#----------------------------------------------------------------------- # 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: https://www.ncdc.noaa.gov/paleo/study/15976 # Online_Resource: ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014deterium.txt # Online_Resource: ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014d13c.txt # Online_Resource: ftp.ncdc.noaa.gov/pub/data/paleo/paleolimnology/africa/eastafrica/tana2014.xls # # Original_Source_URL: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleolimnology #-------------------- # Contribution_Date # Date: 2013-12-2014 #-------------------- # Title # Study_Name: Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia #-------------------- # Investigators # Investigators: Costa,K.;Russel,J.;Konecky,B.L.;Lamb,H.F.; #-------------------- # Description_and_Notes # Description: δD of the C28 n-alkanoic acid (δDwax) fromcore 03TL3 taken from Lake Tana, Ethiopia (12 N, 37.25 E, 1830m) in 2007. Keywords - Tropical paleoclimate, East Africa, Compound specific hydrogen isotopes, African Humid Period, Holocene paleoclimate, Air mass trajectories, Congo Air Boundary, Tropics, Hydrology, Intertropical Convergence Zone (ITCZ), Abrupt climate change, Precipitation, Hydrogen isotopes, Carbon isotopes. #-------------------- # Publication # Authors: Costa, K., Russell, J., Konecky, B.L., Lamb, H. # Published_Date_or_Year: 2014 # Published_Title: Isotopic reconstruction of the African Humid Period and Congo Air Boundary migration at Lake Tana, Ethiopia # Journal_Name: Quaternary Science Reviews # Volume: 83 # Edition: # Issue: # Pages: 58-67 # Report_Number: # DOI: http://dx.doi.org/10.1016/j.quascirev.2013.10.031 # Publication_Place: # Publisher: # ISBN: # Online_Resource: # Other_Reference_Details: # Full_Citation: # Abstract: The African Humid Period of the early to mid-Holocene (12,000e5000 years ago) had dramatic ecological and societal consequences, including the expansion of vegetation and civilization into the “green Sahara.” While the humid period itself is well documented throughout northern and equatorial Africa, mechanisms behind observed regional variability in the timing and magnitude of the humid period remain disputed. This paper presents a new hydrogen isotope record from leaf waxes (dDwax) in a 15,000-year sediment core from Lake Tana, Ethiopia (12°N, 37°E) to provide insight into the timing, duration, and intensity of the African Humid Period over northeastern Africa. dDwax at Lake Tana ranges between 80‰ and 170 ‰, with an abrupt transition from D-enriched to D-depleted waxes between 13,000 e11,500 years before present (13e11.5 ka). A similarly abrupt transition from D-depleted to D-enriched waxes occurs ca 8.5e8 ka and is followed by generally D-enriched waxes throughout the late Holocene. Trends in dDwax covary with changes in Northern Hemisphere summer insolation and reflect increased precipitation at Lake Tana during the AHP; however, the transition from D-depleted to D-enriched waxes occurs earlier at Lake Tana (ca 8 ka, vs 5 ka) than in many other regional records, and the amplitude of Ddepletion during the AHP is larger at Lake Tana as well.We attribute this early enrichment to a reduction of moisture derived from westerly sources (the Congo Basin and Atlantic Ocean) which we suggest are Ddepleted relative to moisture sourced from the east (Indian Ocean) and the north (Red Sea and Mediterranean Sea). Our new record highlights the importance of both the northward migration of the tropical rain belt as well as east-west migration of the Congo Air Boundary to precipitation source and amount during the African Humid Period. #------------------ # Funding_Agency # Funding_Agency_Name: US National Science Foundation # Grant: #------------------ # Site_Information # Site_Name: Tana Lake # Location: Africa>East Africa>Ethiopia # Region: East Africa # Country: Ethiopia # Northernmost_Latitude: 12 # Southernmost_Latitude: 12 # Easternmost_Longitude: 37.25 # Westernmost_Longitude: 37.25 # Elevation: 1830 #------------------ # Data_Collection # Collection_Name: 03TL3-deterium # Earliest_Year: 15132 # Most_Recent_Year: 1390 # Time_Unit: cal yr BP # Core_Length: # Notes: #------------------ # Species: #------------------ # Chronology: #---------------- # Variables # Short_name What,Material,Error,Units, Seasonality,Archive,Details,Method,Data_type ## depth_cm Depth,,,cm,,,,,N ## age_BP Age,,,years BP,,,,,N ## dDleafwax DeltaD,leafwax,,per mil VSMOW,,Paleolimnology,,,N ## dDleafwaxcorrected DeltaD,leafwax,,per mil VSMOW,,Paleolimnology,ice volume corrected,,N ## dDleafwaxerror DeltaD,leafwax,two sigma,per mil VSMOW,,Paleolimnology,ice volume corrected,,N #---------------- # Data # Missing_Values: depth_cm age_BP dDleafwax dDleafwaxcorrected dDleafwaxerror 133 1390 -95 -94 0.8 153 1599 -111 -110 5.6 168 1755 -100 -100 0.7 193 2016 -80 -79 2.0 213 2215 -93 -92 227 2355 -111 -111 2.5 238 2465 -93 -92 1.5 261 2695 -106 -106 2.4 322 3354 -100 -100 -2.1 333 3509 -99 -99 -0.7 347 3706 -115 -115 -0.4 368 4003 -99 -99 -0.1 382 4201 -104 -104 2.4 398 4486 -94 -94 -1.2 403 4580 -99 -99 0.5 415 4807 -112 -112 2.7 456 5580 -98 -99 1.9 465 5788 -100 -100 3.2 491 6386 -113 -114 -2.8 499 6570 -115 -116 -1.1 506 6731 -118 -119 0.9 514 6936 -124 -125 1.6 526 7250 -89 -90 533 7432 -106 -107 1.7 540 7615 -100 -102 -0.8 549 7851 -97 -99 2.2 571 8426 -153 -155 1.2 576 8561 -147 -149 -1.1 585 8806 -156 -159 1.0 590 8942 -159 -162 2.0 598 9159 -162 -165 2.3 606 9377 -159 -161 1.2 630 10029 -153 -156 1.6 644 10405 -152 -156 -1.0 653 10638 -156 -160 -2.8 659 10794 -152 -156 -1.9 668 11027 -155 -159 -1.5 676 11226 -157 -161 -0.1 683 11397 -154 -158 -4.1 692 11617 -159 -163 2.4 713 12050 -140 -145 1.8 731 12378 -122 -127 742 12578 -126 -132 1.2 766 13016 -118 -124 0.1 776 13198 -110 -116 0.1 799 13618 -78 -84 2.6 812 13802 -102 -109 1.4 828 14019 -104 -110 -2.9 839 14169 -103 -110 1.8 859 14420 -102 -109 -2.4 875 14598 -91 -98 -1.3 894 14809 -101 -109 0.8 911 14999 -76 -83 -0.1 923 15132 -94 -102 -2.5