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Chang, Yuan-pin; Chen, Min-te; Yokoyama, Yusuke; Matsuzaki, Hiroyuki; Thompson, William G.; Kao, Shuh-ji; Kawahata, Hodaka. |
We analyzed the high-resolution foraminifer isotope records, total organic carbon (TOC), and opal content from an Okinawa Trough core MD012404 in order to estimate the monsoon hydrography and productivity changes in the East China Sea (ECS) of the tropical western Pacific over the past 100,000 years. The variability shown in the records on orbital time scales indicates that high TOC intervals coincide with the increases of boreal May-September insolation driven by precession cycles (similar to 21 ka), implying a strong connection to the variations in monsoons. We also observed possibly nearly synchronous, millennial-scale changes of the ECS surface hydrography (mainly driven by salinity changes but also by temperature effects) and productivity coincident... |
Tipo: Text |
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Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00218/32929/31435.pdf |
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Huang, Yin-sheng; Hsu, Shu-kun; Su, Chih-chieh; Lin, Andrew Tien-shun; Yu, Pai-sen; Babonneau, Nathalie; Ratzov, Gueorgui; Lallemand, Serge; Huang, Pi-chuen; Lin, Shiao-shan; Lin, Jing-yi; Wei, Kuo-yen; Chang, Yuan-pin; Yu, Neng-ti; Tsai, Ching-hui. |
We have collected two shallow gas hydrate samples at two sites having different geological settings off southwest Taiwan during the cruise MD214 in 2018. The first core site, MD18-3542, is on the South Yuan-An East Ridge at ~ 1200 m water deep, where a structural unconformity covered by fine-silt sediments appears at ~ 5.5 m below the seafloor. The second core site, MD18-3543, is close to the Good-Weather Ridge at ~ 1100 m water deep, where a gas-related pockmark structure and authigenic carbonates are present at shallow strata with fine-silt sediments near the seafloor. Sediment properties of core MD18-3542 are distinctively different above and below the layer corresponding to the unconformity. Both cores show obvious gaps or voids in the lower core... |
Tipo: Text |
Palavras-chave: MD core; Shallow gas hydrate; Hydrate dissociation; Off SW Taiwan. |
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00680/79253/81769.pdf |
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Zheng, Li-wei; Hsiao, Silver Sung-yun; Ding, Xiao-dong; Li, Dawei; Chang, Yuan-pin; Kao, Shuh-ji. |
Total organic carbon to total nitrogen ratios (C/N) and their isotopic compositions (δ13CTOC and δ15NTN) are oft-applied proxies to discern terrigenous from marine-sourced organics and to unravel ancient environmental information. In high depositional Asian marginal seas, the inclusion of N-bearing minerals in the bulk sediment dilutes or masks signals sought after in δ15N and δ13C analyses, thus leading to incorrect and even contradictory interpretations. We used KOH-KOBr to separate operationally defined total organic matter into oxidizable (labile) and residual fractions for content and isotope measurements. In a sediment core in the Okinawa Trough, significant amounts of carbon and nitrogen existed in the residual phase, in which the C/N ratio was ~9,... |
Tipo: Text |
Palavras-chave: Carbon; Nitrogen; Isotope; Okinawa Trough; Sediment; Total organic carbon. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00295/40584/39503.pdf |
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Chang, Yuan-pin; Wang, Wei-lung; Yokoyama, Yusuke; Matsuzaki, Hiroyuki; Kawahata, Hodaka; Chen, Min-te. |
High resolution planktic foraminifer fauna assemblage data are used to reconstruct the millennial-scale sea surface temperature (SST) variability of the past 40000 years at an IMAGES core site (MD012404) in the Okinawa Trough in the East China Sea (ECS). The fauna assemblages in core MD012404 are dominated by five species - Globigerinoides ruber, Globigerina bulloides, Neogloboquadrina dutertrei, Pulleniatina obliquiloculata, and Globigerinita glutinata, which account for > 70% in relative abundance. Our Q-mode factor analysis decomposed the fauna abundance data into three factors, which indicate cold water mass, warm water mass, and possibly coastal water flow with low salinity in the ECS. The MD012404 fauna data show abrupt changes at similar to 16... |
Tipo: Text |
Palavras-chave: Planktic foraminifer; Sea surface temperature; ITCZ; East China Sea; Okinawa Trough; IMAGES. |
Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00237/34818/33684.pdf |
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