scavenging of 210Pb contributes 0.36 dpm cm−2 year−1 to this sink area on the basis of a mass balance model evaluation. Lateral transport of 210Pb to this region, quantified by 234Th and 210Pb in the water column, varied from 3.34 to 6.39 dpm cm−2 year−1 with an average of 4.83 dpm cm−2 year−1, also supporting its sink characteristic. To the southwest of the Cheju Island, the f values were less than unity, revealing a source region of 210Pb. The average export flux of 210Pb from this region was 1.64 dpm cm−2 year−1. Therefore, 210Pb sedimentation/settling showed significantly heterogeneous sedimentation of particulate matter over the ECS Shelf.