# Late Miocene to Present Global Ocean Alkenone and SST Reconstruction Data #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite original publication, online resource and date accessed when using this data. # If there is no publication information, please cite Investigator, title, online resource and date accessed. # # Description/Documentation lines begin with # # Data lines have no # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/25390 # Description: NOAA Landing Page # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/herbert2016/herbert2016-odp1085.txt # Description: NOAA location of the template # # Archive: Paleoceanography # # Dataset_DOI: # # Parameter_Keywords: biomarkers #--------------------------------------- # Contribution_Date # Date: 2018-10-10 #--------------------------------------- # File_Last_Modified_Date # Date: 2018-10-10 #--------------------------------------- # Title # Study_Name: Late Miocene to Present Global Ocean Alkenone and SST Reconstruction Data #--------------------------------------- # Investigators # Investigators: Herbert, T.D.; Lawrence, K.T.; Tzanova, A.; Peterson, L.C.; Caballero-Gill, R.; Kelly, C.S. #--------------------------------------- # Description_Notes_and_Keywords # Description: Note: age models for Sites 907 and 982 refined following publication of Herbert et al., 2016 NGS # Provided Keywords: Global ocean cooling, mid-Miocene to Present #--------------------------------------- # Publication # Authors: Herbert, T.D., K.T. Lawrence, A. Tzanova, L.C. Peterson, R. Caballero-Gill, and C.S. Kelly # Published_Date_or_Year: 2016 # Published_Title: Late Miocene Global Cooling and the Rise of Modern Ecosystems # Journal_Name: Nature Geoscience # Volume: 9 # Edition: # Issue: # Pages: 843-847 # Report_Number: # DOI: 10.1038/ngeo2813 # Online_Resource: # Full_Citation: # Abstract: During the late Miocene epoch, about seven million years ago, large areas of the continents experienced drying, enhanced seasonality, and a restructuring of terrestrial plant and animal communities. These changes are seen throughout the subtropics, but have typically been attributed to regional tectonic forcing. Here we present a set of globally distributed sea surface temperature records spanning the past 12 million years based on the alkenone unsaturation method. We find that a sustained late Miocene cooling occurred synchronously in both hemispheres, and culminated with ocean temperatures dipping to near-modern values between about 7 and 5.4 million years ago. The period of maximum cooling coincides with evidence for transient glaciations in the Northern Hemisphere and with a steepening of the pole-to-equator temperature gradient, as well. We thus infer that late Miocene aridity and terrestrial ecosystem changes occurred in a global context of increasing meridional temperature gradients. We conclude that a global forcing mechanism, such as the previously hypothesized decline in atmospheric CO2 levels between eight and six million years ago, is required to explain the late Miocene changes in temperature, climate and ecosystems. #--------------------------------------- # Publication # Authors: Rommerskirchen, F., T. Condon, G. Mollenhauer, L. Dupont, and E. Schefuss # Published_Date_or_Year: 2011 # Published_Title: Miocene to Pliocene development of surface and subsurface temperatures in the Benguela Current system # Journal_Name: Paleoceanography # Volume: 26 # Edition: # Issue: # Pages: # Report_Number: # DOI: 10.1029/2010PA002074 # Online_Resource: # Full_Citation: # Abstract: The initiation of the Benguela upwelling has been dated to the late Miocene, but estimates of its sea surface temperature evolution are not available. This study presents data from Ocean Drilling Program (ODP) Site 1085 recovered from the southern Cape Basin. Samples of the middle Miocene to Pliocene were analyzed for alkenone-based (U37K', SSTUK) and glycerol dialkyl glycerol tetraether (GDGT) based (TEX86, TempTEX) water temperature proxies. In concordance with global cooling during the Miocene, SSTUK and TempTEX exhibit a decline of about 8°C and 16°C, respectively. The temperature trends suggest an inflow of cold Antarctic waters triggered by Antarctic ice sheet expansion and intensification of Southern Hemisphere southeasterly winds. A temperature offset between both proxies developed with the onset of upwelling, which can be explained by differences in habitat: alkenone-producing phytoplankton live in the euphotic zone and record sea surface temperatures, while GDGT-producing Thaumarchaeota are displaced to colder subsurface waters in upwelling-influenced areas and record subsurface water temperatures. We suggest that variations in subsurface water temperatures were driven by advection of cold Antarctic waters and thermocline adjustments that were due to changes in North Atlantic deep water formation. A decline in surface temperatures, an increased offset between temperature proxies, and an increase in primary productivity suggest the establishment of the Benguela upwelling at 10 Ma. During the Messinian Salinity Crisis, between 7 and 5 Ma, surface and subsurface temperature estimates became similar, likely because of a strong reduction in Atlantic overturning circulation, while high total organic carbon contents suggest a “biogenic bloom.†In the Pliocene the offset between the temperature estimates and the cooling trend was reestablished. #--------------------------------------- # Funding_Agency # Funding_Agency_Name: National Science Foundation Ocean Sciences # Grant: 1459280, 1545859 #--------------------------------------- # Funding_Agency # Funding_Agency_Name: Evolving Earth Foundation # Grant: #--------------------------------------- # Site_Information # Site_Name: ODP 1085 # Location: South Atlantic Ocean # Country: # Northernmost_Latitude: -29.375 # Southernmost_Latitude: -29.375 # Easternmost_Longitude: 13.99 # Westernmost_Longitude: 13.99 # Elevation: -1713 #--------------------------------------- # Data_Collection # Collection_Name: ODP1085-2016alkenones Herbert # First_Year: 13670100 # Last_Year: 10700 # Time_Unit: cal yr BP # Core_Length: # Notes: alkenone data reported from Rommerskirchen et al, 2011; interpreted in anomaly framework by Herbert et al., 2016. chronology taken from Rommerskichen et al., 2011 #--------------------------------------- # Chronology_Information # Chronology: #--------------------------------------- # Variables # Data variables follow that are preceded by "##" in columns one and two. # Variables list, one per line, shortname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## sitename sample identification,,,,,paleoceanography,,,C,Site ## Hole notes,,,,,paleoceanography,,,C,hole name ## core notes,,,,,paleoceanography,,,C,core ## section notes,,,,,paleoceanography,,,C,section ## cm_top depth at sample end,,,centimeter,,paleoceanography,,,N, ## cm_base depth at sample start,,,centimeter,,paleoceanography,,,N, ## depth_mbsf depth,,,meter,,paleoceanography,,,N,shipboard meters below sea floor ## depth_mcd depth,,,meter,,paleoceanography,,,N,composite depth ## age_kaBP age,,,calendar kiloyear before present,,paleoceanography,,,N, ## age_uncert_ka age,,90% confidence interval margin of error,calendar kiloyear before present,,paleoceanography,,,N, ## Uk'37 alkenone unsaturation index,sediment,,dimensionless,,paleoceanography,,gas chromatography - flame ionization detection,N,GC-FID ## SST_P sea surface temperature,alkenone unsaturation index,,degree Celsius,,climate reconstructions,,,N,SST calibration following F.G. Prahl et al., 1988; estimated ## SST_M sea surface temperature,alkenone unsaturation index,,degree Celsius,,climate reconstructions,,,N,SST calibration following P.J. Muller et al. 1998; estimated ## SST_anom-M sea surface temperature,alkenone unsaturation index,,degree Celsius,,climate reconstructions,anomalized,,N,SST anomaly relative to modern; Muller calibration ## SST_anom_back sea surface temperature,alkenone unsaturation index,,degree Celsius,,climate reconstructions,anomalized,,N,SST anomaly relative to modern; backtraced for paleolatitude/longitude #------------------------ # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing_Values: NaN sitename Hole core section cm_top cm_base depth_mbsf depth_mcd age_kaBP age_uncert_ka Uk'37 SST_P SST_M SST_anom-M SST_anom_back 1085 A 1 1 50 NaN 0.5 NaN 10.7 13.45 0.640 18.06 0.73 -4.2 -4.2 1085 A 1 1 109 NaN 1.1 NaN 23.4 28.65 0.590 16.55 -0.78 -1.7 -1.8 1085 A 1 2 87 NaN 2.38 NaN 50.6 61.35 0.640 18.06 0.73 0.9 0.9 1085 A 15 6 38. NaN 135.09 NaN 2946.5 224.05 0.690 19.58 2.25 -2.8 -2.8 1085 A 15 6 112 NaN 135.83 NaN 2958.4 220.05 0.680 19.27 1.94 0.0 0.0 1085 A 16 2 40 NaN 138.61 NaN 3002.4 222.75 0.640 18.06 0.73 -0.1 -0.1 1085 A 17 3 55 NaN 149.76 NaN 3228.3 199.75 0.680 19.27 1.94 -1.7 -1.7 1085 A 18 4 55 NaN 160.76 NaN 3387.9 189.05 0.720 20.48 3.15 1.2 1.2 1085 A 19 1 55 NaN 165.76 NaN 3464.5 145.25 0.710 20.18 2.85 -3.2 -3.2 1085 A 20 2 70 NaN 176.9 NaN 3635.9 111.95 0.690 19.58 2.25 2.2 2.2 1085 A 21 5 70 NaN 190.9 NaN 3816.0 179.75 0.680 19.27 1.94 -3.8 -3.9 1085 A 22 3 88 NaN 197.59 NaN 3893.0 193.4 0.760 21.70 4.37 -0.4 -0.4 1085 A 23 2 103 NaN 205.74 NaN 4016.5 182.65 0.720 20.48 3.15 0.7 0.7 1085 A 25 4 58 NaN 227.28 NaN 4318.9 83.85 0.770 22.00 4.67 -2.0 -2.1 1085 A 26 1 70 NaN 232.44 NaN 4410.9 79.55 0.720 20.48 3.15 0.1 0.0 1085 A 26 7 45 NaN 241.16 NaN 4561.3 86.75 0.730 20.79 3.46 -2.2 -2.2 1085 A 27 5 58 NaN 247.79 NaN 4653.8 84.2 0.740 21.09 3.76 -0.7 -0.8 1085 A 28 4 57 NaN 255.77 NaN 4742.0 118.85 0.730 20.79 3.46 -4.6 -4.6 1085 A 29 2 25 NaN 261.95 NaN 4799.1 112.5 0.710 20.18 2.85 -2.2 -2.2 1085 A 29 6 137 NaN 269.06 NaN 4881.4 105.8 0.750 21.39 4.06 -2.4 -2.4 1085 A 31 2 76 NaN 281.38 NaN 5067.8 149.9 0.780 22.30 4.97 -2.0 -2.0 1085 A 33 4 69 NaN 303.39 NaN 5582.1 76.6 0.760 21.70 4.37 -1.4 -1.4 1085 A 36 5 77 NaN 331.17 NaN 5990.2 87.05 0.660 18.67 1.34 -1.1 -1.1 1085 A 38 6 115 NaN 352.16 NaN 6254.0 77.45 0.740 21.09 3.76 -1.9 -2.0 1085 A 39 5 35 NaN 359.84 NaN 6460.2 61.3 0.740 21.09 3.76 -0.9 -0.9 1085 A 39 5 67 NaN 360.07 NaN 6469.7 61.7 0.740 21.09 3.76 -1.7 -1.7 1085 A 39 5 116 NaN 360.44 NaN 6489.7 56.5 0.760 21.70 4.37 1.7 1.7 1085 A 40 1 15 NaN 363.15 NaN 6636.2 53.2 0.750 21.39 4.06 0.7 0.7 1085 A 40 3 68 NaN 366.77 NaN 6804.2 59.1 0.730 20.79 3.46 1.0 1.0 1085 A 40 6 88 NaN 371.17 NaN 6978.3 70.75 0.790 22.61 5.28 -2.6 -2.7 1085 A 40 6 137 NaN 371.63 NaN 6997.8 64.7 0.770 22.00 4.67 0.2 0.1 1085 A 40 7 17 NaN 371.92 NaN 7010.2 61.95 0.760 21.70 4.37 2.2 2.2 1085 A 42 2 76 NaN 384.33 NaN 7403.6 25.8 0.790 22.61 5.28 0.9 0.9 1085 A 43 2 67 NaN 393.94 NaN 7583.9 19.9 0.780 22.30 4.97 -0.7 -0.7 1085 A 44 2 37 NaN 404.41 NaN 7818.4 22.95 0.840 24.12 6.79 -1.2 -1.2 1085 A 45 2 86 NaN 414.01 NaN 8217.2 20.55 0.800 22.91 5.58 -2.2 -2.3 1085 A 46 2 76 NaN 423.67 NaN 8601.2 20.85 0.830 23.82 6.49 1.4 1.4 1085 A 46 5 86 NaN 427.92 NaN 8774.2 17.9 0.810 23.21 5.88 -3.6 -3.7 1085 A 47 2 118 NaN 433.34 NaN 9007.6 23.5 0.860 24.73 7.40 -0.4 -0.4 1085 A 47 3 37 NaN 433.8 NaN 9028.1 27.2 0.820 23.52 6.19 -1.8 -1.9 1085 A 47 3 68 NaN 434.15 NaN 9043.7 30.85 0.840 24.12 6.79 -3.2 -3.2 1085 A 48 4 87 NaN 445.43 NaN 9377.7 31.45 0.880 25.33 8.00 0.1 0.1 1085 A 49 1 75 NaN 451.04 NaN 9539.8 22.4 0.830 23.82 6.49 0.6 0.6 1085 A 50 5 17 NaN 467 NaN 10050.4 20.75 0.880 25.33 8.00 -0.2 -0.3 1085 A 50 5 37 NaN 467.14 NaN 10053.1 20.6 0.880 25.33 8.00 0.7 0.6 1085 A 50 5 67 NaN 467.34 NaN 10056.9 20.5 0.870 25.03 7.70 2.5 2.4 1085 A 52 2 118 NaN 480.96 NaN 10411.6 16.2 0.870 25.03 7.70 0.7 0.6 1085 A 53 2 17 NaN 489.75 NaN 10561.4 23.4 0.870 25.03 7.70 0.5 0.4 1085 A 54 3 67 NaN 499.85 NaN 10672.0 23.6 0.900 25.94 8.61 0.6 0.5 1085 A 56 2 17 NaN 518.56 NaN 10986.3 15.4 0.920 26.55 9.22 -0.3 -0.4 1085 A 56 2 37 NaN 518.81 NaN 10990.7 16.55 0.900 25.94 8.61 1.6 1.5 1085 A 56 2 77 NaN 519.31 NaN 10999.6 19.55 0.890 25.64 8.31 0.8 0.7 1085 A 58 1 86 NaN 537.44 NaN 11360.5 15.1 0.910 26.24 8.91 1.2 1.1 1085 A 59 4 67 NaN 550.47 NaN 11602.5 19.15 0.930 26.85 9.52 1.1 1.0 1085 A 60 2 116 NaN 558.41 NaN 11905.7 13.15 0.950 27.45 10.12 -0.3 -0.4 1085 A 60 5 76.5 NaN 562.43 NaN 12092.6 11.5 0.940 27.15 9.82 0.4 0.3 1085 A 61 2 116 NaN 568.09 NaN 12373.0 13.65 0.940 27.15 9.82 0.4 0.3 1085 A 61 6 116 NaN 572.98 NaN 12598.9 12.85 0.930 26.85 9.52 0.6 0.5 1085 A 62 2 37.5 NaN 576.91 NaN 12770.1 13.85 0.920 26.55 9.22 -0.3 -0.4 1085 A 62 4 17 NaN 579.53 NaN 12897.9 19.2 0.910 26.24 8.91 0.5 0.4 1085 A 62 4 37 NaN 579.72 NaN 12907.2 19.75 0.910 26.24 8.91 -0.8 -0.9 1085 A 62 4 57 NaN 579.91 NaN 12916.5 20.45 0.900 25.94 8.61 1.2 1.1 1085 A 62 5 64 NaN 581.39 NaN 13010.8 14.65 0.910 26.24 8.91 1.7 1.6 1085 A 63 1 57 NaN 585.26 NaN 13263.0 22.05 0.910 26.24 8.91 1.4 1.3 1085 A 63 3 78 NaN 588.39 NaN 13486.3 13.55 0.940 27.15 9.82 -1.2 -1.3 1085 A 63 5 76.5 NaN 591.3 NaN 13670.1 14.05 0.940 27.00 9.67 0.4 0.3