Western Equatorial Pacific Pliocene Mg/Ca and Subsurface Temperature Ford, H.L.; Ravelo, A.C.; Dekens, P.S.; LaRiviere, J.P.; Wara, M.W. Ford, H.L. Ravelo, A.C. Dekens, P.S. LaRiviere, J.P. Wara, M.W. earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,composited,null,N,null) earth science/paleoclimate/paleoceanography (magnesium/calcium,Globorotalia tumida,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,sample info) earth science/paleoclimate/paleoceanography (age,null,null,million years ago,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate reconstructions|paleoceanography (sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,Mohtani et al. 2011 calibration; based on Globorotalia tumida (depth habitat ~50-100m)) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (ODP 806>LATITUDE .318333>LONGITUDE 159.361667) The tropical Pacific thermocline strength, depth, and tilt are critical to tropical mean state and variability. During the early Pliocene (~3.5 to 4.5 Ma), the Eastern Equatorial Pacific (EEP) thermocline was deeper and the cold tongue was warmer than today, which resulted in a mean state with a reduced zonal sea surface temperature gradient or El Padre. However, it is unclear whether the deep thermocline was a local feature of the EEP or a basin-wide condition with global implications. Our measurements of Mg/Ca of Globorotalia tumida in a western equatorial Pacific site indicate Pliocene subsurface temperatures warmer than today; thus, El Padre included a basin-wide thermocline that was relatively warm, deep, and weakly tilted. At ~4 Ma, thermocline steepening was coupled to cooling of the cold tongue. Since ~4 Ma, the basin-wide thermocline cooled/shoaled gradually, with implications for thermocline feedbacks in tropical dynamics and the interpretation of TEX86-derived temperatures. STUDY NOTES: Mg/Ca values from Globorotalia tumida and reconstructed subsurface temperature from Western Pacific Warm Pool ODP Site 806. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Ford, H.L. Investigator : Ravelo, A.C. Investigator : Dekens, P.S. Investigator : LaRiviere, J.P. Investigator : Wara, M.W. 2015-06-19 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/18915 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2015b/ford2015b.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2015b/ford2015b.txt English https://www.ncdc.noaa.gov/paleo/study/18915 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ford2015b/ford2015b.txt Heather L. Ford, A. Christina Ravelo, Petra S. Dekens, Jonathan P. LaRiviere and Michael W. Wara2015The evolution of the equatorial thermocline and the early Pliocene El Padre mean stateGeophysical Research Letters4210.1002/2015GL064215http://onlinelibrary.wiley.com/doi/10.1002/2015GL064215/full START YEAR: 4807253 cal yr BP * END YEAR: 24000 cal yr BP 159.361667 .318333 159.361667 .318333