Iberian Margin IODP U1385 High Resolution Isotope and Trace Metal Data 1235 to 1320 ka Birner, B.; Hodell, D.A.; Tzedakis, P.C.; Skinner, L.C. Birner, B. Hodell, D.A. Tzedakis, P.C. Skinner, L.C. earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,corrected,null,N,revised meter composite) earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides mundula,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Globigerina bulloides,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,null) earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides wuellerstorfi,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 13C,Cibicidoides wuellerstorfi,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (sample identification,null,null,null,null,paleoceanography,null,null,C,null) earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,corrected,null,N,corrected revised meter composite) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,age based on tuning sediment lightness L* to orbital precession) earth science/paleoclimate/paleoceanography (magnesium/calcium,Uvigerina peregrina,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,corrected,null,N,based on tuning sediment lightness to orbital precession) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,based on Mediterranean-tuned age model of Hodel et al. 2015) earth science/paleoclimate/paleoceanography (delta 18O,Uvigerina peregrina,null,per mil PDB,null,paleoceanography,null,null,N,add 0.64 per mil to C. wuellerstorfi and C. mundulus values) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,based on insolation-tuned age model of Hodel et al. 2015) earth science/paleoclimate/climate reconstructions|paleoceanography (sea water temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,bottom water temperature using Mg/Ca U.peregrina) earth science/paleoclimate/climate reconstructions|paleoceanography (delta 18O,delta 18O|magnesium/calcium|sea water,null,per mil SMOW,null,climate reconstructions|paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (IODP U1385>LATITUDE 37.571417>LONGITUDE -10.126033) Although millennial-scale climate variability (<10 ka) has been well studied during the last glacial cycles, little is known about this important aspect of climate in the early Pleistocene, prior to the Middle Pleistocene Transition. Here we present an early Pleistocene climate record at centennial resolution for two representative glacials (marine isotope stages (MIS) 37-41 from approximately 1235 to 1320 ka) during the "41 ka world" at Integrated Ocean Drilling Program Site U1385 (the "Shackleton Site") on the southwest Iberian margin. Millennial-scale climate variability was suppressed during interglacial periods (MIS 37, MIS 39, and MIS 41) and activated during glacial inceptions when benthic d18O exceeded 3.2‰. Millennial variability during glacials MIS 38 and MIS 40 closely resembled Dansgaard-Oeschger events from the last glacial (MIS 3) in amplitude, shape, and pacing. The phasing of oxygen and carbon isotope variability is consistent with an active oceanic thermal bipolar see-saw between the Northern and Southern Hemispheres during most of the prominent stadials. Surface cooling was associated with systematic decreases in benthic carbon isotopes, indicating concomitant changes in the meridional overturning circulation. A comparison to other North Atlantic records of ice rafting during the early Pleistocene suggests that freshwater forcing, as proposed for the late Pleistocene, was involved in triggering or amplifying perturbations of the North Atlantic circulation that elicited a bipolar see-saw response. Our findings support similarities in the operation of the climate system occurring on millennial time scales before and after the Middle Pleistocene Transition despite the increases in global ice volume and duration of the glacial cycles. STUDY NOTES: The study uses sections 1 to 6 in Core 339-U1385D-15H (123.59–135.82 meter below sea floor (mbsf)) and sections 5 and 6 in Core 339-U1385E-16H (135.24–136.97 mbsf). The splice tie point between the cores occurs at 147.32 corrected revised meters composite depth (crmcd) where U1385D-15H-6, 80 cm is tied to U1385E-16H-5, 59 cm, yielding a ~8 m long section (140.26–148.88 crmcd) spanning MIS 37–41. Depth is a corrected revised meter composite depth across all cores. Instrument precision of repeated standard measurements was 0.06 per mil for d13C and 0.08 per mil for d18O. d18O U. peregrina record uses C. wuellerstorfi and C. mundulus values adjusted by +0.64 per mil. Precision of deep water temperature calculation is 0.87 degrees C. Precision of d18O water is 0.23 per mil SMOW. Error on Mg/Ca U. peregrina analysis: ~4-6%. Provided Keywords: millennial variability, early Pleistocene, Iberian margin NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Birner, B. Investigator : Hodell, D.A. Investigator : Tzedakis, P.C. Investigator : Skinner, L.C. 2016-02-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/19747 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/birner2016/birner2016-trace.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/birner2016/birner2016-isot.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/birner2016/birner2016-trace.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/birner2016/birner2016-isot.txt English https://www.ncdc.noaa.gov/paleo/study/19747 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/birner2016/birner2016-trace.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/birner2016/birner2016-isot.txt Birner, B., D.A. Hodell, P.C. Tzedakis, and L.C. Skinner2016Similar millennial climate variability on the Iberian margin during two early Pleistocene glacials and MIS 3Paleoceanography3110.1002/2015PA002868 START YEAR: 1320000 cal yr BP * END YEAR: 1235000 cal yr BP -10.126033 37.571417 -10.126033 37.571417