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| Titel |
Stable isotope and trace element investigation of two contemporaneous annually-laminated stalagmites from northeastern China surrounding the "8.2 ka event" |
| VerfasserIn |
J. Y. Wu, Y. J. Wang, H. Cheng, X. G. Kong, D. B. Liu |
| 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 ; 8, no. 5 ; Nr. 8, no. 5 (2012-10-10), S.1497-1507 |
| Datensatznummer |
250005838
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| Publikation (Nr.) |
 copernicus.org/cp-8-1497-2012.pdf |
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| Zusammenfassung |
| The prominent "8.2 ka event" was well documented in the Greenland ice
cores. It remains unclear, however, about its duration, structure and
forcing mechanism at low- to mid-latitude regions. Here we use the physical
and geochemical data of stalagmites from the Nuanhe Cave in Liaoning
Province, northeastern China, to reconstruct a detailed history of East
Asian monsoons covering the entire duration of the event. High-resolution
chronologies of two contemporaneous stalagmites, each consisting of at least
770 yr annual growth bands, were established by calibrating and anchoring
the floating band-counting ages against five high-precision 230Th
dates. Two oxygen isotope profiles replicate each other on annual-decadal
timescales despite their difference in growth rates, indicating that the
δ18O variability has a climatic origin largely associated with changes
in the rainfall δ18O from the West Pacific during summer season. A
signal from the "8.2ka event" was faint in our δ18O records, not as
significant as Indian monsoon dominated stalagmite δ18O records from
Qunf in Oman and Dongge in Southern China. However, our δ13C and Ba/Ca
profiles, as indicators of local environmental changes, provide strong
support for a climate reversal centred at 8.2 ka BP, which is likely
controlled by winter monsoon circulations via the westerly winds associated
with North Atlantic climate. Therefore, we concluded that the winter- and
summer-Asian monsoons responded independently to the high northern latitude
climate. |
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