North Atlantic ODP 984C 25KYr Grain Size and Stable Isotope Data ----------------------------------------------------------------------- World Data Center for Paleoclimatology, Boulder and NOAA Paleoclimatology Program ----------------------------------------------------------------------- NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THIS DATA!!!!! NAME OF DATA SET: North Atlantic ODP 984C 25KYr Grain Size and Stable Isotope Data LAST UPDATE: 1/2009 (Original receipt by WDC Paleo) CONTRIBUTOR: Summer Praetorius, Oregon State University IGBP PAGES/WDCA CONTRIBUTION SERIES NUMBER: 2009-005 WDC PALEO CONTRIBUTION SERIES CITATION: Praetorius, S.K., et al. 2009. North Atlantic ODP 984C 25KYr Grain Size and Stable Isotope Data. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2009-005. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA. ORIGINAL REFERENCE: Praetorius, S.K., J.F. McManus, D.W. Oppo, and W.B. Curry. 2008. Episodic reductions in bottom-water currents since the last ice age. Nature Geoscience, Vol. 1, pp. 449-452, July 2008. doi:10.1038/ngeo227 ABSTRACT: Past changes in the freshwater balance of the surface North Atlantic Ocean are thought to have influenced the rate of deep-water formation, and consequently climate. Although water-mass proxies are generally consistent with an impact of freshwater input on meridional overturning circulation, there has been little dynamic evidence to support this linkage. Here we present a 25,000 year record of variations in sediment grain size from south of Iceland, which indicates vigorous bottom-water currents during both the last glacial maximum and the Holocene period. Together with reconstructions of North Atlantic water-mass distribution, vigorous bottom currents suggest a shorter residence time of northern- source waters during the last glacial maximum, relative to the Holocene period. The most significant reductions in flow strength occur during periods that have been associated with freshening of the surface North Atlantic. The short-term deglacial oscillations in bottom current strength are closely coupled to changes in Greenland air temperature, with a minimum during the Younger Dryas cold reversal and a maximum at the time of rapid warming at the onset of the Holocene. Our results support a strong connection between ocean circulation and rapid climate change. GEOGRAPHIC REGION: North Atlantic PERIOD OF RECORD: 25 KYrBP - present FUNDING SOURCES: US National Science Foundation, WHOI-OCCI, and the Comer Science and Research Foundation. DESCRIPTION: Grain size and stable isotope data from North Atlantic ODP site 984, south of Iceland, as a proxy for bottom current strength. ODP 984C core location: 61° 25.524'N, 24° 4.951'W, 1648.5 water depth, Reykjanes Ridge. DATA: 1. Age model for ODP984C (Table 1, Praetorius et al. 2008) Accelerator mass spectrometer radiocarbon measurements and calibrated (calendar) ages. Column 1: Depth (mcd) Column 2: Species Column 3: Uncorrected Radiocarbon age Column 4: Calibrated Age Depth Species Uncorr. 14C Age Calibrated Age 0.01 G.bulloides 805 ± 40 448 0.31 G.bulloides 1440 ± 35 980 0.59 G.bulloides 2200 ± 40 1794 0.95 G.bulloides 3690 ± 40 3596 1.23 G.bulloides 4380 ± 40 4511 1.63 G.bulloides 5670 ± 45 6064 1.95 G.bulloides 6830 ± 65 7346 2.15 G.bulloides 7390 ± 50 7842 2.54 G.bulloides 8730 ± 55 9255 2.74 G.bulloides 9360 ± 45 10029 2.84 G.bulloides 9410 ± 55 10064 3.05 V.ash 10600 ± 100 11707 3.35 N.pacyderma s. 15500 ± 60 17949 3.45 N.pacyderma s. 16250 ± 90 18812 3.81 N.pacyderma s. 17850 ± 100 20649 4.05 N.pacyderma s. 18500 ± 80 21398 4.41 N.pacyderma s. 19950 ± 80 23072 4.65 N.pacyderma s. 21000 ± 90 24000 Analyses from NOSAMS Radiocarbon ages to 12,000 years calibrated according to (1 ) using CALIB 4.0.3; value is midpoint of 2 sigma range from probability method in (1 ). Dates for 0.01 - 2.84 mcd from (2 ). 1). M. Stuiver, P.J. Reimer, E. Bard, J.W. Beck, G.S Burr, K.A. Hughen, B. Kromer, G. McCormac, J. van der Plicht, M. Spurk, Radiocarbon 40, 3 , 1041-1083 (1998). 2). Came, R.E., Oppo, D.W., and McManus, J.F., 2007, Amplitude and timing of salinity and temperature variability in the high-latitude North Atlantic: Geology, v. 35, p. 315–318, doi: 10.1130/G23455A. 2. ODP 984C grain size data, Praetorius et al. 2008 Grain size data from ODP site 984. Included are the calculations for the standard Sortable Silt (SS) mean (10-63 um), the 10-45 um mean, and the variable mean. The interval designated for the calculation of the variable mean is indicated for each sample. The percent SS represents the amount of material in 10-63 um range relative to the entire measured sample (0.5-63 um). The final data set (plotted in Fig 3) is also listed, which is an average of the three size brackets calculations along with a three-point running mean. The standard error is calculated from the difference between the three-point smoothed data set of each grain size bracket. Column 1: Mean Depth (mcd) Column 2: Age (kya) Column 3: Mean Sortable Silt (SS) (um) Column 4: Mean 10-45 (um) Column 5: Variable 100% mean (um) (fraction in Column 8) Column 6: Averaged 3-pt smooth (um) Column 7: St. error smoothed data sets Column 8: Interval for 100% (um) (Column 5) Column 9: SS % Depth Age MeanSS 10-45um Var.Mean 3-pt. Error Int. SS% 0.07 0.554 17.75 16.73 17.75 10-63 37.19 0.15 0.696 21.53 18.71 19.84 18.52 0.41 10-40 39.34 0.17 0.732 18.43 18.03 17.93 19.50 0.66 10-37 39.90 0.21 0.803 21.38 17.92 21.76 19.54 0.96 10-50 38.80 0.25 0.874 22.69 17.08 20.69 19.65 0.88 10-55 37.72 0.27 0.909 18.90 18.98 17.47 19.13 0.68 10-30 37.80 0.37 1.154 19.85 18.80 17.73 19.24 0.50 10-36 43.23 0.41 1.271 21.57 19.91 19.91 19.70 0.37 10-45 42.60 0.45 1.387 19.86 19.45 20.18 20.18 0.46 10-43 34.92 0.55 1.678 21.70 19.06 19.95 19.64 0.62 10-43 38.90 0.57 1.736 21.10 18.37 17.10 19.43 0.55 10-29 38.85 0.61 1.894 18.74 18.80 20.10 19.23 0.17 10-44 31.58 0.67 2.194 18.86 20.00 20.00 19.62 0.02 10-45 31.69 0.75 2.595 21.18 20.01 18.87 19.28 0.17 10-36 43.66 0.77 2.695 17.43 18.83 18.39 19.70 0.10 10-35 40.06 0.85 3.095 21.06 20.11 21.38 19.27 0.04 10-50 42.46 0.87 3.196 19.07 19.04 18.08 19.41 0.21 10-35 35.82 0.97 3.661 19.08 17.94 18.96 19.25 0.48 10-37 47.24 1.01 3.792 22.29 18.54 20.26 19.48 0.57 10-48 37.52 1.05 3.923 18.85 18.53 20.91 19.13 0.49 10-44 43.89 1.07 3.988 17.70 17.37 17.74 19.51 0.37 10-33 38.73 1.15 4.250 21.02 21.34 22.09 18.96 0.08 10-49 42.82 1.17 4.315 18.33 17.70 17.36 20.03 0.20 10-32 35.96 1.21 4.446 21.51 19.90 21.06 19.31 0.15 10-41 35.66 1.25 4.589 19.00 20.10 18.87 19.68 0.29 10-39 45.70 1.27 4.666 20.29 18.08 18.34 19.22 0.27 10-39 40.30 1.37 5.055 19.73 19.55 19.01 19.00 0.26 10-42 43.79 1.41 5.210 18.57 18.61 18.87 19.44 0.35 10-35 39.78 1.43 5.288 22.12 18.92 19.60 19.11 0.26 10-39 47.35 1.45 5.365 18.21 18.91 18.21 19.08 0.31 10-63 35.06 1.47 5.443 18.72 18.77 18.21 19.18 0.17 10-32 38.78 1.51 5.598 20.68 20.71 20.18 19.25 0.15 10-41 50.07 1.61 5.986 19.21 18.05 18.74 19.61 0.25 10-29 34.15 1.71 6.385 20.36 19.02 19.50 19.45 0.30 10-39 45.09 1.75 6.545 20.53 20.07 19.53 19.37 0.22 10-37 50.89 1.77 6.625 18.52 18.66 18.19 19.91 0.17 10-37 40.26 1.85 6.945 21.53 21.09 21.10 19.63 0.23 10-44 47.03 1.87 7.026 20.18 18.84 18.59 19.96 0.32 10-38 41.65 1.91 7.186 20.08 19.30 18.95 19.00 0.41 10-38 46.18 1.97 7.396 19.15 17.86 18.02 19.54 0.36 10-34 47.27 2.01 7.495 19.93 22.99 19.53 19.22 0.40 10-33 39.61 2.05 7.594 17.44 19.22 18.81 19.32 0.41 10-37 41.80 2.07 7.644 19.29 18.23 18.42 19.37 0.15 10-39 36.65 2.15 7.842 22.21 20.56 20.17 19.24 0.31 10-55 35.86 2.17 7.915 18.05 18.20 18.03 19.34 0.30 10-36 37.66 2.31 8.429 19.29 19.32 18.26 18.64 0.43 10-32 36.66 2.35 8.576 20.93 18.18 17.55 18.35 0.45 10-33 35.20 2.37 8.649 17.50 16.66 17.49 18.05 0.45 10-33 35.19 2.45 8.943 17.95 16.84 19.35 18.03 0.27 10-32 31.87 2.47 9.016 19.76 19.05 17.70 18.85 0.20 10-34 36.58 2.51 9.163 18.87 21.70 18.43 19.43 0.45 10-35 33.24 2.65 9.700 21.17 18.72 19.47 19.59 0.23 10-37 37.46 2.67 9.777 19.43 18.99 19.48 19.27 0.26 10-48 35.49 2.71 9.932 18.70 19.00 18.49 20.16 0.34 10-33 29.45 2.735 10.029 24.36 21.24 21.75 20.45 0.39 10-39 51.81 2.75 10.034 20.21 21.33 18.97 21.05 0.31 10-42 41.44 2.77 10.041 20.28 20.36 20.92 20.86 0.50 10-49 37.49 2.835 10.064 24.62 21.03 19.99 21.04 0.80 10-33 46.61 2.85 10.179 23.01 18.92 20.20 20.72 0.81 10-39 44.97 2.87 10.332 19.38 19.64 19.72 20.10 0.45 10-42 34.05 2.91 10.637 20.50 19.81 19.72 21.31 0.40 10-47 29.56 2.93 10.790 25.61 22.12 25.33 22.23 0.42 10-54 41.92 2.97 11.096 22.90 22.80 21.25 21.31 0.25 10-41 25.23 3.01 11.401 16.67 17.69 17.42 19.38 0.18 10-32 26.43 3.03 11.592 18.55 18.61 18.52 18.40 0.08 10-36 33.51 3.05 11.707 19.87 18.57 19.71 18.29 0.18 10-37 25.22 3.07 12.123 16.45 16.76 17.60 17.69 0.18 10-38 22.73 3.09 12.539 16.67 16.87 16.71 16.70 0.21 10-27 25.00 3.11 12.955 15.92 16.37 16.94 18.12 0.18 10-30 28.95 3.13 13.372 22.80 20.41 20.35 18.89 0.13 10-30 22.57 3.15 13.788 18.72 19.40 19.10 19.89 0.21 10-37 24.75 3.17 14.204 19.33 19.61 19.28 19.64 0.44 10-37 23.94 3.19 14.620 18.27 21.54 21.54 19.19 0.43 10-45 24.78 3.21 15.036 17.42 18.09 17.62 18.75 0.26 10-33 21.93 3.23 15.452 19.12 17.86 17.26 17.80 0.22 10-38 28.20 3.25 15.868 17.99 17.43 17.40 17.79 0.29 10-36 25.52 3.27 16.285 17.99 17.08 18.01 18.04 0.07 10-37 23.56 3.29 16.701 17.87 19.43 19.14 19.06 0.06 10-40 27.84 3.31 17.117 21.48 20.31 20.21 19.65 0.14 10-37 19.64 3.33 17.533 19.13 18.84 20.48 20.21 0.12 10-63 22.72 3.35 17.949 19.44 22.13 19.86 20.07 0.17 10-35 12.70 3.37 18.122 21.63 20.13 19.00 20.03 0.50 10-35 17.46 3.41 18.467 19.45 20.20 18.41 19.92 0.58 10-31 17.16 3.45 18.812 22.08 18.40 19.95 20.00 0.44 10-37 13.13 3.47 18.914 21.07 20.34 20.06 19.10 0.26 10-34 11.59 3.55 19.322 15.69 17.86 16.43 19.22 0.25 10-30 18.10 3.61 19.628 19.73 20.81 20.97 19.15 0.64 10-44 18.59 3.65 19.833 18.36 21.64 20.83 19.38 0.21 10-32 13.78 3.67 19.935 18.99 15.69 17.46 19.64 0.35 10-35 15.05 3.75 20.343 22.81 19.49 21.55 19.21 0.79 10-37 15.66 3.77 20.445 19.38 17.95 19.57 20.60 0.52 10-40 15.15 3.81 20.649 20.42 21.34 22.90 19.83 0.40 10-35 11.34 3.85 20.774 19.73 18.15 19.08 20.75 0.30 10-41 21.12 3.95 21.050 22.14 21.19 21.85 20.75 0.43 10-42 36.62 3.97 21.148 22.84 20.94 20.89 21.24 0.06 10-37 15.02 4.05 21.398 18.84 21.23 21.23 20.37 0.39 10-45 22.40 4.07 21.491 17.73 21.17 18.51 20.17 0.35 10-30 9.67 4.15 21.863 22.82 20.20 19.80 19.50 0.32 10-41 34.27 4.27 22.421 18.34 18.57 18.34 20.11 0.20 10-63 7.69 4.35 22.793 18.55 22.75 21.61 20.23 0.30 10-35 15.96 4.37 22.886 22.20 19.50 22.20 20.32 0.32 10-63 10.55 4.41 23.072 18.43 19.03 18.63 21.03 0.54 10-33 13.02 4.45 23.227 23.97 21.30 23.97 20.00 0.20 10-63 46.43 4.51 23.459 18.70 18.69 17.26 19.65 0.39 10-35 24.35 4.55 23.613 18.27 16.91 17.82 18.05 0.14 10-31 25.07 4.57 23.691 16.38 19.10 19.35 18.01 0.10 10-37 16.07 4.65 24.000 19.90 17.54 16.82 18.40 0.29 10-33 26.17 4.67 24.077 17.18 19.68 19.61 18.97 0.21 10-38 13.96 4.75 24.387 18.67 20.68 20.68 19.17 0.47 10-45 37.95 4.85 24.773 18.98 17.69 19.37 20.61 0.58 10-38 19.84 4.87 24.851 21.39 23.01 25.01 20.48 0.49 10-44 9.33 4.91 25.005 19.46 19.39 20.01 20.76 0.31 10-37 24.91 4.97 25.237 21.21 18.38 18.99 10-38 20.04 3. ODP 984C stable isotope data, Praetorius et al. 2008 Column 1: Mean Depth (mcd) Column 2: Age (kya) Column 3: Mean d13C, C. wuellerstorfi, per mil Column 4: Mean d18O, C. wuellerstorfi, per mil Depth Age Mean 13C Mean 18O 0.01 0.448 1.005 2.765 0.05 0.519 1.01 2.68 0.15 0.696 1.125 2.665 0.21 0.803 1.3 3.11 0.25 0.874 1.275 2.775 0.35 1.096 1.38 2.83 0.41 1.271 1.05 3 0.45 1.387 1.25 2.715 0.55 1.678 0.98 2.39 0.61 1.894 1.27 2.82 0.65 2.094 1.29 2.67 0.75 2.595 0.9 2.41 0.81 2.895 0.97 2.82 0.85 3.095 0.82 2.56 0.95 3.596 1.09 2.79 1.01 3.792 0.8 2.83 1.05 3.923 1.06 2.48 1.21 4.446 1.43 2.73 1.25 4.589 1.11 2.76 1.41 5.210 1.06 2.72 1.43 5.288 1.48 3.25 1.71 6.385 1.22 2.82 1.81 6.785 1.3 2.77 2.05 7.594 0.88 2.72 2.65 9.700 0.775 3.235 2.71 9.932 0.765 3.06 2.75 10.034 0.72 3.17 2.81 10.055 1.02 3.52 2.85 10.179 0.875 3.055 2.87 10.332 1.05 3.42 2.89 10.484 1.16 3.67 2.91 10.637 0.99 3.71 2.93 10.790 1.03 3.74 2.95 10.943 1.1 3.69 2.97 11.096 0.68 3.08 3.01 11.401 0.58 3.07 3.03 11.554 1.12 3.65 3.05 11.707 0.92 3.44 3.07 12.123 0.87 3.99 3.09 12.539 0.59 2.94 3.11 12.955 0.22 3.64 3.13 13.372 1.08 3.54 3.15 13.788 0.935 3.37 3.17 14.204 0.715 3.47 3.19 14.620 0.88 3.555 3.21 15.036 0.765 3.71 3.23 15.452 0.78 3.78 3.25 15.868 0.31 3.41 3.27 16.285 0.76 3.26 3.29 16.701 0.64 2.51 3.33 17.533 0.87 3.59 3.35 17.949 1.375 4.59 3.39 18.294 0.39 3.13 3.41 18.467 1.5 4.55 3.45 18.812 1.58 4.515 3.47 18.914 1.59 4.63 3.49 19.016 1.57 4.8 3.51 19.118 1.33 4.43 3.55 19.322 1.6 4.7 3.61 19.628 1.59 4.84 3.65 19.833 1.525 4.725 3.71 20.139 1.53 4.8 3.75 20.343 1.585 4.695 3.81 20.649 1.53 4.7 3.85 20.774 1.56 4.65 3.91 20.961 1.41 4.44 3.95 21.086 1.455 4.72 4.01 21.273 1.6 4.67 4.05 21.398 1.545 4.715 4.15 21.863 1.61 4.72 4.21 22.142 1.55 4.63 4.31 22.607 1.61 4.46 4.61 23.845 1.45 4.67 4.75 24.387 1.15 4.45 4.83 24.696 0.95 4.35 4.85 24.773 1.245 4.34 4.87 24.851 1.39 4.515 4.89 24.928 1.29 4.43 4.91 25.005 1.53 4.37 4.95 25.160 1.32 4.5 4.97 25.237 1.625 4.5 4.99 25.315 1.66 4.42