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  • 1
    Electronic Resource
    Electronic Resource
    Old radiocarbon ages in the southwest Pacific Ocean during the last glacial period and deglaciation (2000)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 405 (2000), S. 555-559 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Marine radiocarbon (14C) dates are widely used for dating oceanic events and as tracers of ocean circulation, essential components for understanding ocean–climate interactions. Past ocean ventilation rates have been determined by the difference between radiocarbon ages of ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/35014581
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    Paper (German National Licenses)
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  • 2
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    (Table 1) Age-depth relation in sediment core TTN057-13-PC4 (2002)
    PANGAEA
    In:  Supplement to: Shemesh, Aldo; Hodell, David A; Crosta, Xavier; Kanfoush, Sharon L; Charles, Christopher D; Guilderson, Thomas P (2002): Sequence of events during the last deglaciation in Southern Ocean sediments and Antarctic ice cores. Paleoceanography, 17(4), 1056, https://doi.org/10.1029/2000PA000599
    Details
    Publication Date: 2023-11-04
    Description: The last glacial to interglacial transition was studied using down core records of stable isotopes in diatoms and foraminifera as well as surface water temperature, sea ice extent, and ice-rafted debris (IRD) concentrations from a piston core retrieved from the Atlantic sector of the Southern Ocean. Sea ice is the first variable to change during the last deglaciation, followed by nutrient proxies and sea surface temperature. This sequence of events is independent of the age model adopted for the core. The comparison of the marine records to Antarctic ice CO2 variation depends on the age model as 14C determinations cannot be obtained for the time interval of 29.5-14.5 ka. Assuming a constant sedimentation rate for this interval, our data suggest that sea ice and nutrient changes at about 19 ka B.P. lead the increase in atmospheric pCO2 by approximately 2000 years. Our diatom-based sea ice record is in phase with the sodium record of the Vostok ice core, which is related to sea ice cover and similarly leads the increase in atmospheric CO2. If gas exchange played a major role in determining glacial to interglacial CO2 variations, then a delay mechanism of a few thousand years is needed to explain the observed sequence of events. Otherwise, the main cause of atmospheric pCO2 change must be sought elsewhere, rather than in the Southern Ocean.
    Keywords: Age, 14C AMS; Age, 14C calibrated; Age, dated; Age, dated standard deviation; Calendar age; DEPTH, sediment/rock; PC; Piston corer; Reference/source; Sample code/label; TN057-13-PC4
    Type: Dataset
    Format: text/tab-separated-values, 74 data points
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    DATA PANGAEA
  • 3
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    Age determination of ODP Hole 108-658C (Table 1) (2000)
    PANGAEA
    In:  Supplement to: deMenocal, Peter B; Ortiz, Joseph D; Guilderson, Thomas P; Adkins, Jess F; Sarnthein, Michael; Baker, Linda; Yarusinsky, Martha (2000): Abrupt onset and termination of the African Humid Period: rapid climate responses to gradual insolation forcing. Quaternary Science Reviews, 19(1-5), 347-361, https://doi.org/10.1016/S0277-3791(99)00081-5
    Details
    Publication Date: 2024-01-09
    Description: A detailed (ca. 100 yr resolution) and well-dated (18 AMS 14C dates to 23 cal. ka BP) record of latest Pleistocene–Holocene variations in terrigenous (eolian) sediment deposition at ODP Site 658C off Cap Blanc, Mauritania documents very abrupt, large-scale changes in subtropical North African climate. The terrigenous record exhibits a well-defined period of low influx between 14.8 and 5.5 cal. ka BP associated with the African Humid Period, when the Sahara was nearly completely vegetated and supported numerous perennial lakes; an arid interval corresponding to the Younger Dryas Chronozone punctuates this humid period. The African Humid Period has been attributed to a strengthening of the African monsoon due to gradual orbital increases in summer season insolation. However, the onset and termination of this humid period were very abrupt, occurring within decades to centuries. Both transitions occurred when summer season insolation crossed a nearly identical threshold value, which was 4.2% greater than present. These abrupt climate responses to gradual insolation forcing require strongly non-linear feedback processes, and current coupled climate model studies invoke vegetation and ocean temperature feedbacks as candidate mechanisms for the non-linear climate sensitivity. The African monsoon climate system is thus a low-latitude corollary to the bi-stable behavior of high-latitude deep ocean thermohaline circulation, which is similarly capable of rapid and large-amplitude climate transitions.
    Keywords: 108-658C; Age, 14C AMS; Age, 14C calibrated; Age, comment; Age, dated; Age, dated standard deviation; Age, maximum/old; Age, minimum/young; Canarias Sea; DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Joides Resolution; Leg108; Ocean Drilling Program; ODP; Sample code/label
    Type: Dataset
    Format: text/tab-separated-values, 129 data points
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    DATA PANGAEA
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