noaa-other-9958 eng; USA utf8 dataset Bauer, Bruce DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce +1 303-497-6280 +1 303-497-6513 325 Broadway, E/CC23 Boulder CO 80305-3328 USA paleo@noaa.gov pointOfContact 2018-12-11 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) NOAA/WDS Paleoclimatology - Namibia 5000 Year Rock Hyrax Midden Nitrogen Isotope Data 2010-07-19 publication noaa-other-9958 NCEI DSI 1200_01 Chase, B.M. originator Chase, B.M. author Meadows, M.E. originator Meadows, M.E. author Carr, A.S. originator Carr, A.S. author Reimer, P.J. originator Reimer, P.J. author NOAA National Centers for Environmental Information publisher tableDigital This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology. The associated NCEI study type is Other Collections. The data include parameters of others with a geographic location of Namibia, Southern Africa. The time period coverage is from 4877 to 1461 in calendar years before present (BP). See metadata information for parameter and study location details. Please cite this study when using the data. Data of past climate and environment derived from unusual proxy evidence. Parameter keywords describe what was measured in this data set. Additional summary information can be found in the abstracts of papers listed in the data set citations. completed Bauer, Bruce DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce +1 303-497-6280 +1 303-497-6513 325 Broadway, E/CC23 Boulder CO 80305-3328 USA paleo@noaa.gov pointOfContact https://www.ncdc.noaa.gov/c/images/pc-default-other.png Paleoclimatology - Other Collections PNG Earth Science > Climate Indicators > Paleoclimate Indicators > Paleoclimate Reconstructions theme Global Change Master Directory (GCMD) Science Keywords 2018 revision Version 8.6 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords HTTPS Web Browser Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher earth science > paleoclimate > others theme Global Change Master Directory (GCMD) Science Keywords 2018 revision Version 8.6 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords HTTPS Web Browser Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Continent > Africa > Southern Africa > Namibia> Austerlitz Cave > LATITUDE -20.4638 > LONGITUDE 14.4423 place otherRestrictions Cite as: Chase, B.M.; Meadows, M.E.; Carr, A.S.; Reimer, P.J. (2010-07-19): NOAA/WDS Paleoclimatology - Namibia 5000 Year Rock Hyrax Midden Nitrogen Isotope Data. [indicate subset used]. NOAA National Centers for Environmental Information. https://www.ncdc.noaa.gov/paleo/study/9958. Accessed [date]. otherRestrictions Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives. otherRestrictions Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose. otherRestrictions None otherRestrictions Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. eng; USA geoscientificInformation Date Range: 4877 cal yr BP to 1461 cal yr BP; 14.4423 14.4423 -20.4638 -20.4638 Study Coordinates -20.4638 14.4423 -2927 489 STUDY NOTES: This dataset comprises stable nitrogen isotope data from a rock hyrax (Procavia capensis) middens from northwestern Namibia that record a series of rapid aridification events beginning at c. 3800 cal yr BP, and which mark a progressive decrease in regional humidity across the Holocene. Strong correlations exist between this record and other terrestrial and marine archives from southern Africa, indicating that the observed pattern of climate change is regionally coherent. Combined, these data indicate hemispheric synchrony in tropical African climate change during the Holocene, with similar trends characterising the termination of the 'African Humid Period' (AHP) in both the northern and southern tropics. These findings run counter to the widely accepted model of direct low latitude insolation forcing, which requires an anti-phase relationship to exist between the hemispheres. The combined dataset highlights: 1) the importance of forcing mechanisms influencing the high northern latitudes in effecting low latitude climate change in Africa, and 2) the potential importance of solar forcing and variations in the Earth's geomagnetic shield in determining both long-term and rapid centennial-scale climate changes, identifying a possible mechanism for the variations marking the AHP termination in both the southern and northern tropics. Stable isotope data (d15N) from a rock hyrax midden recovered from northwest-facing Austerlitz cave in northwestern Namibia (20°27.83'S, 14°26.54'E) on the southern margin of the limestone karstveld region, south of the Etendeka and Kamajab plateaus. AMS radiocarbon analyses of the Austerlitz midden indicate that it was deposited between 4538-4825 cal (calibrated) yr BP (UBA 9441) and 1385-1522 cal yr BP (UBA-9436). The distribution of ages as a function of depth shows continuous deposition, with no apparent hiatuses. Accumulation rates average ~30 µm yr-1, with slightly higher rates (~48 µm yr-1) at the base of the section. Each 1 mm isotope sample thus integrates approximately 20 – 35 years of accumulation. The d15N values of the Austerlitz midden vary from 12.5 to -19.4‰. From the beginning of the record, there is a clear, progressive enrichment in d15N values, with sharp increases occurring between c. 3500 – 3400 cal yr BP and c. 3000 – 2800 cal yr BP. These trends show close similarities with the d15N record from the hyrax middens recovered from Spitzkoppe massif, 160 km to the southwest (Chase et al., 2009), and reveal a coherent, regional-scale midden 15N signal at this time. The potential of nitrogen stable isotope compositions as a climatic indicator has long been recognised, but studies of modern ecosystems have produced complex data sets, that have proved difficult to interpret (e.g. Heaton, 1987; Heaton et al., 1986). Among herbivores, 15N abundance in animal tissues is strongly influenced by climate, diet and/or physiology (Ambrose and DeNiro, 1986; Heaton et al., 1986). While early studies focused on the possible effects that animal metabolism would have on the signal (Ambrose and DeNiro, 1986), subsequent studies of d15N values in plants across aridity gradients have indicated that it may not be necessary to look towards herbivore metabolism for the link between d15N values and rainfall, as clear correlations are identified between higher d15N values and decreased rainfall in both C3 and C4 plants (Heaton, 1987; Murphy and Bowman, 2006; Swap et al., 2004) and soils (Aranibar et al., 2004). Murphy and Bowman's (2006) spatially-extensive studies of d15N values in both grass and kangaroo bone from across Australia reveal a remarkably consistent relationship between plant and bone d15N signals, suggesting that water availability, through its influence on the isotopic signature of plants/diet, is the primary control on animal d15N with metabolism having no clear effect. ABSTRACT SUPPLIED BY ORIGINATOR: Presented here are stable nitrogen isotope data from a rock hyrax (Procavia capensis) middens from northwestern Namibia that record a series of rapid aridification events beginning at ca. 3800 cal yr BP, and which mark a progressive decrease in regional humidity across the Holocene. Strong correlations exist between this record and other terrestrial and marine archives from southern Africa, indicating that the observed pattern of climate change is regionally coherent. Combined, these data indicate hemispheric synchrony in tropical African climate change during the Holocene, with similar trends characterising the termination of the 'African Humid Period' (AHP) in both the northern and southern tropics. These findings run counter to the widely accepted model of direct low-latitude insolation forcing, which requires an antiphase relationship to exist between the hemispheres. The combined dataset highlights: 1) the importance of forcing mechanisms influencing the high northern latitudes in effecting low-latitude climate change in Africa, and 2) the potential importance of solar forcing and variations in the Earth's geomagnetic shield in determining both long-term and rapid centennial-scale climate changes, identifying a possible mechanism for the variations marking the AHP termination in both the southern and northern tropics. 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Native Format(s) https://data.nodc.noaa.gov/cgi-bin/iso?id=noaa-other-9958 HTTPS Landing Page NCEI landing page for this dataset Dataset landing page with general information and links to access the data. information https://www.ncdc.noaa.gov/paleo/study/9958 HTTPS Web Browser NCEI Study Page Study page with dataset access information. search https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/other-collections HTTPS Information NCEI Other Collections Page General information for this data type. information https://www1.ncdc.noaa.gov/pub/data/paleo/midden/africa/austerlitz2010d15n.xls HTTP Download NCEI Direct Download Direct download links for dataset files. download https://www1.ncdc.noaa.gov/pub/data/paleo/midden/africa/austerlitz2010d15n.txt HTTP Download NCEI Direct Download Direct download links for dataset files. download asNeeded This metadata record was translated from DIF using dif-9x-to-iso-19115-2.xsl Version: 2018-10-25