# Lake Turkana, Kenya, 6000 Year TEX86 Temperature #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # # Online_Resource: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:16589 # # Original_Source_URL: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/eastafrica/turkana2012lt84-7p.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleolimnology #-------------------- # Contribution_Date # Date: 2014-06-18 #-------------------- # Title # Study_Name: Lake Turkana, Kenya, 6000 Year TEX86 Temperature #-------------------- # Investigators # Investigators: Berke, M.A.; Johnson, T.C.; Werne, J.P.; Schouten, S.; Sinninghe Damsté, J.S. #-------------------- # Description_and_Notes # Description: This dataset includes TEX86 data from Lake Turkana cores LT84-2P, LT84-7P, and LT94-14FC. # The TEX86 temperature data are provided with both the uncalibrated TEX86 value and and the Kim et al., 2010 # calibration used in the manuscript. Also, the calculated BIT Index (as described in the text) are provided here. # #-------------------- # Publication # Authors: Melissa A. Berke, Thomas C. Johnson, Josef P. Werne, Stefan Schouten, Jaap S. Sinninghe Damsté # Published_Date_or_Year: 2012-10-15 # Published_Title: A mid-Holocene thermal maximum at the end of the African Humid Period # Journal_Name: Earth and Planetary Science Letters # Volume: 351-352 # Edition: # Issue: # Pages: 95-104 # DOI: 10.1016/j.epsl.2012.07.008 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0012821X12003676 # Full_Citation: # Abstract: The termination of the African Humid Period (AHP) about 5 thousand years ago (ka) was the most dramatic climate shift in northern and equatorial Africa since the end of the Pleistocene. Based on TEX86 paleotemperature data from Lake Turkana, Kenya, we show that a temperature shift of 2-4C occurred over the two millennia spanning the end of the AHP, with the warmest conditions occurring at ~5 ka. We note a similar shift, though of a smaller magnitude, in other East African temperature records from Lakes Malawi and Tanganyika, as well as Mt. Kilimanjaro. Additionally, we document the temperature history for the last 220 years from Lake Turkana that indicates the thermal anomaly at 5 ka was warmer than the present day Lake Turkana temperatures and on par with modern temperatures of Lakes Tanganyika and Malawi. We suggest that the thermal response at the end of the AHP may be linked to local insolation during September-November, when local air temperature rises to an annual maximum over Lakes Malawi and Tanganyika and a secondary maximum over Lake Turkana and Mt. Kilimanjaro. September-November insolation peaked at ~5 ka and likely caused air and water temperatures in the region to rise to maxima at that time. #------------------ # Funding_Agency # Funding_Agency_Name: US National Oceanic and Atmospheric Administration (NOAA) # Grant: NA-060-AR4310113 #------------------ # Site_Information # Site_Name: Lake Turkana LT84-7P # Location: Africa>Eastern Africa>Kenya # Country: Kenya # Northernmost_Latitude: 3.76 # Southernmost_Latitude: 3.76 # Easternmost_Longitude: 35.95 # Westernmost_Longitude: 35.95 # Elevation: 360 m #------------------ # Data_Collection # Collection_Name: Turkana2012LT84-7P # Earliest_Year: 2528 # Most_Recent_Year: 476 # Time_Unit: Cal. Year BP # Core_Length: m # Notes: #------------------ # Chronology: # # Table S1. # AMS 14C dates from cores LT84-2P and LT84-7P from Halfman et al. (1994). # Depth (cm) represents the midpoint of sampled core range. # All calibrations were done using CalPal online calibration program (Weninger et al., 2011). # # LT84-2P # Core Depth (cm) Radiocarbon Age (ybp) Cal ybp Material # 20 1310 1237 mag. susceptibility correlation # 49 1530±40 1437±58 AMS on Ostracod >150um # 50 1410 1331 carbonate correlation # 215 1970 1929 mag. susceptibility correlation # 270 2160 2184 carbonate correlation # 305 2275 2265 mag. susceptibility correlation # 480 2875 3016 mag. susceptibility correlation # 495 2990±45 3179 AMS on Ostracod >150?m # 520 3010 3214 carbonate correlation # 630 3385 3632 carbonate correlation # 760 3825 4251 carbonate correlation # 995 4570±45 5214±110 AMS on Ostracod >150um # # LT84-7P # Core Depth (cm) Radiocarbon Age (ybp) Cal ybp Material # 40 1005±50 902±61 AMS on Ostracod >150um # 130 790 726 carbonate correlation # 160 720 653 mag. susceptibility correlation # 250 880 818 mag. susceptibility correlation # 275 1015 912 carbonate correlation # 360 1145 1069 carbonate correlation # 390 1130 1055 mag. susceptibility correlation # 509 1335±50 1250±48 AMS on Ostracod >150um # 510 1380 1307 carbonate correlation # 540 1390 1317 mag. susceptibility correlation # 760 1765 1692 carbonate correlation # 833 1910±50 1853±61 AMS on Ostracod >150um # 860 1955 1912 mag. susceptibility correlation # 870 1935 1889 carbonate correlation # 1020 2170 2197 mag. susceptibility correlation # 1114 2470±40 2562±110 AMS on Ostracod >150um # 1135 2345 2393 carbonate correlation # 1207 2310±40 2288 AMS on Ostracod >150um # 1165 2395 2468 mag. susceptibility correlation # # #---------------- # Variables # # Data variables follow that are preceded by "##" in columns one and two. # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) # ##depth_cm Composite Depth (cm), , , cm, , , , , N ##age_calBP Age (calendar years BP), , ,cal year BP, , , , , N ##tex86 tetraether index of 86 carbon tetraethers, , , , , , , ,N ##lst Lake Surface Temperature, , , deg C, annual, , , Kim 2010 Calibration, N ##BITindex branched and isoprenoid tetraether (BIT) index, , , , , , , , N ##notes notes-Lake Turkana ID,,,,,,,,C # # #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # Depths in cm below lake floor # depth_cm age_calBP tex86 lst BITindex notes 10 476.933 0.688 27.491 0.246 LT84 1W 48.5 542.082 0.681 27.18 0.147 LT84 2A 73.5 584.387 0.683 27.268 0.147 LT84 2A 98.5 626.691 0.681 27.177 0.134 LT84 2A 123.5 668.996 0.69 27.556 0.147 LT 84 3A 148.5 711.3 0.684 27.311 0.116 LT84 3A 176.5 758.681 0.688 27.49 0.151 LT84 3A 198.5 795.909 0.671 26.756 0.153 LT84 3A 226.5 843.291 0.684 27.332 0.102 LT 84 4A 251.5 885.595 0.673 26.842 0.1 LT84 4A 275.5 926.207 0.649 25.774 0.096 LT84 4A 298.5 965.128 0.666 26.513 0.127 LT84 4A 372 1089.503 0.683 27.255 0.178 LT84 5W 388.5 1117.424 0.674 26.895 0.204 LT84 5W 412.5 1158.036 0.662 26.366 0.178 LT84 5W 430.5 1188.496 0.695 27.774 0.15 LT84 6A 453.5 1227.416 0.658 26.146 0.193 LT 84 6W 478.5 1269.72 0.662 26.343 0.147 LT84 6A 502.5 1310.333 0.643 25.475 0.198 LT84 6A 526.5 1350.945 0.677 26.999 0.197 LT84 7W 553.5 1396.634 0.64 25.333 0.15 LT84 7W 576.5 1435.554 0.657 26.136 0.164 LT 7W 601.5 1477.859 0.662 26.348 0.152 LT84 7W 627.5 1521.856 0.649 25.773 0.214 LT84 8A 652.5 1564.16 0.674 26.873 0.182 LT8A 677.5 1606.465 0.695 27.786 0.24 LT84 8A 702.5 1648.769 0.673 26.825 0.162 LT 8A 727.5 1691.074 0.652 25.892 0.107 LT84 9A 750.5 1729.994 0.679 27.098 0.203 LT 9A 775.5 1772.299 0.668 26.623 0.129 LT84 9A 800.5 1814.603 0.665 26.493 0.172 LT84 9A 846.5 1892.444 0.665 26.49 0.145 LT84 11A 871.5 1934.748 0.664 26.428 0.11 LT84 11A 896.5 1977.053 0.676 26.955 0.127 LT84 11A 921.5 2019.357 0.656 26.084 0.071 LT-11A 947.5 2063.354 0.649 25.771 0.079 LT84 12W 967.5 2097.198 0.678 27.036 0.13 LT84 12W 997.5 2147.963 0.676 26.949 0.156 LT12W 1014.5 2176.73 0.704 28.16 0.192 LT 12W 1038.5 2217.342 0.663 26.408 0.106 LT 13A 1061.5 2256.263 0.658 26.161 0.13 LT 13A 1076.5 2281.645 0.653 25.921 0.086 LT 13A 1101.5 2323.95 0.653 25.96 0.121 LT84 13A 1118.5 2352.717 0.647 25.656 0.112 LT84 13A 1147.5 2401.79 0.65 25.803 0.126 LT14A 1172.5 2444.095 0.651 25.866 0.097 LT 14A 1197.5 2486.399 0.672 26.796 0.156 LT 84 14A 1222.5 2528.704 0.667 26.557 0.244 LT 84 14A