# 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/turkana2012lt94.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 LT94-14FC # Location: Africa>Eastern Africa>Kenya # Country: Kenya # Northernmost_Latitude: 2.7 # Southernmost_Latitude: 2.7 # Easternmost_Longitude: 36.487 # Westernmost_Longitude: 36.487 # Elevation: 360 m #------------------ # Data_Collection # Collection_Name: Turkana2012LT94 # Earliest_Year: 1777 # Most_Recent_Year: 1990 # Time_Unit: AD # Core_Length: m # Notes: #------------------ # Chronology: # # The age model for LT94-14FC (Ricketts and Anderson, 1998) is based on 210Pb analyses back to AD 1850 # and an assumed constant mass accumulation rate prior to this. All radiocarbon dates are presented as # calibrated years before 1950 based on the IntCal09 calibration (Reimer et al., 2009) and calculated # using CalPal calibration software (Weninger et al., 2011). # # #---------------- # 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_AD Age, , , year AD, , , , , 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_AD tex86 lst BITindex notes 4.5 1990.2179 0.631 24.941 0.122 LT94 0-9 10.5 1982.1233 0.663 26.374 0.073 LT94 B-67 9-12 11.5 1980.635 0.647 25.648 0.081 LT94 11-12 12 1979.8796 0.636 25.171 0.134 LT94 B-41 11-13 14 1976.7904 0.639 25.278 0.125 LT94 B-42 13-15 16 1973.6044 0.657 26.135 0.103 LT94 B-43 15-17 18 1970.334 0.671 26.739 0.124 LT94 B-44 17-19 20 1966.9887 0.663 26.405 0.130 LT94 B-45 19-21 22 1963.576 0.668 26.624 0.121 LT94 21-23 24 1960.1021 0.635 25.091 0.118 LT94 B-50 23-25 26 1956.5722 0.642 25.422 0.119 LT94 B-2 25-27 28.5 1952.0876 0.639 25.315 0.091 LT94 B-4 27-29 30 1949.3611 0.644 25.546 0.120 LT94 B-17 29-31 32 1945.6869 0.643 25.486 0.114 LT94 B-20 31-33 34 1941.9709 0.634 25.058 0.093 LT94 B-21 33-35 36 1938.2154 0.645 25.588 0.092 LT94 B-22 35-37 38 1934.4228 0.642 25.417 0.103 LT94 B-23 37-39 40 1930.595 0.651 25.863 0.149 LT94 B-24 39-41 44.5 1921.8628 0.639 25.301 0.106 LT94 B-26 43-46 48 1914.965 0.646 25.611 0.127 LT94 B-27 46-50 52 1906.978 0.647 25.68 0.100 LT94 EP-361 50-54 56 1898.8883 0.656 26.058 0.105 LT94 EP-362 54-58 60 1890.7035 0.655 26.008 0.092 LT94 EP-363 58-62 64 1882.4298 0.646 25.606 0.087 LT94 EP-364 62-66 68 1874.0729 0.636 25.152 0.075 LT94 EP-365 66-70 72 1865.6378 0.633 25.007 0.075 LT94 EP-366 70-74 76 1857.1289 0.629 24.851 0.066 LT94 EP-367 74-78 80 1848.55 0.641 25.408 0.081 LT94 EP-368 78-82 84 1839.9048 0.645 25.569 0.102 LT94 EP-369 82-86 88 1831.1963 0.638 25.231 0.076 LT94 EP-370 86-90 92 1822.4276 0.633 25.002 0.092 LT94 EP-371 90-94 96 1813.6012 0.619 24.328 0.102 LT94 EP-372 94-98 100 1804.7196 0.64 25.343 0.101 LT94 EP-373 98-102 104 1795.785 0.631 24.903 0.124 LT94 EP-374 102-106 108 1786.7994 0.634 25.068 0.105 LT94 EP-375 106-110 112 1777.7649 0.647 25.666 0.120 LT94 EP-376 110-114