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| Titel |
Boron isotopic composition of Porites corals over the past 500 years in the South China Sea: Evaluating the potential controlling factors |
| VerfasserIn |
Tzu-Hao Wang, Chen-Feng You, Yi Liu, Chuan-Hsiung Chung, Hou-Chun Liu |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130902
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| Publikation (Nr.) |
 EGU/EGU2016-11230.pdf |
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| Zusammenfassung |
| As the largest marginal sea in the East Asia, the South China Sea is sensitive to the
environmental changes both in Asia landmass and western Pacific Ocean. Thus, the
cause-consequence feedback systems between the seawater chemistry and environmental
change in the South China Sea encompass various interactions and controlling factors on
different spatial and temporal scales. Global and regional (e.g., continental sources, and the
East Asian monsoon system) factors may have a simultaneous impact on the coral records.
However, the representative meanings of coral records in the South China Sea are still poorly
understood. Here we present an age-controlled coral boron isotopic (δ11B ) record in the
Xisha Islands, the northern South China Sea, from AD 1466 to AD 1960. We applied
micro-sublimation technique and MC-ICP-MS measurement to provide a low-blank
and highly precise δ11B measurement. The δ11B values of the coral specimens
varied from 20.8‰ to 26.0‰ which the variation is larger than the observation
in the western Pacific Ocean within the same periods. The δ11B data showed a
gradual increase during AD 1466-1829 and a relatively sharp decline then until AD
1960. The anthropogenic emission of CO2 may explain the decline of coral-inferred
seawater pH over the past 200 years but not for the period of AD 1466-1829. An
evaluated correlation was observed between the variation of coral δ11B values and the
monsoon-associated upwelling phenomenon, which implies a significant influence of the
Asian monsoon system on boron geochemistry in the northern SCS. This study will
provide a comprehensive discussion regarding the potential factors controlling the
boron isotopic composition in the northern South China Sea over the past 500 years. |
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