Fluxes and balance of Pb in the northwestern Japan Sea

Otosaka, Shigeyoshi  ; Baba, Masami*; Togawa, Orihiko ; Karasev, E. V.*

A sediment trap experiment and sediment coring were carried out in the northwestern Japan Sea (Sta MS), and lead-210 (Pb) and major components in settling particles were measured. By drawing up a balance of Pb in the water column, it was estimated that the cycle of Pb in the Sta MS was controlled by 3 processes, (1) removal and vertical transport of Pb from the surface layer by settling particles, (2) decomposition of particles in the deep layer, and (3) export by the deep current. Flux of Pb at 3 km depth was large in winter and spring. The large Pb flux in this season would be caused by the horizontal import of Pb -rich seawater from the coastal region to the bottom layer of Sta MS. It was suggested that seasonal variation of particulate Pb flux at the deep layer in the northwestern Japan Basin indicated the renewal of the deep water in this area.