@article{fdi:010089471,
  title = {{I}nvestigation of hydrothermal activity in the {S}outh {W}est {I}ndian ridge region using {R}a isotopes and 227{A}c as tracers},
  author = {{L}{\'e}on, {M}. and van {B}eek, {P}. and {S}anial, {V}. and {B}audet, {C}. and {C}harette, {M}. {A}. and {S}ouhaut, {M}. and {V}ivier, {F}. and {K}estenare, {E}lodie and {J}eandel, {C}. and {P}lanquette, {H}.},
  editor = {},
  language = {{ENG}},
  abstract = {{H}ydrothermal vents have been shown to be important vectors for various chemical elements into the ocean. {H}owever, both the intensity of the chemical fluxes associated with these systems and the fate of the chemical elements along the plume are still largely overlooked. {A}t two stations located above the {S}outh {W}est {I}ndian {R}idge ({SWIR}), we investigate the distributions of the {R}a quartet (223{R}a, 224{R}a, 226{R}a and 228{R}a) and 227{A}c that have been used as tracers of hydrothermal activity. {W}hile the vertical distributions of 226{R}a, 228{R}a and 227{A}c do not show a clear enrichment at depth, unusual signatures of excess 223{R}a and 224{R}a near the seafloor are attributed to the presence of a hydrothermal activity. {T}he discrepancy observed between the different isotopes is attributed to different chemical reactivity when seawater circulates within the crust and/or to different regeneration rates within the fluid. {A} 1{D} diffusion model applied to the vertical profiles of short-lived {R}a isotopes provided an estimation of the vertical eddy diffusivity coefficients ({KZ}) between 38 cm2 s-1 and 149 cm2 s- 1. {T}hese high values suggest strong mixing likely favored by the complex bathymetry in the region. {B}y combining these {KZ} with the vertical gradient of dissolved {F}e (d{F}e), we estimate a vertical flux of d{F}e that ranges from 139 to 1173 nmol m- 2 d-1. {T}hese results confirm that low -expansion -rate ridges could be significant sources of d{F}e to the deep ocean.},
  keywords = {{OCEAN} {INDIEN}},
  booktitle = {},
  journal = {{P}rogress in {O}ceanography},
  volume = {221},
  numero = {},
  pages = {103191 [15 p.]},
  ISSN = {0079-6611},
  year = {2024},
  DOI = {10.1016/j.pocean.2023.103191},
  URL = {https://www.documentation.ird.fr/hor/fdi:010089471},
}