The marine geochemistry of actinium‐227: Evidence for its migration through sediment pore water
The marine geochemistry of actinium‐227: Evidence for its migration through sediment pore water
复制标题
锕-227 的海洋地球化学：其通过沉积物孔隙水迁移的证据
DOI：
10.1029/gl017i011p01933
复制
发表时间：
1990
影响因子：
5.2
通讯作者：
Hirofumi Nikaido
中科院分区：
文献类型：
--
作者：
Y. Nozaki;M. Yamada;Hirofumi Nikaido
{sup半衰期为21.8年的227}Ac作为时间尺度小于100年的深水循环和混合研究的示踪剂具有潜在的实用性。本文首次对西北太平洋深海沉积物孔隙水和伊豆-小笠原海沟约10，000 m水柱中的{sup 227}Ac剖面进行了测量。结果表明，沉积物中的{sup 227}Ac主要通过孔隙水向上覆水迁移。模型计算表明，通过沉积物孔隙水的分子扩散单独可以支持只有一半的过剩{sup 227}Ac在水柱和增强供应的{sup 227}Ac的颗粒混合是必要的占剩余部分。因此，深海生物扰动在控制某些短寿命放射性核素（如{sup 227}Ac和{sup 228}Ra）穿过沉积物-水界面的通量方面起着重要作用。
{sup 227}Ac with a half life of 21.8 years has a potential utility as a tracer of deep water circulation and mixing studies on time scales less than 100 years. Here the authors present the first measurement of {sup 227}Ac profile in the pore water of Northwest Pacific deep-sea sediment and in the {approximately}10,000 m long water column of Izu-Ogasawara Trench. The results clearly show that {sup 227}Ac is supplied from the sediment to the overlying water through migration in the pore water. The model calculation indicates that the molecular diffusion alone through sediment porewater can support only a half of the standing crop of excess {sup 227}Ac in the water column and the enhanced supply of {sup 227}Ac by particle mixing is necessary to account for the remainder. Thus, bioturbation in the deep sea plays an important role in controlling the flux of some short-lived radionuclides such as {sup 227}Ac and {sup 228}Ra across the sediment-water interface.