Central Equatorial Pacific Dust Flux, Productivity and d15N Data for 0-27ka Costa, K.; McManus, J.F.; Anderson, R.F.; Ren, H.; Sigman, D.M.; Winckler, G.; Fleisher, M.Q.; Marcantonio, F.; Ravelo, A.C. Costa, K. McManus, J.F. Anderson, R.F. Ren, H. Sigman, D.M. Winckler, G. Fleisher, M.Q. Marcantonio, F. Ravelo, A.C. Last Glacial Maximum earth science/paleoclimate/paleoceanography (age,null,one standard error,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium,sediment,two standard deviations,parts per million,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,milligram per square centimeter per kiloyear,null,paleoceanography,null,null,N,Opal mass accumulation rate) earth science/paleoclimate/paleoceanography (delta 15N,Trilobatus sacculifer,null,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,Globorotalia tumida,null,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleoceanography (barium excess,sediment,null,milligram per square centimeter per kiloyear,null,paleoceanography,null,null,N,mass accumulation rate) earth science/paleoclimate/paleoceanography (sample identification,null,null,null,null,paleoceanography,null,null,C,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (accumulation rate,sediment,null,gram per square centimeter per kiloyear,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (dust,sediment,two standard deviations,milligram per square centimeter per year,null,paleoceanography,null,null,N,dust flux) earth science/paleoclimate/paleoceanography (231Pa/230Th excess,sediment,null,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,Globigerinoides ruber,two standard deviations,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,Globorotalia tumida,two standard deviations,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,two standard deviations,milligram per square centimeter per kiloyear,null,paleoceanography,null,null,N,Opal mass accumulation rate) earth science/paleoclimate/paleoceanography (231Pa/230Th excess,sediment,two standard deviations,dimensionless,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (accumulation rate,sediment,two standard deviations,gram per square centimeter per kiloyear,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium excess,sediment,two standard deviations,milligram per square centimeter per kiloyear,null,paleoceanography,null,null,N,mass accumulation rate) earth science/paleoclimate/paleoceanography (delta 15N,Globigerinoides ruber,null,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,weight percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (dust,sediment,null,milligram per square centimeter per year,null,paleoceanography,null,null,N,dust flux) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,Time Slice name) earth science/paleoclimate/paleoceanography (latitude,null,null,degree north,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium,sediment,null,parts per million,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium excess,sediment,null,parts per million,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (barium excess,sediment,two standard deviations,parts per million,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,Trilobatus sacculifer,two standard deviations,per mil,null,paleoceanography,averaged,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (Line Islands>LATITUDE 3.3>LONGITUDE -158.5) The “major” nutrients for phytoplankton growth (nitrogen, phosphorus, and silicon) are supplied to the surface waters of the Equatorial Pacific (EP) by wind-driven upwelling along the equator. Their consumption by phytoplankton is thought to be limited in part by the low concentrations of the critical micro-nutrient iron. Greater atmospheric dust deposition may have fertilized the EP with iron during the Last Glacial Period (LGP, 17-27,000 years ago). Here we present meridional transects of dust (232Th), phytoplankton productivity (opal, 231Pa/230Th, excess Ba), and the degree of nitrate consumption (foraminifera-bound d15N) from the Central EP for Holocene and LGP time slices. Despite two- to three-fold greater dust deposition in the Central EP, productivity was the same or lower during the LGP compared to the Holocene, and the degree of nitrate consumption was unchanged. These biogeochemical findings suggest that the relatively greater ice age dust fluxes were inadequate to drive significant iron fertilization in the Central EP, which may be because the absolute rate of dust deposition in the LGP, despite being greater than the Holocene rate, was still very low. The lower productivity coupled with unchanged nitrate consumption suggests lower subsurface major nutrient concentrations in the Central EP during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, the Central EP data are consistent with more complete nutrient consumption in the Subantarctic, apparently because of iron fertilization in that region, where absolute dust fluxes were much higher. Thus, ice age iron fertilization ultimately worked to lower, not raise, Equatorial Pacific productivity. STUDY NOTES: Site Information: MC # BB # Lat(N) Long(W) Depth(m) 14 13 -0.22 156 3049 21 20 1.27 157.3 2850 26 25 2.46 159.4 3545 29 28 2.97 159.2 3152 33 32 5.2 160.4 2933 39 36 6.83 161 2859 Provided Keywords: Holocene, Last Glacial Period, dust, productivity, Th isotopes, opal, barium NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Costa, K. Investigator : McManus, J.F. Investigator : Anderson, R.F. Investigator : Ren, H. Investigator : Sigman, D.M. Investigator : Winckler, G. Investigator : Fleisher, M.Q. Investigator : Marcantonio, F. Investigator : Ravelo, A.C. 2015-10-23 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/19441 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-opal.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-d15n.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-barium.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-th-pa.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-opal.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-d15n.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-barium.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-th-pa.txt English https://www.ncdc.noaa.gov/paleo/study/19441 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-opal.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-d15n.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-barium.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/costa2015/costa2015-th-pa.txt Costa, K.M.; McManus, J.F.; Anderson, R.F.; Ren, H.; Sigman, D.M.; Winckler, G.; Fleisher, M.Q.; Marcantonio, F. and Ravelo, A.C.2015No iron fertilization in the Equatorial Pacific during the Last Ice AgeNature529519-52210.1038/nature16453 START YEAR: 27000 cal yr BP * END YEAR: 2000 cal yr BP -161 -.22 -156 6.83