{"NOAAStudyId":"24090","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"2018-05-16","dataPublisher":"NOAA","dataType":"PALEOCEANOGRAPHY","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/paleoceanography","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-ocean-24090.xml","doi":null,"earliestYearBP":1093000,"earliestYearCE":-1091050,"entryId":"noaa-ocean-24090","funding":[],"investigators":"Billups, K.; York, K.; Bradtmiller, L.I.","mostRecentYearBP":643000,"mostRecentYearCE":-641050,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/24090","originalSource":null,"publication":[{"abstract":"We use biogenic silica (opal) mass accumulating rates (MARs) at Ocean Drilling Program Site 745B to infer upwelling, and by extension upper water column stratification, on glacial to interglacial time scales during the mid-Pleistocene climate transition (MPT; 1.2–0.6 Ma). Distinct variations in the percent biogenic silica content of the sediments parallel the global benthic foraminiferal d18O stack affording the derivation of an orbital-scale age model. Opal MARs confirm that silica production/preservation was indeed at a minimum at each of the glacial maxima during the entire MPT consistent with the late Pleistocene model that links upwelling of dissolved silica with water column stratification. A unique relationship between opal MARs and benthic foraminiferal d13C values in the South Atlantic suggests that during the midpoint of the MPT stratification may also be causally related to deep water circulation. However, there is no evidence that cooling during the MPT and the evolution of the 100 kyr climate cycle are linked to changes in water column stratification. Terrigenous sediment MARs, on the other hand, which can be inferred from the proportion of biogenic silica in the sediments at this particular site, provide evidence for increased glacial activity on Antarctica beginning with the onset of the MPT and culminating in a maximum during its midpoint (Marine Isotope Stage 22, 0.9 Ma). Thereafter, glacial activity decreases and we speculate that the evolution of the 100 kyr cycle is associated with a thickening ice sheet after reaching maximum extent somewhat analogous to the processes proposed for Northern Hemisphere ice sheets.","author":{"name":"Billups, K., K. York, and L.I. Bradtmiller"},"citation":"Billups, K., K. York, and L.I. Bradtmiller. 2018. Water column stratification in the Antarctic zone of the Southern Ocean during the mid-Pleistocene climate transition. Paleoceanography and Paleoclimatology, 33. doi: 10.1029/2018PA003327","edition":null,"identifier":{"id":"10.1029/2018PA003327","type":"doi","url":"http://dx.doi.org/10.1029/2018PA003327"},"issue":null,"journal":"Paleoceanography and Paleoclimatology","pages":null,"pubRank":"1","pubYear":2018,"reportNumber":null,"title":"Water column stratification in the Antarctic zone of the Southern Ocean during the mid-Pleistocene climate transition","type":"publication","volume":"33"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"57648","geo":{"geoType":"Feature","geometry":{"coordinates":["-59.616667","86.866667"],"type":"POINT"},"properties":{"easternmostLongitude":"86.866667","maxElevationMeters":"-4802","minElevationMeters":"-4802","northernmostLatitude":"-59.616667","southernmostLatitude":"-59.616667","westernmostLongitude":"86.866667"}},"locationName":"Ocean>Indian Ocean","mappable":"Y","paleoData":[{"NOAADataTableId":"35853","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>paleocean>geochemistry"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/billups2018/billups2018-745b.txt","linkText":"ODP 745B Biogenic Silica Data","urlDescription":"NOAA Template File","variables":[{"cvAdditionalInfo":"hole","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Character","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>sample identification"},{"cvAdditionalInfo":"core","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Character","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>sample identification"},{"cvAdditionalInfo":"site","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>sample identification"},{"cvAdditionalInfo":"section","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>sample identification"},{"cvAdditionalInfo":"depth at top of core section","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth>depth at sample start"},{"cvAdditionalInfo":"depth at bottom of core section","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"centimeter","cvWhat":"depth variable>depth>depth at sample end"},{"cvAdditionalInfo":"below sea floor","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":"based on magnetostratigraphy using the ages of Ogg et al. (2012)","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"million years ago","cvWhat":"age variable>age"},{"cvAdditionalInfo":"based on tuning of the biogenic silica to the d18O stack of Lisiecki and Raymo (2005)","cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"million years ago","cvWhat":"age variable>age"},{"cvAdditionalInfo":null,"cvDataType":"PALEOCEANOGRAPHY","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"geological material>bulk geological material>sediment","cvMethod":"spectrophotometry","cvSeasonality":null,"cvShortName":null,"cvUnit":"percent","cvWhat":"chemical composition>compound>inorganic compound>silicon dioxide>biogenic silica"}]}],"dataTableName":"ODP745B silica Billups2018","dataTableNotes":null,"earliestYear":1093000,"earliestYearBP":1093000,"earliestYearCE":-1091050,"mostRecentYear":643000,"mostRecentYearBP":643000,"mostRecentYearCE":-641050,"species":[],"timeUnit":"cal yr BP"}],"siteName":"ODP 745B"}],"studyCode":null,"studyName":"Biogenic Silica Data from the Indian Ocean sector of the Southern Ocean during the mid-Pleistocene climate transition","studyNotes":null,"version":"1.0","xmlId":"22234"}