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| Titel |
Volcanic synchronization of Dome Fuji and Dome C Antarctic deep ice cores over the past 216 kyr |
| VerfasserIn |
S. Fujita, F. Parrenin, M. Severi, H. Motoyama, E. W. Wolff |
| 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. 10 ; Nr. 11, no. 10 (2015-10-19), S.1395-1416 |
| Datensatznummer |
250117438
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| Publikation (Nr.) |
 copernicus.org/cp-11-1395-2015.pdf |
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| Zusammenfassung |
| Two deep ice cores, Dome Fuji (DF) and EPICA Dome C (EDC), drilled at remote
dome summits in Antarctica, were volcanically synchronized to improve our
understanding of their chronologies. Within the past 216 kyr, 1401 volcanic
tie points have been identified. DFO2006 is the chronology for the DF core
that strictly follows O2 / N2 age constraints with interpolation
using an ice flow model. AICC2012 is the chronology for five cores, including
the EDC core, and is characterized by glaciological approaches combining ice
flow modelling with various age markers. A precise comparison between the
two chronologies was performed. The age differences between them are within
2 kyr, except at Marine Isotope Stage (MIS) 5. DFO2006 gives ages older than
AICC2012, with peak values of 4.5 and 3.1 kyr at MIS 5d
and MIS 5b, respectively. Accordingly, the ratios of duration
(AICC2012 / DFO2006) range between 1.4 at MIS 5e and 0.7 at MIS 5a. When
making a comparison with accurately dated speleothem records, the age of
DFO2006 agrees well at MIS 5d, while the age of AICC2012 agrees well at
MIS 5b, supporting their accuracy at these stages. In addition, we found that
glaciological approaches tend to give chronologies with younger ages and
with longer durations than age markers suggest at MIS 5d–6. Therefore, we
hypothesize that the causes of the DFO2006–AICC2012 age differences at MIS 5
are (i) overestimation in surface mass balance at around MIS 5d–6 in the
glaciological approach and (ii) an error in one of the O2 / N2 age
constraints by ~ 3 kyr at MIS 5b. Overall, we improved our
knowledge of the timing and duration of climatic stages at MIS 5. This new
understanding will be incorporated into the production of the next common
age scale. Additionally, we found that the deuterium signals of ice, δDice, at DF tends to lead the one at EDC, with the DF lead being more
pronounced during cold periods. The lead of DF is by +710 years (maximum)
at MIS 5d, −230 years (minimum) at MIS 7a and +60 to +126 years on average. |
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