@article{fdi:010064024,
  title = {{U}se of {R}a isotopes to deduce rapid transfer of sediment-derived inputs off {K}erguelen},
  author = {{S}anial, {V}. and van {B}eek, {P}. and {L}ansard, {B}. and {S}ouhaut, {M}. and {K}estenare, {E}lodie and d'{O}vidio, {F}. and {Z}hou, {M}. and {B}lain, {S}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {S}outhern {O}cean is known to be the largest high-nutrient, low-chlorophyll ({HNLC}) region of the global ocean due to iron limitation. {H}owever, a large phytoplankton bloom develops annually downstream of the {K}erguelen {I}slands, a bloom which is sustained partly by iron released from the sediments deposited onto the shelves. {I}n the framework of the {KEOPS}-2 project, we used radium isotopes ({R}a-224, {T}-1/2 = 3.66 d; {R}a-223, {T}-1/2 = 11.4 d; {R}a-228, {T}-1/2 = 5.75 yr) to provide information on the origin of iron fertilization and on the timescales of the transfer of sedimentderived inputs (including iron and other micronutrients) towards offshore waters. {S}ignificant {R}a-224 and {R}a-223 activities were found in the near vicinity of the {K}erguelen {I}slands, in agreement with the short half-lives of these isotopes. {S}ignificant {R}a-224 and {R}a-223 activities were also detected up to 200 km downstream of the islands and more unexpectedly in offshore waters south of the polar front. {T}hese observations thus clearly indicate (i) that the sediment-derived inputs are rapidly transferred towards offshore waters (on timescales on the order of several days up to several weeks) and (ii) that the polar front is not a physical barrier for the chemical elements released from the sediments of the {K}erguelen {P}lateau. {T}he {R}a data set suggests that iron and other micronutrients released by the shelves of the {K}erguelen {I}slands may contribute to fueling the phytoplankton bloom downstream of the islands, despite the presence of the polar front. {H}owever, the heterogeneous distribution of the {R}a-224 and {R}a-223 activities in surface waters suggests that this supply across the front is not a continuous process but rather a process that is highly variable in space and time.},
  keywords = {{KERGUELEN} ; {OCEAN} {AUSTRAL}},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {12},
  numero = {5},
  pages = {1415--1430},
  ISSN = {1726-4170},
  year = {2015},
  DOI = {10.5194/bg-12-1415-2015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064024},
}