Excess ~(210)Pb in the sediment and benthic biological acivity in the western North Pacific

摘要

The radioactive disequilibrium between ~(210)Pb and ~(226)Ra was studied inrnsediments from the western North Pacific. Inventory of excess ~(210)Pb hadrnlarge spatial variation. The bioturbation coefficients ranged from 0.003rnto 0.44 cm~2 yr~(-1) and had the same spatial trend as the inventory. Thern210Pbex penetration depth correlated linearly with the inventory. It isrnsuggested that particulate material brings a large amount of organicrncarbon and ~(210)Pb to the sediment-water interface and the activity of thernbenthic organisms is stimulated in the area where biologicalrnproductivity in the surface layer is high, such as the middle latitude ofrnthe western North Pacific.