Deep-sea oxygen depletion and ocean carbon sequestration during the last ice age Anderson, R.F.; Sachs, J.P.; Fleisher, M.Q.; Allen, K.A.; Yu, J.; Koutavas, A.; Jaccard, S.L. Anderson, R.F. Sachs, J.P. Fleisher, M.Q. Allen, K.A. Yu, J. Koutavas, A. Jaccard, S.L. earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (RC11-238>LATITUDE -1.52>LONGITUDE -85.82) (VM19-27>LATITUDE -.4667>LONGITUDE -82.0667) (TT013-18PC>LATITUDE -1.84>LONGITUDE -139.71) (VM21-30>LATITUDE -1.2167>LONGITUDE -89.6833) (VM19-30>LATITUDE -3.383>LONGITUDE -83.517) (TT013-MC19>LATITUDE -1.868>LONGITUDE -139.7157) (VM19-28>LATITUDE -2.3667>LONGITUDE -84.65) (TT013-72PC>LATITUDE .11>LONGITUDE -139.4) A possible imprint on equatorial Pacific sediments of a deglacial reinvigoration of the Southern Ocean overturning is increased opal accumulation rate. This would arise from the transmission of silica-rich deep water to the equatorial thermocline via Subantarctic Mode Water and an associated increase in diatom productivity. In search of this imprint, sediment cores from the central (TT013-PC72) and eastern (V19-30) equatorial Pacific have been analyzed for 230Th-normalized opal accumulation rates over the past five and three glacial terminations, respectively. Equatorial opal accumulation rates sustained relatively low values over much of the records and were punctuated by large increases centered on some terminations, but not all. Furthermore, two periods of increased opal flux were observed that do not coincide with terminations. Sources other than the Southern Ocean may need to be considered in the silica budget of the equatorial Pacific, but the d13C of Neogloboquadrina dutertrei can be used to support the presence of a deepwater nutrient signal in each case. Although a common deglacial mechanism, or a common imprint thereof, for each of the late Pleistocene glaciations remains elusive, the combination of opal flux and d13C of N. dutertrei provides a diagnostic for past injection of deepwater nutrients into the Equatorial Undercurrent. STUDY NOTES: Combination of data from previous publications and new data Provided Keywords: Pacific Ocean, deglacial, last ice age NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Anderson, R.F. Investigator : Sachs, J.P. Investigator : Fleisher, M.Q. Investigator : Allen, K.A. Investigator : Yu, J. Investigator : Koutavas, A. Investigator : Jaccard, S.L. 2018-11-23 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/25630 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm21-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-pc72.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-mc19.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-rc11-238.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-28.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-pc18.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-27.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm21-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-pc72.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-mc19.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-rc11-238.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-28.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-pc18.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-27.txt English https://www.ncdc.noaa.gov/paleo/study/25630 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm21-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-pc72.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-mc19.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-rc11-238.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-28.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-pc18.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/anderson2019/anderson2018-vm19-27.txt Anderson R.F., J.P. Sachs, M.Q. Fleisher, K.A. Allen, J. Yu, A. Koutavas, S.L. Jaccard2018Deep-sea oxygen depletion and ocean carbon sequestration during the last ice ageGlobal Biogeochemical Cyclesunder review Anderson, R.F., M.Q. Fleisher, and Y. Lao2006Glacial-Interglacial variability in the delivery of dust to the central equatorial Pacific OceanEarth and Planetary Science Letters242406-41410.1016/j.epsl.2005.11.061 Anderson, R.F., M.Q. Fleisher, Y. Lao, and G. Winckler2008Modern CaCO3 preservation in equatorial Pacific sediments in the context of recent glacial cyclesMarine Chemistry11130-4610.1016/j.marchem.2007.11.011 Bradtmiller, L.I., R.F. Anderson, M.Q. Fleisher, and L.H. Burckle2007Opal burial in the equatorial Atlantic Ocean over the last 30 ka: Implications for glacial-interglacial changes in the ocean silicon cyclePaleoceanography10.1029/2006PA001282 Hayes, C.T., R.F. Anderson, and M.Q. Fleisher2011Opal accumulation rates in the equatorial Pacific and mechanisms of deglaciationPaleoceanography10.1029/2010PA002008 Koutavas, A., and J.P. Sachs2008Northern timing of deglaciation in the eastern equatorial Pacific from alkenone paleothermometryPaleoceanography23PA420510.1029/2008PA001593 Koutavas, A. and J. Lynch-Stieglitz. 2003. Glacial-interglacial dynamics of the eastern equatorial Pacific cold tongue-Intertropical Convergence Zone system reconstructed from oxygen isotope records. Paleoceanography 18(4), 1089. Lyle, M., A.C. Mix, and N.G. Pisias2002Patterns of CaCO3 deposition in the eastern tropical Pacific Ocean for the last 150 kyr: Evidence for a southeast Pacific depositional spike during marine isotope stage (MIS) 2Paleoceanography1710.1029/2000PA000538 Martinson, D.G., N.G. Pisias, J.D. Hays, J. Imbrie, T.C. Moore, and N.J. Shackleton1987Age dating and the orbital theory of the ice ages - Development of a high-resolution 0 to 300,000-year chronostratigraphyQuaternary Research271-2910.1016/0033-5894(87)90046-9 Murray, R.W., C. Knowlton, M. Leinen, A.C. Mix, and C.H. Polsky2000Export production and carbonate dissolution in the central equatorial Pacific Ocean over the past 1 MaPaleoceanography10.1029/1999PA000457 Shackleton, N.J., M.A. Hall, J. Line, and C. Shuxi1983Carbon isotope data In core V19-30 confirm reduced carbon-dioxide concentration In the ice-age atmosphereNature306319-32210.1038/306319a0 Winckler, G., R.F. Anderson, S.L. Jaccard, and F. Marcantonio2016Ocean dynamics, not dust, have controlled equatorial Pacific productivity over the past 500,000 yearsProceedings of the National Academy of Sciences113226119-612410.1073/pnas.1600616113 START YEAR: 40000 cal yr BP * END YEAR: 0 cal yr BP -139.7157 -3.383 -82.0667 .11