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| Titel |
The WAIS Divide deep ice core WD2014 chronology – Part 1: Methane synchronization (68–31 ka BP) and the gas age–ice age difference |
| VerfasserIn |
C. Buizert, K. M. Cuffey, J. P. Severinghaus, D. Baggenstos, T. J. Fudge, E. J. Steig, B. R. Markle, M. Winstrup, R. H. Rhodes, E. J. Brook, T. A. Sowers, G. D. Clow, H. Cheng, R. L. Edwards, M. Sigl, J. R. McConnell, K. C. Taylor |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 2 ; Nr. 11, no. 2 (2015-02-05), S.153-173 |
| Datensatznummer |
250117160
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| Publikation (Nr.) |
 copernicus.org/cp-11-153-2015.pdf |
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| Zusammenfassung |
| The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly
drilled, high-accumulation deep ice core that provides Antarctic climate
records of the past ∼68 ka at unprecedented temporal resolution. The
upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer
counting. Here we present a chronology for the deep part of the core
(67.8–31.2 ka BP), which is based on stratigraphic matching to
annual-layer-counted Greenland ice cores using globally well-mixed
atmospheric methane. We calculate the WD gas age–ice age difference
(Δage) using a combination of firn densification modeling, ice-flow
modeling, and a data set of δ15N-N2, a proxy for past firn column
thickness. The largest Δage at WD occurs during the Last Glacial
Maximum, and is 525 ± 120 years. Internally consistent solutions can be
found only when assuming little to no influence of impurity content on
densification rates, contrary to a recently proposed hypothesis. We
synchronize the WD chronology to a linearly scaled version of the
layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of
Dansgaard–Oeschger (DO) events into agreement with the U/Th absolutely
dated Hulu Cave speleothem record. The small Δage at WD provides
valuable opportunities to investigate the timing of atmospheric greenhouse
gas variations relative to Antarctic climate, as well as the interhemispheric
phasing of the "bipolar seesaw". |
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