Equatorial Pacific Late Pleistocene Sediment Accumulation Rate Data Hayes, C.T.; Anderson, R.F.; Fleisher, M.Q. Hayes, C.T. Anderson, R.F. Fleisher, M.Q. Meridional Overturning Circulation (MOC) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (231Pa excess,sediment,null,disintegration per minute per gram,null,paleoceanography,corrected,null,N,corrected for ingrowth of 231Pa from sedimentary and detrital uranium) earth science/paleoclimate/paleoceanography (231Pa/230Th excess,sediment,unspecified margin of error,dimensionless,null,paleoceanography,corrected,null,N,corrected for half life decays) earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (231Pa,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (carbonate,sediment,null,percent,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (232Th,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (230Th,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (230Th,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (230Th,sediment,unspecified margin of error,dimensionless,null,paleoceanography,normalized,null,N,mass accumulation rate (flux)) earth science/paleoclimate/paleoceanography (238U,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (231Pa,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (230Th,sediment,null,dimensionless,null,paleoceanography,normalized,null,N,mass accumulation rate (flux)) earth science/paleoclimate/paleoceanography (231Pa/230Th excess,sediment,null,dimensionless,null,paleoceanography,corrected,null,N,corrected for half life decays) earth science/paleoclimate/paleoceanography (232Th,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (238U,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (230Th excess,sediment,null,disintegration per minute per gram,null,paleoceanography,corrected,null,N,corrected for ingrowth of 230Th from sedimentary and detrital uranium) earth science/paleoclimate/paleoceanography (230Th excess,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,corrected,null,N,corrected for ingrowth of 230Th from sedimentary and detrital uranium) earth science/paleoclimate/paleoceanography (231Pa excess,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,corrected,null,N,corrected for ingrowth of 231Pa from sedimentary and detrital uranium) earth science/paleoclimate/paleoceanography (biogenic silica,sediment,null,gram per square centimeter per kiloyear,null,paleoceanography,null,null,N,opal(%)*230Th-norm flux) earth science/paleoclimate/paleocean (TT013-PC72>LATITUDE .1>LONGITUDE -139.4) (V19-30>LATITUDE -3>LONGITUDE -83) 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: NOTES: Data from TT013-PC72 reported here combine previously reported results with new data for the convenience of comparison. This compilation was done with data reports from Bradtmiller et al. (2006) and Anderson et al. (2008). Data from V19-30 also combines new data with those reported by Bradtmiller et al. (2006). Data from both Bradtmiller et al. (2006) and Anderson et al. (2008) have been updated to incorporate a more accurate half life of Th-230 from 75,200 yrs to 75,690 years (Cheng et al. 2000). Age Models: In the case of PC72, we used the age model of Murray et al. (2000) as modified in the upper meter based on C-14 data of Anderson et al. (2008). For V19-30, we used the age model from Shackelton et al. (1983). EXPLANATION OF DERIVED PARAMETERS: xs230Th o and xs231Pa o xs230Th o and xs231Pa o refer to the measured value as corrected for ingrowth of 230Th (or 231Pa) from sedimentary and detrital uranium. These values are calculated using measured concentrations of 230Th (and 231Pa), 232Th and 238U, and assuming that all 232Th is detrital in nature. It also assumes a detrital U/Th ratio, which varies by region. Concentrations are finally corrected for decay since deposition. xs(Pa/Th)o The initial xs231Pa/xs230Th ratio refers to the ratio of xs230Th and xs231Pa after both have been decay corrected using their respective half-lives. 230Th-norm flux (g/cm^2/kyr) --230Th-normalized mass accumulation rate (or flux) For a discussion of this proxy and the relevant corrections and parameters, please see Francois et al. (2004) F(opal) (g/cm^2/kyr) ---230Th-normalized opal accumulation rate (or flux) = opal(%)*230Th-norm flux NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Hayes, C.T. Investigator : Anderson, R.F. Investigator : Fleisher, M.Q. 2011-02-21 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/10528 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hayes2011/hayes2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hayes2011/hayes2011.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hayes2011/hayes2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hayes2011/hayes2011.txt English https://www.ncdc.noaa.gov/paleo/study/10528 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hayes2011/hayes2011.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/hayes2011/hayes2011.txt Hayes, C.T., R.F. Anderson, and M.Q. Fleisher2011Opal accumulation rates in the equatorial Pacific and mechanisms of deglaciationPaleoceanography10.1029/2010PA002008 START YEAR: 488300 cal yr BP * END YEAR: 0 cal yr BP -139.4 -3 -83 .1