Subtropical NW Atlantic ODP1058 Mid-Pleistocene G. ruber d18O Data Weirauch, D.; Billups, K.; Martin, P.A. Weirauch, D. Billups, K. Martin, P.A. earth science/paleoclimate/paleoceanography (depth,null,null,meter,null,paleoceanography,composited,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Globigerinoides ruber white,null,per mil,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean (ODP 1058>LATITUDE 31.69>LONGITUDE -75.43) We use the oxygen isotopic composition of planktonic foraminifera Globigerinoides ruber (white) from Ocean Drilling Program Site 1058 in the subtropical northwestern Atlantic to construct a high- resolution (~800 year) climate record spanning the mid-Pleistocene climate transition (~410 ka to 1350 ka). We investigate whether or not millennial-scale instabilities in the proxy record are associated with the extent of continental glaciation. G. ruber d18O values display high-frequency fluctuations throughout the record, but the amplitude about mean glacial and interglacial d18O values increases at marine isotope stage (MIS) 22 (880 ka) and is highest during MIS 12. These observations support that millennial-scale climate instabilities are associated with ice sheet size. Time series analysis illustrates that these variations have significant concentration of spectral power centered on periods of ~10-12 ka and ~5 ka. The timing of these fluctuations agrees well, or coincides with, the periodicities of the second and fourth harmonics, respectively, of precessional forcing at the equator. An insolation-based origin of the millennial-scale instabilities would be independent of ice volume and explains the presence of these fluctuations before the mid-Pleistocene climate transition as well as during interglacial intervals (e.g., MIS 37 and 17). Because the amplitude of the millennial-scale variations increases during the mid-Pleistocene transition, feedback mechanisms associated with the growth of large, 100-ka-paced, polar ice sheets may be important amplifiers of regional surface water hydrographic changes. STUDY NOTES: The data set summarizes Globigerinoides ruber d18O data from Site 1058 spanning Marine Isotope Stages 12-42 (410-1350 Ka). Note that G. ruber between 56.30 and 85.13 mcd were published by Billups et al. 2006. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Weirauch, D. Investigator : Billups, K. Investigator : Martin, P.A. 2011-09-12 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/11934 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/weirauch2008/weirauch2008.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/weirauch2008/weirauch2008.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/weirauch2008/weirauch2008.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/weirauch2008/weirauch2008.txt English https://www.ncdc.noaa.gov/paleo/study/11934 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/weirauch2008/weirauch2008.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/weirauch2008/weirauch2008.txt Weirauch, D., K. Billups, and P. Martin. 2008. Evolution of millennial-scale climate variability during the mid-Pleistocene. Paleoceanography, 23, PA3216, doi:10.1029/2007PA001584. START YEAR: 1350400 cal yr BP * END YEAR: 411000 cal yr BP -75.43 31.69 -75.43 31.69