论文部分内容阅读
讨论了在冲绳海槽伊平屋海岭和南奄西海丘两处海底热液喷出口附近海水中的铀系子体放射性核素2 10 Pb和2 10 Po浓度的垂直分布剖面 .在伊平屋海岭 ,甲烷及2 2 2 Rn的数据表明海底热液活动不强 ,总2 10 Pb和2 10 Po放射性均低于它们各自母体的放射性 ,2 10 Pb和2 10 Po在海水中的平均停留时间分别为 2 0和 2～ 5a ,而在以“黑色烟雾”为特征的海底热液活动强烈的南奄西海丘 ,在”烟雾”中的总2 10 Pb含量 ( 0 1 6 7× 1 0 -3～ 2 50× 1 0 -3Bq/kg)相对其母体2 2 6Ra贫乏 ,而总2 10 Po含量 ( 1 83× 1 0 -3～ 2 83×1 0 -3Bq/kg)则相对其母体2 10 Pb过剩 .该处海水中的2 10 Po的放射性高于东海陆架区及冲绳海槽其他海区 ,并且显示了2 10 Po过剩 .2 10 Pb/ 2 2 6Ra以及2 10 Po/ 2 10 Pb放射性比值的范围分别为 0 1～ 0 4和 1 1～ 7 8.在热液扩散带中2 10 Pb被优先从海水中清除 .控制南奄西海丘海水中2 10 Pb浓度的可能机制涉及到2 10 Pb通过扩散作用的横向输送 .在热液扩散带中高2 10 Po/ 2 10 Pb放射性比值表明2 10 Pb的耗尽及2 10 Po从海底热液喷出口的加入 .
The vertical profiles of the concentrations of 2 10 Pb and 2 10 Po in the seawater near the seabed hydrothermal vents at two submarine hydrothermal vents in the Yincong Ridge and the South Sudanese Hilly of the Okinawa Trough are discussed. The data of 2 2 2 Rn indicate that the activity of the seafloor hydrothermal is not strong, the total 2 10 Pb and 2 10 Po radioactivity are lower than the radioactivity of their respective precursors, and the average residence time of 2 10 Pb and 2 10 Po in seawater is 20 And 2 ~ 5 a, respectively. However, the total 2 10 Pb content in the “smog” (0 1 6 7 × 10 -3 -2 2 5) was significantly higher in the submarine hilly area with strong seabed hydrothermal activity characterized by “black smoke” × 10 -3 Bq / kg) was relatively poor relative to its parent population of 226 R a, while the total 2 10 Po content (1 83 × 10 -3 -2 8 × 10 -3 Bq / kg) was relative to its parent 2 10 Pb excess. The radioactivity of 210 Po in the seawater was higher than that in the East China Sea shelf area and other parts of the Okinawa Trough and showed an excess of 2 10 Po. The ranges of radioactivity ratios of 2 10 Pb / 2 2 6Ra and 2 10 Po / 2 10 Pb Is 0 1 ~ 0 4 and 1 1 ~ 7 8. In the hydrothermal diffusion zone, 2 10 Pb is preferentially removed from the seawater, controlling the concentration of 2 10 Pb in the seawater of the southern Meixi Sea The mechanism may involve 2 10 Pb transverse transport by diffusion of high hydrothermal diffusion zone 2 10 Po / 2 10 Pb radioactivity ratios indicate a depletion of 2 10 Pb 2 10 Po added and hydrothermal discharge from the outlet.