# 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/turkana2012lt84-2p.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 LT84-2P # Location: Africa>Eastern Africa>Kenya # Country: Kenya # Northernmost_Latitude: 2.7125 # Southernmost_Latitude: 2.7125 # Easternmost_Longitude: 36.537 # Westernmost_Longitude: 36.537 # Elevation: 360 m #------------------ # Data_Collection # Collection_Name: Turkana2012LT84-2P # Earliest_Year: 6022 # Most_Recent_Year: 1093 # 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 2.5 1093.599 0.649 25.748 0.09 LT84 2-K-1 2-3 22.5 1176.029 0.617 24.266 0.071 LT84 2-K-1 22-23 82.5 1423.319 0.634 25.083 0.095 LT84 2-K-1 82-83 90.5 1456.291 0.634 25.075 0.09 LT84 2-K-1 90-91 110.5 1538.722 0.639 25.281 0.085 LT84 2-K-2 10-11 130.5 1621.152 0.613 24.074 0.086 LT84 2K-2 30-31 154.5 1720.068 0.634 25.052 0.094 LT84 2-K-2 54-55 170.5 1786.012 0.633 25.007 0.095 LT84 2-K-2 70-71 190.5 1868.442 0.631 24.912 0.098 LT84 2-K-2 90-91 211 1952.932 0.642 25.457 0.107 LT84 2-K-3 10-12 231 2035.362 0.641 25.412 0.101 LT84 2-K-3 30-32 255.5 2136.339 0.645 25.579 0.108 LT84 2-K-3 54-57 271.5 2202.283 0.644 25.55 0.113 LT84 2-K-3 70-73 291 2282.653 0.648 25.712 0.107 LT84 2-K-3 90-92 311 2365.083 0.623 24.566 0.104 LT84 2-K-4 10-12 333.5 2457.816 0.62 24.392 0.096 LT84 2-K-4 32-35 351 2529.943 0.637 25.197 0.116 LT84 2-K-4 50-52 371 2612.373 0.637 25.182 0.119 LT84 2-K-4 70-72 389 2686.56 0.637 25.223 0.123 LT84 2-K-4 88-90 410 2773.111 0.638 25.267 0.12 LT84 2-K-5 9-11 432 2863.784 0.636 25.153 0.144 LT84 2-K-5 31-33 452 2946.214 0.652 25.892 0.142 LT84 2-K-5 51-53 471 3024.523 0.656 26.067 0.058 LT84 2-K-5 70-72 491 3106.953 0.657 26.135 0.141 LT84 2-K-5 90-92 509.5 3183.201 0.638 25.259 0.106 LT84 2-K-6 9-10 531 3271.813 0.631 24.937 0.1 LT84 2-K-6 30-32 548 3341.879 0.653 25.923 0.136 LT84 2-K-6 47-49 571 3436.673 0.651 25.86 0.156 LT84 2-K-6 70-72 591 3519.103 0.646 25.604 0.168 LT84 2-K-6 90-92 611 3601.533 0.636 25.138 0.097 LT84 2-K-7 10-12 621 3642.748 0.644 25.509 0.117 LT84 2-K-7 20-22 651 3766.393 0.644 25.508 0.145 LT84 2-K-7 50-52 671 3848.823 0.64 25.327 0.138 LT84 2-K-7 70-72 691 3931.253 0.635 25.133 0.119 LT84 2-K-7 90-92 712.5 4019.866 0.668 26.61 0.198 LT84 2-K-8 12-13 736 4116.721 0.629 24.817 0.138 LT84 2-K-8 35-37 758 4207.394 0.661 26.28 0.139 LT84 2-K-8 57-59 769.5 4254.791 0.631 24.922 0.148 LT84 2-K-8 69-70 790 4339.282 0.665 26.478 0.154 LT84 2-K-8 89-91 809 4417.591 0.661 26.297 0.133 LT84 2-K-9 8-10 828 4495.899 0.656 26.077 0.146 LT84 2-K-9 27-29 863.5 4642.212 0.664 26.416 0.131 LT84 2-K-9 63-64 872.5 4679.306 0.669 26.681 0.12 LT84 2-K-9 72-73 894 4767.918 0.656 26.064 0.117 LT84 2-K-9 93-95 938.5 4951.325 0.706 28.255 0.133 LT84 2-K-10 38-39 958 5031.694 0.684 27.331 0.166 LT84 2-K-10 57-59 979 5118.246 0.687 27.435 0.137 LT84 2-K-10 78-80 1011.5 5252.195 0.657 26.114 0.145 LT84 2-K-11 11-12 1033 5340.807 0.641 25.408 0.146 LT84 2-K-11 32-34 1054.5 5429.419 0.643 25.488 0.143 LT84 2-K-11 54-55 1070 5493.303 0.666 26.515 0.149 LT84 2-K-11 69-71 1090.5 5577.793 0.66 26.243 0.23 LT84 2-K-11 90-91 1112.5 5668.466 0.59 22.917 0.163 LT84 2-K-12 12-13 1129.25 5737.502 0.62 24.405 0.236 LT84 2-K-12 28.5-30 1154.5 5841.569 0.619 24.348 0.247 LT84 2-K-12 54-55 1189.5 5985.822 0.651 25.859 0.164 LT84 2-K-12 89-90 1198.5 6022.916 0.65 25.819 0.165 LT84 2-K-12 98-99