Enhanced scavenging of 210Pb and 210Po by processes associated with the East Pacific Rise near 8°45′N Article

Kadko, D, Bacon, MP, Hudson, A. (1987). Enhanced scavenging of 210Pb and 210Po by processes associated with the East Pacific Rise near 8°45′N . Earth and Planetary Science Letters, 81(4), 349-357. 10.1016/0012-821X(87)90122-1

cited authors

  • Kadko, D; Bacon, MP; Hudson, A

abstract

  • In 1977 and 1981 a hydrothermal plume was detected at the East Pacific Rise (EPR) near 8°45′N and at MANOP Site M, 25 km east of the EPR, by anomalous 222Rn and Mn concentrations. In 1981, samples were also taken for 210Pb, 210Po and 226Ra analyses to determine if enhanced scavenging of these elements occurred in the plume. At both the ridge crest and at Site M, the 210Pb 226Ra ratios range from 0.09 to 0.35, which are among the lowest values ever measured. It appears that removal of the 210Pb is occurring by processes operating at or near the seafloor. There is also significant 210Po 210Pb disequilibrium at both locations, which appears to increase away from the seafloor towards the plume (as indicated by elevated Mn concentrations). An in-situ water column scavenging process is suggested by correlation of [210Pb210Po] and Mn concentrations in the plume. The residence time of the 210Po is only about 1 year, which is close to its residence time in surface waters but quite short compared to typical deep sea values. Thus rapid scavenging of the polonium in the plume and relatively rapid settling of particles from the plume is suggested. © 1987.

authors

publication date

  • January 1, 1987

published in

Digital Object Identifier (DOI)

start page

  • 349

end page

  • 357

volume

  • 81

issue

  • 4