Southwest Pacific Isotope, Chemistry and Alkenone Data: Surface and Intermediate Water Temperature Reconstructions over the last 3.5 Ma McClymont, E.L.; Elmore, A.C.; Kender, S.; Leng, M.J.; Greaves, M.; Elderfield, H. McClymont, E.L. Elmore, A.C. Kender, S. Leng, M.J. Greaves, M. Elderfield, H. earth science/paleoclimate/climate reconstructions|paleoceanography (sea surface temperature,alkenone unsaturation index,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,UK'37 = 0.033T + 0.044; calculated using Mueller et al. (1998) UK'37 calibration) earth science/paleoclimate/climate reconstructions|paleoceanography (sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,intermediate water temperature calculated using Elderfield et al. (2010) Mg/Ca calibration for Uvigerina peregrina) earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides wuellerstorfi,null,per mil VPDB,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,null) earth science/paleoclimate/paleoceanography (alkenone unsaturation index Uk37 prime,null,null,dimensionless,null,paleoceanography,null,gas chromatography|isotope ratio mass spectrometry,N,original UK'37 values used to quantify sea surface temperatures) earth science/paleoclimate/paleoceanography (magnesium/calcium,Uvigerina peregrina,null,unspecified unit,null,paleoceanography,null,null,N,original Mg/Ca values used to calculate intermediate water temperatures) earth science/paleoclimate/paleoceanography (age,null,null,million years ago,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (alkenone,dry sediment,null,microgram per gram,null,paleoceanography,null,gas chromatography|isotope ratio mass spectrometry,N,null) earth science/paleoclimate/paleoceanography (delta 13C,Cibicidoides wuellerstorfi,null,per mil VPDB,null,paleoceanography,null,inductively-coupled plasma mass spectrometry,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,null,null,N,mbsf) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (DSDP 593>LATITUDE -40.507833>LONGITUDE 167.6745) Reconstruction of intermediate water properties is important for understanding feedbacks within the ocean-climate system, particularly since these water masses are capable of driving high-low latitude teleconnections. Nevertheless, information about intermediate water mass evolution through the late Pleistocene remains limited. This paper examines changes in Antarctic Intermediate Water (AAIW), the most extensive intermediate water mass in the modern ocean through the last 400 kyr using the stable isotopic composition (d18O and d13C) and trace element concentration (Mg/Ca and B/Ca) of two benthic foraminiferal species from the same samples: epifaunal Planulina wuellerstorfi and infaunal Uvigerina peregrina. Our results confirm that the most reasonable estimates of AAIW temperature and D[CO32-] are generated by Mg/CaU. peregrina and B/CaP. wuellerstorfi, respectively. We present a 400 kyr record of intermediate water temperature and D[CO32-] from a sediment core from the Southwest Pacific (DSDP site 593; 40°30’S, 167°41’E, 1068 m water depth), which lies within the core of modern AAIW. Our results suggest that a combination of geochemical analyses on both infaunal and epifaunal benthic foraminiferal species yields important information about this critical water mass through the late Pleistocene. When combined with two nearby records of water properties from deeper depths, our data demonstrate that during interglacial stages of the late Pleistocene, AAIW and Circumpolar Deep Water (CPDW) have more similar water mass properties (temperature and d13C), while glacial stages are typified by dissimilar properties between AAIW and CPDW in the Southwest Pacific. Our new D[CO32-] record shows short time-scale variations, but a lack of coherent glacial-interglacial variability indicating that large quantities of carbon were not stored in intermediate waters during recent glacial periods. STUDY NOTES: Alkenone sea-surface temperature (SST) and benthic foraminifera Mg/Ca ratios are presented from DSDP Site 593 across the late Pliocene and Pleistocene (0-3.5 Ma). The data record changes in the position of the subtropical front in the Tasman Sea, and Antarctic Intermediate Water temperatures. The results indicate long-term patterns of subtropical front displacement and changes to surface ocean conditions in the Subantarctic zone, linked to global transitions towards the larger and longer-duration glacial-interglacial cycles of the mid and late Pleistocene. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : McClymont, E.L. Investigator : Elmore, A.C. Investigator : Kender, S. Investigator : Leng, M.J. Investigator : Greaves, M. Investigator : Elderfield, H. 2016-06-02 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/20225 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2016/mcclymont2016-dsdp593.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2016/mcclymont2016-dsdp593.txt English https://www.ncdc.noaa.gov/paleo/study/20225 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mcclymont2016/mcclymont2016-dsdp593.txt McClymont, E.L., A.C. Elmore, S. Kender, M.J. Leng, M. Greaves, and H. Elderfield2016Pliocene-Pleistocene evolution of sea surface and intermediate water temperatures from the Southwest PacificPaleoceanography3110.1002/2016PA002954 Elmore, Aurora C., Erin L. McClymont, Henry Elderfield, Sev Kender, Michael R. Cook, Melanie J. Leng, Mervyn Greaves, and Sambuddha Misra2015Antarctic Intermediate Water properties since 400 ka recorded in infaunal (Uvigerina peregrina) and epifaunal (Planulina wuellerstorfi) benthic foraminiferaEarth and Planetary Science Letters428193-20310.1016/j.epsl.2015.07.013 Kender, S., E.L. McClymont, A.C. Elmore, D. Emanuele, M.J. Leng, and H. Elderfield2016Mid-Pleistocene foraminiferal mass extinction coupled with phytoplankton evolutionNature Communications710.1038/ncomms11970 START YEAR: 3495500 cal yr BP * END YEAR: 0 cal yr BP 167.6745 -40.507833 167.6745 -40.507833