@article{fdi:010049043,
  title = {{A}brupt sea surface p{H} change at the end of the {Y}ounger {D}ryas in the central sub-equatorial {P}acific inferred from boron isotope abundance in corals ({P}orites)},
  author = {{D}ouville, {E}. and {P}aterne, {M}. and {C}abioch, {G}uy and {L}ouvat, {P}. and {G}aillardet, {J}. and {J}uillet-{L}eclerc, {A}. and {A}yliffe, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he 'delta {B}-11-p{H}' technique was applied to modern and ancient corals {P}orites from the sub-equatorial {P}acific areas ({T}ahiti and {M}arquesas) spanning a time interval from 0 to 20.720 calendar years to determine the amplitude of p{H} changes between the {L}ast {G}lacial {P}eriod and the {H}olocene. {B}oron isotopes were measured by {M}ulti-{C}ollector - {I}nductively {C}oupled {P}lasma {M}ass {S}pectrometry ({MC}-{ICPMS}) with an external reproducibility of 0.25 parts per thousand, allowing a precision of about +/- 0.03 p{H}-units for p{H} values between 8 and 8.3. {T}he boron concentration [{B}] and isotopic composition of modern samples indicate that the temperature strongly controls the partition coefficient {K}-{D} for different aragonite species. {M}odern coral delta {B}-11 values and the reconstructed sea surface p{H} values for different {P}acific areas match the measured p{H} expressed on the seawater scale and confirm the calculation parameters that were previously determined by laboratory calibration exercises. {M}ost ancient sea surface p{H} reconstructions near {M}arquesas are higher than modern values. {T}hese values range between 8.19 and 8.27 for the {H}olocene and reached 8.30 at the end of the last glacial period (20.7 kyr {BP}). {A}t the end of the {Y}ounger {D}ryas (11.50 +/- 0.1 kyr {BP}), the central sub-equatorial {P}acific experienced a dramatic drop of up to 0.2 p{H}-units from the average p{H} of 8.2 before and after this short event. {U}sing the marine carbonate algorithms, we recalculated the aqueous p{CO}(2) to be 440 +/- 25 ppm{V} at around 11.5 kyr {BP} for corals at {M}arquesas and similar to 500 ppm{V} near {T}ahiti where it was assumed that p{CO}(2) in the atmosphere was 250 ppm{V}. {T}hroughout the {H}olocene, the difference in p{CO}(2) between the ocean and the atmosphere at {M}arquesas ({D}elta p{CO}(2)) indicates that the surface waters behave as a moderate {CO}2 sink or source (-53 to 20 ppm{V}) during {E}l {N}ino-like conditions. {B}y contrast, during the last glacial/interglacial transition, this area was a marked source of {CO}2 (21 to 92 ppm{V}) for the atmosphere, highlighting predominant {L}a {N}ino-like conditions. {S}uch conditions were particularly pronounced at the end of the {Y}ounger {D}ryas with a large amount of {CO}2 released with {D}elta p{CO}(2) of +185 +/- 25 ppm{V}. {T}his last finding provides further evidence of the marked changes in the surface water p{H} and temperature in the equatorial {P}acific at the {Y}ounger {D}ryas-{H}olocene transition and the strong impact of oceanic dynamic on the atmospheric {CO}2 content.},
  keywords = {},
  booktitle = {},
  journal = {{B}iogeosciences},
  volume = {7},
  numero = {8},
  pages = {2445--2459},
  ISSN = {1726-4170},
  year = {2010},
  DOI = {10.5194/bg-7-2445-2010},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049043},
}