WorldWideScience

Sample records for china sea area

  1. Territorial disputes simmer in areas of South China Sea

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that China's award of an exploration cooperation contact in the Nansha area of the South China Sea has revived territorial disputes in the area centering ton the Spratly and Paracel islands. The key dispute is between China and Viet Nam, which earlier engaged in military action over ownership of the islands, believed to have world class potential for hydrocarbon discoveries. Those two nations, as well as Brunei, Malaysia, Philippines, and Taiwan, lay claim to overlapping boundaries of the Spratly Islands. Separately, China and Viet Nam dispute territorial claims in the Paracels. Tensions continue to mount, and regional governments are trying to negotiate compromises to avoid a repeat of warfare

  2. South China Sea Dispute

    OpenAIRE

    Tanderup, Kasper Buch; Grinderslev, Emil Juhler; Tønnesen-Højbjerg, Asser Laurits Svend

    2017-01-01

    China is rising rapidly in terms of economics, military spending, sphere of influence and claims to in their view former territory. This paper has aimed to discuss the latter through analysis of the present dispute concerning islands and maritime territory in the South China Sea. The Chinese have become increasingly assertive in their claims formulated through a U-shaped line entailing most of the area within the South China Sea. The claims are contested by Vietnam, the Philippines, Indonesia...

  3. South China Sea

    Science.gov (United States)

    Morton, Brian; Blackmore, Graham

    2001-01-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshop and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km2 and depths range from the shallowest coastal fringe to 5377 m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economies on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of the three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken on the South

  4. South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Morton, Brian [Hong Kong Univ., Swire Inst. of Marine Science, Hong Kong (China); Hong Kong Univ., Dept. of Ecology and Biodiversity, Hong Kong (China); Blackmore, Graham [Hong Kong Univ. of Science and Technology, Dept. of Biology, Hong Kong (China)

    2001-07-01

    The South China Sea is poorly understood in terms of its marine biota, ecology and the human impacts upon it. What is known is most often contained in reports and workshops and conference documents that are not available to the wider scientific community. The South China Sea has an area of some 3.3 million km{sup 2} and depths range from the shallowest coastal fringe to 5377m in the Manila Trench. It is also studded with numerous islets, atolls and reefs many of which are just awash at low tide. It is largely confined within the Tropic of Cancer and, therefore, experiences a monsoonal climate being influenced by the Southwest Monsoon in summer and the Northeast Monsoon in winter. The South China Sea is a marginal sea and, therefore, largely surrounded by land. Countries that have a major influence on and claims to the sea include China, Malaysia, the Philippines and Vietnam, although Thailand, Indonesia and Taiwan have some too. The coastal fringes of the South China Sea are home to about 270 million people that have had some of the fastest developing and most vibrant economics on the globe. Consequently, anthropogenic impacts, such as over-exploitation of resources and pollution, are anticipated to be huge although, in reality, relatively little is known about them. The Indo-West Pacific biogeographic province, at the centre of which the South China Sea lies, is probably the world's most diverse shallow-water marine area. Of three major nearshore habitat types, i.e., coral reefs, mangroves and seagrasses, 45 mangrove species out of a global total of 51, most of the currently recognised 70 coral genera and 20 of 50 known seagrass species have been recorded from the South China Sea. The island groups of the South China Sea are all disputed and sovereignty is claimed over them by a number of countries. Conflicts have in recent decades arisen over them because of perceived national rights. It is perhaps because of this that so little research has been undertaken

  5. The characteristics of heat flow in the Shenhu gas hydrate drilling area, northern South China Sea

    Science.gov (United States)

    Xu, Xing; Wan, Zhifeng; Wang, Xianqing; Sun, Yuefeng; Xia, Bin

    2016-12-01

    Marine heat flow is of great significance for the formation and occurrence of seabed oil, gas and gas hydrate resources. Geothermal gradient is an important parameter in determining the thickness of the hydrate stability zone. The northern slope of the South China Sea is rich in gas hydrate resources. Several borehole drilling attempts were successful in finding hydrates in the Shenhu area, while others were not. The failures demand further study on the distribution regularities of heat flow and its controlling effects on hydrate occurrence. In this study, forty-eight heat flow measurements are analyzed in the Shenhu gas hydrate drilling area, located in the northern South China Sea, together with their relationship to topography, sedimentary environment and tectonic setting. Canyons are well developed in the study area, caused mainly by the development of faults, faster sediment supply and slumping of the Pearl River Estuary since the late Miocene in the northern South China Sea. The heat flow values in grooves, occurring always in fault zones, are higher than those of ridges. Additionally, the heat flow values gradually increase from the inner fan, to the middle fan, to the external fan subfacies. The locations with low heat flow such as ridges, locations away from faults and the middle fan subfacies, are more conducive to gas hydrate occurrence.

  6. Petroleum in the South China Sea : a Chinese national interest

    OpenAIRE

    Snildal, Knut

    2000-01-01

    The thesis analyses the relationship between China's petroleum policies and China's involvement in the South China Sea conflict. The aim of the thesis is to determine what China's national interest are in the South China Sea, and to detect who forms, and how, China's South China Sea policy. The thesis discusses whether China's assumed interest in the South China Sea of exploiting the petroleum reserves of the territorially disputed areas of the South China Sea is a short-term national interes...

  7. Gas hydrate saturation from acoustic impedance and resistivity logs in the shenhu area, south china sea

    Science.gov (United States)

    Wang, X.; Wu, S.; Lee, M.; Guo, Y.; Yang, S.; Liang, J.

    2011-01-01

    During the China's first gas hydrate drilling expedition -1 (GMGS-1), gas hydrate was discovered in layers ranging from 10 to 25 m above the base of gas hydrate stability zone in the Shenhu area, South China Sea. Water chemistry, electrical resistivity logs, and acoustic impedance were used to estimate gas hydrate saturations. Gas hydrate saturations estimated from the chloride concentrations range from 0 to 43% of the pore space. The higher gas hydrate saturations were present in the depth from 152 to 177 m at site SH7 and from 190 to 225 m at site SH2, respectively. Gas hydrate saturations estimated from the resistivity using Archie equation have similar trends to those from chloride concentrations. To examine the variability of gas hydrate saturations away from the wells, acoustic impedances calculated from the 3 D seismic data using constrained sparse inversion method were used. Well logs acquired at site SH7 were incorporated into the inversion by establishing a relation between the water-filled porosity, calculated using gas hydrate saturations estimated from the resistivity logs, and the acoustic impedance, calculated from density and velocity logs. Gas hydrate saturations estimated from acoustic impedance of seismic data are ???10-23% of the pore space and are comparable to those estimated from the well logs. The uncertainties in estimated gas hydrate saturations from seismic acoustic impedances were mainly from uncertainties associated with inverted acoustic impedance, the empirical relation between the water-filled porosities and acoustic impedances, and assumed background resistivity. ?? 2011 Elsevier Ltd.

  8. Occurrence of perfluorinated alkyl substances in sediment from estuarine and coastal areas of the East China Sea.

    Science.gov (United States)

    Yan, Hong; Zhang, Chaojie; Zhou, Qi; Yang, Shouye

    2015-02-01

    Perfluorinated alkyl substances (PFAS) have drawn much attention due to their environmental persistence, ubiquitous existence, and bioaccumulation potential. The occurrence and spatial variation of PFAS were investigated through collection of riverine and marine sediments from estuarine and coastal areas of the East China Sea. Among them, perfluorooctanesulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), and perfluorooctanoic acid (PFOA) were the three predominant PFAS with the highest detection frequencies in the sediment. PFOS up to 32.4 ng g(-1) dw and ∑PFAS up to 34.8 ng g(-1) dw were detected. Compared to other studies, high levels of PFOS were found in sediments from the East China Sea. PFHpA was also detected at higher frequency and concentration than those of other studies, which suggests point sources in this area. Concentrations of PFAS in riverine sediments were much higher than in marine sediments. Analysis of spatial variations presented overall decreasing trends of PFAS from inshore to offshore areas.

  9. Methane-metabolizing microbial communities in sediments of the Haima cold seep area, northwest slope of the South China Sea.

    Science.gov (United States)

    Niu, Mingyang; Fan, Xibei; Zhuang, Guangchao; Liang, Qianyong; Wang, Fengping

    2017-09-01

    Cold seeps are widespread chemosynthetic ecosystems in the deep-sea environment, and cold seep microbial communities of the South China Sea are poorly constrained. Here we report on the archaeal communities, particularly those involved in methane metabolization, in sediments of a newly discovered cold seep (named 'Haima') on the northwest slope of the South China Sea. Archaeal diversity, abundance and distribution were investigated in two piston cores collected from a seep area (QDN-14B) and a non-seep control site (QDN-31B). Geochemical investigation of the QDN-14B core identified an estimated sulfate-methane transition zone (Estimated SMTZ) at 300-400 cm below sea floor (cmbsf), where a high abundance of anaerobic methane-oxidizing archaea (ANME) occurred, as revealed by analysis of the 16S rRNA gene and the gene (mcrA) encoding the α-subunit of the key enzyme methyl-coenzyme M reductase. ANME-2a/b was predominant in the upper and middle layers of the estimated SMTZ, whereas ANME-1b outcompeted ANME-2 in the sulfate-depleted bottom layers of the estimated SMTZ and the methanogenic zone. Fine-scale phylogenetic analysis further divided the ANME-1b group into three subgroups with different distribution patterns: ANME-1bI, ANME-1bII and ANME-1bIII. Multivariate analyses indicated that dissolved inorganic carbon and sulfate may be important factors controlling the composition of the methane-metabolizing community. Our study on ANME niche separation and interactions with other archaeal groups improves our understanding of the metabolic diversity and flexibility of ANME, and the findings further suggest that ANME subgroups may have evolved diversified/specified metabolic capabilities other than syntrophic anaerobic oxidation of methane coupled with sulfate reduction in marine sediments. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Methane Metabolizing Microbial Communities in the Cold Seep Areas in the Northern Continental Shelf of South China Sea

    Science.gov (United States)

    Wang, F.; Liang, Q.

    2016-12-01

    Marine sediment contains large amount of methane, estimated approximately 500-2500 gigatonnes of dissolved and hydrated methane carbon stored therein, mainly in continental margins. In localized specific areas named cold seeps, hydrocarbon (mainly methane) containing fluids rise to the seafloor, and support oases of ecosystem composed of various microorganisms and faunal assemblages. South China Sea (SCS) is surrounded by passive continental margins in the west and north and convergent margins in the south and east. Thick organic-rich sediments have accumulated in the SCS since the late Mesozoic, which are continuing sources to form gas hydrates in the sediments of SCS. Here, Microbial ecosystems, particularly those involved in methane transformations were investigated in the cold seep areas (Qiongdongnan, Shenhu, and Dongsha) in the northern continental shelf of SCS. Multiple interdisciplinary analytic tools such as stable isotope probing, geochemical analysis, and molecular ecology, were applied for a comprehensive understanding of the microbe mediated methane transformation in this project. A variety of sediments cores have been collected, the geochemical profiles and the associated microbial distribution along the sediment cores were recorded. The major microbial groups involved in the methane transformation in these sediment cores were revealed, known methane producing and oxidizing archaea including Methanosarcinales, anaerobic methane oxidizing groups ANME-1, ANME-2 and their niche preference in the SCS sediments were found. In-depth comparative analysis revealed the presence of SCS-specific archaeal subtypes which probably reflected the evolution and adaptation of these methane metabolizing microbes to the SCS environmental conditions. Our work represents the first comprehensive analysis of the methane metabolizing microbial communities in the cold seep areas along the northern continental shelf of South China Sea, would provide new insight into the

  11. Characterization of PBDEs and novel brominated flame retardants in seawater near a coastal mariculture area of the Bohai Sea, China.

    Science.gov (United States)

    Wang, Yan; Wu, Xiaowei; Zhao, Hongxia; Xie, Qing; Hou, Minmin; Zhang, Qiaonan; Du, Juan; Chen, Jingwen

    2017-02-15

    The concentrations and distributions of PBDEs and novel brominated flame retardants (NBFRs) in dissolved phase of surface seawater near a coastal mariculture area of the Bohai Sea were investigated. The total concentrations of PBDE and NBFRs were in the range of 15.4-65.5 and 2.12-13.6ng/L, respectively. The highest concentration was discovered in the water near an anchorage ground, whereas concentrations in water samples from offshore cage-culture area were not elevated. Relatively high concentrations of BDE28, 99, and 100 were discovered in the medium range of distance from shore, where is the path of tidal or coastal current. This suggested that inputs from ships or through tidal current rather than mariculture activities may be the main sources of BFRs in this area. BDE209, BDE47, hexabromobenzene (HBB), and 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) were the most abundant BFR congeners. Relatively high proportions of these BFRs may originate from discharge of wastewater nearby or degradation from higher brominated PBDEs. No correlations were found between BFR concentrations and water dissolved organic carbon, suggesting that concentrations and distributions of BFRs in this area were source-dependent. The relatively high concentrations in this study emphasized the importance of monitoring and managing BFR contaminations in mariculture areas of China. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Tracing perfluoroalkyl substances (PFASs) in soils along the urbanizing coastal area of Bohai and Yellow Seas, China.

    Science.gov (United States)

    Meng, Jing; Wang, Tieyu; Song, Shuai; Wang, Pei; Li, Qifeng; Zhou, Yunqiao; Lu, Yonglong

    2018-07-01

    With the shift of fluorine chemical industry from developed countries to China and increasing demand for fluorine chemical products, occurrence of perfluoroalkyl substances (PFASs) in production and application areas has attracted more attention. In this study, 153 soil samples were collected from 21 cities along the urbanizing coastal area of the Bohai and Yellow Seas. PFASs in this area were relatively higher, compared with other study areas. The concentrations ranged from 2.76 to 64.0 ng g -1 , and those in most sites were between 2.76 and 13.9 ng g -1 , with a predominance of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Among the 21 coastal cities, contaminations of PFASs in Zibo, Nantong and Binzhou were elevated, which was likely affected by local fluorine chemical plants, equipment manufacturing and chemical industry, respectively. The total emissions of PFOA and PFOS were similar, with amount of 4431 kg and 4335 kg, respectively. Atmospheric deposition was the largest source, accounting for 93.2% of total PFOA and 69.6% of PFOS, respectively. In addition, due to application of aqueous film-forming foams (AFFFs) and sulfluramid, disposal of sewage sludge and stacking of solid waste, emission of PFOA and PFOS to soil was 1617 kg, accounting for 9.29% of the whole China. In general, pollution in Jiangsu, Shandong and Tianjin was more serious than those in Liaoning and Hebei, which was consistent with industrialization level and size of industrial sectors emitting PFASs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Temporal distribution of bacterial community structure in the Changjiang Estuary hypoxia area and the adjacent East China Sea

    International Nuclear Information System (INIS)

    Liu Min; Huang Huiqin; Bao Shixiang; Xiao Tian; Zhang Wuchang; Wu Ying; Zhou Feng

    2012-01-01

    Bacterial community structure and the effects of environmental factors on the microbial community distribution were investigated in the Changjiang Estuary hypoxia area and its adjacent area in the East China Sea (ECS) in June, August and October, 2006. Profiles of bacterial communities were generated by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes followed by DNA sequence analysis. The dominant bacterial groups were affiliated to Gammaproteobacteria, Cytophaga–Flavobacteria–Bacteroides (CFB), Deltaproteobacteria, Cyanobacteria and Firmicutes, which were mostly from the marine seawater ecosystem. Effects of environmental factors on the bacterial community distribution were analyzed by the ordination technique of canonical correspondence analysis (CCA). The environmental factors significantly influencing bacterial community structure were different in the three months; dissolved organic carbon (DOC) and temperature in June and nitrite in August. No environmental variables displayed significant influence on the bacterial community at the 5% level in October. The seasonal environmental heterogeneity in the Changjiang Estuary and the adjacent ECS, such as seasonal hydrodynamic conditions and riverine input of nutrients, might be the reason for the difference in the key environmental factors determining the bacterial community in the three months. (letter)

  14. Residual concentrations of micropollutants in benthic mussels in the coastal areas of Bohai Sea, North China

    International Nuclear Information System (INIS)

    Liu Wenxin; Chen Jianglin; Lin Xiumei; Fan Yongsheng; Tao Shu

    2007-01-01

    Studies of heavy metals and organic pollutants in different benthic mussel species from Bohai Sea show that concentrations of Cd in mussels commonly exceed national biological quality standards. In addition, a site located in Laizhou Bay exhibits higher average concentrations of As, Hg and Pb with respect to the other sites. Residual levels of petroleum hydrocarbons at several sites in Liaodong Bay also exceed quality guidelines. Contents and compositional characteristics of DDT and its metabolites in mussels suggest the probability of recent inputs and potential ecological risks to the local benthic environment. - Residual Cd contents of mussels at many sites in Bohai Sea exceed national marine biological quality standard and compositions of DDT metabolites indicate recent inputs and potential risk

  15. Microplastics in a wind farm area: A case study at the Rudong Offshore Wind Farm, Yellow Sea, China.

    Science.gov (United States)

    Wang, Teng; Zou, Xinqing; Li, Baojie; Yao, Yulong; Li, Jiasheng; Hui, Hejiu; Yu, Wenwen; Wang, Chenglong

    2018-03-01

    Despite the rapid construction of offshore wind farms, the available information regarding the risks of this type of development in terms of emerging pollutants, particularly microplastics, is scarce. In this study, we quantified the level of microplastic pollution at an offshore wind farm in the Yellow Sea, China, in 2016. The abundance of microplastics was 0.330 ± 0.278 items/m 3 in the surface water and 2.58 ± 1.14 items/g (dry) in the sediment. To the best of our knowledge, the level of microplastic pollution in our study area was slightly higher than that in coastal areas around the world. The microplastics detected in the surface waters and sediments were mainly fibrous (75.3% and 68.7%, respectively) and consisted of some granules and films. The microplastics in the samples might originate from garments or ropes via wastewater discharge. The abundance of plastic in the water and sediment samples collected from the wind farm area was lower than that in the samples collected from outside the wind farm area. The anthropogenic hydrodynamic effect was the main factor affecting the local distribution of microplastics. The presence of a wind farm could increase the bed shear stress during ebb tide, disturbing the bed sediment, facilitating its initiation and transport, and ultimately increasing the ease of washing away the microplastics adhered to the sediment. This study will serve as a reference for further studies of the distribution and migration of microplastics in coastal zones subjected to similar marine utilization. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Microbial diversity in the hydrate-containing and -free surface sediments in the Shenhu area, South China Sea

    Directory of Open Access Journals (Sweden)

    Lu Jiao

    2015-07-01

    Full Text Available Microbial diversity in the hydrate-containing (sites SH3B and SH7B and -free (sites SH1B, SH5B, SH5C sediments collected from the Shenhu area of the South China Sea (SCS was investigated using 16S rRNA gene phylogenetic analysis. The phylogenetic results indicate difference in microbial communities between hydrate-containing and -free sediments. At the gas hydrate-containing sites, bacterial communities were dominated by Deltaproteobacteria (30.5%, and archaeal communities were dominated by Miscellaneous Crenarchaeotic Group (33.8%; In contrast, Planctomycetes was the major group (43.9% in bacterial communities, while Marine Benthic Group-D (MBG-D (32.4% took up the largest proportion in the archaeal communities. Moreover, the microbial communities have characteristics different from those in other hydrate-related sediments around the world, indicating that the presence of hydrates can affect the microbial distribution. In addition, the microbial community composition in the studied sediments has its own uniqueness, which may result from co-effect of geochemical characteristics and presence/absence of hydrate.

  17. Heat flow pattern in the gas hydrate drilling areas of northern south china sea and the implication for further study

    Science.gov (United States)

    Wang, Lifeng; Sha, Zhibin

    2015-04-01

    Numerous seismic reflection profiles have been acquired by China Geological Survey (CGS) in the Northern Slope of South China Sea (SCS), clearly indicating widespread occurrence of free gases and/or gas hydrates in the sediments. In the year 2007 and 2013 respectively the gas hydrate samples are successfully recovered during two offshore drilling exploratory programs. Results of geothermal data during previous field studies along the north continental margin, however, show that the gas hydrate sites are associated with high geothermal background in contrast to the other offshore ones where the gas hydrates are more likely to be found in the low geothermal regional backgrounds. There is a common interesting heat flow pattern during the two drilling expeditions that the gas hydrate occurrences coincide with the presences of comparatively low geothermal anomalies against the high thermal background which is mainly caused by concentrated fluid upward movements into the stability zone (GHSZ) detected by the surface heat flow measurements over the studied fields. The key point for understanding the coupling between the presences of the gas hydrates and heat flow pattern at regional scale is to know the cause of high heat flows and the origin of forming gases at depth. We propose that these high heat flows are attributed to elevated shallow fault-fissure system due to the tectonic activities. A remarkable series of vertical faults and fissures are common on the upper continental slope and the forming gases are thought to have migrated with hot advective fluid flows towards seafloor mainly via fault-fissure system from underlying source rocks which are deeper levels than those of the GHSZ. The present study is based on an extensive dataset on hydrate distribution and associated temperature field measurements collected in the vicinity of studied areas during a series of field expeditions organized within the framework of national widely collaborative projects. Those

  18. Physical and Mechanical Properties of Surface Sediments and methane hydrate-bearing sediments in the Shenhu area of South China Sea

    Science.gov (United States)

    Jiang, J.; Shen, Z.; Jia, Y.

    2017-12-01

    Methane hydrates are superior energy resources and potential predisposing factors of geohazard. With the success in China's persistent exploitation of methane hydrates in the Shenhu area of South China Sea for 60 days, there is an increasing demand for detailed knowledge of sediment properties and hazard assessment in this area. In this paper, the physical and mechanical properties of both the surface sediments and methane hydrate-bearing sediments (MHBS) in the exploitation area, the Shenhu area of South China Sea, were investigated using laboratory geotechnical experiments, and triaxial tests were carried out on remolded sediment samples using a modified triaxial apparatus. The results show that sediments in this area are mainly silt with high moisture content, high plasticity, low permeability and low shear strength. The moisture content and permeability decrease while the shear strength increases with the increasing depth. The elastic modulus and peak strength of MHBS increase with the increasing effective confining pressure and higher hydrate saturation. The cohesion increases with higher hydrate saturation while the internal friction angle is barely affected by hydrate saturation. The obtained results demonstrate clearly that methane hydrates have significant impacts on the physical and mechanical properties of sediments and there is still a wide gap in knowledge about MHBS.

  19. Internal Waves, South China Sea

    Science.gov (United States)

    1983-01-01

    Subsurface ocean currents, frequently referred to as internal waves, are frequently seen from space under the right lighting conditions when depth penetration can be achieved. These internal waves observed in the South China Sea off the SE coast of the island of Hainan (18.5N, 110.5E) visibly demonstrate turbidity in the ocean's depths at the confluence of conflicting currents.

  20. Natural gas geological characteristics and great discovery of large gas fields in deep-water area of the western South China Sea

    Directory of Open Access Journals (Sweden)

    Zhenfeng Wang

    2015-12-01

    Full Text Available To accelerate the petroleum exploration in deep sea of China, since the period of “the 11th Five-Year Plan”, the sedimentary process, source rock formation and hydrocarbon generation and expulsion process in deep-water area of the Qiongdongnan Basin in the western South China Sea have been studied systematically using the data like large-area 3D seismic survey, logging, drill core (cuttings and geochemical analysis, providing three innovative understandings, i.e. excellent hydrocarbon source conditions, good accumulation conditions, and grouping and zonal distribution of large exploration targets. From the study, the following conclusions are drawn. First, the deep-water area located in the southern and central parts of the Qiongdongnan Basin was formed under the control of such tectonic events as Indosinian–Eurasian Plate collision, Himalayan uplifting and South China Sea expansion, and experienced Paleogene lift and Neogene depression stages. Second, accompanied by lacustrine deposition, faulting activity was violent in Eocene; whereas in Early Oligocene, rift continued to develop under a sedimentary environment of marine–terrestrial transitional facies and littoral-neritic facies. Third, oil generation predominated Eocene lacustrine mudstone and gas generation predominated Lower Oligocene marine–terrestrial transitional facies coal-measure strata compose two sets of major source rocks. Fourth, analysis in respect of thermal evolution level, hydrocarbon generation volume and hydrocarbon generation intensity shows that Ledong, Lingshui, Baodao and Changchang sags belong to potential hydrocarbon-rich kitchens, among which Ledong and Lingshui sags have been proved to have great hydrocarbon generation potential by drilling. Fifth, researches of deep-water sedimentology and hydrocarbon accumulation dynamics reveal that Paleogene and Neogene plays are developed vertically, and favorable hydrocarbon accumulation zones like the Central

  1. Is South China Sea the new 'inalienable' part of China?

    OpenAIRE

    Jash, Amrita

    2016-01-01

    China’s growing military posture and unilateral behavior in South China Sea has raised red alarms in international politics, vehemently challenging the existing status quo. What is apparent is that China’s uncompromising attitude in the South China Sea presents China’s obsession over its territorial claims, wherein, South China Sea can be called the ‘new inalienable part’ of China.

  2. Clay mineralogy and source-to-sink transport processes of Changjiang River sediments in the estuarine and inner shelf areas of the East China Sea

    Science.gov (United States)

    Zhao, Yifei; Zou, Xinqing; Gao, Jianhua; Wang, Chenglong; Li, Yali; Yao, Yulong; Zhao, Wancang; Xu, Min

    2018-02-01

    We examined the source-to-sink sediment transport processes from the Changjiang River to the estuarine coastal shelf area by analyzing the clay mineral assemblages in suspended sediment samples from the Changjiang River catchment and surface samples from the estuarine coastal shelf area following the impoundment of the Three Gorges Dam (TGD) in 2003. The results indicate that the clay mineral compositions throughout the study area are dominated by illite, with less abundant kaolinite and chlorite and scarce smectite. The clay minerals display distinct differences in the tributaries and exhibit obvious changes in the trunk stream compared with the periods before 2003, and the source of sediment has largely shifted to the mid- to lower reaches of the river after 2003. Spatially, the clay mineral assemblages in the estuarine area define two compositionally distinct provinces. Province I covers the mud area of the Changjiang River estuary and the Zhe-Min coastal region, where sediment is primarily supplied by the Changjiang River. Province II includes part of the Changjiang River estuary and the southeastern portion of the study area, where the sediment is composed of terrestrial material from the Changjiang River and re-suspended material from the Huanghe River carried by the Jiangsu coastal current. Moreover, the other smaller rivers in China (including the Oujiang and Minjiang rivers of mainland China and the rivers of West Taiwan) also contribut sediments to the estuarine and inner shelf areas. In general, the clay mineral assemblages in the Changjiang River estuarine area are have mainly been controlled by sediment supplied from upstream of the Changjiang River tributaries. However, since the completion of the TGD in 2003, the mid- to downstream tributaries have become the main source of sediments from the Changjiang catchment into the East China Sea. These analyses further demonstrate that the coastal currents and the decrease in the sediment load of the river

  3. China's South China Sea Conundrum - No Easier Pass

    OpenAIRE

    Jash, Amrita

    2016-01-01

    On July 12, 2016, The Hague- based Permanent Court of Arbitration (PCA) finally hit the hammer on the verdict of the landmark case of South China Sea arbitration. This case was unilaterally initiated by the Republic of the Philippines on January 22, 2013, on its relevant disputes in the South China Sea with the People’s Republic of China. At the very outset, this case brought China at crossroads to its international repute given Philippines’ allegations against its assertive and unlawful clai...

  4. Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea

    Science.gov (United States)

    Wang, Xiujuan; Hutchinson, Deborah R.; Wu, Shiguo; Yang, Shengxiong; Guo, Yiqun

    2011-01-01

    Gas hydrate saturations were estimated using five different methods in silt and silty clay foraminiferous sediments from drill hole SH2 in the South China Sea. Gas hydrate saturations derived from observed pore water chloride values in core samples range from 10 to 45% of the pore space at 190–221 m below seafloor (mbsf). Gas hydrate saturations estimated from resistivity (Rt) using wireline logging results are similar and range from 10 to 40.5% in the pore space. Gas hydrate saturations were also estimated by P wave velocity obtained during wireline logging by using a simplified three-phase equation (STPE) and effective medium theory (EMT) models. Gas hydrate saturations obtained from the STPE velocity model (41.0% maximum) are slightly higher than those calculated with the EMT velocity model (38.5% maximum). Methane analysis from a 69 cm long depressurized core from the hydrate-bearing sediment zone indicates that gas hydrate saturation is about 27.08% of the pore space at 197.5 mbsf. Results from the five methods show similar values and nearly identical trends in gas hydrate saturations above the base of the gas hydrate stability zone at depths of 190 to 221 mbsf. Gas hydrate occurs within units of clayey slit and silt containing abundant calcareous nannofossils and foraminifer, which increase the porosities of the fine-grained sediments and provide space for enhanced gas hydrate formation. In addition, gas chimneys, faults, and fractures identified from three-dimensional (3-D) and high-resolution two-dimensional (2-D) seismic data provide pathways for fluids migrating into the gas hydrate stability zone which transport methane for the formation of gas hydrate. Sedimentation and local canyon migration may contribute to higher gas hydrate saturations near the base of the stability zone.

  5. Thermal-history reconstruction of the Baiyun Sag in the deep-water area of the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Tang, Xiaoyin; Yang, Shuchun; Hu, Shengbiao

    2017-11-01

    The Baiyun Sag, located in the deep-water area of the northern South China Sea, is the largest and deepest subbasin in the Pearl River Mouth Basin and one of the most important hydrocarbon-accumulation depression areas in China. Thermal history is widely thought to be of great importance in oil and gas potential assessment of a basin as it controls the timing of hydrocarbon generation and expulsion from the source rock. In order to unravel the paleo-heat flow of the Baiyun Sag, we first analyzed tectonic subsidence of 55 pseudo-wells constructed based on newly interpreted seismic profiles, along with three drilled wells. We then carried out thermal modeling using the multi-stage finite stretching method and calibrated the results using collected present-day vitrinite reflectance data and temperature data. Results indicate that the first and second heating of the Baiyun Sag after 49 Ma ceased at 33.9 Ma and 23 Ma. Reconstructed average basal paleoheat flow values at the end of the rifting periods are 57.7-86.2 mW/m2 and 66.7-97.3 mW/m2, respectively. Following the last heating period at 23 Ma, the study area has undergone a persistent thermal attenuation phase, and basal heat flow has cooled down to 64.0-79.2 mW/m2 at present.

  6. Concentrations and human health implications of heavy metals in wild aquatic organisms captured from the core area of Daya Bay's Fishery Resource Reserve, South China Sea.

    Science.gov (United States)

    Gu, Yang-Guang; Huang, Hong-Hui; Lin, Qin

    2016-07-01

    Heavy metal concentrations in edible organisms from the core area of Daya Bay's Fishery Resource Reserve, South China Sea, were determined. Samples of 14 crustacean, fish, and shellfish species were collected and analyzed. The As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn concentrations were 0.18-1.16, 0.002-0.919, 0.40-2.85, 0.07-4.10, 0.004-0.055, 0.14-1.19, 0.014-0.070, and 4.57-15.94μg/g wet weight, respectively. The As concentrations were higher than the Chinese maximum permissible levels in all of the fish and shellfish species and two crustacean species, indicating that consumption of these wild species by humans may pose health risks. However, calculations of the health risks posed to humans indicated that no significant adverse health effects would be associated with consuming these species. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. [Growth characteristics of Porites lutea skeleton in east sea area of Hainan Island, China and main affecting environmental factors.

    Science.gov (United States)

    Jiang, Qiao Wen; Cao, Zhi Min; Wang, Dao Ru; Li, Yuan Chao; Ni, Jian Yu

    2016-03-01

    The growth characteristics of Porites lutea skeleton in east sea area of Hainan Island were studied by CoralXDS software based on X-ray chronology. The growth parameters obtained included extension rate (ER), skeleton density (D), and calcification rate (CR). The results showed that ER varied from 0.49 to 1.10 cm·a -1 with an annual average of 0.76 cm·a -1 , D varied from 1.11 to 1.35 g·cm -3 with an annual average of 1.22 g·cm -3 , and CR varied from 0.55 to 1.41 g·cm -2 ·a -1 with an annual average of 0.94 g·cm -2 ·a -1 . Statistical analyses indicated that sea surface temperature (SST) was the key environmental factor that controlled the growth characteristics, as it highly co-varied with ER and CR, less so with D. All of the three growth characteristics increased with the increase of SST. There were other factors that influenced the growth characteristics of the coral column, such as light, water salinity, and hydrodynamics, etc. In addition, typhoon and severe tropical storms also imposed a significant impact on the growth pattern of Porites lutea coral. The change in growth pattern of coral skeleton in east of Hainan Island was a response to complex climate fluctuation. Over the past century, SST of east Hainan Island dramatically increased at a rate of 0.15 ℃·(10 a) -1 . The SST increase trend for the oceanic region could be divided into two stages, early 1940s and early 1980s. The human activities and global warming was the main causes for the increase of SST.

  8. Sea Reclamation Status of Countries around the South China Sea from 1975 to 2010

    Directory of Open Access Journals (Sweden)

    Junjue Zhang

    2017-05-01

    Full Text Available As a way of turning sea into land for living space for humans, the actions of sea reclamation bring about significant benefits. Nevertheless, it is also an under-recognized threat to the environment and the marine ecosystem. Based on images in two periods, sea reclamation information of countries around the South China Sea was extracted from 1975 to 2010. The spatial state and driven forces of sea reclamation are then discussed. Results show that the overall strength of sea reclamation in the South China Sea was great. New reclaimed land added up to 3264 km2. Sea reclamation for fish farming was the main reclamation type and widely distributed in the whole area, especially on the coast from the Pearl River Delta to the Red River Delta, and the coast of Ca Mau Peninsula. Sea reclamation in China and Vietnam was rather significant, which occupies 80.6% of the total reclamation area. Singapore had the highest level of sea reclamation. New reclaimed land for fish farming holds a key role in China, Vietnam, and Indonesia, while new reclaimed land for construction and docks dominated in Malaysia, Singapore, and Brunei. Areas and use-type compositions of new reclaimed land in countries varied greatly due to the differences of economic factors, policy inclination, and landscapes in the respective countries.

  9. Countering Chinas Economic Statecraft in the South China Sea

    Science.gov (United States)

    2018-04-09

    Economic Statecraft in the South China Sea 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Bradford D...created and employed a vision and strategy to control it. China continually demonstrates its economic might in the region and conducts economic ...power to counter China’s rising influence in the South China Sea. The policy and strategy should incorporate establishing strong economic ties in

  10. Sea Surface Temperature and Ocean Color Variability in the South China Sea

    Science.gov (United States)

    Conaty, A. P.

    2001-12-01

    The South China Sea is a marginal sea in the Southeast Asian region whose surface circulation is driven by monsoons and whose surface currents have complex seasonal patterns. Its rich natural resources and strategic location have made its small islands areas of political dispute among the neighboring nations. This study aims to show the seasonal and interannual variability of sea surface temperature and ocean color in South China Sea. It makes use of NOAA's Advanced Very High Resolution Radiometer (AVHRR) satellite data sets on sea surface temperature for the period 1981-2000 and NASA's Nimbus-7 Coastal Zone Color Scanner (CZCS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite data sets on pigment concentration (ocean color) for the period 1981-1996 and 1997-2000, respectively. Transect lines were drawn along several potential hotspot areas to show the variability in sea surface temperature and pigment concentration through time. In-situ data on sea surface temperature along South China Sea were likewise plotted to see the variability with time. Higher seasonal variability in sea surface temperature was seen at higher latitudes. Interannual variability was within 1-3 Kelvin. In most areas, pigment concentration was higher during northern hemisphere winter and autumn, after the monsoon rains, with a maximum of 30 milligrams per cubic meter.

  11. Spatial distribution and ecological risk assessment of heavy metals in coastal surface sediments in the Hebei Province offshore area, Bohai Sea, China.

    Science.gov (United States)

    Ding, Xigui; Ye, Siyuan; Yuan, Hongming; Krauss, Ken W

    2018-06-01

    Seven hundred and nine surface sediment samples, along with deeper sediment samples, were collected from Hebei Province along the coastal section of the Bohai Sea, China, and analyzed for grain size, concentrations of organic carbon (Corg) and heavy metals (Cu, Pb, Zn, Cr, Cd, As, and Hg). Results indicated that the average concentrations in the sediments were 16.1 mg/kg (Cu), 19.4 mg/kg (Pb), 50 mg/kg (Zn), 48.8 mg/kg (Cr), 0.1 mg/kg (Cd), 8.4 mg/kg (As), and 20.3 μg/kg (Hg). These concentrations generally met the China Marine Sediment Quality criteria. However, both pollution assessments indicated moderate to strong Cd and Hg contamination in the study area. The potential ecological risk index suggested that the combined ecological risk of the seven studied metals may be low, but that 24.5% of the sites, where sediments were finer and higher in Corg concentration, had high ecological risk in Hg and Cd pollution. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Spatial distribution and ecological risk assessment of heavy metals in coastal surface sediments in the Hebei Province offshore area, Bohai Sea, China

    Science.gov (United States)

    Ding, Xigui; Ye, Siyuan; Yuan, Hongming; Krauss, Ken W.

    2018-01-01

    Seven hundred and nine surface sediment samples, along with deeper sediment samples, were collected from Hebei Province along the coastal section of the Bohai Sea, China, and analyzed for grain size, concentrations of organic carbon (Corg) and heavy metals (Cu, Pb, Zn, Cr, Cd, As, and Hg). Results indicated that the average concentrations in the sediments were 16.1 mg/kg (Cu), 19.4 mg/kg (Pb), 50 mg/kg (Zn), 48.8 mg/kg (Cr), 0.1 mg/kg (Cd), 8.4 mg/kg (As), and 20.3 μg/kg (Hg). These concentrations generally met the China Marine Sediment Quality criteria. However, both pollution assessments indicated moderate to strong Cd and Hg contamination in the study area. The potential ecological risk index suggested that the combined ecological risk of the seven studied metals may be low, but that 24.5% of the sites, where sediments were more finer and higher in Corg concentration, had high ecological risk in Hg and Cd pollution.

  13. [Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

    Science.gov (United States)

    Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

    2014-09-01

    The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd heavy metals in surface sediments was in the order of Cd heavy metals in water, suspended solids and sediment. In particular, the effects of salinity and suspended solids matter were most significant. The integrated pollution index assessment showed that the water quality was good except individual stations. The geoaccumulation index assessment showed that As was the major pollution element in surface sediments.

  14. Deep-sea geohazards in the South China Sea

    Science.gov (United States)

    Wu, Shiguo; Wang, Dawei; Völker, David

    2018-02-01

    Various geological processes and features that might inflict hazards identified in the South China Sea by using new technologies and methods. These features include submarine landslides, pockmark fields, shallow free gas, gas hydrates, mud diapirs and earthquake tsunami, which are widely distributed in the continental slope and reefal islands of the South China Sea. Although the study and assessment of geohazards in the South China Sea came into operation only recently, advances in various aspects are evolving at full speed to comply with National Marine Strategy and `the Belt and Road' Policy. The characteristics of geohazards in deep-water seafloor of the South China Sea are summarized based on new scientific advances. This progress is aimed to aid ongoing deep-water drilling activities and decrease geological risks in ocean development.

  15. Radioactive status of seawater and its assessment in the northeast South China Sea and the Luzon Strait and its adjacent areas from 2011 to 2014.

    Science.gov (United States)

    Zhou, Peng; Li, Dongmei; Zhao, Li; Li, Haitao; Zhao, Feng; Zheng, Yuanlai; Fang, Hongda; Lou, Quansheng; Cai, Weixu

    2018-06-01

    To understand the impact of the Fukushima nuclear accident (FNA), 137 Cs, 134 Cs, 90 Sr, and gross beta were analyzed in the northeast South China Sea (NSCS), the Luzon Strait (LS) and its adjacent areas. 137 Cs, 90 Sr, and gross beta values in the NSCS were similar to those prior to the FNA. 90 Sr and 137 Cs in the LS and its adjacent areas were consistent with those in the NSCS. The high 137 Cs-peak values occurred at depth of 150 m whereas the high 90 Sr-peak values occurred at depth of 0.5 m. The 137 Cs and gross beta mean values in Cruise I were higher than those in Cruise II whereas the 90 Sr mean value was just the reverse. 134 Cs in all seawater were below the minimum detectable activity. The past and present data since the 1970s suggested 137 Cs and 90 Sr in the study areas still originated from global fallout and the FNA influence were negligible. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Aircraft measurements of SO2, NOx, CO, and O3 over the coastal and offshore area of Yellow Sea of China.

    Science.gov (United States)

    Yang, Xiaoyang; Wang, Xinhua; Yang, Wen; Xu, Jun; Ren, Lihong; He, Youjiang; Liu, Bing; Bai, Zhipeng; Meng, Fan; Hu, Min

    2016-09-01

    In order to investigate long-range transport of the air pollution in the East Asia, air pollutants, including SO2, NOx, CO, and O3, were observed by aircraft measurement over the coastal and offshore area of Yellow Sea of China in April 2011. NOx and SO2 seemed to become moderate in recent years, and the concentrations during the whole observations ranged from 0.49 to 9.57 ppb and from 0.10 to 16.02 ppb, respectively. The high concentrations of CO were measured with an average value of 0.98 ppm. The measured O3 average concentration was 76.25 ppb, which showed a higher level comparing with the results from some previous studies. Most of the results for the concentration values generally followed the typical characteristic of vertical and spatial distribution, which were "low altitude > high altitude" and "land/coastal > sea," respectively. Transport of polluted air mass from the continent to the aircraft measurement area was confirmed in some days during the observation by the meteorological analysis, while the measurement results supposed to represent the background level of the pollutants in rest days. Additionally, some small-scale air pollution plumes were observed. Significant positive correlations between NOx and SO2 indicated that these two species originated from the same region. On the other hand, good positive correlations between NOx and O3 found during 2-day flight suggested that the O3 formation was probably under "NOx-limited" regime in these days.

  17. Reverse trends of TEX86 temperature in coastal areas of the East China Sea over the last 100 years: implication for global warming and regional circulation

    Science.gov (United States)

    Cao, Y.; Xing, L.; Zhang, T.

    2017-12-01

    To reconstruct and compare the SST changes in different regions of the ECS over the last 100 years, in this study, we analyzed iGDGTs compounds and TEX86 index in two sediment cores (DH5-1 and DH6-2) from the inner shelf of the East China Sea (ECS). GDGT-0 and GDGT-5 in the two cores account for 80% of iGDGTs, significantly more abundant than the other iGDGTs compounds. It is also found that iGDGTs are mainly derived from marine Thaumarchaeota. TEXH86 temperatures varied from 17 °C to 22 °C (average 19.4 °C), showing a gradual increase in Core DH5-1 near the Changjiang River Estuary, corresponding to global warming and temperature rise in the ECS over the last 100 years. However, in Core DH6-2 further away from the Changjiang River Estuary, TEXH86 temperatures gradually decreased over the last 80 years with a range of 15.3 °C-18.3 °C, which is attributed to the strengthened near-shore Kuroshio Branch Current transporting more subsurface cold water to the ECS coastal area. In future, more sites should be investigated to confirm the range of the coastal area where the decrease in SST is caused by upwelling subsurface water.

  18. Early Chinese Voyaging in the South China Sea: Implications on Territorial Claims

    Directory of Open Access Journals (Sweden)

    Michael Flecker

    2017-07-01

    Full Text Available The main purpose of this paper is to examine historically issues of territorial claims over the South China Sea. As it is known that at present there are at least six countries claiming part or all of South China Sea territory. In this case China is the most ambitious country to control all areas in the South China Sea. This has led to political and military tensions in the region. It is strange that the South China Sea waters has actually been a shipping thoroughfare for the last two millennia. Therefore, this historical study will contribute to an understanding of the issues that could provoke international conflict.

  19. Philippines – China Relations: The Case of the South China Sea (Spratly Islands Claims

    Directory of Open Access Journals (Sweden)

    Mark Anthony M. Velasco

    2014-12-01

    Full Text Available The research is focused on examining by describing historically the relationship between the Philippines and China in the disputed claims over the islands in South China Sea. To crystalize this goal, the discourse in the paper heavily employs inter-textual analysis that is logically arranged into an opening idea on the context of the conflicting issue over the islands situated in Spratlys, then followed by an extensive illustration of the relationship between the Philippines and China concerning the territorial claims over the islands of South China Sea. Subsequently, a brief reflection guided by the principle of territoriality is portrayed with the goal to authoritatively explain the idea of jurisdiction over the islands in the Spratly area. After that, the paper briefly concludes with a prospectus on the issue of South China Sea.

  20. Geological controls on the occurrence of gas hydrate from core, downhole log, and seismic data in the Shenhu area, South China Sea

    Science.gov (United States)

    Xiujuan Wang,; ,; Collett, Timothy S.; Lee, Myung W.; Yang, Shengxiong; Guo, Yiqun; Wu, Shiguo

    2014-01-01

    Multi-channel seismic reflection data, well logs, and recovered sediment cores have been used in this study to characterize the geologic controls on the occurrence of gas hydrate in the Shenhu area of the South China Sea. The concept of the "gas hydrate petroleum system" has allowed for the systematic analysis of the impact of gas source, geologic controls on gas migration, and the role of the host sediment in the formation and stability of gas hydrates as encountered during the 2007 Guangzhou Marine Geological Survey Gas Hydrate Expedition (GMGS-1) in the Shenhu area. Analysis of seismic and bathymetric data identified seventeen sub-linear, near-parallel submarine canyons in this area. These canyons, formed in the Miocene, migrated in a northeasterly direction, and resulted in the burial and abandonment of canyons partially filled by coarse-grained sediments. Downhole wireline log (DWL) data were acquired from eight drill sites and sediment coring was conducted at five of these sites, which revealed the presence of suitable reservoirs for the occurrence of concentrated gas hydrate accumulations. Gas hydrate-bearing sediment layers were identified from well log and core data at three sites mainly within silt and silt clay sediments. Gas hydrate was also discovered in a sand reservoir at one site as inferred from the analysis of the DWL data. Seismic anomalies attributed to the presence of gas below the base of gas hydrate stability zone, provided direct evidence for the migration of gas into the overlying gas hydrate-bearing sedimentary sections. Geochemical analyses of gas samples collected from cores confirmed that the occurrence of gas hydrate in the Shenhu area is controlled by the presence thermogenic methane gas that has migrated into the gas hydrate stability zone from a more deeply buried source.

  1. Zooplankton community structure in the Yellow Sea and East China Sea in autumn

    Directory of Open Access Journals (Sweden)

    Hongju Chen

    2015-12-01

    Full Text Available Abstract Study on zooplankton spatial distribution is essential for understanding food web dynamics in marine ecosystems and fishery management. Here we elucidated the composition and distribution of large mesozooplankton on the continental shelf of the Yellow Sea and East China Sea, and explored the zooplankton community structure in these water masses. Sixty vertical hauls (bottom or 200 m in deep water to surface using a ring net (diameter 0.8 m, 505-μm mesh were exploited in November 2007. The biogeographic patterns of zooplankton communities were investigated using multivariate analysis methods; copepod biodiversity was analyzed using univariate indices. Copepods and protozoans were dominate in the communities. Based on the species composition, we divided the study areas into six station groups. Significant differences in zooplankton assemblages were detected between the Yellow Sea and East China Sea. Species richness was higher in East China Sea groups than those in Yellow Sea, whereas taxonomic distinctness was higher in Yellow Sea than in East China Sea. There was a clear relationship between the species composition and water mass group.

  2. Quarter-Century Offshore Winds from SSM/I and WRF in the North Sea and South China Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Astrup, Poul; Zhu, Rong

    2016-01-01

    We study the wind climate and its long-term variability in the North Sea and South China Sea, areas relevant for offshore wind energy development, using satellite-based wind data, because very few reliable long-term in-situ sea surface wind observations are available. The Special Sensor Microwave...

  3. Status of marine biodiversity of the China seas.

    Directory of Open Access Journals (Sweden)

    J Y Liu

    Full Text Available China's seas cover nearly 5 million square kilometers extending from the tropical to the temperate climate zones and bordering on 32,000 km of coastline, including islands. Comprehensive systematic study of the marine biodiversity within this region began in the early 1950s with the establishment of the Qingdao Marine Biological Laboratory of the Chinese Academy of Sciences. Since that time scientists have carried out intensive multidisciplinary research on marine life in the China seas and have recorded 22,629 species belonging to 46 phyla. The marine flora and fauna of the China seas are characterized by high biodiversity, including tropical and subtropical elements of the Indo-West Pacific warm-water fauna in the South and East China seas, and temperate elements of North Pacific temperate fauna mainly in the Yellow Sea. The southern South China Sea fauna is characterized by typical tropical elements paralleled with the Philippine-New Guinea-Indonesia Coral triangle typical tropical faunal center. This paper summarizes advances in studies of marine biodiversity in China's seas and discusses current research mainly on characteristics and changes in marine biodiversity, including the monitoring, assessment, and conservation of endangered species and particularly the strengthening of effective management. Studies of (1 a tidal flat in a semi-enclosed embayment, (2 the impact of global climate change on a cold-water ecosystem, (3 coral reefs of Hainan Island and Xisha-Nansha atolls, (4 mangrove forests of the South China Sea, (5 a threatened seagrass field, and (6 an example of stock enhancement practices of the Chinese shrimp fishery are briefly introduced. Besides the overexploitation of living resources (more than 12.4 million tons yielded in 2007, the major threat to the biodiversity of the China seas is environmental deterioration (pollution, coastal construction, particularly in the brackish waters of estuarine environments, which are

  4. Gas hydrate identified in sand-rich inferred sedimentary section using downhole logging and seismic data in Shenhu area, South China Sea

    Science.gov (United States)

    Wang, Xiujuan; Lee, Myung W.; Collett, Timothy S.; Yang, Shengxiong; Guo, Yiqun; Wu, Shiguo

    2014-01-01

    Downhole wireline log (DWL) data was acquired from eight drill sites during China's first gas hydrate drilling expedition (GMGS-1) in 2007. Initial analyses of the acquired well log data suggested that there were no significant gas hydrate occurrences at Site SH4. However, the re-examination of the DWL data from Site SH4 indicated that there are two intervals of high resistivity, which could be indicative of gas hydrate. One interval of high resistivity at depth of 171–175 m below seafloor (mbsf) is associated with a high compressional- wave (P-wave) velocities and low gamma ray log values, which suggests the presence of gas hydrate in a potentially sand-rich (low clay content) sedimentary section. The second high resistivity interval at depth of 175–180 mbsf is associated with low P-wave velocities and low gamma values, which suggests the presence of free gas in a potentially sand-rich (low clay content) sedimentary section. Because the occurrence of free gas is much shallower than the expected from the regional depth of the bottom simulating reflector (BSR), the free gas could be from the dissociation of gas hydrate during drilling or there may be a local anomaly in the depth to the base of the gas hydrate stability zone. In order to determine whether the low P-wave velocity with high resistivity is caused by in-situ free gas or dissociated free gas from the gas hydrate, the surface seismic data were also used in this analysis. The log analysis incorporating the surface seismic data through the construction of synthetic seismograms using various models indicated the presence of free gas directly in contact with an overlying gas hydrate-bearing section. The occurrence of the anomalous base of gas hydrate stability at Site SH4 could be caused by a local heat flow conditions. This paper documents the first observation of gas hydrate in what is believed to be a sand-rich sediment in Shenhu area of the South China Sea.

  5. Evaluation of abundant hydrocarbon-generation depressions in the deepwater area of Qiongdongnan Basin, South China Sea

    Institute of Scientific and Technical Information of China (English)

    LIU Zhen; SUN Zhipeng; WANG Zisong; ZHANG Wei; LI Tingan; HE Weijun; LI Fengxia

    2016-01-01

    It has been confirmed that the key source rocks of Qiongdongnan Basin are associated with the Yacheng Formation, which was deposited in a transitional marine-continental environment. Because the distribution and evolution patterns of the source rocks in the major depressions are different, it is important to determine the most abundant hydrocarbon-generation depressions in terms of exploration effectiveness. Based on an analysis of organic matter characteristics of the source rocks, in combination with drilling data and seismic data, this paper establishes a model to evaluate the hydrocarbon-generation depressions in the deepwater area of Qiongdongnan Basin. First of all, by using the method of seismic-facies model analysis, the distribution of sedimentary facies was determined. Then, the sedimentary facies were correlated with the organic facies, and the distribution of organic facies was predicted. Meanwhile, the thickness of source rocks for all the depressions was calculated on the basis of a quantitative analysis of seismic velocity and lithology. The relationship between mudstone porosity and vitrinite reflectance (Ro) was used to predict the maturity of source rocks. Second, using the parameters such as thickness and maturity of source rocks, the quantity and intensity of gas generation for Yacheng and Lingshui Formations were calculated. Finally, in combination with the identified hydrocarbon resources, the quantity and intensity of gas generation were used as a guide to establish an evaluation standard for hydrocarbon-generation depressions, which was optimized for the main depressions in the Central Depression Belt. It is proposed that Lingshui, Ledong, Baodao and Changchang Depressions are the most abundant hydrocarbon depressions, whilst Songnan and Beijiao Depressions are rich hydrocarbon depressions. Such an evaluation procedure is beneficial to the next stage of exploration in the deep-water area of Qiongdongnan Basin.

  6. Data fusion in data scarce areas using a back-propagation artificial neural network model: a case study of the South China Sea

    Science.gov (United States)

    Wang, Zheng; Mao, Zhihua; Xia, Junshi; Du, Peijun; Shi, Liangliang; Huang, Haiqing; Wang, Tianyu; Gong, Fang; Zhu, Qiankun

    2018-06-01

    The cloud cover for the South China Sea and its coastal area is relatively large throughout the year, which limits the potential application of optical remote sensing. A HJ-charge-coupled device (HJ-CCD) has the advantages of wide field, high temporal resolution, and short repeat cycle. However, this instrument suffers from its use of only four relatively low-quality bands which can't adequately resolve the features of long wavelengths. The Landsat Enhanced Thematic Mapper-plus (ETM+) provides high-quality data, however, the Scan Line Corrector (SLC) stopped working and caused striping of remote sensed images, which dramatically reduced the coverage of the ETM+ data. In order to combine the advantages of the HJ-CCD and Landsat ETM+ data, we adopted a back-propagation artificial neural network (BP-ANN) to fuse these two data types for this study. The results showed that the fused output data not only have the advantage of data intactness for the HJ-CCD, but also have the advantages of the multi-spectral and high radiometric resolution of the ETM+ data. Moreover, the fused data were analyzed qualitatively, quantitatively and from a practical application point of view. Experimental studies indicated that the fused data have a full spatial distribution, multi-spectral bands, high radiometric resolution, a small difference between the observed and fused output data, and a high correlation between the observed and fused data. The excellent performance in its practical application is a further demonstration that the fused data are of high quality.

  7. Countermeasure Study on Deep-sea Oil Exploitation in the South China Sea——A Comparison between Deep-sea Oil Exploitation in the South China Sea and the Gulf of Mexico

    Science.gov (United States)

    Zhao, Hui; Qiu, Weiting; Qu, Weilu

    2018-02-01

    The unpromising situation of terrestrial oil resources makes the deep-sea oil industry become an important development strategy. The South China Sea has a vast sea area with a wide distribution of oil and gas resources, but there is a phenomenon that exploration and census rates and oil exploitation are low. In order to solve the above problems, this article analyzes the geology, oil and gas exploration and exploration equipment in the South China Sea and the Gulf of Mexico. Comparing the political environment of China and the United States energy industry and the economic environment of oil companies, this article points out China’s deep-sea oil exploration and mining problems that may exist. Finally, the feasibility of oil exploration and exploitation in the South China Sea is put forward, which will provide reference to improve the conditions of oil exploration in the South China Sea and promoting the stable development of China’s oil industry.

  8. Gas hydrates distribution in the Shenhu area, northern South China Sea: comparisons between the eight drilling sites with gashydrate petroleum system

    Energy Technology Data Exchange (ETDEWEB)

    Su, M.; Yang, R.; Wang, H.; Sha, Z.; Liang, J.; Wu, N.; Qiao, S.; Cong, X.

    2016-07-01

    The results of the first marine gas hydrate drilling expedition of Guangzhou Marine Geological Survey (GMGS-1) in northern continental slope of the South China Sea revealed a variable distribution of gas hydrates in the Shenhu area. In this study, comparisons between the eight sites with gas-hydrate petroleum system were used to analyze and re-examine hydrate potential. In the Shenhu gas hydrate drilling area, all the sites were located in a suitable low-temperature, high-pressure environment. Biogenic and thermogenic gases contributed to the formation of hydrates. Gas chimneys and some small-scale faults (or micro-scale fractures) compose the migration pathways for gas-bearing fluids. Between these sites, there are three key differences: the seafloor temperatures and pressures; geothermal gradient and sedimentary conditions. Variations of seafloor temperatures and pressures related to water depths and geothermal gradient would lead to changes in the thickness of gas hydrate stability zones. Although the lithology and grain size of the sediments were similar, two distinct sedimentary units were identified for the first time through seismic interpretation, analysis of deep-water sedimentary processes, and the Cm pattern (plotted one-percentile and median values from grain-size analyses), implying the heterogeneous sedimentary conditions above Bottom Simulating Reflectors (BSRs). Based on the analyses of forming mechanisms and sedimentary processes, these two fine-grained sedimentary units have different physical properties. Fine-grained turbidites (Unit I) with thin-bedded chaotic reflectors at the bottom acted as the host rocks for hydrates; whereas, finegrained sediments related to soft-sediment deformation (Unit II) characterized by thick continuous reflectors at the top would serve as regional homogeneous caprocks. Low-flux methane that migrated upwards along chimneys could be enriched preferentially in fine-grained turbidites, resulting in the formation of

  9. Spatial and temporal characteristics of PM2.5 acidity during autumn in marine and coastal area of Bohai Sea, China, based on two-site contrast

    Science.gov (United States)

    Zhou, Ming; Zhang, Yufen; Han, Yan; Wu, Jianhui; Du, Xiang; Xu, Hong; Feng, Yinchang; Han, Suqin

    2018-04-01

    In-situ pH of atmospheric particulate, defined as the pH value of aqueous phase in ambient aerosol, has been reported to have significant influence on the formation progress of secondary aerosol, especially through the heterogeneous pathway. In this study, PM2.5 samples were collected in the marine and costal area of Bohai Sea from September 8th to October 8th in 2013, with daytime and nighttime separated. Eight water-soluble ions including SO42 -, NO3-, Cl-, NH4+, K+, Ca2 +, Na+ and Mg2 + were analyzed by ion chromatography. The in-situ pH of PM2.5 was estimated using Aerosol Inorganics Model II, with meteorological parameters (temperature and relative humidity) and basic chemical composition data (concentrations of water-soluble ions) serving as input. Five indicators were conjunctively applied to describe the spatial and temporal characteristics of PM2.5 acidity over Bohai Sea during autumn. As a result, strong acidity was found in both marine and coastal area. Marine area had a stronger acidity under a more NH4+-deficiency and humid condition. And the difference of PM2.5 acidity between daytime and nighttime was more obvious in coastal area than that in marine area, with stronger acidity observed during the daytime. Local SO2 emission was identified as an important factor influencing the diurnal variation of aerosol acidity. Meanwhile, sulfurous species were identified as a mixture of NH4HSO4 and H2SO4 in marine area while a mixture of NH4HSO4 and (NH4)2SO4 in the coastal area. Analysis in the impact of aerosol acidity on nitrate formation has indicated that heterogeneous pathways were important in nitrate formation in coastal area of Bohai Sea as well as the homogeneous pathways.

  10. Sea surface temperatures and salinities from platforms in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and the South China Sea (Nan Hai) from 1896-1950 (NODC Accession 0000506)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Surface temperatures and salinities were collected in the Barents Sea, Sea of Japan, North Atlantic Ocean, Philippine Sea, Red Sea, and South China Sea (Nan Hai)...

  11. Submarine sand ridges and sand waves in the eastern part of the China Sea

    Science.gov (United States)

    Wu, Ziyin; Li, Shoujun; Shang, Jihong; Zhou, Jieqiong; Zhao, Dineng; Liang, Yuyang

    2016-04-01

    Integrated with multi-beam and single-beam echo sounding data, as well as historical bathymetric data, submarine bathymetric maps of the eastern part of the China Sea, including the Bohai Sea, Huanghai Sea, and East China Sea, are constructed to systematically study submarine sand ridges and sand waves in the eastern part of the China Sea, combined with high-resolution seismic, sub-bottom profile and borehole data. Submarine sand ridges are extraordinarily developed in the eastern part of the China Sea, and 7 sand ridge areas can be divided from north to south, that is, the Laotieshan Channel sand ridge area in the Bohai Sea, the Korea Bay sand ridge area in the southern Huanghai Sea, the sand ridge area in the eastern Huanghai islands and the Huanghai Troughs, the Jianggang sand ridge area in the western Huanghai Sea, the sand ridge area in the East China Sea shelf, and the sand ridge and sand wave area in the Taiwan Strait and Taiwan Banks. The distribution area of the sand ridges and sand waves covers more than 450,000 km2, wherein ~10,000 km2 in the Bohai Bay, ~200,000 km2 in the Huanghai Sea, ~200,000 km2 in the East China Sea shelf, and ~40,000 km2 in the Taiwan Strait and Taiwan Banks, respectively. The great mass of sand ridges are distributed within water depth of 5-160 m, with a total length of over 160 km and a main width of 5-10 km. The inner structure of the sand ridges presents features of high-angle inclined beddings, with main lithology of sands, sand-mud alternations partly visible, and a small number of mud cores. Dating results indicate that the sand ridges in the eastern part of the China Sea are mainly developed in the Holocene. Sea-level variation dominates the sand ridge evolution in the eastern part of the China Sea since the LGM, and the sand ridges developed in the area of < 60m water depth are appeared in bad activity, meanwhile sand ridges with good activity are still developed in large scale.

  12. A comparison of the radioactivity levels in the coastal waters between the great wall and Zhongshan stations in Antarctica and the Pohai, Huanghai, east China and south China seas of China

    International Nuclear Information System (INIS)

    Chen Jinxing

    1992-01-01

    A comparison of radioactivity levels in the coastal sediments and plants between the Great Wall and Zhongshan Stations in Antarctica and the four seas (i.e. the Pohai Sea, Huanghai Sea, East China Sea and South China Sea) in China shows that in general the radioactivity levels in the coastal sediments and plants in Antarctica are lower than those in the four seas in China. The contents of the total β in the sediments decrease from higher to lower in amount in the order of East China Sea, South China Sea, Pohai Sea, Huanghai Sea and the Great Wall Bay in Antarctica successively, but the contents of 238 U, 232 Th, 226 Ra, 40 K and the total β in marine plants decrease from higher to lower in amount in the order of Daya Bay in the South China Sea, Hanzhou Bay in the East China Sea and the Great Wall Bay in Antarctica successively. The results show that the contamination levels of radioactivity, especially the artificial radioactive contamination in the Antarctic coastal area are far lower than those in China Coastal area, with the remarkable exception of 137 Cs

  13. PM2.5 and Associated Ionic Species in a Sub-urban Coastal Area of Kuala Terengganu, Southern South China Sea (Malaysia)

    International Nuclear Information System (INIS)

    Norhayati Mohd Tahir; Meikee, Koh; Suhaimi Suratman

    2013-01-01

    PM 2.5 mass concentration and associated water-soluble ionic species in a sub-urban coastal area of Kuala Terengganu, Malaysia were investigated intermittently from year 2006 to 2009. A total of 78 weekly PM 2.5 samples were analyzed. The mass concentration of PM 2.5 exhibited annual, seasonal and diurnal variations. Temporal distributions of rainfall, sporadic haze episodes and local air flow (sea breeze circulation) were factors controlling PM 2.5 mass variations in the study area. Although the PM 2.5 concentrations were increased during haze episodes in 2006 (August and October) and 2007 (October), their concentrations however, were still within the international guidelines. The average concentration of individual ions was in decreasing trend; SO 4 2- > NH 4 + > K + > Na + > NO 3 - > Cl - > Ca 2+ . The concentrations of SO 42- and NH 4 + accounted for > 70 % of the water-soluble aerosol mass. More than 80 % of ionic species associated with PM 2.5 are from non-marine sources. Major processes affecting the ionic composition of PM 2.5 are biomass burning, crustal loading and sea spray. Air quality mitigation strategies should focus on anthropogenic activities emitting SO 2 , which promotes aerosol SO 4 2- formation. (author)

  14. Model of modern dynamic deposition in the east China Sea

    Science.gov (United States)

    Zhou, Fugen

    1989-09-01

    Since the last rising of sea level, two branches of the Kuroshio, the Huanghai (Yellow Sea) coastal current (HCC; mainly cold water mass) and the Changjiang River outflow have controlled the modern dynamic deposition in the East China Sea. There are three depositing areas on the sea-bed under the above currents: a relict sand area un der the Taiwan Warm Current and the Huanghai Warm Current at the south-eastern area, the about 60 km2 round mud bank under the Huanghai Coastal Current at the northern area and the large subaqueous delta of mainly fine sand and silt under the Changjiang discharge flow in its estuary and the large narrow mud bank under the Zhejiang-Fujian Coastal Current, another round mud bank under the Changjiang discharge flow off Hangzhou Bay. The relict sand area has a coarsesand block under the Taiwan Warm Current bypassing Taiwan at the northern part of the island. The two round mud banks were formed in relatively static states by an anticlockwise converging cyclonic eddy. The coarsesand block was formed by a clockwise diverging cyclonic eddy. This new dynamic deposition theory can be used to explain not only the dynamic deposition process of clay, but also the patchy distribution of sediments on the shelves of the world ocean s.

  15. The application of compound-specific isotope analysis of fatty acids for traceability of sea cucumber (Apostichopus japonicus) in the coastal areas of China.

    Science.gov (United States)

    Liu, Yu; Zhang, Xufeng; Li, Ying; Wang, Haixia

    2017-11-01

    Geographical origin traceability is an important issue for controlling the quality of seafood and safeguarding the interest of consumers. In the present study, a new method of compound-specific isotope analysis (CSIA) of fatty acids was established to evaluate its applicability in establishing the origin traceability of Apostichopus japonicus in the coastal areas of China. Moreover, principal component analysis (PCA) and discriminant analysis (DA) were applied to distinguish between the origins of A. japonicus. The results show that the stable carbon isotope compositions of fatty acids of A. japonicus significantly differ in terms of both season and origin. They also indicate that the stable carbon isotope composition of fatty acids could effectively discriminate between the origins of A. japonicus, except for between Changhai Island and Zhangzi Island in the spring of 2016 because of geographical proximity or the similarity of food sources. The fatty acids that have the highest contribution to identifying the geographical origins of A. japonicus are C22:6n-3, C16:1n-7, C20:5n-3, C18:0 and C23:1n-9, when considering the fatty acid contents, the stable carbon isotope composition of fatty acids and the results of the PCA and DA. We conclude that CSIA of fatty acids, combined with multivariate statistical analysis such as PCA and DA, may be an effective tool for establishing the traceability of A. japonicus in the coastal areas of China. The relevant conclusions of the present study provide a new method for determining the traceability of seafood or other food products. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. Forecasting sea fog on the coast of southern China

    Science.gov (United States)

    Huang, H.; Huang, B.; Liu, C.; Tu, J.; Wen, G.; Mao, W.

    2016-12-01

    Forecast sea fog is still full of challenges. We have performed the numerical forecasting of sea fog on the coast of southern China by using the operational meso-scale regional model GRAPES (Global/Regional assimilation and prediction system). The GRAPES model horizontal resolution was 3km and with 66 vertical levels. A total of 72 hours forecasting of sea fog was conducted with hourly outputs over the sea fog event. The results show that the model system can predict reasonable characteristics of typical sea fog events on the coast of southern China. The scope of sea fog coincides with the observations of meteorological stations, the observations of the Marine Meteorological Science Experiment Base (MMSEB) at Bohe, Maoming and satellite products of sea fog. The goal of this study is to establish an operational numerical forecasting model system of sea fog on the coast of southern China.

  17. Observational analysis of air-sea fluxes and sea water temperature offshore South China Sea

    Science.gov (United States)

    Bi, X.; Huang, J.; Gao, Z.; Liu, Y.

    2017-12-01

    This paper investigates the air-sea fluxes (momentum flux, sensible heat flux and latent heat flux) from eddy covariance method based on data collected at an offshore observation tower in the South China Sea from January 2009 to December 2016 and sea water temperature (SWT) on six different levels based on data collected from November 2011 to June 2013. The depth of water at the tower over the sea averages about 15 m. This study presents the in-situ measurements of continuous air-sea fluxes and SWT at different depths. Seasonal and diurnal variations in air-sea fluxes and SWT on different depths are examined. Results show that air-sea fluxes and all SWT changed seasonally; sea-land breeze circulation appears all the year round. Unlike winters where SWT on different depths are fairly consistent, the difference between sea surface temperature (SST) and sea temperature at 10 m water depth fluctuates dramatically and the maximum value reaches 7 °C during summer.

  18. Future Scenarios of the South China Sea Maritime Disputes

    OpenAIRE

    Shee, Poon Kim

    2014-01-01

    The focus of this paper is to analyze three future scenarios in the maritime disputes in the South China Sea. These namely are No War Scenario, Impasse Scenario and Peace Scenario. Ultimately, the way forward towards a viable solution to resolving the South China Sea maritime disputes between China and other claimant states depends on the political wisdom, will and determination of the disputing states. Lofty nationalistic aspirations have to be tempered with a degree of flexibility and pragm...

  19. China in the South China Sea Dispute: Between Status Quo and Revisionist

    OpenAIRE

    Triwibowo, Albert

    2014-01-01

    The paper is trying to look whether China is a status quo power or a revisionist power in theSouth China Sea dispute based on status quo indicator developed by Johnston and perspectives onconformity towards norms. Meanwhile, this paper argues that China is neither a status quo nor arevisionist in the South China Sea dispute to the extent of its compliance with the Declaration on theConduct of Parties (DoC) in the South China Sea. Using status quo indicators developed by Johnstonand also the p...

  20. China (country/area statements).

    Science.gov (United States)

    1985-09-01

    According to this statement presented to the Committee on Population of the UN Economic and Social Commission for Asia and the Pacific, China is similar to other countries in the region in that its rate of population growth has declined due to government family planning efforts while the absolute size of the population continues to increase because of the widening population base. However, China's enormous population of over 1 billion sets it apart and places great strain on economic development efforts. In the past decade the Chinese government has provided population education for the masses, explaining the relationship between population and socioeconomic development, and its overall family planning program has helped reduce population growth from 24.82/1000 in 1974 to 10.81/1000 in 1984. The net population increase has been over 100 million in the past 10 years, and if the present rate of increase with a total fertility rate of 2.1 is maintained for another 15 years, the total population would exceed 1.3 billion by 2000, posing a grave threat to China's socioeconomic development. The nucleus of China's population policy is its birth policy, whose main points are to promote family planning so that population growth will be in keeping with socioeconomic development and the utilization of natural resources and environmental protection. The policy is in line with the principles and objectives of the World Population Plan of Action adopted in 1974. The government has advocated the practice of "1 couple, 1 child" since 1979 to carry out the population policy and limit the total population to about 1.2 billion by the century's end. 28.17 million couples, 18.25% of the 150 million married couples of childbearing age, had received 1-child certificates by the end of 1984. Generally speaking, most couples in urban areas would be satisfied with 1 child, while those in rural areas usually prefer 2 children. The family planning program is carried out through publicity

  1. Mesozoic Compressional Folds of the Nansha Waters, Southern South China Sea

    Science.gov (United States)

    Zhu, R.; Liu, H.; Yao, Y.; Wang, Y.

    2017-12-01

    As an important part of the South China Sea, the southern margin of the South China Sea is fundamental to understand the interaction of the Eurasian, Pacific and Indian-Australian plates and the evolution of the South China Sea. Some multi-channel seismic profiles of the Nansha waters together with published drillings and dredge data were correlated for interpretation. The strata of the study region can be divided into the upper, middle and lower structural layers. The upper and middle structural layers with extensional tectonics are Cenozoic; the lower structural layer suffered compression is Mesozoic. Further structural restoration was done to remove the Cenozoic tectonic influence and to calculate the Mesozoic tectonic compression ratios. The results indicate that two diametrically opposite orientations of compressive stress, S(S)E towards N(N)W orientation and N(N)W towards S(S)E orientation respectively, once existed in the lower structural layer of the study area and shared the same variation trend. The compression ratio values gradually decrease both from the north to the south and from the west to the east in each stress orientation. The phenomena may be related to the opening of the proto-South China Sea (then located in south of the Nansha block) and the rate of the Nansha block drifted northward in Late Jurassic to Late Cretaceous, which had pushed the Nansha block drifted northward until it collided and sutured with the Southern China Margin. Thus the opening of the present-day South China Sea may be related to this suture zone, which was tectonically weakness zone.Key words: Mesozoic compression; structural restoration; proto-South China Sea; Nansha waters; Southern South China Sea; Acknowledgements: The work was granted by the National Natural Science Foundation of China (Grant Nos. 41476039, 91328205, 41576068 and 41606080).

  2. Application of isostatic gravity anomaly in the Yellow Sea area

    Science.gov (United States)

    Hao, Z.; Qin, J.; Huang, W.; Wu, X.

    2017-12-01

    In order to study the deep crustal structure of the Yellow Sea area, we used the Airy-Heiskanen model to calculate the isostatic gravity anomaly of this area. Based on the Bouguer gravity anomaly and water depth data of this area, we chose the calculating parameters as standard crustal thickness 30 km, crust-mantle density difference 0.6g/cm3and grid spacing 0.1°×0.1°. This study reveals that there are six faults and four isostatic negative anomalies in the study area. The isostatic anomalies in much of Yellow Sea areas give priority to those with positive anomalies. The isostatic anomalies in North Yellow Sea are higher than South Yellow Sea with Jiashan-Xiangshui fault as the boundary. In the north of the study area, isostatic anomalies are characterized by large areas of positive anomaly. The change is relatively slow, and the trends give priority to the trend NE or NEE. In the middle of the north Yellow Sea basin, there is a local negative anomaly, arranged as a string of beads in NE to discontinuous distribution. Negative anomaly range is small, basically corresponds to the region's former Cenozoic sedimentary basin position. To the south of Jiashan-Xiangshui fault and west of Yellow Sea eastern margin fault, including most of the south Yellow Sea and Jiangsu province, the isostatic anomalies are lower. And the positive and negative anomalies are alternative distribution, and negative anomaly trap in extensive development. The trends give priority to NE, NEE, both to the NW. On the basis of the characteristics of isostatic gravity anomalies, it is concluded that the Yellow Sea belongs to continental crustal isostatic area whose isostatic anomalies is smooth and slow. ReferencesHeiskanen, W. A., F. A. V. Meinesz, and S. A. Korff (1958), The Earth and Its Gravity Field, McGraw-Hill, New York. Meng, X. J., X. H. Zhang, and J. Y. Yang (2014), Geophysical survey in eastern China seas and the characteristics of gravity and magnetic fields, Marine Geoglogy

  3. Potential of sea level rise impact on South China Sea: a preliminary ...

    African Journals Online (AJOL)

    The effect of the sea level rise was involved the existence of sea water intrusion and coastal erosion phenomenon in the coastal of Terengganu. This study aim to determine fluctuation of high and low tides of the South China Sea in their relation to water quality value of Marang and Paka Rivers as well as from wells ...

  4. Regional characteristics of the effects of the El Niño-Southern Oscillation on the sea level in the China Sea

    Science.gov (United States)

    Wang, Hui; Liu, Kexiu; Wang, Aimei; Feng, Jianlong; Fan, Wenjing; Liu, Qiulin; Xu, Yao; Zhang, Zengjian

    2018-05-01

    Based on coastal tide level, satellite altimetry, and sea surface temperature (SST) data of offshore areas of China's coast and the equatorial Pacific Ocean, the regional characteristics of the effects of the El Niño-Southern Oscillation (ENSO) on the sea level in the China Sea were investigated. Singular value decomposition results show a significant teleconnection between the sea level in the China Sea and the SST of the tropical Pacific Ocean; the correlation coefficient decreases from south to north. Data from tide gauges along China's coast show that the seasonal sea-level variations are significantly correlated with the ENSO. In addition, China's coast was divided into three regions based on distinctive regional characteristics. Results obtained show that the annual amplitude of sea level was low during El Niño developing years, and especially so during the El Niño year. The ENSO intensity determined the response intensity of the annual amplitude of the sea level. The response region (amplitude) was relatively large for strong ENSO intensities. Significant oscillation periods at a timescale of 4-7 years existed in the sea level of the three regions. The largest amplitude of oscillation was 1.5 cm, which was the fluctuation with the 7-year period in the South China Sea. The largest amplitude of oscillation in the East China Sea was about 1.3 cm. The amplitude of oscillation with the 6-year period in the Bohai Sea and Yellow Sea was the smallest (less than 1 cm).

  5. Estimation of potential distribution of gas hydrate in the northern South China Sea

    Science.gov (United States)

    Wang, Chunjuan; Du, Dewen; Zhu, Zhiwei; Liu, Yonggang; Yan, Shijuan; Yang, Gang

    2010-05-01

    Gas hydrate research has significant importance for securing world energy resources, and has the potential to produce considerable economic benefits. Previous studies have shown that the South China Sea is an area that harbors gas hydrates. However, there is a lack of systematic investigations and understanding on the distribution of gas hydrate throughout the region. In this paper, we applied mineral resource quantitative assessment techniques to forecast and estimate the potential distribution of gas hydrate resources in the northern South China Sea. However, current hydrate samples from the South China Sea are too few to produce models of occurrences. Thus, according to similarity and contrast principles of mineral outputs, we can use a similar hydrate-mining environment with sufficient gas hydrate data as a testing ground for modeling northern South China Sea gas hydrate conditions. We selected the Gulf of Mexico, which has extensively studied gas hydrates, to develop predictive models of gas hydrate distributions, and to test errors in the model. Then, we compared the existing northern South China Sea hydrate-mining data with the Gulf of Mexico characteristics, and collated the relevant data into the model. Subsequently, we applied the model to the northern South China Sea to obtain the potential gas hydrate distribution of the area, and to identify significant exploration targets. Finally, we evaluated the reliability of the predicted results. The south seabed area of Taiwan Bank is recommended as a priority exploration target. The Zhujiang Mouth, Southeast Hainan, and Southwest Taiwan Basins, including the South Bijia Basin, also are recommended as exploration target areas. In addition, the method in this paper can provide a useful predictive approach for gas hydrate resource assessment, which gives a scientific basis for construction and implementation of long-term planning for gas hydrate exploration and general exploitation of the seabed of China.

  6. The South China Sea Thermohaline Structure and Circulation

    National Research Council Canada - National Science Library

    Chu, Peter C; Ma, Binbing; Chen, Yuchun

    2002-01-01

    ...), consisting of 116,019 temperature and 9,617 salinity profiles, during 1968-1984 to investigate the temporal and spatial variabilities of South China Sea thermohaline structures and circulation...

  7. Distribution of aliphatic and polycyclic aromatic hydrocarbon in South China sea sediments

    International Nuclear Information System (INIS)

    Md Suhaimi Elias; Ab Khalik Wood; Zaleha Hashim; Wee Boon Siong; Nazaratul Ashifa; Mohd Suhaimi Hamzah; Shamsiah Ab Rahman; Ariffin Talib

    2006-01-01

    Petroleum hydrocarbon (Hcp) consist of three major components namely alkanes, cyclo-alkanes and aromatics. HCP are pollutant and can cause adverse effect to the marine organisms. The study was done to identify the source of pollution in the South China Sea coastal area. The South China Sea is one of the major oil production area in Malaysia. Sampling was done at 15 stations along the coastal area of South China Sea off Peninsular Malaysia, which involved two zone namely coastal (zone 1) and offshore (zone 2) areas. Samples were analyzed using GC-MS for determination of HCP. The results showed, that concentration of aliphatic and polycyclic aromatic hydrocarbon at coastal area, range from 0.51 - 1.31 mg/g and 0.18 - 0.42 mg/g dry weight, respectively whilst, concentration of aliphatic and polycyclic aromatic hydrocarbon at offshore area, range from 0.44 - 1.09 mg/g and 0.20 - 0.49 mg/g dry weight, respectively. SHCP (Aliphatic + PAH) concentration in the sediment at the study area range from 0.64 - 1.68 mg/g dry weight. In this study, it was found that, pollution source for the South China Sea off Peninsular Malaysia was originated from pyrolytic sources (combustion fossil fuel), while some other area had been polluted by pyrolytic or petrogenic (unburned fossil) sources. (Author)

  8. China's Crisis Bargaining in the South China Sea Dispute (2010-2013)

    OpenAIRE

    Ramadhani, Eryan

    2014-01-01

    As one of China’s most intricate territorial dispute, the South China Sea dispute has sufficiently consumed significant amount of Chinese leaders’ attention in Beijing. This paper reveals that China exerts signaling strategy in its crisis bargaining over the South China Sea dispute. This strategy contains reassurance as positive signal through offering negotiation and appearing self-restraint and of negative signal by means of escalatory acts and verbal threats. China’s crisis bargaining in t...

  9. A low-angle normal fault and basement structures within the Enping Sag, Pearl River Mouth Basin: Insights into late Mesozoic to early Cenozoic tectonic evolution of the South China Sea area

    Science.gov (United States)

    Ye, Qing; Mei, Lianfu; Shi, Hesheng; Shu, Yu; Camanni, Giovanni; Wu, Jing

    2018-04-01

    The basement structure of the Cenozoic Enping Sag, within the Pearl River Mouth Basin on the northern margin of South China Sea, is revealed by borehole-constrained high-quality 3D seismic reflection data. Such data suggest that the Enping Sag is bounded in the north by a low-angle normal fault. We interpret this low-angle normal fault to have developed as the result of the reactivation of a pre-existing thrust fault part of a pre-Cenozoic thrust system. This is demonstrated by the selective reactivation of the pre-existing thrust and by diffuse contractional deformation recognized from the accurate analysis of basement reflections. Another significant result of this study is the finding of some residual rift basins within the basement of the Enping Sag. Both the thrust system and the residual basins are interpreted to have developed after the emplacement of continental margin arc-related granitoids (J3-K1) that define the basement within the study area. Furthermore, seismic sections show that the pre-existing residual rift basins are offset by the main thrust fault and they are both truncated by the Tg unconformity. These structural relationships, interpreted in the frame of previous studies, help us to reconstruct a six-event structural evolution model for the Enping Sag from the late Mesozoic to the early Cenozoic. In particular, we interpret the residual rift basins to have formed as the result of back-arc extension due to the slab roll-back of the Paleo-Pacific Plate subduction in the early K2. The thrust system has recorded a compressional event in the late K2 that followed the back-arc extension in the SCS area. The mechanism of this compressional event is still to be clarified, and might be related to continuous subduction of the Paleo-Pacific Plate or to the continent-continent collision between a micro-continental block and the South China margin.

  10. Organic Carbon Storage in China's Urban Areas

    Science.gov (United States)

    Zhao, Shuqing; Zhu, Chao; Zhou, Decheng; Huang, Dian; Werner, Jeremy

    2013-01-01

    China has been experiencing rapid urbanization in parallel with its economic boom over the past three decades. To date, the organic carbon storage in China's urban areas has not been quantified. Here, using data compiled from literature review and statistical yearbooks, we estimated that total carbon storage in China's urban areas was 577±60 Tg C (1 Tg  = 1012 g) in 2006. Soil was the largest contributor to total carbon storage (56%), followed by buildings (36%), and vegetation (7%), while carbon storage in humans was relatively small (1%). The carbon density in China's urban areas was 17.1±1.8 kg C m−2, about two times the national average of all lands. The most sensitive variable in estimating urban carbon storage was urban area. Examining urban carbon storages over a wide range of spatial extents in China and in the United States, we found a strong linear relationship between total urban carbon storage and total urban area, with a specific urban carbon storage of 16 Tg C for every 1,000 km2 urban area. This value might be useful for estimating urban carbon storage at regional to global scales. Our results also showed that the fraction of carbon storage in urban green spaces was still much lower in China relative to western countries, suggesting a great potential to mitigate climate change through urban greening and green spaces management in China. PMID:23991014

  11. The South China Sea Dispute: Perspective of International Law

    OpenAIRE

    Ma, Xuechan

    2016-01-01

    This article discusses the South China Sea dispute from the perspective of international law. First, it introduces some basic knowledge about international law in this field. In the second part, Spratly islands dispute is used as a concrete example to show how international law analyzes this kind of dispute. Finally, it analyzes the arbitration case between the Philippines and China.

  12. Distinguishing Terrestrial Organic Carbon in Marginal Sediments of East China Sea and Northern South China Sea

    Science.gov (United States)

    Kandasamy, Selvaraj; Lin, Baozhi; Wang, Huawei; Liu, Qianqian; Liu, Zhifei; Lou, Jiann-Yuh; Chen, Chen-Tung Arthur; Mayer, Lawrence M.

    2016-04-01

    Knowledge about the sources, transport pathways and behavior of terrestrial organic carbon in continental margins adjoining to large rivers has improved in recent decades, but uncertainties and complications still exist with human-influenced coastal regions in densely populated wet tropics and subtropics. In these regions, the monsoon and other episodic weather events exert strong climatic control on mineral and particulate organic matter delivery to the marginal seas. Here we investigate elemental (TOC, TN and bromine-Br) and stable carbon isotopic (δ13C) compositions of organic matter (OM) in surface sediments and short cores collected from active (SW Taiwan) and passive margin (East China Sea) settings to understand the sources of OM that buried in these settings. We used sedimentary bromine to total organic carbon (Br/TOC) ratios to apportion terrigenous from marine organic matter, and find that Br/TOC may serve as an additional, reliable proxy for sedimentary provenance in both settings. Variations in Br/TOC are consistent with other provenance indicators in responding to short-lived terrigenous inputs. Because diagenetic alteration of Br is insignificant on shorter time scales, applying Br/TOC ratios as a proxy to identify organic matter source along with carbon isotope mixing models may provide additional constraints on the quantity and transformation of terrigenous organics in continental margins. We apply this combination of approaches to land-derived organic matter in different depositional environments of East Asian marginal seas.

  13. The Intertemporal Principle in International Judicial Practice and Its Implications for the South China Sea Dispute

    NARCIS (Netherlands)

    Ma, Xuechan

    2016-01-01

    The intertemporal problem demonstrated in the South China Sea dispute is whether UNCLOS supersedes the previous legal order governing the disputed areas during the pre-UNCLOS period. In order to solve this problem, this article will conduct a detailed investigation into relevant international

  14. Environment and security in the South China Sea region : the role of experts, non-governmental actors and governments in regime building processes

    OpenAIRE

    Næss, Tom

    1999-01-01

    Background: The Spratly islands in the South China Sea are today the focal point of a territorial dispute that represents a serious threat to the regional security in Southeast Asia. Six governments - China, Vietnam, Taiwan, the Philippines, Malaysia and Brunei - have laid claims to all or some of the more than 230 islets, reefs and shoals in the Spratly area. The Peoples Republic of China (PRC) is a key player in the South China Sea conflict. However, the South China Sea is not jus...

  15. Bioturbational structures record environmental changes in the upwelling area off Vietnam (South China Sea) for the last 150,000 years

    NARCIS (Netherlands)

    Wetzel, A.; Tjallingii, R.; Wiesner, M.G.

    2011-01-01

    The sediments in the upwelling area off central Vietnam are totally bioturbated and display a low-diverse assemblage of bioturbational structures. During interglacial times (Marine Isotope Stage MIS 1, 5a, 5c, 5e), summer monsoon leads to pronounced upwelling and seasonally pulsed arrival of organic

  16. Analysis of sea use landscape pattern based on GIS: a case study in Huludao, China.

    Science.gov (United States)

    Suo, Anning; Wang, Chen; Zhang, Minghui

    2016-01-01

    This study aims to analyse sea use landscape patterns on a regional scale based on methods of landscape ecology integrated with sea use spatial characteristics. Several landscape-level analysis indices, such as the dominance index, complex index, intensivity index, diversity index and sea congruency index, were established using Geographic Information System (GIS) and applied in Huludao, China. The results indicated that sea use landscape analysis indices, which were created based on the characteristics of sea use spatial patterns using GIS, are suitable to quantitatively describe the landscape patterns of sea use. They are operable tools for the landscape analysis of sea use. The sea use landscape in Huludao was dominated by fishing use with a landscape dominance index of 0.724. The sea use landscape is a complex mosaic with high diversity and plenty of fishing areas, as shown by the landscape complex index of 27.21 and the landscape diversity index of 1.25. Most sea use patches correspond to the marine functional zonation plan and the sea use congruency index is 0.89 in the fishing zone and 0.92 in the transportation zone.

  17. Sea-level trend in the South China Sea observed from 20 years of along-track satellite altimetric data

    DEFF Research Database (Denmark)

    Cheng, Yongcun; Xu, Qing; Andersen, Ole Baltazar

    2014-01-01

    The sea-level trend in the South China Sea (SCS) is investigated based on 20 years of along-track data from TOPEX and Jason-1/2 satellite altimetry. The average sea-level rise over all the regions in the study area is observed to have a rate of 5.1 ± 0.8 mm year-1 for the period from 1993 to 2012....... The steric sea level contributes 45% to the observed sea-level trend. These results are consistent with previous studies. In addition, the results demonstrate that the maximum sea-level rise rate of 8.4 mm year-1 is occurring off the east coast of Vietnam and eastern part of SCS. During 2010-2011, the La...... Niña event was highly correlated with the dramatic sea-level rise in the SCS; La Niña events were also associated with the maximum rate of sea rise off the east coast of Vietnam, which occurred during 1993 and 2012. We also evaluated the trends in the geophysical (e.g. dynamical atmospheric correction...

  18. Planaxidae (Mollusca, Gastropoda) from the South China Sea

    Science.gov (United States)

    Chen, Zhiyun; Zhang, Junlong; Lian, Xiping; Tan, Yehui

    2018-03-01

    Planaxidae is a family of tropical and subtropical marine gastropods that are adapted to an intertidal, rocky environment. The present study deals with three species in the family Planaxidae from the South China Sea: Planaxis sulcatus (von Born, 1778), Angiola longispira (Smith, 1872), and Supplanaxis niger (Quoy and Gaimard, 1833), based on specimens deposited in the Marine Biodiversity Collections of the South China Sea, Chinese Academy of Sciences. The taxonomic status, main morphological characteristics of the shell and radula, distribution, and habitat of these three planaxid species are presented. We also briefly discuss their morphological differences and the biogeographic distribution.

  19. Mitigating the Security Risks in the South China Sea Island Disputes

    Science.gov (United States)

    2014-02-13

    third of the global crude oil and more than half of global gas shipping passes through the South China Sea. 2 For the United States, $1.2 trillion...China Sea. China, Taiwan, Vietnam, Philippines, Malaysia , and Brunei contest the sovereignty of these islands. In recent years, China has become...Administration estimates that the South China Sea holds approximately 11 billion barrels of oil 2 and 190 trillion cubic feet of natural gas

  20. The diplomacy of scientific research in the South China Sea: the case of join to oceanographic marine scientific research expedition between Vietnam and the Philippines

    Science.gov (United States)

    Satyawan, I. A.

    2018-03-01

    The South China Sea is one of the hot-spot areas in the world. This area is claimed by China, Malaysia, Brunei, Taiwan, Vietnam and the Philippines. It also noted, the South China Sea is rich in biodiversity as well as oil and gas. On the other side, environmental degradation is still happening in the South China Sea due to the reluctance of surrounding states to conduct a preservation program and mitigating action on climate change effects. Joint Oceanographic Marine Scientific Research Expedition between Vietnam and the Philippines is a breakthrough to start collaboration actions as well as to conduct Science Diplomacy.

  1. Distribution and Diversity of Microbial Eukaryotes in Bathypelagic Waters of the South China Sea.

    Science.gov (United States)

    Xu, Dapeng; Jiao, Nianzhi; Ren, Rui; Warren, Alan

    2017-05-01

    Little is known about the biodiversity of microbial eukaryotes in the South China Sea, especially in waters at bathyal depths. Here, we employed SSU rDNA gene sequencing to reveal the diversity and community structure across depth and distance gradients in the South China Sea. Vertically, the highest alpha diversity was found at 75-m depth. The communities of microbial eukaryotes were clustered into shallow-, middle-, and deep-water groups according to the depth from which they were collected, indicating a depth-related diversity and distribution pattern. Rhizaria sequences dominated the microeukaryote community and occurred in all samples except those from less than 50-m deep, being most abundant near the sea floor where they contributed ca. 64-97% and 40-74% of the total sequences and OTUs recovered, respectively. A large portion of rhizarian OTUs has neither a nearest named neighbor nor a nearest neighbor in the GenBank database which indicated the presence of new phylotypes in the South China Sea. Given their overwhelming abundance and richness, further phylogenetic analysis of rhizarians were performed and three new genetic clusters were revealed containing sequences retrieved from the deep waters of the South China Sea. Our results shed light on the diversity and community structure of microbial eukaryotes in this not yet fully explored area. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  2. Dynamics of the Water Circulations in the Southern South China Sea and Its Seasonal Transports.

    Science.gov (United States)

    Daryabor, Farshid; Ooi, See Hai; Samah, Azizan Abu; Akbari, Abolghasem

    2016-01-01

    A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re-analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic currents while those in the southern areas are due solely to the wind stress because of negligible Coriolis force there. This study clearly shows that individual surface freshwater flux (evaporation minus precipitation) controls the sea salinity balance in the Southern South China Sea thermohaline circulations. Analysis of climatological data from a high resolution Regional Ocean Modeling System reveals that the complex bathymetry is important not only for water exchange through the Southern South China Sea but also in regulating various transports across the main passages in the Southern South China Sea, namely the Sunda Shelf and the Strait of Malacca. Apart from the above, in comparision with the dynamics of the Sunda Shelf, the Strait of Malacca reflects an equally significant role in the annual transports into the Andaman Sea.

  3. Past and Present Resource Disputes in the South China Sea: The Case of Reed Bank

    Directory of Open Access Journals (Sweden)

    Micah S. Muscolino

    2013-09-01

    Full Text Available In 2012, tensions flared between China and the Philippines over plans to drill for oil in the Reed Bank, a disputed shoal in the South China Sea, rekindling fears about the possibility of military conflict over the area’s energy resources. This article shows that international controversy centering on the Reed Bank’s hydrocarbon reserves initially emerged during the oil crisis of the 1970s, when the pursuit of energy resources transformed the islets into a hotly contested area. As in recent years, oil exploration by multinational corporations in conjunction with the Philippines catalyzed international disputes. Vigorous protests from China and other nations that lay claim to territories in the South China Sea prompted the Philippines to assert its own jurisdictional claims. The territorial dispute pushed claimants to the brink of military confrontation in the 1970s, yet armed conflict failed to materialize. By examining the initial round of tensions surrounding oil exploration at Reed Bank, this article situates the current international competition for the South China Sea’s energy resources in historical perspective. Analyzing past disputes and their ultimate resolution offers insights into the dynamics of present tensions, while making it possible to critically engage with arguments predicting future “resource wars” in the South China Sea.

  4. Illicit drugs and their metabolites in 36 rivers that drain into the Bohai Sea and north Yellow Sea, north China.

    Science.gov (United States)

    Wang, De-Gao; Zheng, Qiu-Da; Wang, Xiao-Ping; Du, Juan; Tian, Chong-Guo; Wang, Zhuang; Ge, Lin-Ke

    2016-08-01

    Illicit drugs and their metabolites have recently been recognized as an emerging group of contaminants due to their potential ecotoxicological impact in aquatic ecosystems. To date, information on the occurrence of these compounds in the aquatic environment of China remains limited. In this study, we collected surface water samples from 36 rivers in north China that discharge into the Bohai Sea and north Yellow Sea and measured the concentrations of amphetamine-like compounds, ketamines, cocainics, and opioids. The occurrence and spatial patterns of these substances show significant differences between the rivers and regions. Two designer drugs, methamphetamine (METH) and ketamine (KET), were the most abundant compounds detected in the entire set of samples (detection frequency of 92 and 69 %). The concentrations of METH and KET ranged from illicit drugs consumed in China. The high concentrations of these illicit drugs and their metabolites were found in areas that have a high population density. The riverine input of total illicit drugs into the Bohai Sea and north Yellow Sea was estimated to be in the range of 684 to 1160 kg per year.

  5. Distribution and sea-to-air flux of isoprene in the East China Sea and the South Yellow Sea during summer.

    Science.gov (United States)

    Li, Jian-Long; Zhang, Hong-Hai; Yang, Gui-Peng

    2017-07-01

    Spatial distribution and sea-to-air flux of isoprene in the East China Sea and the South Yellow Sea in July 2013 were investigated. This study is the first to report the concentrations of isoprene in the China marginal seas. Isoprene concentrations in the surface seawater during summer ranged from 32.46 to 173.5 pM, with an average of 83.62 ± 29.22 pM. Distribution of isoprene in the study area was influenced by the diluted water from the Yangtze River, which stimulated higher in-situ phytoplankton production of isoprene rather than direct freshwater input. Variations in isoprene concentrations were found to be diurnal, with high values observed during daytime. A significant correlation was observed between isoprene and chlorophyll a in the study area. Relatively higher isoprene concentrations were recorded at stations where the phytoplankton biomass was dominated by Chaetoceros, Skeletonema, Pennate-nitzschia, and Thalassiosira. Positive correlation was observed between isoprene and methyl iodide. In addition, sea-to-air fluxes of isoprene approximately ranged from 22.17 nmol m -2  d -1 -537.2 nmol m -2  d -1 , with an average of 161.5 ± 133.3 nmol m -2  d -1 . These results indicate that the coastal and shelf areas may be important sources of atmospheric isoprene. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Investigation of glyphosate resistance levels and target-site based resistance (TSR) mechanisms in Conyza canadensis (L.) from apple orchards around areas of Bohai seas and Loess Plateau in China.

    Science.gov (United States)

    Mei, Yu; Xu, Yufang; Wang, Shipeng; Qiu, Lihong; Zheng, Mingqi

    2018-04-01

    The resistance levels to glyphosate and target-site based resistance mechanisms in susceptible (S) and resistant (R) Conyza canadensis (L.) populations, which were collected from apple orchards around areas of Bohai seas and Loess Plateau in China, were investigated. Among forty C. canadensis populations, eighteen populations (45%) were still susceptible; fourteen populations (35%) evolved low resistance levels resistance to glyphosate with resistance index (RI) of 2.02 to 3.90. In contrast, eight populations (20%) evolved medium resistance levels with RI of 4.35 to 8.38. The shikimic acid concentrations in R populations were highly negative relative with the glyphosate resistance levels in C. canadensis, the Pearson correlation coefficient was -0.82 treated by glyphosate at 1.8mg/L. Three 5-enoylpyruvylshikimate 3'-phosphate synthase genes (EPSPS1, EPSPS2 and EPSPS3) were cloned in all S and glyphosate-resistant C. canadensis populations. No amino acid substitution was identified at site of 102 and 106 in three EPSPS genes, which were reported to confer glyphosate resistance in other weed species. The relative expression level of EPSPS mRNA in R populations (SD07, LN05, SHX06 and SD09) was 4.5 to 13.2 times higher than in S biotype. The Pearson correlation coefficient between EPSPS expression levels and RI was 0.79, which indicated the over expression of EPSPS mRNA may cause these R populations evolve higher resistance level to glyphosate. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Wind Profiles and Wave Spectra for Potential Wind Farms in South China Sea. Part II: Wave Spectrum Model

    Directory of Open Access Journals (Sweden)

    Yichao Liu

    2017-01-01

    Full Text Available Along with the commercialization of offshore wind energy in China, the South China Sea has been identified as ideal for constructing offshore wind farms, especially for farms consisting of floating wind turbines over deep waters. Since the wind profiles and wave spectra are somewhat primitive for the design of an offshore wind turbine, engineering models describing the wind and wave characteristics in the South China Sea area are necessary for the offshore wind energy exploitation given the meteorological, hydrological, and geographical differences between the South China Sea and the North/Norwegian Sea, where the commonly used wind profile and wave spectrum models were designated. In the present study; a series of numerical simulations were conducted to reveal the wave characteristics in the South China Sea under both typhoon and non-typhoon conditions. By analyzing the simulation results; the applicability of the Joint North Sea Wave Project (JONSWAP spectrum model; in terms of characterizing the wind-induced wave fields in the South China Sea; was discussed. In detail; the key parameters of the JONSWAP spectrum model; such as the Phillips constant; spectral width parameter; peak-enhancement factor, and high frequency tail decay; were investigated in the context of finding suitable values.

  8. Assessment of the Joint Development Potential of Wave and Wind Energy in the South China Sea

    Directory of Open Access Journals (Sweden)

    Yong Wan

    2018-02-01

    Full Text Available The South China Sea is a major shipping hub between the West Pacific and Indian Oceans. In this region, the demand for energy is enormous, both for residents’ daily lives and for economic development. Wave energy and wind energy are two major clean and low-cost ocean sources of renewable energy. The reasonable development and utilization of these energy sources can provide a stable energy supply for coastal cities and remote islands of China. Before wave energy and wind energy development, however, we must assess the potential of each of these sources. Based on high-resolution and high-accuracy wave field data and wind field data obtained by ERA-Interim reanalysis for the recent 38-year period from 1979–2016, the joint development potential of wave energy and wind energy was assessed in detail for offshore and nearshore areas in the South China Sea. Based on potential installed capacity, the results revealed three promising areas for the joint development of nearshore wave energy and wind energy, including the Taiwan Strait, Luzon Strait and the sea southeast of the Indo-China Peninsula. For these three dominant areas (key stations, the directionality of wave energy and wind energy propagation were good in various seasons; the dominant wave conditions and the dominant wind conditions were the same, which is advantageous for the joint development of wave and wind energy. Existing well-known wave energy converters (WECs are not suitable for wave energy development in the areas of interest. Therefore, we must consider the distributions of wave conditions and develop more suitable WECs for these areas. The economic and environmental benefits of the joint development of wave and wind energy are high in these promising areas. The results described in this paper can provide references for the joint development of wave and wind energy in the South China Sea.

  9. Study of southern CHAONAN sag lower continental slope basin deposition character in Northern South China Sea

    Science.gov (United States)

    Tang, Y.

    2009-12-01

    area includes three stages,that is Eogene,middle stage of lately Oligocene to early Miocene and middle Miocene to Present.Result shows that there are a good association of petroleum source rocks,reservoir rocks and seal rocks and structural traps in the Cenozoic and Mesozoic strata,as well as good conditions for the generation-migration-accumulation-preservation of petroleum in the lower continatal slope of Southern Chaoshan Sag.So the region has good petroleum prospect. Key words:Northern South China Sea;Chaoshan Sag; lower continental slope; deposition.

  10. Spatial and Temporal Distribution of Sea Surface Salinity in Coastal Waters of China Based on Aquarius

    International Nuclear Information System (INIS)

    Wang, Ying; Jiang, Hong; Zhang, Xiuying; Jin, Jiaxin

    2014-01-01

    Sea surface salinity (SSS) is a fundamental parameter for the study of global ocean dynamics, water cycle, and climate variability. Aquarius launched by NASA and the Space Agency of Argentina is a breakthrough which could achieve the remote sensing data of SSS. The present paper takes the coastal of China as study area, which is a representative area of ocean boundary and influenced by continental rivers (Yangtze River and Pearl River). After analyze the temporal and spatial variation of SSS in the coastal of China, the estuary area has obvious low salinity because the injected of freshwater from continent. Take the East China Sea (ECS) and South China Sea (SCS) as representative region to discuss the effect of freshwater to SSS. The salinity is almost equal in winter when the diluted water is inadequate in both rivers. However, an obvious decrease appeared in summer especial July in Yangtze River for abundance discharge inflow the ECS. This is a reasonable expression of Yangtze River discharge is remarkable influence the SSS in coastal area then Pearl River. Survey the distribution range of Yangtze River diluted water (SSS<31psu). The range is small in winter and expands to peak value in summer

  11. Time trends of polybrominated diphenyl ethers in East China Seas: Response to the booming of PBDE pollution industry in China.

    Science.gov (United States)

    Li, Yuanyuan; Lin, Tian; Hu, Limin; Feng, Jialiang; Guo, Zhigang

    2016-01-01

    The East China Seas (ECSs) are the receptors of the land-based persistent organic pollutants (POPs), such as polybrominated diphenyl ethers (PBDEs) mainly from China through atmospheric deposition driven by the East Asian winter monsoon and fluvial discharge (e.g., Yangtze River and Yellow River), making the offshore sediments to be a good proxy to reconstruct history of those pollutants in China. In this work, four well-placed sediment cores were extracted from the mud areas in the ECSs, and the (210)Pb-dated cores were analyzed to yield historical concentration profiles of PBDEs in the area. The results showed that there was a persistent increase from 1970s and almost no clear sign in the decline of PBDEs until recently in China. More importantly, there was a faster increase of PBDEs from 1990s in China; while this period was just shown as gradually leveling off or even declining trends in developed countries. The persistently increasing trend of PBDEs in China since 1990s could be largely due to the booming of the manufacturing industry and unexpectedly transfer of PBDE pollution from developed countries to China. Besides, the relative high concentrations and fluxes of PBDEs in the core from coastal ECS located near a well-known electrical/electronic waste (e-waste) recycling area suggests an important contribution of PBDE emissions from recycling centers of e-waste in China. Although efforts in environmental monitoring of PBDE contamination have been substantially increased over the last decade, China is still lagging behind in terms of nationwide regulation of PBDE usage and treatment of disposal PBDE-containing products. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Tides and their dynamics over the Sunda Shelf of the southern South China Sea

    DEFF Research Database (Denmark)

    Daryabor, Farshid; Ooi, See Hai Ooi; Samah, Azizan Abu

    2016-01-01

    A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performe...... on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area....

  13. The South China Sea Dispute : Perspective of International Law

    NARCIS (Netherlands)

    Ma, Xuechan

    2016-01-01

    This article discusses the South China Sea dispute from the perspective of international law. First, it introduces some basic knowledge about international law in this field. In the second part, Spratly islands dispute is used as a concrete example to show how international law analyzes this kind of

  14. Diverse deep-sea fungi from the South China Sea and their antimicrobial activity.

    Science.gov (United States)

    Zhang, Xiao-Yong; Zhang, Yun; Xu, Xin-Ya; Qi, Shu-Hua

    2013-11-01

    We investigated the diversity of fungal communities in nine different deep-sea sediment samples of the South China Sea by culture-dependent methods followed by analysis of fungal internal transcribed spacer (ITS) sequences. Although 14 out of 27 identified species were reported in a previous study, 13 species were isolated from sediments of deep-sea environments for the first report. Moreover, these ITS sequences of six isolates shared 84-92 % similarity with their closest matches in GenBank, which suggested that they might be novel phylotypes of genera Ajellomyces, Podosordaria, Torula, and Xylaria. The antimicrobial activities of these fungal isolates were explored using a double-layer technique. A relatively high proportion (56 %) of fungal isolates exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among four marine pathogenic microbes (Micrococcus luteus, Pseudoaltermonas piscida, Aspergerillus versicolor, and A. sydowii). Out of these antimicrobial fungi, the genera Arthrinium, Aspergillus, and Penicillium exhibited antibacterial and antifungal activities, while genus Aureobasidium displayed only antibacterial activity, and genera Acremonium, Cladosporium, Geomyces, and Phaeosphaeriopsis displayed only antifungal activity. To our knowledge, this is the first report to investigate the diversity and antimicrobial activity of culturable deep-sea-derived fungi in the South China Sea. These results suggest that diverse deep-sea fungi from the South China Sea are a potential source for antibiotics' discovery and further increase the pool of fungi available for natural bioactive product screening.

  15. Cnooc's fourth bidding round offers first tracts in East China Sea

    International Nuclear Information System (INIS)

    Ganapathy, V.

    1992-01-01

    This paper reports that China National Offshore Oil Corp. (Cnooc) has unveiled details of China's fourth offshore bidding round. It features the first offering of acreage in the East China Sea. Cnooc, China's state agency for offshore oil cooperation with foreign firms, has sweetened fiscal and tax terms for operators in the fourth round, announced June 30 (OGJ, July 6, Newsletter). Cnooc put up for bids two groups of acreage in the East China Sea that cover a total area of almost 73,000 sq km. The northern acreage, consisting of four blocks, covers 18,800 sq km and is 230 km east of Shanghai. The southern acreage, consisting of 16 blocks, covers 54,000 sq km and is 110 km east of Wenzhou, Zhejiang province. The area waters are 50-100 m deep and relatively calm year round. Chines explorationists have conducted 60,000 line km of seismic surveys and drilled five wildcats in the two areas, Data indicate the two areas have thick sediments, good source rocks, and strong conditions for oil traps

  16. Comparison of modern pollen distribution between the northern and southern parts of the South China Sea.

    Science.gov (United States)

    Luo, Chuanxiu; Chen, Muhong; Xiang, Rong; Liu, Jianguo; Zhang, Lanlan; Lu, Jun

    2015-04-01

    The authors conducted a palynological analysis based on different number of air pollen samples for the northern and southern parts of the South China Sea, respectively, in order to give a reference to reconstruct the paleoclimate of the area. (1) Fifteen air pollen samples were collected from the northern part of the South China Sea from August to September 2011, and 13 air pollen samples were collected from the southern part of the South China Sea in December 2011. The pollen types were more abundant in the north than in the south. The total pollen number and concentration in the north was 10 times more than that in the south, which may be because of the sampling season. Airborne pollen types and concentrations have a close relationship with wind direction and distance from the sampling point to the continent. (2) Seventy-four samples were collected from surface sediments in the northern part of the South China Sea in the autumn. Thirty-three samples were collected from surface sediments in the southern part of the South China Sea in the winter. Pollen concentrations in the north were nearly 10 times higher than that in the south. This is because trilete spores are transported by rivers from Hainan Island to the sea and also by the summer monsoon-forced marine current. (3) Ten air pollen samples and 10 surface sediments samples were selected for comparison. The pollen and spores in the air were mainly herbaceous and woody pollen, excluding fern spores, having seasonal pollen characteristics. Pollen in the surface sediments were mainly trilete, Pinus, and herbaceous, and may also show a combination of annual pollen characteristics.

  17. [Chemical characteristics of precipitation in South China Sea].

    Science.gov (United States)

    Xiao, Hong-Wei; Long, Ai-Min; Xie, Lu-Hua; Xiao, Hua-Yun; Liu, Cong-Qiang

    2014-02-01

    Rainwater samples were collected in the summer on "Shiyan 3" during the 2012 South China Sea Sectional Scientific Survey. The concentrations of anion and cation, and pH in precipitation were determined and backward trajectories of air mass were simulated to analyze the chemical characteristics of ions and examine the source of ions. The results indicated that the mean pH value of precipitation was 6.3, with 5.6 of minimal value in summer in South China Sea. The order of anion and cation abundance was Cl(-) > S04(2-) > NO3(-) and Na(+) > Mg(2+) > Ca(2+) > K(+). Cl(-) was the major anion and Na(+) was the major cation, with concentrations of 2 637.5 microeq x L(-1) and 2095.5 microeq x L(-1), respectively, showing that they were the characteristics of marine atmospheric precipitation. There was a good linear relationship between each pair of 7 ions, with correlation coefficient above 0.9, suggesting that they may have a common source. However, the correlation coefficients were lower between NO3(-) and other ions than the others, suggesting that NO3(-) had more complex sources. The concentrations of Ca(2+) and K(+) in precipitation may be related to coral environment in South China Sea. The backward trajectories in 6 stations showed that the air mass was from south and southwest of South China Sea, without passing through above the continent. These results suggested that precipitation affected by human ion source can be ignored in summer in South China Sea.

  18. INDONESIAN TRADE UNDER CHINA FREE TRADE AREA

    Directory of Open Access Journals (Sweden)

    Tavi Supriana

    2011-09-01

    Full Text Available This paper investigates the implementation of CAFTA (China-Asean Free Trade Area on the international trade flows across Indonesia, China and the rest of ASEAN using a gravitation model. It finds the evidence that the influence of diversion and creation effects on China are significant, while the influence of both effects on Indonesia are not significant. It also finds that the diversion effect, which leads to a decrease in society’s wealth, is greater than that of the creation effect. As a consequence, the gap across countries involved in the trade agreement is wider. Keywords: CAFTA, gravitation model, diversion effect, creation effectJEL classification numbers: F13, F14, F15

  19. Matching Deep Tow Camera study and Sea Floor geochemical characterization of gas migration at the Tainan Ridge, South China Sea

    Science.gov (United States)

    Fan, L. F.; Lien, K. L.; Hsieh, I. C.; Lin, S.

    2017-12-01

    Methane seep in deep sea environment could lead to build up of chemosynthesis communities, and a number of geological and biological anomalies as compare to the surrounding area. In order to examine the linkage between seep anomalies and those at the vicinity background area, and to detail mapping those spatial variations, we used a deep towed camera system (TowCam) to survey seafloor on the Tainan Ridge, Northeastern South China Sea (SCS). The underwater sea floor pictures could provide better spatial variations to demonstrate impact of methane seep on the sea floor. Water column variations of salinity, temperature, dissolved oxygen were applied to delineate fine scale variations at the study area. In addition, sediment cores were collected for chemical analyses to confirm the existence of local spatial variations. Our results show large spatial variations existed as a result of differences in methane flux. In fact, methane is the driving force for the observed biogeochemical variations in the water column, on the sea floor, and in the sediment. Of the area we have surveyed, there are approximately 7% of total towcam survey data showing abnormal water properties. Corresponding to the water column anomalies, underwater sea floor pictures taken from those places showed that chemosynthetic clams and muscles could be identified, together with authigenic carbonate buildups, and bacterial mats. Moreover, sediment cores with chemical anomalies also matched those in the water column and on the sea floor. These anomalies, however, represent only a small portion of the area surveyed and could not be identified with typical (random) coring method. Methane seep, therefore, require tedious and multiple types of surveys to better understand the scale and magnitude of seep and biogeochemical anomalies those were driven by gas migrations.

  20. Inter-annual sea level variability in the southern South China Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Soumya, M.; Vethamony, P.; Tkalich, P.

    (SCS) is one of the western marginal seas of the Pacific Ocean, surrounded by South China, Indo China Peninsula, Malaysian Peninsula, Philippines and Borneo Island. The SCS is a semi- enclosed basin connected to the western Pacific Ocean through Taiwan.... Sea level trend and variability in the Singapore Strait. Ocean Science, 9(2). Torrence, C. and Compo, G.P., 1998. A practical guide to wavelet analysis. Bulletin of the American Meteorological Society, 79(1): 61-78. Vargas‐Hernandez, J.M., Wijffels...

  1. Post-rift magmatism in the Pearl River Mouth Basin, northern South China Sea

    Science.gov (United States)

    Xu, H.; Zhao, F.; Xia, S.; Sun, J.; Fan, C.

    2017-12-01

    Multi-beam, 2D seismic reflection and borehole data reveal that post-rift magmatism are widespread in the northern margin of South China Sea. A large-scale volcanic complex was identified at water depths of 500 to 3000 m, covering an area of ca. 8000 km2. This volcanic complex includes seamounts, igneous sills, dykes and intruded volcanic bodies. Combining data from exploration wells BY7-1 and BY2 with published seismic stratigraphic data, we can highlight multiple extrusive events from the Early Oligocene to Early Miocene, reflecting progressive continental breakup in the South China Sea. Most intruded magma through the continental crust also uplifted sediments up to the T6 unconformity. Given the evidence in this work that Early Miocene magmatic bodies were developed above or along faults, we suggest that post-rift magmatism in the northern margin of the South China Sea was largely controlled by the faults. Reactivation events in the faults are suggested to have generated preferential vertical pathways for the ascent of magma within a context of progressive continental breakup and thinned continental crust, as the South China Sea was being formed.

  2. Seismicity and stress state in the South China Sea, Indochina and their vicinity

    Science.gov (United States)

    Zang, Shaoxian; Wu, Zhongliang; Li, Aibing

    1992-02-01

    The distribution of earthquakes from 1973 to 1982 in the South China Sea, Indochina and their vicinity was studied using the data from I. S. C. It was found that the earthquakes are mainly concentrated along the boundaries of plates. Beside, some of shallow eartqhuakes are distributed in west part of Burma and the boundary between Burma and China, a few of earthquakes occurred in South China Sea. The features of Benioff zone along the boundaries between India plate, Philippine Sea plate and Eurasia plate were studied. The plate do not coupled well under the Java trench and the Philippine trench. The subducted India plate under Burmese range, Andaman—Nicobar arc moves NNE. The fault plane solutions of earthquakes were studied using the first motions of P wave. The stress state on subduction zones and within the area were deduced from the fault plane solutions and the fault movement. It was found that the direction of principal compression axis of stress is in the NNE in west part of Burma, in S—N in south and middle part of Bruma and Thailand, and in NNE or S—N in the South China Sea. It was also found that the stress state has close relation with the interaction of plates.

  3. Modal recovery of sea-level variability in the South China Sea using merged altimeter data

    Science.gov (United States)

    Jiang, Haoyu; Chen, Ge

    2015-09-01

    Using 20 years (1993-2012) of merged data recorded by contemporary multi-altimeter missions, a variety of sea-level variability modes are recovered in the South China Sea employing three-dimensional harmonic extraction. In terms of the long-term variation, the South China Sea is estimated to have a rising sea-level linear trend of 5.39 mm/a over these 20 years. Among the modes extracted, the seven most statistically significant periodic or quasi-periodic modes are identified as principal modes. The geographical distributions of the magnitudes and phases of the modes are displayed. In terms of intraannual and annual regimes, two principal modes with strict semiannual and annual periods are found, with the annual variability having the largest amplitudes among the seven modes. For interannual and decadal regimes, five principal modes at approximately 18, 21, 23, 28, and 112 months are found with the most mode-active region being to the east of Vietnam. For the phase distributions, a series of amphidromes are observed as twins, termed "amphidrome twins", comprising rotating dipole systems. The stability of periodic modes is investigated employing joint spatiotemporal analysis of latitude/longitude sections. Results show that all periodic modes are robust, revealing the richness and complexity of sea-level modes in the South China Sea.

  4. Taxonomic research on deep-sea macrofauna in the South China Sea using the Chinese deep-sea submersible Jiaolong.

    Science.gov (United States)

    Li, Xinzheng

    2017-07-01

    This paper reviews the taxonomic and biodiversity studies of deep-sea invertebrates in the South China Sea based on the samples collected by the Chinese manned deep-sea submersible Jiaolong. To date, 6 new species have been described, including the sponges Lophophysema eversa, Saccocalyx microhexactin and Semperella jiaolongae as well as the crustaceans Uroptychus jiaolongae, Uroptychus spinulosus and Globospongicola jiaolongi; some newly recorded species from the South China Sea have also been reported. The Bathymodiolus platifrons-Shinkaia crosnieri deep-sea cold seep community has been reported by Li (2015), as has the mitochondrial genome of the glass sponge L. eversa by Zhang et al. (2016). The population structures of two dominant species, the shrimp Shinkaia crosnieri and the mussel Bathymodiolus platifrons, from the cold seep Bathymodiolus platifrons-Shinkaia crosnieri community in the South China Sea and the hydrothermal vents in the Okinawa Trough, were compared using molecular analysis. The systematic position of the shrimp genus Globospongicola was discussed based on 16S rRNA gene sequences. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  5. Retrieval of Secchi disk depth in the Yellow Sea and East China Sea using 8-day MODIS data

    International Nuclear Information System (INIS)

    Yu, D F; Xing, Q G; Lou, M J; Shi, P

    2014-01-01

    Secchi disk depth (SDD), is widely used as an indicator of water clarity. The traditional sampling method is not only time-consuming and labor-intensive but also limited in terms of temporal and spatial coverage. Remote sensing technology may deal with these limitations. In this paper, the applicability of 8-day MODIS-Aqua remote sensing reflectance data with 4 km spatial resolution for estimating water clarity in the Yellow Sea and the East China Sea was investigated. Field data such as Secchi depths were collected from two cruises conducted in the Yellow Sea and the East China Sea from 5 May to 7 June 2009. A three-band algorithm to retrieve SDD was developed based on remote sensing reflectance at bands of 488, 555, and 678 nm, which performed better than single-band model and band ratio algorithm, with a determination coefficient of 0.72 and a mean relative error of 19%. This suggests that 8-day MODIS-Aqua products of remote sensing reflectance could be used to assess water transparency in the study area

  6. Distribution of Bottom Trawling Effort in the Yellow Sea and East China Sea.

    Directory of Open Access Journals (Sweden)

    Shengmao Zhang

    Full Text Available Bottom trawling is one of the most efficient fishing activities, but serious and persistent ecological issues have been observed by fishers, scientists and fishery managers. Although China has applied the Beidou fishing vessel position monitoring system (VMS to manage trawlers since 2006, little is known regarding the impacts of trawling on the sea bottom environments. In this study, continuous VMS data of the 1403 single-rig otter trawlers registered in the Xiangshan Port, 3.9% of the total trawlers in China, were used to map the trawling effort in 2013. We used the accumulated distance (AD, accumulated power distance (APD, and trawling intensity as indexes to express the trawling efforts in the Yellow Sea (YS and East China Sea (ECS. Our results show that all three indexes had similar patterns in the YS and ECS, and indicated a higher fishing effort of fishing grounds that were near the port. On average, the seabed was trawled 0.73 times in 2013 over the entire fishing region, and 51.38% of the total fishing grounds were with no fishing activities. Because of VMS data from only a small proportion of Chinese trawlers was calculated fishing intensity, more VMS data is required to illustrate the overall trawling effort in China seas. Our results enable fishery managers to identify the distribution of bottom trawling activities in the YS and ECS, and hence to make effective fishery policy.

  7. South China sea off Viet Nam to see more exploration

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    British and Japanese operators are posed for exploration campaigns off southern Viet Nam. This paper reports that a 50-50 partnership of Lasmo International Ltd., London, and C. Itoh Exploration Co. of Japan signed a heads of agreement covering Block 04-2, and AEDC Vietnam Oil Development Co. and Teikoku Oil Co. acquired Block 05-3 under a production sharing contract. AEDC is a unit of AOC Energy Development Co., a subsidiary of Arabian Oil Co. (AOC) of Japan. Both tracts are in the Con Son basin in the South China Sea. Site is 15 km north of 500 million bbl Dai Hung (Big Bear) oil field for which state owned Petrovietnam is evaluating bids to place on production. A unit of the Royal Dutch/shell Group acquired a west offset, Block 10, early this year. The Lasmo-C. Itoh acreage is among five blocks offered in Vietnam's second round of offshore licensing. All are in the area that once was reserved entirely for Vietsovpetro, a partnership of Petrovietnam and the former Soviet Union

  8. The distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea

    Science.gov (United States)

    Woo, Sau Pinn; Yasin, Zulfigar; Ismail, Siti Hasmah; Tan, Shau Hwai

    2013-11-01

    A study on the distribution and diversity of sea cucumbers in the coral reefs of the South China Sea, Sulu Sea and Sulawesi Sea was carried out in July 2009. The survey was done using wandering transect underwater with SCUBA. Twelve species of sea cucumber were found from four different families and nine genera. The most dominant family was Holothuriidae (five species), followed by Stichopodidae (three species), Synaptidae (three species) and Cucumariidae with only one species. The most dominant species found around the island was Pearsonothuria graffei, which can be found abundantly on substrate of dead corals in a wide range of depth (6-15 m). The Sulawesi Sea showed a higher diversity of sea cucumber with seven different species compared to the South China Sea with only six different species and Sulu Sea with only two species. Ordination by multidimensional scaling of Bray-Curtis similarities clustered the sampling locations to three main clusters with two outgroups. Previous studies done indicated a higher diversity of sea cucumber as compared to this study. This can be indication that the population and diversity of sea cucumbers in the reef is under threat.

  9. Screening of seaweeds in the East China Sea as potential bio-monitors of heavy metals.

    Science.gov (United States)

    Pan, Yaoru; Wernberg, Thomas; de Bettignies, Thibaut; Holmer, Marianne; Li, Ke; Wu, Jiaping; Lin, Fang; Yu, Yan; Xu, Jiang; Zhou, Chaosheng; Huang, Zhixing; Xiao, Xi

    2018-03-30

    Seaweeds are good bio-monitors of heavy metal pollution and have been included in European coastal monitoring programs. However, data for seaweed species in China are scarce or missing. In this study, we explored the potential of seaweeds as bio-monitor by screening the natural occurring seaweeds in the "Kingdom of seaweed and shellfish" at Dongtou Islands, the East China Sea. Totally, 12 seaweed species were collected from six sites, with richness following the sequence of Rhodophyta > Phaeophyta > Chlorophyta. The concentration of heavy metals (Cu, Cr, Ni, Zn, Pb, Cd, As) in the seaweeds was determined, and the bioaccumulation coefficient was calculated. A combination of four seaweeds, Pachydictyon coriaceum, Gelidium divaricatum, Sargassum thunbergii, and Pterocladiella capillacea, were proposed as bio-monitors due to their high bioaccumulation capabilities of specific heavy metals in the East China Sea and hence hinted the importance of using seaweed community for monitoring of pollution rather than single species. Our results provide first-hand data for the selection of bio-monitor species for heavy metals in the East China Sea and contribute to selection of cosmopolitan bio-monitor communities over geographical large area, which will benefit the establishment of monitoring programs for coastal heavy metal contamination.

  10. Air-sea exchange of gaseous mercury in the East China Sea.

    Science.gov (United States)

    Wang, Chunjie; Ci, Zhijia; Wang, Zhangwei; Zhang, Xiaoshan

    2016-05-01

    Two oceanographic cruises were carried out in the East China Sea (ECS) during the summer and fall of 2013. The main objectives of this study are to identify the spatial-temporal distributions of gaseous elemental mercury (GEM) in air and dissolved gaseous mercury (DGM) in surface seawater, and then to estimate the Hg(0) flux. The GEM concentration was lower in summer (1.61 ± 0.32 ng m(-3)) than in fall (2.20 ± 0.58 ng m(-3)). The back-trajectory analysis revealed that the air masses with high GEM levels during fall largely originated from the land, while the air masses with low GEM levels during summer primarily originated from ocean. The spatial distribution patterns of total Hg (THg), fluorescence, and turbidity were consistent with the pattern of DGM with high levels in the nearshore area and low levels in the open sea. Additionally, the levels of percentage of DGM to THg (%DGM) were higher in the open sea than in the nearshore area, which was consistent with the previous studies. The THg concentration in fall was higher (1.47 ± 0.51 ng l(-1)) than those of other open oceans. The DGM concentration (60.1 ± 17.6 pg l(-1)) and Hg(0) flux (4.6 ± 3.6 ng m(-2) h(-1)) in summer were higher than those in fall (DGM: 49.6 ± 12.5 pg l(-1) and Hg(0) flux: 3.6 ± 2.8 ng m(-2) h(-1)). The emission flux of Hg(0) from the ECS was estimated to be 27.6 tons yr(-1), accounting for ∼0.98% of the global Hg oceanic evasion though the ECS only accounts for ∼0.21% of global ocean area, indicating that the ECS plays an important role in the oceanic Hg cycle. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Exploring coral microbiome assemblages in the South China Sea.

    Science.gov (United States)

    Cai, Lin; Tian, Ren-Mao; Zhou, Guowei; Tong, Haoya; Wong, Yue Him; Zhang, Weipeng; Chui, Apple Pui Yi; Xie, James Y; Qiu, Jian-Wen; Ang, Put O; Liu, Sheng; Huang, Hui; Qian, Pei-Yuan

    2018-02-05

    Coral reefs are significant ecosystems. The ecological success of coral reefs relies on not only coral-algal symbiosis but also coral-microbial partnership. However, microbiome assemblages in the South China Sea corals remain largely unexplored. Here, we compared the microbiome assemblages of reef-building corals Galaxea (G. fascicularis) and Montipora (M. venosa, M. peltiformis, M. monasteriata) collected from five different locations in the South China Sea using massively-parallel sequencing of 16S rRNA gene and multivariate analysis. The results indicated that microbiome assemblages for each coral species were unique regardless of location and were different from the corresponding seawater. Host type appeared to drive the coral microbiome assemblages rather than location and seawater. Network analysis was employed to explore coral microbiome co-occurrence patterns, which revealed 61 and 80 co-occurring microbial species assembling the Galaxea and Montipora microbiomes, respectively. Most of these co-occurring microbial species were commonly found in corals and were inferred to play potential roles in host nutrient metabolism; carbon, nitrogen, sulfur cycles; host detoxification; and climate change. These findings suggest that the co-occurring microbial species explored might be essential to maintain the critical coral-microbial partnership. The present study provides new insights into coral microbiome assemblages in the South China Sea.

  12. The Kuroshio exchange with the South and East China Seas

    Directory of Open Access Journals (Sweden)

    T. Matsuno

    2009-08-01

    Full Text Available The Kuroshio flows along the edges of the marginal East Asian seas such as the South China Sea (SCS and East China Sea (ECS. Exchanges of materials and energy between the Kuroshio and the marginal seas partly control the environments of the marginal seas. In particular, saline water from the Kuroshio maintains certain salinity in the shelf water in the ECS. Nutrients from the subsurface of the Kuroshio may influence primary production on the shelf. We summarize how the Kuroshio comes into contact with the shelf water or marginal seas, describing phenomena related to the exchange between the Kuroshio and the ECS along with the SCS, using reports in the literature along with original data. The Kuroshio tends to intrude into the SCS through the Luzon Strait in various manners such as direct intrusion, associated with eddies and as a loop current. The Kuroshio intrusion into the shelf region of the ECS has distinct seasonal variation and the Taiwan Warm Current plays a significant role in the determination of water properties in the outer shelf associated with the Kuroshio intrusion. We then examine physical processes related to the interaction between the Kuroshio and shelf water. Interaction between the Kuroshio and the bottom topography is an important process in the control of the exchange around the shelf break. Vertical mixing and frontal eddies are also important factors that control the water exchange and formation of water masses in the outer shelf. Wind stress plays a significant role in the exchange with a rather event-like manner. To determine the source of the water masses, chemical tracers could be powerful tools and it is suggested that a significant part of the shelf water consists of Kuroshio intermediate water.

  13. Aliphatic hydrocarbons in surface sediments from South China Sea off Kuching Division, Sarawak

    International Nuclear Information System (INIS)

    Hafidz Yusoff; Zaini Assim; Samsur Mohamad

    2012-01-01

    Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/ MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 μg/ g to 1466.1 μg/ g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C 31 / C 19 and C 29 / C 31 indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world. (author)

  14. South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004

    National Research Council Canada - National Science Library

    Chu, Peter C; Cheng, Kuo-Feng

    2008-01-01

    Ocean wave characteristics in the western Atlantic Ocean (Hurricane Region) to tropical cyclones have been investigated extensively, but not the regional seas in the western Pacific such as the South China Sea (Typhoon Region...

  15. Distributions and sources of volatile chlorocarbons and bromocarbons in the Yellow Sea and East China Sea

    International Nuclear Information System (INIS)

    Yang, Bin; Yang, Gui-Peng; Lu, Xiao-Lan; Li, Li; He, Zhen

    2015-01-01

    Highlights: • Concentrations of the six VHOC were determined in the Yellow Sea and East China Sea. • VHOC distributions were affected by anthropogenic, biologic and hydrographic factors. • Diurnal variations of the six VHOC were observed. • Relationships between VHOC and related parameters were discussed. • Sources of the six VHOC were identified by principal component analysis. - Abstract: Six volatile halogenated organic compounds (VHOC), namely, chloroform, carbon tetrachloride, trichloroethylene, bromodichloromethane, dibromochloromethane, and bromoform, were studied in the Yellow Sea and East China Sea from April to May, 2009. The spatial variability of these VHOC was influenced by various factors, including anthropogenic inputs, biogenic production and complicated hydrographic features such as Changjiang Diluted Water, Yellow Sea Cold Water Mass, and Kuroshio Current. Diurnal study results showed that factors such as solar irradiation, biological activity, and tide affected the abundance of these VHOC. Correlation analyses revealed that bromodichloromethane was positively correlated with chlorophyll a in surface seawater. Principal component analysis suggested that chlorinated compounds like carbon tetrachloride originated from anthropogenic sources whereas brominated compounds such as bromodichloromethane originated from biogenic sources. Sources of other chlorinated and brominated compounds may not be governed by biological processes in the marine environment

  16. Antifouling potentials of eight deep-sea-derived fungi from the South China Sea.

    Science.gov (United States)

    Zhang, Xiao-Yong; Xu, Xin-Ya; Peng, Jiang; Ma, Chun-Feng; Nong, Xu-Hua; Bao, Jie; Zhang, Guang-Zhao; Qi, Shu-Hua

    2014-04-01

    Marine-derived microbial secondary metabolites are promising potential sources of nontoxic antifouling agents. The search for environmentally friendly and low-toxic antifouling components guided us to investigate the antifouling potentials of eight novel fungal isolates from deep-sea sediments of the South China Sea. Sixteen crude ethyl acetate extracts of the eight fungal isolates showed distinct antibacterial activity against three marine bacteria (Loktanella hongkongensis UST950701-009, Micrococcus luteus UST950701-006 and Pseudoalteromonas piscida UST010620-005), or significant antilarval activity against larval settlement of bryozoan Bugula neritina. Furthermore, the extract of Aspergillus westerdijkiae DFFSCS013 displayed strong antifouling activity in a field trial lasting 4 months. By further bioassay-guided isolation, five antifouling alkaloids including brevianamide F, circumdatin F and L, notoamide C, and 5-chlorosclerotiamide were isolated from the extract of A. westerdijkiae DFFSCS013. This is the first report about the antifouling potentials of metabolites of the deep-sea-derived fungi from the South China Sea, and the first stage towards the development of non- or low-toxic antifouling agents from deep-sea-derived fungi.

  17. 47 CFR 80.1069 - Maritime sea areas.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Maritime sea areas. 80.1069 Section 80.1069... MARITIME SERVICES Global Maritime Distress and Safety System (GMDSS) General Provisions § 80.1069 Maritime... continuous DSC alerting is available as defined by the International Maritime Organization. (2) Sea area A2...

  18. Disputes About Disputes: Understanding the South China Sea

    Directory of Open Access Journals (Sweden)

    Bill Hayton

    2017-12-01

    Full Text Available Steve Chan. China’s Troubled Waters: Maritime Disputes in Theoretical Perspectives. Cambridge: Cambridge University Press, 2016. Do Thanh Hai. Vietnam and the South China Sea: Politics, Security and Legality. New York: Routledge, 2017. The two books under review here demonstrate some of the diversity of writing within the discipline of international relations. In China’s Troubled Waters: Maritime Disputes in Theoretical Perspectives, political scientist Steve Chan, following Kant, describes his style as “nomothetic,” “which emphasizes attention to classes of events rather than specific episodes” (vii. Strategic and defense studies scholar Do Thanh Hai’s Vietnam and the South China Sea: Politics, Security and Legality is an example of what Chan calls the “idiographic approach,” focusing “on the more unique or specific aspects of the situation” (vii. Chan wants to be able to generalize and compare, and he explicitly eschews narratives of “who did what to whom.” Hai, on the other hand, is keen to make clear that it is China who did something to Vietnam. The most obvious criticism to make of his book is that it is written from an overtly Vietnamese perspective. That is a weakness, but also potentially a draw for those interested in the formulation of Vietnamese policy. Chan writes from an ostensibly neutral position, but, as we shall see, his analysis is rooted within a Chinese world view.

  19. Preventing Escalation in the South China Sea Disputed Waters: A Comparative Study of Republic of the Philippines and Socialist Republic of Vietnam

    Science.gov (United States)

    2015-03-01

    Problem of Maritime Cooperation in the South China Sea,” in Security and International Politics in the South China Sea, eds. Sam Bateman and Ralf Emmers...South China Sea,” in Security and International Politics in the South China Sea: Towards a cooperative management regime, eds. Sam Bateman and Ralf...Cooperation in the South China Sea.” In Security and International Politics in the South China Sea, edited by Sam Bateman and Ralf Emmers. Oxon, UK

  20. Situation in the sea area between the North Sea and the Baltic Sea. Situationen i havsomraadet mellan Nordsjoen och Oestersjoen

    Energy Technology Data Exchange (ETDEWEB)

    Dybern, B.I.; Soederstroem, J.; Thorell, L.

    1984-01-01

    Due to the special topographical and hydrological features the seas surrounding Sweden are very sensitive to both natural changes and changes caused by man. The sea area between the North Sea and the Baltic Sea has come into focus during the last few decades due to problems with pollution and its impact on the ecosystems and to overfishing of some commer- cially important species. In order to elucidate the present situation from the Swedish viewpoint, the National Board of Fisheries, the National Environment Protection Board and the County Council of the County Goeteborg and Bohyslaen arranged a Symposium on the Situation in the Sea Area between the North Sea and the Baltic Sea in Goeteborg, 14-16 March, 1983. This volume contains lectures given at that Symposium. In most cases there are English summaries and English translations of texts to figures and tables.

  1. Characterization of bacterial diversity associated with deep sea ferromanganese nodules from the South China Sea.

    Science.gov (United States)

    Zhang, De-Chao; Liu, Yan-Xia; Li, Xin-Zheng

    2015-09-01

    Deep sea ferromanganese (FeMn) nodules contain metallic mineral resources and have great economic potential. In this study, a combination of culture-dependent and culture-independent (16S rRNA genes clone library and pyrosequencing) methods was used to investigate the bacterial diversity in FeMn nodules from Jiaolong Seamount, the South China Sea. Eleven bacterial strains including some moderate thermophiles were isolated. The majority of strains belonged to the phylum Proteobacteria; one isolate belonged to the phylum Firmicutes. A total of 259 near full-length bacterial 16S rRNA gene sequences in a clone library and 67,079 valid reads obtained using pyrosequencing indicated that members of the Gammaproteobacteria dominated, with the most abundant bacterial genera being Pseudomonas and Alteromonas. Sequence analysis indicated the presence of many organisms whose closest relatives are known manganese oxidizers, iron reducers, hydrogen-oxidizing bacteria and methylotrophs. This is the first reported investigation of bacterial diversity associated with deep sea FeMn nodules from the South China Sea.

  2. Walrus areas of use in the Chukchi Sea during sparse sea ice cover

    Science.gov (United States)

    Jay, Chadwick V.; Fischbach, Anthony S.; Kochnev, Anatoly A.

    2012-01-01

    The Pacific walrus Odobenus rosmarus divergens feeds on benthic invertebrates on the continental shelf of the Chukchi and Bering Seas and rests on sea ice between foraging trips. With climate warming, ice-free periods in the Chukchi Sea have increased and are projected to increase further in frequency and duration. We radio-tracked walruses to estimate areas of walrus foraging and occupancy in the Chukchi Sea from June to November of 2008 to 2011, years when sea ice was sparse over the continental shelf in comparison to historical records. The earlier and more extensive sea ice retreat in June to September, and delayed freeze-up of sea ice in October to November, created conditions for walruses to arrive earlier and stay later in the Chukchi Sea than in the past. The lack of sea ice over the continental shelf from September to October caused walruses to forage in nearshore areas instead of offshore areas as in the past. Walruses did not frequent the deep waters of the Arctic Basin when sea ice retreated off the shelf. Walruses foraged in most areas they occupied, and areas of concentrated foraging generally corresponded to regions of high benthic biomass, such as in the northeastern (Hanna Shoal) and southwestern Chukchi Sea. A notable exception was the occurrence of concentrated foraging in a nearshore area of northwestern Alaska that is apparently depauperate in walrus prey. With increasing sea ice loss, it is likely that walruses will increase their use of coastal haul-outs and nearshore foraging areas, with consequences to the population that are yet to be understood.

  3. Holocene megathermal abrupt environmental changes derived from {sup 14}C dating of a coral reef at Leizhou Peninsula, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Shen Chengde; Yi Weixi E-mail: cdshen@gig.ac.cn; Yu Kefu; Sun Yanmin; Liu Tungsheng; Beer, J.; Hajdas, I.; Bonani, G

    2004-08-01

    A depth profile of a Goniopora coral reef at Leizhou Peninsula, South China Sea, was radiocarbon dated using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The time of formation, during 6600-7400 cal BP, can be divided into nine stages, each terminated by abrupt growth cessation of Goniopora and appearance of Ostrea shells. The results show that, during the Holocene megathermal (8.2-3.3 ka BP), large climatic changes have occurred in the South China Sea area.

  4. Comparative study of SEA experiences between EU and China

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    Strategic Environmental Assessment (SEA) can be a useful tool in the pursuit of achieving sustainable development. It is used to assess the environmental consequences of proposed policies, plans and programmes (PPP) and also ensures that environmental knowledge is integrated at an early stage...... making, such as: How inclusive will the system be in relation to environmental, economic and social indicators? And how can the appropriate aggregation level for indicators be found? This paper makes a comparative study of the experiences of using indicators in SEA in two European countries and China......, in order to investigate the following questions: Are indicators used when performing an assessment? How are they used? Do indicators lead to opportunities or limitations in an evaluation process? And, are they positive or negative in providing information for decision making? Through a review of national...

  5. Are master plans effective in limiting development in China's disaster-prone areas?

    OpenAIRE

    Kim, Saehoon; Rowe, Peter G.

    2013-01-01

    The effectiveness of urban master plans in limiting development in a disaster-prone area of China was empirically investigated by measuring cities’ land-cover changes against their master plans. If a master plan serves as guidance for urban polices that reduce property loss from earthquakes, floods, landslides,land subsidence, and rises in sea level, it will substantially limit urban development in areas at risk from environmental hazards. An environmental risk map weighted toward valuable...

  6. Variation of phytoplankton community structure from the Pearl River estuary to South China Sea.

    Science.gov (United States)

    Jiang, Zhao-Yu; Wang, You-Shao; Cheng, Hao; Sun, Cui-Ci; Wu, Mei-Lin

    2015-10-01

    The Pearl River is located in the northern part of South China Sea. The environment of the Pearl River estuary (PRE) is significantly impacted by nutrients from anthropogenic activities. Along the anthropogenic pollution gradient from the PRE to South China Sea, the phylogenetic diversity and biomass of phytoplankton was examined in relation to physic-chemical variables. The richness of rbcL gene was higher in the open sea than the estuary, while the concentration of chlorophyll a (Chl a) was higher in the estuary than in the open sea. The cluster analysis of the sequences data resulted in seven phytoplankton community types and the dominant species of phytoplankton changed from Cryptophytes and Diatoms to Prymnesiophytes and Diatoms along the gradient. The community structure of phytoplankton was shaped by nutrients and salinity. The phytoplankton biomass was significantly positively affected by phosphorus, nitrite and ammonium (P < 0.01) but negatively by salinity (P < 0.05); the phytoplankton diversity was highly positively affected by salinity (P < 0.05) but negatively by silicate and nitrate (P < 0.01; P < 0.05, respectively). Anthropogenic activities played a critical role in the phytoplankton distribution and biomass of the study area. Further research is necessary to reveal the influence mechanism of environmental factors on the phytoplankton.

  7. Ocean pollution from land-based sources: East China Sea, China.

    Science.gov (United States)

    Li, Daoji; Daler, Dag

    2004-02-01

    The environment of East China Sea (ECS) has been faced by huge stresses from anthropogenic activities and population growth in the Yangtze River drainage basin and the areas along the coasts. Improper use of natural resources and short-term economic objectives have resulted in severe environmental degradation in a fairly short time frame and the degradation has now reached a level where the health and well being of the coastal populations are threatened. The main pollutants are inorganic nitrogen, phosphate, oil hydrocarbons, organic matters and heavy metals. Nutrients cause eutrophication of the coastal waters and the estuarine area and very often stimulate the occurrence of red tides. The environmental pollution of Yangtze River basin directly impact on the state of the marine environment in the ECS. The ecosystem stability is maintained by a steady water discharge from the river, that mixes with the marine salty water in the estuary, and the sediment loads from the river that balance ocean erosion in the delta and its adjacent coastal area. The large-scale water transfer and dam constructions in the Yangtze River basin will change this basis. For the ECS the challenge is to reverse the negative processes taking place and to restore ecosystem balance. The main challenge is to integrate socioeconomic and environmental decision making in order to promote sustainable development. A better understanding of the driving forces in society that cause these environmental pressures is required in order to overcome these obstacles. International cooperation may be an important contributor to the progress and in particular provide access to financial, technological, scientific and human resource assistance.

  8. Regional sea level projections with observed gauge, altimeter and reconstructed data along China coast

    Science.gov (United States)

    Du, L.; Shi, H.; Zhang, S.

    2017-12-01

    Acting as the typical shelf seas in northwest Pacific Ocean, regional sea level along China coasts exhibits complicated and multiscale spatial-temporal characteristics under circumstance of global change. In this paper, sea level variability is investigated with tide gauges records, satellite altimetry data, reconstructed sea surface height, and CMIP simulation fields. Sea level exhibits the interannual variability imposing on a remarkable sea level rising in the China seas and coastal region, although its seasonal signals are significant as the results of global ocean. Sea level exhibits faster rising rate during the satellite altimetry era, nearly twice to the rate during the last sixty years. AVISO data and reconstructed sea surface heights illustrate good correlation coefficient, more than 0.8. Interannual sea level variation is mainly modulated by the low-frequency variability of wind fields over northern Pacific Ocean by local and remote processes. Meanwhile sea level varies obviously by the transport fluctuation and bimodality path of Kuroshio. Its variability possibly linked to internal variability of the ocean-atmosphere system influenced by ENSO oscillation. China Sea level have been rising during the 20th century, and are projected to continue to rise during this century. Sea level can reach the highest extreme level in latter half of 21st century. Modeled sea level including regional sea level projection combined with the IPCC climate scenarios play a significant role on coastal storm surge evolution. The vulnerable regions along the ECS coast will suffer from the increasing storm damage with sea level variations.

  9. Past 140-year environmental record in the northern South China Sea: Evidence from coral skeletal trace metal variations

    International Nuclear Information System (INIS)

    Song, Yinxian; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Shi, Qi; Zhang, Huiling; Ayoko, Godwin A.; Frost, Ray L.

    2014-01-01

    About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986–1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities. -- Highlights: • Geochemical behaviors of trace elements in corals from South China Sea were investigated. • Terrestrial input, SST, war and infrastructure explain about 77.4% of elements behaviors in coral. • Changes of trace elements in coral of Xisha Islands were mainly impacted by local activities. • Spatial change of elements in seawater by was evaluated in 1986–1997 using distribution coefficient K D of coral. -- 140-year changes in the trace metals in corals from South China Sea were investigated. The spatiotemporal change model of the metals in seawater was reconstructed using coral record

  10. Managing potential conflicts in the South China Sea

    International Nuclear Information System (INIS)

    Wisnumurti, N.

    1994-01-01

    The strategic significance of the South China Sea (SCS) is beyond doubt. The four workshops conducted so far have discussed a wide range of issues and areas for possible cooperation, instead of focusing on the factors-sovereignty and territorial claims-for conflict. They have shown the potential for such cooperation. Various proposals offered and the principles enunciated offer sufficient evidence for this. By expanding cooperation on less contentious issues on the basis of common interest and mutual benefit, an atmosphere more conducive to productive negotiations has been created. Such informal meetings and contacts can continue to play an important part in clarifying the issues involved and in furthering the regional marine agenda. These workshops are virtually risk-free for the Governments concerned; in fact, they could benefit from the plethora of proposals and recommendations that have emanated from these endeavours, which have also created a more cooperative environment for dialogue among the SCS States. In sum, the workshop process is a novel approach to conflict prevention and avoidance. Yet some pertinent questions need to be raised. Where do we go from here? Will the numerous proposals and recommendations discussed at length simply be filed? Do the SCS States have the necessary political will to implement them in a spirit of cooperation and compromise? Hence, the issue of formal meetings, institutions and/or mechanisms should now be considered. The role of such structures, possibly modelled on the experience gained by Western Europe and the South Pacific, where agencies have been established for designated areas to act on behalf of the regional States, warrants serious attention. What is called for at this juncture is the concretization of specific cooperative projects of a non-controversial nature. Such endeavours would ultimately lead to a 'sense of community' among the littoral States. However, cooperation for resource exploitation does not appear

  11. Contrasting Photophysiological Characteristics of Phytoplankton Assemblages in the Northern South China Sea.

    Science.gov (United States)

    Jin, Peng; Gao, Guang; Liu, Xin; Li, Futian; Tong, Shanying; Ding, Jiancheng; Zhong, Zhihai; Liu, Nana; Gao, Kunshan

    2016-01-01

    The growth of phytoplankton and thus marine primary productivity depend on photophysiological performance of phytoplankton cells that respond to changing environmental conditions. The South China Sea (SCS) is the largest marginal sea of the western Pacific and plays important roles in modulating regional climate and carbon budget. However, little has been documented on photophysiological characteristics of phytoplankton in the SCS. For the first time, we investigated photophysiological characteristics of phytoplankton assemblages in the northern South China Sea (NSCS) using a real-time in-situ active chlorophyll a fluorometry, covering 4.0 × 105 km2. The functional absorption cross section of photosystem II (PSII) in darkness (σPSII) or under ambient light (σPSII') (A2 quanta-1) increased from the surface to deeper waters at all the stations during the survey period (29 July to 23 August 2012). While the maximum (Fv/Fm, measured in darkness) or effective (Fq'/Fm', measured under ambient light) photochemical efficiency of PSII appeared to increase with increasing depth at most stations, it showed inverse relationship with depth in river plume areas. The functional absorption cross section of PSII changes could be attributed to light-adapted genotypic feature due to niche-partition and the alteration of photochemical efficiency of PSII could be attributed to photo-acclimation. The chlorophyll a fluorometry can be taken as an analog to estimate primary productivity, since areas of higher photochemical efficiency of PSII coincided with those of higher primary productivity reported previously in the NSCS.

  12. Strategic and Operational Implications of Access to the South China Sea to Maintain Regional Peace and Security

    National Research Council Canada - National Science Library

    Nelson, Robert

    2003-01-01

    .... China currently claims all of the South China Sea and is in dispute with other Southeast Asian nation claimants. China's maritime claim Southeast Asia Nuclear Weapons Free Zone, and People's Liberation Army's Navy modernization are aimed at excluding the U.S. Navy for the South China Sea.

  13. A reanalysis dataset of the South China Sea

    Science.gov (United States)

    Zeng, Xuezhi; Peng, Shiqiu; Li, Zhijin; Qi, Yiquan; Chen, Rongyu

    2014-01-01

    Ocean reanalysis provides a temporally continuous and spatially gridded four-dimensional estimate of the ocean state for a better understanding of the ocean dynamics and its spatial/temporal variability. Here we present a 19-year (1992–2010) high-resolution ocean reanalysis dataset of the upper ocean in the South China Sea (SCS) produced from an ocean data assimilation system. A wide variety of observations, including in-situ temperature/salinity profiles, ship-measured and satellite-derived sea surface temperatures, and sea surface height anomalies from satellite altimetry, are assimilated into the outputs of an ocean general circulation model using a multi-scale incremental three-dimensional variational data assimilation scheme, yielding a daily high-resolution reanalysis dataset of the SCS. Comparisons between the reanalysis and independent observations support the reliability of the dataset. The presented dataset provides the research community of the SCS an important data source for studying the thermodynamic processes of the ocean circulation and meso-scale features in the SCS, including their spatial and temporal variability. PMID:25977803

  14. Prediction of South China sea level using seasonal ARIMA models

    Science.gov (United States)

    Fernandez, Flerida Regine; Po, Rodolfo; Montero, Neil; Addawe, Rizavel

    2017-11-01

    Accelerating sea level rise is an indicator of global warming and poses a threat to low-lying places and coastal countries. This study aims to fit a Seasonal Autoregressive Integrated Moving Average (SARIMA) model to the time series obtained from the TOPEX and Jason series of satellite radar altimetries of the South China Sea from the year 2008 to 2015. With altimetric measurements taken in a 10-day repeat cycle, monthly averages of the satellite altimetry measurements were taken to compose the data set used in the study. SARIMA models were then tried and fitted to the time series in order to find the best-fit model. Results show that the SARIMA(1,0,0)(0,1,1)12 model best fits the time series and was used to forecast the values for January 2016 to December 2016. The 12-month forecast using SARIMA(1,0,0)(0,1,1)12 shows that the sea level gradually increases from January to September 2016, and decreases until December 2016.

  15. 50 CFR 648.59 - Sea Scallop Access Areas.

    Science.gov (United States)

    2010-10-01

    ... each year the Elephant Turnk Access Area is open to scallop fishing as a Sea Scallop Access Area... section. LAGC IFQ vessels will be allocated 285,423 lb (129 mt) in fishing year 2010, which is 5 percent..., LAGC scallop vessels are allocated 714 trips to the Delmarva Access Area in fishing year 2010. This...

  16. Chinese Grand Strategy: How Anti-Access/Area Denial (A2/AD) Fits in China’s Plan

    Science.gov (United States)

    2014-04-01

    ensuing global depression . An electro-magnetic pulse (EMP) attack, from an ICBM, long range cruise missile, or satellite, detonated 400km over the U.S...Philippines, Malaysia , and Brunei all actively disputing some area of the South China Sea. There are several reasons for the intense competition as the area

  17. ANALYSIS OF LOW-FREQUENCY OSCILLATIONS FOR THE SOUTH CHINA SEA SUMMER MONSOON IN 1998

    Institute of Scientific and Technical Information of China (English)

    徐国强; 朱乾根

    2003-01-01

    With NCEP/NCAR reanalysis daily data and SST for 1998, the paper investigates the features of summer monsoon low-frequency oscillation (LFO) over the South China Sea (SCS). Results show that SCS summer monsoon onset is enhanced because of its LFO. Low-frequency (LF) low-level convergence (divergence) region of SCS is in the LF positive (negative) rainfall area. LFO of the SCS region migrates from south to north in the meridian and from west to east in zonal direction. LF divergence of SCS is vertically compensating to each other between high and low level.

  18. Population genetic structure of the mantis shrimp Oratosquilla oratoria (Crustacea: Squillidae) in the Yellow Sea and East China Sea

    Science.gov (United States)

    Yang, Mei; Li, Xinzheng

    2017-09-01

    The mantis shrimp Oratosquilla oratoria is an ecologically and economically important species in the Western Pacific. In present study, the population genetic structure of Oratosquilla oratoria from the Yellow Sea and East China Sea was examined with mitochondrial DNA control region sequences. In total, 394 samples were collected from 18 locations and 102 haplotypes were obtained. For the Yellow Sea, the overall nucleotide diversity and haplotype diversity were 0.006 9 and 0.946 8, respectively; while across all the East China Sea locations, the overall nucleotide diversity and haplotype diversity were 0.027 94 and 0.979 0, respectively. The results of AMOVA and pairwise F ST (0.145 2, P China Sea populations of O. oratoria. However, neither the neighbor-joining tree nor haplotype network showed clades with geographic pattern, which indicated considerable gene flow was existed between the Yellow Sea and East China Sea, and supporting the high larval dispersal ability in this species. Mismatch distribution analysis and neutrality tests suggested that O. oratoria has undergone population expansion event, and the Pleistocene glacial cycles might have an impact on the historical demography of O. oratoria. The genetic information obtained in this study can provide useful information for sustainable improvements for capture fisheries management strategies.

  19. Impacts of typhoon megi (2010) on the South China Sea

    Science.gov (United States)

    Ko, Dong Shan; Chao, Shenn-Yu; Wu, Chun-Chieh; Lin, I.-I.

    2014-07-01

    In October 2010, typhoon Megi induced a profound cold wake of size 800 km by 500 km with sea surface temperature cooling of 8°C in the South China Sea (SCS). More interestingly, the cold wake shifted from the often rightward bias to both sides of the typhoon track and moved to left in a few days. Using satellite data, in situ measurements and numerical modeling based on the East Asian Seas Nowcast/Forecast System (EASNFS), we performed detailed investigations. To obtain realistic typhoon-strength atmospheric forcing, the EASNFS applied typhoon-resolving Weather Research and Forecasting (WRF) model wind field blended with global weather forecast winds from the U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS). In addition to the already known impacts from the slow typhoon translation speed and shallow pre-exiting ocean thermocline, we found the importance of the unique geographical setting of the SCS and the NE monsoon. As the event happened in late October, NE monsoon already started and contributed to the southwestward ambient surface current. Together with the topographicβ effect, the cold wake shifted westward to the left of Megi's track. It was also found that Megi expelled waters away from the SCS and manifested as a gush of internal Kelvin wave exporting waters through the Luzon Strait. The consequential sea level depression lasted and presented a favorable condition for cold dome development. Fission of the north-south elongated cold dome resulted afterward and produced two cold eddies that dissipated slowly thereafter.

  20. Seasonal fluctuations of ichthyoplankton assemblage in the northeastern South China Sea influenced by the Kuroshio intrusion

    Science.gov (United States)

    Huang, Delian; Zhang, Xia; Jiang, Zhijian; Zhang, Jingping; Arbi, Iman; Jiang, Xin; Huang, Xiaoping; Zhang, Wenjing

    2017-09-01

    The distribution and assemblage of ichthyoplankton related to local hydrographic features, especially intrusion of the Kuroshio Current (KC) and Guangdong Coastal Current (GCC) in the northeastern South China Sea (NESCS) were investigated in this study. A total of 193 species of ichthyoplankton belonging to 141 genera and 66 families were recognized in summer 2015 and late-winter 2016. The ichthyoplankton assemblage was identified with distinct seasonal differences, and the differences were responded well with the oceanography conditions. In summer, the assemblages were identified into offshore and inshore groups, as controlled by the South China Sea Warm Current (SCSWC) in off-shelf, upwelling, and the diluted water from the Pearl River in inshore. In winter, three groups were divided, representing the southwestern inshore, intrusion of the KC in the eastern offshore, and the GCC in the northern inshore area, respectively. Furthermore, Sigmops gracilis and Vinciguerria sp.3 were probably brought into the NESCS by intrusion of the KC from the eastern Luzon Strait. In addition, high ichthyoplankton abundance was found in high chlorophyll a located in upwelling areas in the northern coastal area in summer and in the southwestern Taiwan Bank in winter, respectively. The nutrition outcropped by the upwelling together, and those brought from the Pearl River probably supported high food availability of the ichthyoplankton in the northern coast of the NESCS.

  1. Assessment for water quality by artificial neural network in Daya Bay, South China Sea.

    Science.gov (United States)

    Wu, Mei-Lin; Wang, You-Shao; Gu, Ji-Dong

    2015-10-01

    In this study, artificial neural network such as a self-organizing map (SOM) was used to assess for the effects caused by climate change and human activities on the water quality in Daya Bay, South China Sea. SOM has identified the anthropogenic effects and seasonal characters of water quality. SOM grouped the four seasons as four groups (winter, spring, summer and autumn). The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on the water quality in Daya Bay. Spatial pattern is mainly related to anthropogenic activities and hydrodynamics conditions. In spatial characteristics, the water quality in Daya Bay was divided into two groups by chemometrics. The monitoring stations (S3, S8, S10 and S11) were in these area (Dapeng Ao, Aotou Harbor) and northeast parts of Daya Bay, which are areas of human activity. The thermal pollution has been observed near water body in Daya Bay Nuclear Power Plant (S5). The rest of the monitoring sites were in the south, central and eastern parts of Daya Bay, which are areas that experience water exchanges from South China Sea. The results of this study may provide information on the spatial and temporal patterns in Daya Bay. Further research will be carry out more research concerning functional changes in the bay ecology with respect to changes in climatic factor, human activities and bay morphology in Daya Bay.

  2. Variability of thermohaline fields in the East China Sea

    Science.gov (United States)

    Moroz, V. V.; Bogdanov, K. T.

    2007-04-01

    Characteristic features of the water structure and dynamics in the East China Sea, which is the zone of the formation of the Kuroshio Current, are studied from a database of mean multiannual hydrological and meteorological characteristics gathered for more than a half-century period and the data of expeditionary observations in this region. Characteristic distinctions between the waters in different regions of the current zone are shown. It was found that the formation of the structure of the water in the current zone is affected by the variability of the water exchange via the straits of the Ryukyu Islands and by the supply of the shelf waters against the background of the climatic variability.

  3. Trends in significant wave height and surface wind speed in the China Seas between 1988 and 2011

    Science.gov (United States)

    Zheng, Chongwei; Zhang, Ren; Shi, Weilai; Li, Xin; Chen, Xuan

    2017-10-01

    Wind and waves are key components of the climate system as they drive air-sea interactions and influence weather systems and atmospheric circulation. In marine environments, understanding surface wind and wave fields and their evolution over time is important for conducting safe and efficient human activities, such as navigation and engineering. This study considers long-term trends in the sea surface wind speed (WS) and significant wave height (SWH) in the China Seas over the period 1988-2011 using the Cross-Calibrated Multi-Platform (CCMP) ocean surface wind product and a 24-year hindcast wave dataset obtained from the WAVEWATCH-III (WW3) wave model forced with CCMP winds. The long-term trends in WS and SWH in the China Seas are analyzed over the past 24 years to provide a reference point from which to assess future climate change and offshore wind and wave energy resource development in the region. Results demonstrate that over the period 1988-2011 in the China Seas: 1) WS and SWH showed a significant increasing trend of 3.38 cm s-1 yr-1 and 1.52 cm yr-1, respectively; 2) there were notable regional differences in the long-term trends of WS and SWH; 3) areas with strong increasing trends were located mainly in the middle of the Tsushima Strait, the northern and southern areas of the Taiwan Strait, and in nearshore regions of the northern South China Sea; and 4) the long-term trend in WS was closely associated with El Niño and a significant increase in the occurrence of gale force winds in the region.

  4. Indonesia in the South China Sea Dispute: Humble-Hard Power

    OpenAIRE

    Robertua, Verdinand; Sinaga, Obsatar

    2018-01-01

    This research discussed the opportunities for Indonesia to act as humble-hard power in South China Sea dispute. Permanent Court of Arbitration’s decision in July 2016 to give South China Sea based on UNCLOS’s regulation has provoked China’s objection. This research question is on how to understand the conception of humble-hard power and the possibility for Indonesia to be humble-hard power in the South China Sea dispute? This article borrowed the concept of humble-hard power from Adam Nieves ...

  5. The TKE dissipation rate in the northern South China Sea

    Science.gov (United States)

    Lozovatsky, Iossif; Liu, Zhiyu; Fernando, Harindra Joseph S.; Hu, Jianyu; Wei, Hao

    2013-12-01

    The microstructure measurements taken during the summer seasons of 2009 and 2010 in the northern South China Sea (between 18°N and 22.5°N, and from the Luzon Strait to the eastern shelf of China) were used to estimate the averaged dissipation rate in the upper pycnocline of the deep basin and on the shelf. Linear correlation between and the estimates of available potential energy of internal waves, which was found for this data set, indicates an impact of energetic internal waves on spatial structure and temporal variability of . On the shelf stations, the bottom boundary layer depth-integrated dissipation reaches 17-19 mW/m2, dominating the dissipation in the water column below the surface layer. In the pycnocline, the integrated dissipation was mostly ˜10-30 % of . A weak dependence of bin-averaged dissipation on the Richardson number was noted, according to , where ɛ 0 + ɛ m is the background value of for weak stratification and Ri cr = 0.25, pointing to the combined effects of shear instability of small-scale motions and the influence of larger-scale low frequency internal waves. The latter broadly agrees with the MacKinnon-Gregg scaling for internal-wave-induced turbulence dissipation.

  6. Ross sea ice motion, area flux, and deformation

    Science.gov (United States)

    kwok, Ron

    2005-01-01

    The sea ice motion, area export, and deformation of the Ross Sea ice cover are examined with satellite passive microwave and RADARSAT observations. The record of high-resolution synthetic aperture radar (SAR) data, from 1998 and 2000, allows the estimation of the variability of ice deformation at the small scale (10 km) and to assess the quality of the longer record of passive microwave ice motion. Daily and subdaily deformation fields and RADARSAT imagery highlight the variability of motion and deformation in the Ross Sea. With the passive microwave ice motion, the area export at a flux gate positioned between Cape Adare and Land Bay is estimated. Between 1992 and 2003, a positive trend can be seen in the winter (March-November) ice area flux that has a mean of 990 x 103 km2 and ranges from a low of 600 x 103 km2 in 1992 to a peak of 1600 x 103 km2 in 2001. In the mean, the southern Ross Sea produces almost twice its own area of sea ice during the winter. Cross-gate sea level pressure (SLP) gradients explain 60% of the variance in the ice area flux. A positive trend in this gradient, from reanalysis products, suggests a 'spinup' of the Ross Sea Gyre over the past 12 yr. In both the NCEP-NCAR and ERA-40 surface pressure fields, longer-term trends in this gradient and mean SLP between 1979 and 2002 are explored along with positive anomalies in the monthly cross-gate SLP gradient associated with the positive phase of the Southern Hemisphere annular mode and the extrapolar Southern Oscillation.

  7. Mercury in the marine boundary layer and seawater of the South China Sea: Concentrations, sea/air flux, and implication for land outflow

    Science.gov (United States)

    Fu, Xuewu; Feng, Xinbin; Zhang, Gan; Xu, Weihai; Li, Xiangdong; Yao, Hen; Liang, Peng; Li, Jun; Sommar, Jonas; Yin, Runsheng; Liu, Na

    2010-03-01

    Using R/V Shiyan 3 as a sampling platform, measurements of gaseous elemental mercury (GEM), surface seawater total mercury (THg), methyl mercury (MeHg), and dissolved gaseous mercury (DGM) were carried out above and in the South China Sea (SCS). Measurements were collected for 2 weeks (10 to 28 August 2007) during an oceanographic expedition, which circumnavigated the northern SCS from Guangzhou (Canton), Hainan Inland, the Philippines, and back to Guangzhou. GEM concentrations over the northern SCS ranged from 1.04 to 6.75 ng m-3 (mean: 2.62 ng m-3, median: 2.24 ng m-3). The spatial distribution of GEM was characterized by elevated concentrations near the coastal sites adjacent to mainland China and lower concentrations at stations in the open sea. Trajectory analysis revealed that high concentrations of GEM were generally related to air masses from south China and the Indochina peninsula, while lower concentrations of GEM were related to air masses from the open sea area, reflecting great Hg emissions from south China and Indochina peninsula. The mean concentrations of THg, MeHg, and DGM in surface seawater were 1.2 ± 0.3 ng L-1, 0.12 ± 0.05 ng L-1, and 36.5 ± 14.9 pg L-1, respectively. In general, THg and MeHg levels in the northern SCS were higher compared to results reported from most other oceans/seas. Elevated THg levels in the study area were likely attributed to significant Hg delivery from surrounding areas of the SCS primarily via atmospheric deposition and riverine input, whereas other sources like in situ production by various biotic and abiotic processes may be important for MeHg. Average sea/air flux of Hg in the study area was estimated using a gas exchange method (4.5 ± 3.4 ng m-2 h-1). This value was comparable to those from other coastal areas and generally higher than those from open sea environments, which may be attributed to the reemission of Hg previously transported to this area.

  8. Levels of endocrine disrupting compounds in South China Sea.

    Science.gov (United States)

    Zhang, Li-Peng; Wang, Xin-Hong; Ya, Miao-Lei; Wu, Yu-Ling; Li, Yong-Yu; Zhang, Zu-lin

    2014-08-30

    The occurrence of estrogens in the aquatic environment has become a major concern worldwide because of their strong endocrine disrupting potency. In this study, concentrations of four estrogenic compounds, estrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), estriol (E3) were determined with liquid chromatography-tandem mass spectrometry analyses in surface water from South China Sea, and distributions and potential risks of their estrogenic activity were assessed. The estrogenic compounds E1, E2 and E3 were detected in most of the samples, with their concentrations up to 11.16, 3.71 and 21.63 ng L(-1). However, EE2 was only detected in 3 samples. Causality analysis, EEQ values from chemical analysis identified E2 as the main responsible compounds. Based on the EEQ values in the surface water, high estrogenic risks were in the coastal water, and low estrogenic risks in the open sea. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  9. Past 140-year environmental record in the northern South China Sea: evidence from coral skeletal trace metal variations.

    Science.gov (United States)

    Song, Yinxian; Yu, Kefu; Zhao, Jianxin; Feng, Yuexing; Shi, Qi; Zhang, Huiling; Ayoko, Godwin A; Frost, Ray L

    2014-02-01

    About 140-year changes in the trace metals in Porites coral samples from two locations in the northern South China Sea were investigated. Results of PCA analyses suggest that near the coast, terrestrial input impacted behavior of trace metals by 28.4%, impact of Sea Surface Temperature (SST) was 19.0%, contribution of war and infrastructure were 14.4% and 15.6% respectively. But for a location in the open sea, contribution of War and SST reached 33.2% and 16.5%, while activities of infrastructure and guano exploration reached 13.2% and 14.7%. While the spatiotemporal change model of Cu, Cd and Pb in seawater of the north area of South China Sea during 1986-1997 were reconstructed. It was found that in the sea area Cu and Cd contaminations were distributed near the coast while areas around Sanya, Hainan had high Pb levels because of the well-developed tourism related activities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Climatic anomalies in Northern South China Sea during 1986-1987 El Nino

    Energy Technology Data Exchange (ETDEWEB)

    Chen Tegu (Academia Sinica, Beijing (China)); Zhou Qiang

    1990-05-01

    In this paper, the climatic anomalies in Northern South China Sea (NSCS) during 1986-1987 El Nino were analyzed according to meteorological and hydrographic observation data. The results showed that the most apparent anomalies were: (1) continuously weaker monsoon strength, (2) continuously much higher South China Sea High Pressure strength; (3) in 1987 only six typhoons occurred in NSCS (four less than normal), with the first typhoon occurring on 25 June, (about one month later than usual); (4) positive air temperature anomaly, negative annual precipitation and evaporation anomaly; (5) sea surface temperature and surface salinity anomaly was positive; (6) monthly mean sea level was 1 to 10cm lower than normal.

  11. ASSESSMENT OF POTENTIAL TSUNAMI GENERATION IN CHINA'S BOHAI SEA FROM DIRECT GEOTECTONIC AND COLLATERAL SOURCE MECHANISMS

    Directory of Open Access Journals (Sweden)

    G. Pararas Carayannis

    2009-01-01

    Full Text Available The Bohai Sea borders northeastern China's most populous and highest economic valuecoastal areas where several megacities are located. Critical infrastructure facilities exist or areunder construction, including a nuclear power plant and super port facilities. Large reserves of oilhave been discovered and a number of offshore oil platforms have been built. The extent ofdevelopment along coastal areas requires a better assessment of potential tsunami risks. Althoughtsunamis do not pose as much of a threat as earthquakes in this region, locally destructive tsunamishave been generated in the past and future events could have significant impacts on coastalpopulations and China's economy, particularly because most of the development has taken place inlow-lying regions, including river deltas. The present study examines the geotectonics of the Bohaibasin region, the impact of past historical events, and the potential for local tsunami generationfrom a variety of direct and collateral source mechanisms triggered by intra plate earthquakes.More specifically, the present study examines: amajor active faults bounding the Bohai Basin; bthe resulting crustal deformation patterns of tectonic structures that have resulted in catastrophicearthquakes in recent years; c the basin-wide extension - with local inversion - extending into theBohai Sea that generated tsunamigenic earthquakes in 1888 and 1969; and d deformational futureseismic events with the potential to generate local tsunamis directly or by collateral mechanisms offolding, en-echelon bookshelf failures, or from destabilization/dissociation of structuralaccumulations of gas hydrate deposits within the basin's thick sedimentary stratigraphic layers.

  12. Intrusions of Kuroshio and Shelf Waters on Northern Slope of South China Sea in Summer 2015

    Science.gov (United States)

    Li, Denghui; Zhou, Meng; Zhang, Zhaoru; Zhong, Yisen; Zhu, Yiwu; Yang, Chenghao; Xu, Mingquan; Xu, Dongfeng; Hu, Ziyuan

    2018-06-01

    The northern slope region of the South China Sea (SCS) is a biological hot spot characterized by high primary productivity and biomasses transported by cross-shelf currents, which support the spawning and growth of commercially and ecologically important fish species. To understand the physical and biogeochemical processes that promote the high primary production of this region, we conducted a cruise from June 10 and July 2, 2015. In this study, we used fuzzy cluster analysis and optimum multiparameter analysis methods to analyze the hydrographic data collected during the cruise to determine the compositions of the upper 55-m water masses on the SCS northern slope and thereby elucidate the cross-slope transport of shelf water (SHW) and the intrusions of Kuroshio water (KW). We also analyzed the geostrophic currents derived from acoustic Doppler current profiler measurements and satellite data. The results reveal the surface waters on the northern slope of the SCS to be primarily composed of waters originating from South China Sea water (SCSW), KW, and SHW. The SCSW dominated a majority of the study region at percentages ranging between 60% and 100%. We found a strong cross-slope current with speeds greater than 50 cm s-1 to have carried SHW into and through the surveyed slope area, and KW to have intruded onto the slope via mesoscale eddies, thereby dominating the southwestern section of the study area.

  13. Occurrence and distribution of conventional and new classes of per- and polyfluoroalkyl substances (PFASs) in the South China Sea.

    Science.gov (United States)

    Kwok, Karen Y; Wang, Xin-Hong; Ya, Miaolei; Li, Yongyu; Zhang, Xiao-Hua; Yamashita, Nobuyoshi; Lam, James C W; Lam, Paul K S

    2015-03-21

    Concentrations of 23 per- and polyfluoroalkyl substances (PFASs), including new classes of PFASs, in seawater samples were investigated for their occurrence and the interaction of the ocean currents with the distribution of PFASs in the South China Sea. This study revealed that socio-economic development was associated with the PFAS contamination in coastal regions of South China. Significant correlations between concentration of total PFASs with gross domestic product (GDP) per capita and population density were found in the areas, suggesting that the influence of intense human activities in these areas may have resulted in higher PFAS contamination to the adjacent environment. Di-substituted polyfluoroalkyl phosphate (diPAP), one of the potential replacements for PFASs, was only detected in the heavily developed region, namely Pearl River Delta (PRD). Total PFAS concentrations, ranging from 195 to 4925 pg/L, were detected at 51 sampling stations of the South China Sea. The results also confirmed that PFAS contamination in the South China Sea is strongly affected by the ocean currents. In comparison to perfluoroactane sulfonate (PFOS) concentrations measured nine years ago at the same locations, the concentrations in this study were found to be two times higher. This indicated that the use and production of perfluoroalkyl sulfonates (PFSAs) has been continuing in the region. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Detection and temporal variation of 60Co in the digestive glands of the common octopus, Octopus vulgaris, in the East China Sea

    International Nuclear Information System (INIS)

    Morita, Takami; Otosaka, Shigeyoshi; Fujimoto, Ken; Nishiuchi, Kou; Kimoto, Katsunori; Yamada, Haruya; Kasai, Hiromi; Minakawa, Masayuki; Yoshida, Katsuhiko

    2010-01-01

    60 Co were detected in common octopus specimens collected in the East China Sea in 1996-2005. The source of 60 Co has remained unclear yet. Stable isotope analyses showed that there was no difference in stable Co concentrations between octopus samples with 60 Co and without 60 Co. This result showed that the stable Co in the digestive gland of octopus potentially did not include a trace amount of 60 Co and the source of 60 Co existed independently. Furthermore, investigations of octopus in other area and other species indicated that the origin of the source of 60 Co occurred locally in the restricted area in the East China Sea and not in the coastal area of Japan. Concentrations of 60 Co have annually decreased with shorter half-life than the physical half-life. This decrease tendency suggests that the sources of 60 Co were identical and were temporary dumped into the East China Sea as a solid waste.

  15. Chemical and temperature profile data from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean (NODC Accession 9700022)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Chemical and temperature profile data were collected from CTD casts in the East China Sea, Sea of Japan, and North Pacific Ocean. Data were submitted by the Japan...

  16. Distribution, historical trends and inventories of polychlorinated biphenyls in sediments from Yangtze River Estuary and adjacent East China Sea

    International Nuclear Information System (INIS)

    Yang Huayun; Zhuo Shanshan; Xue Bin; Zhang Chunlong; Liu Weiping

    2012-01-01

    A large portion of polychlorinated biphenyls (PCBs) from e-waste released into the coastal areas may be the potential source of PCBs to the global oceans. The paper presents data of PCBs concentrations in fifty surface sediment samples and a dated sediment core in Yangtze River Delta (YRE) and adjacent East China Sea (ECS). The total PCBs levels varied from 5.08 to 19.64 ng/g dry weight, with the highest concentrations situate within the river-sea boundary zone which is so-called “marginal filter”. Concurrent with the operation of e-waste recycling over the last two decades, PCB fluxes started to rise again after 1980s and reached a maximum in this century. The full data set was used to estimate the burden of PCBs in YRE and adjacent ECS. A total sediment burdens were 192.8 tons, with the spatial density of 364 ng/cm 2 which accounts for 1.9% of all the PCBs in China. - Highlights: ► PCBs residues remained widespread in Yangtze River Delta and adjacent East China Sea. ► Highest PCBs concentrations situate within the river-sea boundary zone. ► Congener profiles and PCA highlight the influence of e-waste recycling. ► Temporal distributions indicated PCB fluxes reached a maximum in this century. ► Total sediment burdens accounts for 1.9 % of all the PCBs in China. - Spatial and temporal distributions of polychlorinated biphenyls have been delineated in sediments from Yangtze River Estuary and adjacent East China Sea.

  17. Impact of sea spray on the Yellow and East China Seas thermal structure during the passage of Typhoon Rammasun (2002)

    Science.gov (United States)

    Zhang, Lianxin; Zhang, Xuefeng; Chu, P. C.; Guan, Changlong; Fu, Hongli; Chao, Guofang; Han, Guijun; Li, Wei

    2017-10-01

    Strong winds lead to large amounts of sea spray in the lowest part of the atmospheric boundary layer. The spray droplets affect the air-sea heat fluxes due to their evaporation and the momentum due to the change of sea surface, and in turn change the upper ocean thermal structure. In this study, impact of sea spray on upper ocean temperatures in the Yellow and East China Seas (YES) during typhoon Rammasun's passage is investigated using the POMgcs ocean model with a sea spray parameterization scheme, in which the sea spray-induced heat fluxes are based on an improved Fairall's sea spray heat fluxes algorithm, and the sea spray-induced momentum fluxes are derived from an improved COARE version 2.6 bulk model. The distribution of the sea spray mediated turbulent fluxes was primarily located at Rammasun eye-wall region, in accord with the maximal wind speeds regions. When Rammasun enters the Yellow sea, the sea spray mediated latent (sensible) heat flux maximum is enhanced by 26% (13.5%) compared to that of the interfacial latent (sensible) heat flux. The maximum of the total air-sea momentum fluxes is enhanced by 43% compared to the counterpart of the interfacial momentum flux. Furthermore, the sea spray plays a key role in enhancing the intensity of the typhoon-induced "cold suction" and "heat pump" processes. When the effect of sea spray is considered, the maximum of the sea surface cooling in the right side of Rammasun's track is increased by 0.5°C, which is closer to the available satellite observations.

  18. China and the United Nations Convention on the Law of the Sea: Operational Challenges

    National Research Council Canada - National Science Library

    Vincent, Steven D

    2005-01-01

    ...), and has made maritime claims citing historic waters. China asserts that these actions are consistent with the provisions of the United Nations Convention On The Law Of the Sea (UNCLOS) Treaty...

  19. Recent Seismic Experiments of OBS in the South China Sea

    Science.gov (United States)

    Ruan, A.; Li, J.; Wu, Z.

    2012-12-01

    Since 2006 some research institutions of China have carried out some important seismic experiments by using ocean bottom seismometer(OBS) in the South China Sea (SCS) and obtained many concrete progresses in modeling the crustal structure of SCS and also in understanding of its formation and evolution as well. In 2006 three wide-angle profiles were completed in the northern margin, named OBS2006-1 across the northwestern sub-basin, OBS2006-2 parallel to the sea basin boundary and OBS2006-3 across the Dongsha Rise and Chaoshan Depression respectively. In 2010 two wide- angle profiles were completed, named OBS2010-1 and OBS 2010-2 both perpendicular to the northern off-shore faulting system. During 2009-2011 four wide-angle profiles were completed in the southern margin, named OBS973-1 from southern margin to the southwestern sub-basin, OBS973-2 from Liyue Bank to the southwestern sub-basin and OBS973-3 from Xisha to the southwestern sub-basin, OBS2011-2 from Xisha to Hainan Island respectively. In 2011 two 3D seismic array of OBS were completed in the Zhongnan-Changlong sea mount chain and Huangyan-Zhenbei sea mount chain respectively. Here we present some primary but important results as follows. (1) The velocity model of OBS2006-1 indicates that the crust under the continental slope decreases from 21km to 11km, and to 7.7km in the northwestern sub-basin with Moho depth ascends from 21km to 11km. The tectonic geometry and velocity structure of the northwestern sub-basin and its margins on both sides shows symmetrical and conjugate and indicates pure shear mode of continental margin rifting mechanism. (2) The velocity model of OBS2006-3 reveals remarkable thickness with maximum 8 km of the Mesozoic sediment in Chaoshan Depression in which velocity increases downward from 4.4 km/s at top to 5.3 km/s at the bottom. The buried depth of Moho decreases from 24-25 km under Dongsha Rise to 17 km in the lower slope and an obviously velocity abnormal is detected in the upper

  20. Significant breakthrough in proprietary deepwater natural gas exploration in the northern South China Sea and its inspiration

    Directory of Open Access Journals (Sweden)

    Yuhong Xie

    2014-12-01

    Full Text Available In 2014, Zhanjiang Branch of CNOOC Limited obtained high oil and gas flows (160 × 104 m3/d in Well LS 17-2-1 in northern South China Sea. The tested formation is the Neogene Upper Miocene Huangliu Fm. This is the first self-explored natural gas field in deep water area in China. Exploration in this area underwent three periods: (1 Reconnaissance exploration period (before 2002: Limited by techniques, the major exploration was in shallow water areas; (2 Foreign cooperative exploration period (2002–2012: As the discovered reserve scale was small, and there is no economic benefit, the partners successively gave up their exploration equities in the deep water area of western South China Sea; however, the high quality source rocks and reservoirs were confirmed in the deep water area of the South China Sea, revealing the mask of hydrocarbon exploration in this region; (3 Self-exploration period (since 2013: Relying on national science and technology major projects and its scientific research and production, Zhanjiang Company of CNOOC conducted several scientific researches on seismic data acquisition and processing, high-quality reservoir distribution, key factors for hydrocarbon accumulation in deep water areas, optimized and confirmed Lingshui 17-2 structure as the first drilling target, and obtained significant exploration breakthrough. Lingshui 17-2 structure is located in the Ledong-Lingshui section of the Central Canyon. Its major target layer is the Huangliu Fm. Its total thickness is over 150 m, with sandstone ratio of 75.4%, maximum single layer thickness of 52 m, porosity ranging 30.0%–33.7% (31.5% averagely, permeability ranging 293–2512 mD (633 mD averagely, belonging to reservoir with ultrahigh porosity and high-ultrahigh permeability. The exploration breakthrough in Lingshui 17-2 shows the giant potentiality of hydrocarbon exploration in this deep water area.

  1. Comparison of two Centennial-scale Sea Surface Temperature Datasets in the Regional Climate Change Studies of the China Seas

    Science.gov (United States)

    Qingyuan, Wang; Yanan, Wang; Yiwei, Liu

    2017-08-01

    Two widely used sea surface temperature (SST) datasets are compared in this article. We examine characteristics in the climate variability of SST in the China Seas.Two series yielded almost the same warming trend for 1890-2013 (0.7-0.8°C/100 years). However, HadISST1 series shows much stronger warming trends during 1961-2013 and 1981-2013 than that of COBE SST2 series. The disagreement between data sets was marked after 1981. For the hiatus period 1998-2013, the cooling trends of HadISST1 series is much lower than that of COBE SST2. These differences between the two datasets are possibly caused by the different observations which are incorporated to fill with data-sparse regions since 1982. Those findings illustrate that there are some uncertainties in the estimate of SST warming patterns in certain regions. The results also indicate that the temporal and spatial deficiency of observed data is still the biggest handicap for analyzing multi-scale SST characteristics in regional area.

  2. Cloud amount/frequency, NITRATE and other data from STRANGER, AKADEMIK ALEKSANDR NESMEYANOV and other platforms in the South China Sea from 1947-12-07 to 1988-03-08 (NODC Accession 9200011)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Serial data in this accession was collected in South China Sea (Nan Hai), TOGA Area - Pacific (30 N to 30 S) as part of Tropical Ocean Global Atmosphere...

  3. Hydrological, plankton and pigment observations in the South China Sea (C.S.K. Program, Cruise II) and around Seribu Islands by R.V. Jalanidhi, December 6-December 28, 1971 (NODC Accession 7300974)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hydrological, plankton and pigment observations from the R.V. JALANIDHI in the South China Sea and other areas. Data were collected from 06 December 1971 to 28...

  4. Environmental assessment of rosetta area,mediterranean sea coast - egypt

    International Nuclear Information System (INIS)

    Aly, A.M.A.

    2013-01-01

    This study is titled (Environmental Assessment of Rosetta Area,Mediterranean Sea Coast, Egypt). The environmental assessment can be defined here as the process of assessing the potential impacts (positive or negative) of the presence of certain influential on a particular ecosystem. Samples were collected from Abu Khashaba beach area, Rosetta on the Mediterranean Sea coast. Samples of the beach sediments, sea-water and the scattered shells in this coastal region were collected. Sediments in this region are characterized by its large content of heavy metals, which added to these sediments its black color. It is known that these black sands occurred along the Mediterranean Sea coast from Alexandria to Rafah. The advantage of these black sand deposits is their contents from multiple economic metals which have important industrial uses, such as magnetite, ilmenite, rutile, monazite, zircon, garnet and other important minerals. Ten sampling profiles spaced in-between by about 600 m distance, and extending into the land from the shoreline for about 50 m or less. Along each profile, three sediment samples were collected; the first sample from the surface at the beach line, the second sample from the end of the foreshore area at a depth of about 50 cm and the third sample was taken from the backshore area at a depth of about 1 m. Extending from each profile into the sea, marine-water samples were taken at a distance of about 3 m from the beach line, and from a depth of about 1 m below the sea surface. The shells samples were collected from the scattered shells on the beach. By examination of these samples a 15 different shells types were defined.

  5. Tides and Their Dynamics over the Sunda Shelf of the Southern South China Sea.

    Science.gov (United States)

    Daryabor, Farshid; Ooi, See Hai; Abu Samah, Azizan; Akbari, Abolghasem

    2016-01-01

    A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performed on the inner domain. The model is forced at the sea surface by climatological monthly mean wind stress, freshwater (evaporation minus precipitation), and heat fluxes. Momentum and tracers (such as temperature and salinity) are prescribed in addition to the tidal heights and currents extracted from the Oregon State University TOPEX/Poseidon Global Inverse Solution (TPXO7.2) at the open boundaries. The results are validated against observed tidal amplitudes and phases at 19 locations. Results show that the mean average power energy spectrum (in unit m2/s/cph) for diurnal tides at the southern end of the East Coast of Peninsular Malaysia is approximately 43% greater than that in the East Malaysia region located in northern Borneo. In contrast, for the region of northern Borneo the semidiurnal power energy spectrum is approximately 25% greater than that in the East Coast of Peninsular Malaysia. This implies that diurnal tides are dominant along the East Coast of Peninsular Malaysia while both diurnal and semidiurnal tides dominate almost equally in coastal East Malaysia. Furthermore, the diurnal tidal energy flux is found to be 60% greater than that of the semidiurnal tides in the southern South China Sea. Based on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area.

  6. Five Sarsiellidae ostracods (Crustacea: Myodocopida) from the South Coast of Korea (East China Sea).

    Science.gov (United States)

    Karanovic, Ivana; Soh, Ho-Young

    2015-04-17

    The East China Sea is part of the Warm Temperate Northwest Pacific zoogeographic province and, as such, has a high biodiversity and many tropical and subtropical biotic elements. Nevertheless, many invertebrate groups from this area remain poorly studied. Ostracods are one of them, especially those belonging to the subclass Myodocopa. In this paper we provide the first data on a diverse myodocopid family, Sarsiellidae, not only for the East China Sea, but also for Korea. Five species are reported in this paper from three Korean islands (Jeju, Chuja, and Maemul), and they are only a part of the ostracods collected during this study, indicating a high diversity of the group in this region. Three new species, Eurypylus koreanus sp. nov., Eusarsiella hanguk sp. nov., and Sarsiella nereis sp. nov., clearly stand apart from their respective congeners, mostly by prominent shell characters but also by details of the soft part morphology. Their affinity though clearly indicates a close connection of the region with the more southern zoogeographical realms, especially Central Indo Pacific and partly Temperate Australasia. Two species previously known from Japan (north part of the Sea of Japan and southeastern part of the Pacific Coast of Japan), Sarsiella japonica Hiruta, 1977 and S. misakiensis Kajiyama, 1912, are redescribed. Based on 11 newly obtained COI sequences we construct a preliminary phylogenetic tree, which supports previous hypotheses based on the morphological data, that Eusarsiella Cohen & Kornicker, 1975 is a polyphyletic taxon. With the maps of species distribution provided for each of the three genera, we give an overview of their current zoogeography, and clearly indicate areas that have no data, mostly due to the lack of investigation.

  7. Distributions and sea-to-air fluxes of chloroform, trichloroethylene, tetrachloroethylene, chlorodibromomethane and bromoform in the Yellow Sea and the East China Sea during spring

    International Nuclear Information System (INIS)

    He, Zhen; Yang, Gui-Peng; Lu, Xiao-Lan; Zhang, Hong-Hai

    2013-01-01

    Halocarbons including chloroform (CHCl 3 ), trichloroethylene (C 2 HCl 3 ), tetrachloroethylene (C 2 Cl 4 ), chlorodibromomethane (CHBr 2 Cl) and bromoform (CHBr 3 ) were measured in the Yellow Sea (YS) and the East China Sea (ECS) during spring 2011. The influences of chlorophyll a, salinity and nutrients on the distributions of these gases were examined. Elevated levels of these gases in the coastal waters were attributed to anthropogenic inputs and biological release by phytoplankton. The vertical distributions of these gases in the water column were controlled by different source strengths and water masses. Using atmospheric concentrations measured in spring 2012 and seawater concentrations obtained from this study, the sea-to-air fluxes of these gases were estimated. Our results showed that the emissions of C 2 HCl 3 , C 2 Cl 4, CHBr 2 Cl, and CHBr 3 from the study area could account for 16.5%, 10.5%, 14.6%, and 3.5% of global oceanic emissions, respectively, indicating that the coastal shelf may contribute significantly to the global oceanic emissions of these gases. -- Highlights: ► Distributions of the VHCs were studied in the YS and the ECS. ► Elevated levels of VHCs were related to terrestrial input from the Yangtze River. ► Biogenic production from diatoms was an important source of the VHCs. ► Shelf seas could significantly contribute to the global oceanic VHCs emission. -- The elevated levels of the volatile halocarbons in the coastal waters were attributed to anthropogenic inputs and biological release by phytoplankton (e.g., diatoms)

  8. The relationship between the opening of South China Sea and the formation of the Tibetan Plateau (Invited)

    Science.gov (United States)

    Mo, X.

    2010-12-01

    The South China Sea is one of the largest marginal seas in western Pacific and underwent a complex history. Xu et al.(2004) suggested that the evolution of the South China Sea can be divided into two first order phases: Paleogene (—Early Miocene) rifting and Neogene post- rifting. An oceanic crust was formed during 32-17 Ma. Whether or not the opening of South China Sea were related to Indo-Eurasia collision and the formation of the Tibetan Plateau is one of challenging problem in Earth sciences. With an exception of the southwestern China, the Chinese continent has become an united continent in the Triassic by the Indosinian orogeny. However, the Qinghai-Tibet area in SW China was still an oceanic region, that is, the Neo-Tethys. During the period of 145-100 Ma, the Lhasa terrane collided with the Qiangtang terrane and added to the south margin of the Eurasian continent. On the other hand, the Indian plate subducted underneath the Eurasian continent since Jurassic- Cretaceous. Subsequently, collision between the two continents, India and Eurasia, were completed during 65-40 Ma, and went into a post-collisional stage, characterized by intra-continental movements, including intra-continental subduction, overthrust, strike-slip and so on. The Tibetan Plateau, the highest plateau in the world had been formed by multi-stage uplifts. Several huge strike-slip shear zone such as the Red River Fault and the Altyn were formed during that period. The >1000-km-long Oligocene—Miocene left-lateral Red River shear zone (RRSZ) and the Pliocene—active right-lateral Red River fault (RRF), stretching from SE Tibet to the South China Sea, has been cited as a lithospheric scale strike-slip fault. The age of RRSZ was recently determined no earlier than 31.9-24.2Ma and no later than 21.7 Ma (Searle et al., 2010). Many geologists believe that there possibly be close relationship between the opening of the South China Sea and Indo-Eurasia collision and the formation of the Tibetan

  9. Long-term changes of South China Sea surface temperatures in winter and summer

    Science.gov (United States)

    Park, Young-Gyu; Choi, Ara

    2017-07-01

    Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

  10. CAN INTERNATIONAL LAW MAKE A DIFFERENCE UNCLOS AND THE SOUTH CHINA SEA

    Science.gov (United States)

    2017-03-20

    insignificant to a country that is hedging its bets and its control to become a regional power house. 15 Unfortunately for China, the PCA’s decision...published by China’s think tank, the National Institute for South China Sea Studies, that warns the US that its freedom of navigation patrols in the...Bloomberg, “US Naval Patrols Threaten Sovereignty, China Think Tank Warns,” Stars and Stripes 25 November 2016 https://www.stripes.com/news

  11. Late Eocene sea retreat from the Tarim Basin (west China) and concomitant Asian paleoenvironmental change

    NARCIS (Netherlands)

    Bosboom, R.E.; Dupont-Nivet, G.; Houben, A.J.P.; Brinkhuis, H.; Villa, G.; Mandic, O.; Stoica, M.; Zachariasse, W.J.; Guo, ZJ.; Li, CX.; Krijgsman, W.

    2011-01-01

    The Paleogene sediments of the southwest Tarim Basin along the West Kunlun Shan in western China include the remnants of the easternmost extent of a large epicontinental sea. This shallow sea once extended across the Eurasian continent before it retreated westward and eventually separated as the

  12. Linking Tarim Basin sea retreat (west China) and Asian aridification in the late Eocene

    NARCIS (Netherlands)

    Bosboom, R.; Dupont-Nivet, G.; Grothe, A.; Brinkhuis, H.; Villa, G.; Mandic, O.; Stoica, M.; Huang, W.; Yang, W.; Guo, Z.; Krijgsman, W.

    2014-01-01

    The Tarim Basin in western China formed the easternmost margin of a shallow epicontinental sea that extended across Eurasia and was well connected to the western Tethys during the Paleogene. Climate modelling studies suggest that the westward retreat of this sea from Central Asia may have been as

  13. 137Cs inventories in the water column collected from the South and South China Seas

    International Nuclear Information System (INIS)

    Yamada, M.; Wang, Z.-L.; Zheng, J.

    2006-01-01

    Seawater samples were collected in the Sulu and South China Seas and their 137 Cs activities were determined by γ spectrometry. A significant difference in intermediate water 137 Cs activities in the 750-1500 m depth was observed between the Sulu and South China Seas. The 137 Cs inventories in the Sulu Sea was 5.7 times higher than that of the integrated deposition density of atmospheric global fallout at the same latitude of 0-10degN. A possible mechanism controlling this extremely high 137 Cs inventories may be inflows of 137 Cs rich North Pacific Tropical Water and upper North Pacific Intermediate Water through the Luzon Straight from the West Philippine Sea, and lateral transport across the Mindoro Strait into the Sulu Sea, then conveyance into the deep layer in the Sulu Sea basin. (author)

  14. 50 CFR Figure 20 to Part 679 - Steller sea lion conservation area (SCA) of the Bering Sea

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Steller sea lion conservation area (SCA) of the Bering Sea 20 Figure 20 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT... EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Fig. 20 Figure 20 to Part 679—Steller sea lion conservation area...

  15. Seabed geodiversity in a glaciated shelf area, the Baltic Sea

    Science.gov (United States)

    Kaskela, Anu Marii; Kotilainen, Aarno Tapio

    2017-10-01

    Geodiversity describes the heterogeneity of the physical terrain. We have performed basin-wide geodiversity analysis on a glaciated epicontinental seabed to assess geodiversity measures and patterns, locate areas with high geodiversity, and draw conclusions on contributing processes. Geodiversity quantification is a rather new topic and is mainly practiced in land areas. We applied geodiversity methods developed for terrestrial studies to a seabed environment. Three geodiversity parameters, including the richness, patchiness, and geodiversity index, of the Baltic Sea were assessed in a GIS environment based on broad-scale datasets on seabed substrates, structures, and bedrock. A set of environmental and geological variables, which were considered to reflect geological processes under seabed conditions, were compared with the geodiversity to identify some of its drivers. We observed differences in the geodiversity levels of the Baltic subbasins, which are mainly due to basement type/bedrock, roughness, shore density, and glacier-derived processes. The geodiversity of the Baltic Sea generally increases from South to North and from open-sea to high-shore density areas (archipelagos). Crystalline bedrock areas provide more diverse seabed environments than sedimentary rock areas. The analysis helps to inform scientists, marine spatial planners, and managers about abiotic conservation values, the dynamics of the seabed environment, and potential areas with elevated biodiversity.

  16. Methane in the South China Sea and the Western Philippine Sea

    Science.gov (United States)

    Tseng, Hsiao-Chun; Chen, Chen-Tung Arthur; Borges, Alberto V.; DelValls, T. Angel; Chang, Yu-Chang

    2017-03-01

    Approximately 700 water samples from the South China Sea (SCS) and 300 water samples from the western Philippine Sea (wPS) were collected during eight cruises from August 2003 to July 2007 to determine methane (CH4) distributions from the surface to a depth of 4250 m. The surface CH4 concentrations exceeded atmospheric equilibrium, both in the SCS and the wPS, and the concentrations were 4.5±3.6 and 3.0±1.2 nmol L-1, respectively. The sea-to-air fluxes were calculated, and the SCS and the wPS were found to emit CH4 to the atmosphere at 8.6±6.4 μmol m-2 d-1 and 4.9±4.9 μmol m-2 d-1, respectively. In the SCS, CH4 emissions were higher over the continental shelf (11.0±7.4 μmol m-2 d-1) than over the deep ocean (6.1±6.0 μmol m-2 d-1), owing to greater biological productivity and closer coupling with the sediments on the continental shelf. The SCS emitted 30.1×106 mol d-1 CH4 to the atmosphere and exported 1.82×106 mol d-1 CH4 to the wPS. The concentrations of both CH4 and chlorophyll a were high in the 150 m surface layer of the wPS, but were not significantly correlated with each other. CH4 concentrations generally declined with increasing depth below the euphotic zone but remained constant below 1,000 m, both in the SCS and the wPS. Some high CH4 concentrations were observed at mid-depths and bottom waters in the SCS, and were most likely caused by the release of CH4 from gas hydrates or gas seepage.

  17. Nutrient Dynamics in the Northern South China Sea Shelf-sea (NoSoCS)

    Science.gov (United States)

    Wong, G. T.; Guo, X.

    2011-12-01

    The Northern South China Sea Shelf-sea (NoSoCS) is situated in the sub-tropics along the southern Chinese coast between the southern end of the Taiwan Strait and the Hainan Island. Samples were collected in four cross-shelf transects in summer, 2010 and two cross-shelf transects in winter, 2011 in this Shelf-sea. The shelf may be sub-divided into the inner shelf (1 μM in NO3- and >0.1 μM in soluble reactive phosphate) stretched across the shelf at least to the middle shelf. Thus, vertical mixing, even to relatively shallow depths, on the shelf may supply nutrients to and play a critical role in determining the primary production in the mixed layer. At least three such processes were observed. Through the year, internal waves of various strengths generated at the Luzon Strait propagated westward along the bottom of the mixed layer and dissipated along the middle and outer shelf. The effects of these waves were especially conspicuous north of the Dongsha Atoll and their action enhances vertical mixing. In the summer, upwelling occurred in the inner/middle shelf off Dongshan in response to the along shore southwest monsoon and the topographic forcing by the ridge extending offshore from Dongshan to the Taiwan Bank. In the winter, surface cooling and the strong northeast monsoon led to complete overturn in the shelf. The maximum density, reaching 24.6, in the surface waters was found offshore in the inner and middle shelf. This density was equivalent to the density of the water at >100 m offshore. As a result, this dense water also appeared as a layer of bottom water that extended across the shelf to the shelf edge.

  18. Deep water characteristics and circulation in the South China Sea

    Science.gov (United States)

    Wang, Aimei; Du, Yan; Peng, Shiqiu; Liu, Kexiu; Huang, Rui Xin

    2018-04-01

    This study investigates the deep circulation in the South China Sea (SCS) using oceanographic observations combined with results from a bottom layer reduced gravity model. The SCS water, 2000 m below the surface, is quite different from that in the adjacent Pacific Ocean, and it is characterized by its low dissolved oxygen (DO), high temperature and low salinity. The horizontal distribution of deep water properties indicates a basin-scale cyclonic circulation driven by the Luzon overflow. The results of the bottom layer reduced gravity model are consistent with the existence of the cyclonic circulation in the deep SCS. The circulation is stronger at the northern/western boundary. After overflowing the sill of the Luzon Strait, the deep water moves broadly southwestward, constrained by the 3500 m isobath. The broadening of the southward flow is induced by the downwelling velocity in the interior of the deep basin. The main deep circulation bifurcates into two branches after the Zhongsha Islands. The southward branch continues flowing along the 3500 m isobath, and the eastward branch forms the sub-basin scale cyclonic circulation around the seamounts in the central deep SCS. The returning flow along the east boundary is fairly weak. The numerical experiments of the bottom layer reduced gravity model reveal the important roles of topography, bottom friction, and the upwelling/downwelling pattern in controlling the spatial structure, particularly the strong, deep western boundary current.

  19. A Novel Roseosiphophage Isolated from the Oligotrophic South China Sea

    Directory of Open Access Journals (Sweden)

    Yunlan Yang

    2017-05-01

    Full Text Available The Roseobacter clade is abundant and widespread in marine environments and plays an important role in oceanic biogeochemical cycling. In this present study, a lytic siphophage (labeled vB_DshS-R5C infecting the strain type of Dinoroseobacter shibae named DFL12T, which is part of the Roseobacter clade, was isolated from the oligotrophic South China Sea. Phage R5C showed a narrow host range, short latent period and low burst size. The genome length of phage R5C was 77, 874 bp with a G+C content of 61.5%. Genomic comparisons detected no genome matches in the GenBank database and phylogenetic analysis based on DNA polymerase I revealed phylogenetic features that were distinct to other phages, suggesting the novelty of R5C. Several auxiliary metabolic genes (e.g., phoH gene, heat shock protein and queuosine biosynthesis genes were identified in the R5C genome that may be beneficial to the host and/or offer a competitive advantage for the phage. Among siphophages infecting the Roseobacter clade (roseosiphophages, four gene transfer agent-like genes were commonly located with close proximity to structural genes, suggesting that their function may be related to the tail of siphoviruses. The isolation and characterization of R5C demonstrated the high genomic and physiological diversity of roseophages as well as improved our understanding of host–phage interactions and the ecology of the marine Roseobacter.

  20. Phytoplankton responses to aluminum enrichment in the South China Sea.

    Science.gov (United States)

    Zhou, Linbin; Liu, Jiaxing; Xing, Shuai; Tan, Yehui; Huang, Liangmin

    2018-04-01

    Compared to extensive studies reporting the aluminum (Al) toxicity to terrestrial plants and freshwater organisms, very little is known about how marine phytoplankton responds to Al in the field. Here we report the marine phytoplankton responses to Al enrichment in the South China Sea (SCS) using on-deck bottle incubation experiments during eight cruises from May 2010 to November 2013. Generally, Al addition alone enhanced the growth of diatom and Trichodesmium, and nitrogen fixation, but it inhibited the growth of dinoflagellates and Synechococcus. Nevertheless, Al addition alone did not influence the chlorophyll a concentration of the entire phytoplankton assemblages. By adding nitrate and phosphate simultaneously, Al enrichment led to substantial increases in chlorophyll a concentration (especially that of the picophytoplanktonenrichment. Further, by simultaneously adding different macronutrients and/or sufficient trace metals including iron, we found that the phytoplankton responses to Al enrichment were relevant to nutrients coexisting in the environment. Al enrichment may give some phytoplankton a competitive edge over using nutrients, especially the limited ones. The possible influences of Al on the competitors and grazers (predators) of some phytoplankton might indirectly contribute to the positive responses of the phytoplankton to Al enrichment. Our results indicate that Al may influence marine carbon cycle by impacting phytoplankton growth and structure in natural seawater. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Genetic identification of eggs from four species of Ophichthidae and Congridae (Anguilliformes) in the northern East China Sea

    Science.gov (United States)

    Choi, Hae-young; Oh, Jina

    2018-01-01

    We report the first genetic identification of eggs of four species of Anguilliformes caught in the northern East China Sea during August 2016, where leptocephali and adults have been collected. The species were Ophisurus macrorhynchos and Echelus uropterus belonging to the Ophichthidae, and Ariosoma majus and Gnathophis heterognathos belonging to the Congridae. The eggs were identified using three molecular genetic markers (mitochondrial 12S rRNA, 16S rRNA, and cytochrome c oxidase subunit 1), sequences obtained from local adult specimens, and geographical distribution data. All eggs were in the early or middle developmental stages. For all species except A. majus, the eggs were found near the range of small leptocephali in the East China Sea and the southern Korean Peninsula, which indicates these species had spawned along the continental near these areas during the summer. PMID:29621326

  2. Data from renewable energy assessments for resort islands in the South China Sea

    Directory of Open Access Journals (Sweden)

    M. Reyasudin Basir Khan

    2016-03-01

    Full Text Available Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article “Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea” published in Energy (Khan et al., 2015 [1]. Keywords: South China Sea, Solar radiation,wind speed, rainfall, microhydropower, PV system, Wind energy generation system

  3. Energy audit data for a resort island in the South China Sea

    Directory of Open Access Journals (Sweden)

    M. Reyasudin Basir Khan

    2016-03-01

    Full Text Available The data consists of actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning of a resort island in the South China Sea. The data has been used to propose an optimal combination of hybrid renewable energy systems that able to mitigate the diesel fuel dependency on the island. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The data presented are related to the research article “Optimal Combination of Solar, Wind, Micro-Hydro and Diesel Systems based on Actual Seasonal Load Profiles for a Resort Island in the South China Sea” [1]. Keywords: Tioman, South China Sea, Load profile, Renewable energy, Resort Island, Energy audit

  4. Tree cover changes in- and ouside protected areas in China

    DEFF Research Database (Denmark)

    Nüchel, Jonas; Bøcher, Peder Klith; Svenning, J.-C.

    Protected areas (PAs) are one of the main tools in the global conservation of biodiversity and ecosystems. This is also the case for China. However, only few studies have investigated protected areas´ efficiency in maintaining ecosystems and biodiversity. One way to investigate this is to look...... at tree cover changes inside the PAs and on the surrounding areas. Using MODIS Vegetation Continuous Fields we mapped tree-cover changes between 2000-2010 in- and outside PAs in China. The PAs were extracted from the World Database on Protected Areas. Our aim were to investigated the following four...... between tree cover change and general human pressure. We did not find a significant correlation between tree cover change inside and outside PAs with increasing general human pressures. The lack of correlation could be due to the huge reforestation China has carried out the last years, mainly to stop...

  5. Ozone pollution around a coastal region of South China Sea: interaction between marine and continental air

    Science.gov (United States)

    Wang, Hao; Lyu, Xiaopu; Guo, Hai; Wang, Yu; Zou, Shichun; Ling, Zhenhao; Wang, Xinming; Jiang, Fei; Zeren, Yangzong; Pan, Wenzhuo; Huang, Xiaobo; Shen, Jin

    2018-03-01

    Marine atmosphere is usually considered to be a clean environment, but this study indicates that the near-coast waters of the South China Sea (SCS) suffer from even worse air quality than coastal cities. The analyses were based on concurrent field measurements of target air pollutants and meteorological parameters conducted at a suburban site (Tung Chung, TC) and a nearby marine site (Wan Shan, WS) from August to November 2013. The observations showed that the levels of primary air pollutants were significantly lower at WS than those at TC, while the ozone (O3) value was greater at WS. Higher O3 levels at WS were attributed to the weaker NO titration and higher O3 production rate because of stronger oxidative capacity of the atmosphere. However, O3 episodes were concurrently observed at both sites under certain meteorological conditions, such as tropical cyclones, continental anticyclones and sea-land breezes (SLBs). Driven by these synoptic systems and mesoscale recirculations, the interaction between continental and marine air masses profoundly changed the atmospheric composition and subsequently influenced the formation and redistribution of O3 in the coastal areas. When continental air intruded into marine atmosphere, the O3 pollution was magnified over the SCS, and the elevated O3 ( > 100 ppbv) could overspread the sea boundary layer ˜ 8 times the area of Hong Kong. In some cases, the exaggerated O3 pollution over the SCS was recirculated to the coastal inshore by sea breeze, leading to aggravated O3 pollution in coastal cities. The findings are applicable to similar mesoscale environments around the world where the maritime atmosphere is potentially influenced by severe continental air pollution.

  6. Microbial diversity in cold seep sediments from the northern South China Sea

    Directory of Open Access Journals (Sweden)

    Yong Zhang

    2012-05-01

    Full Text Available South China Sea (SCS is the largest Western Pacific marginal sea. However, microbial studies have never been performed in the cold seep sediments in the SCS. In 2004, “SONNE” 177 cruise found two cold seep areas with different water depth in the northern SCS. Haiyang 4 area, where the water depth is around 3000 m, has already been confirmed for active seeping on the seafloor, such as microbial mats, authigenic carbonate crusts and bivalves. We investigated microbial abundance and diversity in a 5.55-m sediment core collected from this cold seep area. An integrated approach was employed including geochemistry and 16S rRNA gene phylogenetic analyses. Here, we show that microbial abundance and diversity along with geochemistry profiles of the sediment core revealed a coupled reaction between sulphate reduction and methane oxidation. Acridine orange direct count results showed that microbial abundance ranges from 105 to 106 cells/g sediment (wet weight. The depth-related variation of the abundance showed the same trend as the methane concentration profile. Phylogenetic analysis indicated the presence of sulphate-reducing bacteria and anaerobic methane-oxidizing archaea. The diversity was much higher at the surface, but decreased sharply with depth in response to changes in the geochemical conditions of the sediments, such as methane, sulphate concentration and total organic carbon. Marine Benthic Group B, Chloroflexi and JS1 were predominant phylotypes of the archaeal and bacterial libraries, respectively.

  7. Biodiversity of free-living marine nematodes in the southern Yellow Sea, China

    Science.gov (United States)

    Liu, Xiaoshou; Xu, Man; Hua, Er; Zhang, Zhinan

    2016-02-01

    Biodiversity patterns of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener diversity index ( H') in the study area was 3.17. The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters, while the lower values were distributed in the southern Yellow Sea Cold Water Mass (YSCWM). The average of taxonomic diversity ( Δ) was 62.09 in the study region. The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM, while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM. Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent, which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better. A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794 (in the YSCWM) was outside of the 95% probability funnels, which may be due to the environmental stress. Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics (Mdø and Silt-clay fraction) and phaeophorbide a (Pha- a) were the most important factors to determine the biodiversity patterns of marine nematodes.

  8. Prediction for potential landslide zones using seismic amplitude in Liwan gas field, northern South China Sea

    Science.gov (United States)

    Li, Xishuang; Liu, Baohua; Liu, Lejun; Zheng, Jiewen; Zhou, Songwang; Zhou, Qingjie

    2017-12-01

    The Liwan (Lw) gas field located in the northern slope of the South China Sea (SCS) is extremely complex for its sea-floor topograghy, which is a huge challenge for the safety of subsea facilities. It is economically impractical to obtain parameters for risk assessment of slope stability through a large amount of sampling over the whole field. The linkage between soil shear strength and seabed peak amplitude derived from 2D/3D seismic data is helpful for understanding the regional slope-instability risk. In this paper, the relationships among seabed peak, acoustic impedance and shear strength of shallow soil in the study area were discussed based on statistical analysis results. We obtained a similar relationship to that obtained in other deep-water areas. There is a positive correlation between seabed peak amplitude and acoustic impedance and an exponential relationship between acoustic impedance and shear strength of sediment. The acoustic impedance is the key factor linking the seismic amplitude and shear strength. Infinite slope stability analysis results indicate the areas have a high potential of shallow landslide on slopes exceeding 15° when the thickness of loose sediments exceeds 8 m in the Lw gas field. Our prediction shows that they are mainly located in the heads and walls of submarine canyons.

  9. Study on tsunami due to offshore earthquakes for Korea coast. Literature survey and numerical simulation on earthquake and tsunami in the Japan Sea and the East China Sea

    International Nuclear Information System (INIS)

    Matsuyama, Masafumi; Aoyagi, Yasuhira; Inoue, Daiei; Choi, Weon-Hack; Kang, Keum-Seok

    2008-01-01

    In Korea, there has been a concern on tsumami risks for the Nuclear Power Plants since the 1983 Nihonkai-Chubu earthquake tsunami. The maximum run-up height reached 4 m to north of the Ulchin nuclear power plant site. The east coast of Korea was also attacked by a few meters high tsunami generated by the 1993 Hokkaido Nansei-Oki earthquake. Both source areas of them were in the areas western off Hokkaido to the eastern margin of the Japan Sea, which remains another tsunami potential. Therefore it is necessary to study tsunami risks for coast of Korea by means of geological investigation and numerical simulation. Historical records of earthquake and tsunami in the Japan Sea were re-compiled to evaluate tsunami potential. A database of marine active faults in the Japan Sea was compiled to decide a regional potential of tsunami. Many developed reverse faults are found in the areas western off Hokkaido to the eastern margin of the Japan Sea. The authors have found no historical earthquake in the East China Sea which caused tunami observed at coast of Korea. Therefore five fault models were determined on the basis of the analysis results of historical records and recent research results of fault parameter and tunami. Tsunami heights were estimated by numerical simulation of nonlinear dispersion wave theory. The results of the simulations indicate that the tsunami heights in these cases are less than 0.25 m along the coast of Korea, and the tsunami risk by these assumed faults does not lead to severe impact. It is concluded that tsunami occurred in the areas western off Hokkaido to the eastern margin of the Japan Sea leads the most significant impact to Korea consequently. (author)

  10. Biogeochemical characteristics of suspended particulate matter in deep chlorophyll maximum layers in the southern East China Sea

    Directory of Open Access Journals (Sweden)

    Q. Liu

    2018-04-01

    Full Text Available Continental shelves and marginal seas are key sites of particulate organic matter (POM production, remineralization and sequestration, playing an important role in the global carbon cycle. Elemental and stable isotopic compositions of organic carbon and nitrogen are thus frequently used to characterize and distinguish POM and its sources in suspended particles and surface sediments in the marginal seas. Here we investigated suspended particulate matter (SPM collected around deep chlorophyll maximum (DCM layers in the southern East China Sea for particulate organic carbon and nitrogen (POC and PN contents and their isotopic compositions (δ13CPOC and δ15NPN to understand provenance and dynamics of POM. Hydrographic parameters (temperature, salinity and turbidity indicated that the study area was weakly influenced by freshwater derived from the Yangtze River during summer 2013. Elemental and isotopic results showed a large variation in δ13CPOC (−25.8 to −18.2 ‰ and δ15NPN (3.8 to 8.0 ‰, but a narrow molar C ∕ N ratio (4.1–6.3 and low POC ∕ Chl a ratio ( <  200 g g−1 in POM, and indicated that the POM in DCM layers was newly produced by phytoplankton. In addition to temperature effects, the range and distribution of δ13CPOC were controlled by variations in primary productivity and phytoplankton species composition; the former explained  ∼  70 % of the variability in δ13CPOC. However, the variation in δ15NPN was controlled by the nutrient status and δ15NNO3− in seawater, as indicated by similar spatial distribution between δ15NPN and the current pattern and water masses in the East China Sea; although interpretations of δ15NPN data should be verified with the nutrient data in future studies. Furthermore, the POM investigated was weakly influenced by the terrestrial OM supplied by the Yangtze River during summer 2013 due to the reduced sediment supply by the Yangtze River and north

  11. Biogeochemical characteristics of suspended particulate matter in deep chlorophyll maximum layers in the southern East China Sea

    Science.gov (United States)

    Liu, Qianqian; Kandasamy, Selvaraj; Lin, Baozhi; Wang, Huawei; Chen, Chen-Tung Arthur

    2018-04-01

    Continental shelves and marginal seas are key sites of particulate organic matter (POM) production, remineralization and sequestration, playing an important role in the global carbon cycle. Elemental and stable isotopic compositions of organic carbon and nitrogen are thus frequently used to characterize and distinguish POM and its sources in suspended particles and surface sediments in the marginal seas. Here we investigated suspended particulate matter (SPM) collected around deep chlorophyll maximum (DCM) layers in the southern East China Sea for particulate organic carbon and nitrogen (POC and PN) contents and their isotopic compositions (δ13CPOC and δ15NPN) to understand provenance and dynamics of POM. Hydrographic parameters (temperature, salinity and turbidity) indicated that the study area was weakly influenced by freshwater derived from the Yangtze River during summer 2013. Elemental and isotopic results showed a large variation in δ13CPOC (-25.8 to -18.2 ‰) and δ15NPN (3.8 to 8.0 ‰), but a narrow molar C / N ratio (4.1-6.3) and low POC / Chl a ratio ( < 200 g g-1) in POM, and indicated that the POM in DCM layers was newly produced by phytoplankton. In addition to temperature effects, the range and distribution of δ13CPOC were controlled by variations in primary productivity and phytoplankton species composition; the former explained ˜ 70 % of the variability in δ13CPOC. However, the variation in δ15NPN was controlled by the nutrient status and δ15NNO3- in seawater, as indicated by similar spatial distribution between δ15NPN and the current pattern and water masses in the East China Sea; although interpretations of δ15NPN data should be verified with the nutrient data in future studies. Furthermore, the POM investigated was weakly influenced by the terrestrial OM supplied by the Yangtze River during summer 2013 due to the reduced sediment supply by the Yangtze River and north-eastward transport of riverine particles to the northern East China

  12. The origin of gas seeps and shallow gas in northern part of South China Sea

    Science.gov (United States)

    Li, M.; Jin, X.

    2003-04-01

    The northern part of South China Sea is of passive continental margin, which geologic units include shelf, slope and deep sea basin. There are rifting basins forming during Paleogene (or Cretaceous ?) to Quaternary developed on shelf and slope, which sediments are dominated by fluvial and lake clastic rock of Paleogene, and marine clastic rock and carbonate of Neogene - Quaternary. The main basins include the Pearl River Mouth Basin, Beibu Gulf basin, Qiongdongnan Basin and Yinggehai basin. They contain rich oil and gas resources, and have become important industrial oil and gas producing region in South China Sea. With the increasing of petroleum exploration actives and marine petroleum engineering, it has been paid more attention to the investigation and research of gas seeps and shallow gas, for they become a potential threaten to the marine engineering while they are regarded as the indicators of industrial oil and gas. By study the distribution and geochemical characteristics of gas seeps in northeast part of Yinggehai basin and shallow gas in sediments on slope, combined with their regional geologic background, this paper deals with the origin, migration pathway and emission mechanism of gas seeps and shallow gas in northern part of South China Sea, for providing a base knowledge for the evaluation of marine engineering geology. In northeast part of Yinggehai basin gas seeps have been found and recorded for near 100 years. During 1990s, as a part of petroleum exploration, the gas seeps in the basin have been investigated and research by oil companies (Baojia Huang et al., 1992; Jiaqiong He et al., 2000). Gas seeps were found in shallow water area along southwest coast of Hainan Island, water depth usually less than 50 m. The occurrence of gas seeps can be divided into two types: (1) gas continuously emission, continuous gas bubbles groups can be detected by sonar underwater and observed on water surface. (2) gas intermittently emission, the time intervals

  13. Understanding the Tectonic Features in the South China Sea By Analyzing Magnetic Anomalies

    Science.gov (United States)

    Guo, L.; Meng, X.; Shi, L.; Yao, C.

    2011-12-01

    The South China Sea (SCS) is surrounded by the Eurasia, Pacific and India-Australia plates. It formed during Late Oligocene-Early Miocene, and is one of the largest marginal seas in the Western Pacific. The collision of Indian subcontinent and Eurasian plate in the northwest, back-arc spreading in the centre and subduction beneath the Philippine plate along Manila trench in the east and along Palawan trough in the south had produced the complex tectonic features in the SCS that we can see today. In the past few decades, a variety of geophysical methods were conducted to study geological tectonics and evolution of the SCS. Here, we analyzed the magnetic data of this area using new data enhancement techniques to understand the regional tectonic features. We assembled the magnetic anomalies data with a resolution of two arc-minute from the World Digital Magnetic Anomaly Map, and then gridded the data on a regular grid. Then we used the method of reduction to the pole at low latitude with varying magnetic inclinations to stably reduce the magnetic anomalies. Then we used the preferential continuation method based on Wiener filtering and Green's equivalence principle to separate the reduced-to-pole (RTP) magnetic anomalies, and subsequently analyze the regional and residual anomalies. We also calculated the directional horizontal derivatives and the tilt-angle derivative of the data to derive clearer geological structures with more details. Then we calculated the depth of the magnetic basement surface in the area by 3D interface inversion. From the results of the preliminary processing, we analyzed the main faults, geological structures, magma distribution and tectonic features in the SCS. In the future, the integrated interpretation of the RTP magnetic anomalies, Bouguer gravity anomalies and other geophysical methods will be performed for better understanding the deep structure , the tectonic features and evolution of the South China Sea. Acknowledgment: We

  14. Identification of Surface Water Quality along the Coast of Sanya, South China Sea

    Science.gov (United States)

    Wu, Zhen-Zhen; Che, Zhi-Wei; Wang, You-Shao; Dong, Jun-De; Wu, Mei-Lin

    2015-01-01

    Principal component analysis (PCA) and cluster analysis (CA) are utilized to identify the effects caused by human activities on water quality along the coast of Sanya, South China Sea. PCA and CA identify the seasonality of water quality (dry and wet seasons) and polluted status (polluted area). The seasonality of water quality is related to climate change and Southeast monsoons. Spatial pattern is mainly related to anthropogenic activities (especially land input of pollutions). PCA reveals the characteristics underlying the generation of coastal water quality. The temporal and spatial variation of the trophic status along the coast of Sanya is governed by hydrodynamics and human activities. The results provide a novel typological understanding of seasonal trophic status in a shallow, tropical, open marine bay. PMID:25894980

  15. On the recurrent Ulva prolifera blooms in the Yellow Sea and East China Sea

    Science.gov (United States)

    Hu, Chuanmin; Li, Daqiu; Chen, Changsheng; Ge, Jianzhong; Muller-Karger, Frank E.; Liu, Junpeng; Yu, Feng; He, Ming-Xia

    2010-05-01

    A massive bloom of the green macroalgae Ulva prolifera (previously known as Enteromorpha prolifera) occurred in June 2008 in the Yellow Sea (YS), resulting in perhaps the largest "green tide" event in history. Using a novel index (Floating Algae Index) and multiresolution remote sensing data from MODIS and Landsat, we show that U. prolifera patches appeared nearly every year between April and July 2000-2009 in the YS and/or East China Sea (ECS), which all originated from the nearshore Subei Bank. A finite volume numerical circulation model, driven by realistic forcing and boundary conditions, confirmed this finding. Analysis of meteorological/environmental data and information related to local aquaculture activities strongly supports the hypothesis that the recurrent U. prolifera in the YS and ECS resulted from aquaculture of the seaweed Porphyra yezoensis (or nori) conducted along the 200 km shoreline of the Subei Bank north of the Changjiang (Yangtze) River mouth. Given the continuous growth in aquaculture efforts in the region, similar macroalgae bloom events, such as the summer 2008 event, are likely to occur in the future, particularly between May and July. This was confirmed by the 2009 bloom event in the same regions and the same period. The profit of the local P. yezoensis aquaculture industry (˜16,000 Ha in 2007) is estimated as U.S. 53 million, yet the cost to manage the impact of the summer 2008 U. prolifera bloom exceeded U.S. 100 million. Therefore, better strategies are required to balance the economic benefit of seaweed aquaculture and the costs of environmental impacts.

  16. Occurrence of Coccolithophorids in the Northeastern and Central South China Sea

    Directory of Open Access Journals (Sweden)

    Tien-Nan Yang

    2003-03-01

    Full Text Available Coccolithophorids in the northeastern and central South China Sea (SCS were surveyed in March and October 1996. The cell density of coccolithophorids ranged from 25 x 103 cells L-1 to 31 x 103 cells L-1 in sea-surface water (0–25 m in depth, and from 12 x 103 cells L-1 to 62 x 103 cells L-1 in subsurface water (150 m in depth. The lowest cell number was recorded in the subsurface (150 m in depth in the central gyral area, while the highest one was at the same depth in the northeastern realm. A total of thirty-one species were identified. The species richness in the northeastern SCS is higher than in the central area. Emiliania huxleyi (Lohmann Hay et Mohler, Gephyrocapsa oceanica Kamptner, Umbellosphaera Paasche spp. And Syracosphaera Lohmann spp. Dominated the surface assemblages, whereas Florisphaera profunda Okada et Honjo, Gladiolithus flabellatus (Halldal et Markali Jordan et Chamberlain predominated in the subsurface layer. In contrast, Palusphaera vandeli Lecal emend. R. E. Norris presented in both surface and subsurface assemblages.

  17. Submarine landslides on the north continental slope of the South China Sea

    Science.gov (United States)

    Wang, Weiwei; Wang, Dawei; Wu, Shiguo; Völker, David; Zeng, Hongliu; Cai, Guanqiang; Li, Qingping

    2018-02-01

    Recent and paleo-submarine landslides are widely distributed within strata in deep-water areas along continental slopes, uplifts, and carbonate platforms on the north continental margin of the South China Sea (SCS). In this paper, high-resolution 3D seismic data and multibeam data based on seismic sedimentology and geomorphology are employed to assist in identifying submarine landslides. In addition, deposition models are proposed that are based on specific geological structures and features, and which illustrate the local stress field over entire submarine landslides in deep-water areas of the SCS. The SCS is one of the largest fluvial sediment sinks in enclosed or semi-enclosed marginal seas worldwide. It therefore provides a set of preconditions for the formation of submarine landslides, including rapid sediment accumulation, formation of gas hydrates, and fluid overpressure. A new concept involving temporal and spatial analyses is tested to construct a relationship between submarine landslides and different time scale trigger mechanisms, and three mechanisms are discussed in the context of spatial scale and temporal frequency: evolution of slope gradient and overpressure, global environmental changes, and tectonic events. Submarine landslides that are triggered by tectonic events are the largest but occur less frequently, while submarine landslides triggered by the combination of slope gradient and over-pressure evolution are the smallest but most frequently occurring events. In summary, analysis shows that the formation of submarine landslides is a complex process involving the operation of different factors on various time scales.

  18. Seismic investigation of an ocean-continent transition zone in the northern South China Sea

    Science.gov (United States)

    Zhu, J.; Qiu, X.; Xu, H.; Zhan, W.; Sun, Z.

    2011-12-01

    Rifted continental margins and basins are mainly formed by the lithospheric extension. Thined lithosphere of passive continental margins results in decompression melt of magma and created oceanic crust and thined ocean-continent transition (OCT) zone. Two refraction profiles used ocean bottom seismometers deployed in the broad continental shelf and three multi-channel seismic reflection lines in the northern South China Sea, acquired by the ship "Shiyan 2" of the South China Sea Institute of Oceanology, Chinese Academy of Sciences in 2010, are processed and interpreted in this study. Seismic reflection lines cut through the Dongsha rise, Zhu-1 and Zhu-2 depression within a Tertiary basin, Pear River Mouth basin (called as Zhujiangkou basin). These tectonic features are clear imaged in the seismic reflection records. Numerous normal faults, cutted through the basement and related to the stretch of the northern South China Sea margin, are imaged and interpreted. Reflection characteristics of the ocean-continent transition (OCT) zone are summaried and outlined. The COT zone is mainly divided into the northern syn-rift subsidence zone, central volcano or buried volcano uplift zone and tilt faulted block near the South Chia Sea basin. Compared to the previous seismic reflection data and refraction velocity models, the segmentation range of the OCT zone is outlined, from width of about 225 km in the northeastern South China Sea , of 160 km in the central to of 110 km in the north-central South China Sea. Based on the epicenter distribution of sporadic and large than 6 magnitude earthquakes, it suggests the OCT zone in the northern South China Sea at present is still an active seismic zone.

  19. Influence of continental organic aerosols to the marine atmosphere over the East China Sea: Insights from lipids, PAHs and phthalates.

    Science.gov (United States)

    Kang, Mingjie; Yang, Fan; Ren, Hong; Zhao, Wanyu; Zhao, Ye; Li, Linjie; Yan, Yu; Zhang, Yingjie; Lai, Senchao; Zhang, Yingyi; Yang, Yang; Wang, Zifa; Sun, Yele; Fu, Pingqing

    2017-12-31

    Total suspended particle (TSP) samples were collected during a marine cruise in the East China Sea from May 18 to June 12, 2014. They were analyzed for solvent extractable organic compounds (lipid compounds, PAHs and phthalates) using gas chromatography/mass spectrometry (GC/MS) to better understand the sources and source apportionment of aerosol pollution in the western North Pacific. Higher concentrations were observed in the terrestrially influenced aerosol samples on the basis of five-day backward air mass trajectories, especially for aerosols collected near coastal areas. Phthalates were found to be the dominant species among these measured compound classes (707±401ngm -3 for daytime and 313±155ngm -3 for nighttime), followed by fatty acids, fatty alcohols, n-alkanes and PAHs. In general, the daytime abundances for these compounds are higher than nighttime, possibly attributable to more intensive anthropogenic activities during the daytime. The factor analysis indicates that biomass burning, fungal activities and fossil fuel combustion maybe the main emission sources for organic aerosols over the East China Sea. This study demonstrates that the East Asian continent can be a natural emitter of biogenic and anthropogenic organics to the marine atmosphere through long-range transport, which controls the chemical composition and concentration of organic aerosols over the East China Sea. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Organic carbon source and salinity shape sediment bacterial composition in two China marginal seas and their major tributaries.

    Science.gov (United States)

    Wang, Kai; Zou, Li; Lu, Xinxin; Mou, Xiaozhen

    2018-08-15

    Marginal sea sediments receive organic substrates of different origins, but whether and to what extent sediment microbial communities are reflective of the different sources of organic substrates remain unclear. To address these questions, sediment samples were collected in two connected China marginal seas, i.e., Bohai Sea and Yellow Sea, and their two major tributaries (Yellow River and Liao River). Sediment bacterial community composition (BCC) was examined using 16S rRNA gene pyrosequencing. In addition, physicochemical variables that describe environmental conditions and sediment features were measured. Our results revealed that BCCs changed with salinity and organic carbon (OC) content. Members of Gaiellaceae and Comamonadaceae showed a rapid decrease as salinity and phytoplankton-derived OC increased, while Piscirickettsiaceae and Desulfobulbaceae exhibited an opposite distribution pattern. Differences of riverine vs. marginal sea sediment BCCs could be mostly explained by salinity. However, within the marginal seas, sediment BCC variations were mainly explained by OC-related variables, including terrestrial-derived fatty acids (Terr_FA), phytoplankton-derived polyunsaturated fatty acids (Phyto_PUFA), stable carbon isotopes (δ 13 C), and carbon to nitrogen ratio (C/N). In addition to environmental variables, network analysis suggested that interactions among individual bacterial taxa might be important in shaping sediment BCCs in the studied areas. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Lagrangian Observations of Nonlinear Internal Waves and Turbulence Mixing in Luzon Strait and South China Sea and Internal Wave in the Vicinity of the Kuroshio Path

    National Research Council Canada - National Science Library

    Lien, Ren-Chieh; D'Asaro, Eric A

    2008-01-01

    ... mixing in the northern South China Sea. Results are reported. The second was to analyze observations of data taken in the vicinity of the Kuroshio path from Luzon Strait to the southern East China Sea...

  2. Data from renewable energy assessments for resort islands in the South China Sea.

    Science.gov (United States)

    Basir Khan, M Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

    2016-03-01

    Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article "Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea" published in Energy (Khan et al., 2015) [1].

  3. Energy audit data for a resort island in the South China Sea.

    Science.gov (United States)

    Basir Khan, M Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

    2016-03-01

    The data consists of actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning of a resort island in the South China Sea. The data has been used to propose an optimal combination of hybrid renewable energy systems that able to mitigate the diesel fuel dependency on the island. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The data presented are related to the research article "Optimal Combination of Solar, Wind, Micro-Hydro and Diesel Systems based on Actual Seasonal Load Profiles for a Resort Island in the South China Sea" [1].

  4. Area selection for a geological repository of high level radioactive waste in China

    International Nuclear Information System (INIS)

    Jin Yuanxin; Wang Ju; Chen Weiming; Guo Yonghai; Su Rui; Zhao Honggang; Xu Guoqing

    2012-01-01

    China started research on HLW disposal in 1985 and 6 areas, including Northwest, Southwest, East China, South China, Inner Mongolia and Xinjiang area, are selected. The results show that the Northwest area has obvious comprehensive advantages, which can be considered as the first area for site selection, while site characterization and comparison research in the area should be continued. (authors)

  5. Evaluating the impact of sea surface temperature (SST) on spatial distribution of chlorophyll-a concentration in the East China Sea

    Science.gov (United States)

    Ji, Chenxu; Zhang, Yuanzhi; Cheng, Qiuming; Tsou, JinYeu; Jiang, Tingchen; Liang, X. San

    2018-06-01

    In this study, we analyze spatial and temporal sea surface temperature (SST) and chlorophylla (Chl-a) concentration in the East China Sea (ECS) during the period 2003-2016. Level 3 (4 km) monthly SST and Chl-a data from the Moderate Resolution Imaging Spectroradiometer Satellite (MODIS-Aqua) were reconstructed using the data interpolation empirical orthogonal function (DINEOF) method and used to evaluated the relationship between the two variables. The approaches employed included correlation analysis, regression analysis, and so forth. Our results show that certain strong oceanic SSTs affect Chl-a concentration, with particularly high correlation seen in the coastal area of Jiangsu and Zhejiang provinces. The mean temperature of the high correlated region was 18.67 °C. This finding may suggest that the SST has an important impact on the spatial distribution of Chl-a concentration in the ECS.

  6. Cretaceous–Eocene provenance connections between the Palawan Continental Terrane and the northern South China Sea margin

    NARCIS (Netherlands)

    Shao, Lei; Cao, Licheng; Qiao, Peijun; Zhang, Xiangtao; Li, Qianyu; van Hinsbergen, Douwe J.J.

    2017-01-01

    The plate kinematic history of the South China Sea opening is key to reconstructing how the Mesozoic configuration of Panthalassa and Tethyan subduction systems evolved into today's complex Southeast Asian tectonic collage. The South China Sea is currently flanked by the Palawan Continental Terrane

  7. Polybrominated diphenyl ethers (PBDEs) in sediments of the coastal East China Sea: Occurrence, distribution and mass inventory

    International Nuclear Information System (INIS)

    Li Yuanyuan; Lin Tian; Chen Yingjun; Hu Limin; Guo Zhigang; Zhang Gan

    2012-01-01

    Polybrominated diphenyl ethers (PBDEs) of sixty-three sediment samples from the coastal East China Sea (ECS), extending ∼1000 km from the Yangtze River Estuary to the south, were measured. The levels of BDE-209 and ∑PBDE 7 (sum of BDE-28, 47, 99, 100, 153, 154, 183) were 0.3–44.6 ng/g (dry weight) and nd-8.0 ng/g, respectively. BDE-209 was the predominant congener, followed by BDE-99/100. This was consistent with the historical and current usage of PBDE mixtures in China. The compositions and distribution of PBDEs suggest that the PBDEs in this area could be mainly from the coastal electronic waste dismantling/recycling and Yangtze River input. The poor correlations between TOC, grain size of sediments with PBDEs imply that the PBDE distribution is more related to their land-based inputs rather than the sediment characters in the area. The coastal ECS is an important sink of PBDEs (7.5 t/yr) in the world. - Highlights: ► First report on the levels, distribution and inventory of PBDEs in the inner shelf of the ECS. ► PBDEs were mainly from the coastal electronic waste dismantling/recycling and Yangtze River. ► PBDE distribution was related to the land-based inputs rather than the sediment characters. ► The coastal East China Sea is an important sink of the PBDEs in the world. - The levels, distribution, potential sources and mass inventory of PBDEs in sediments of the coastal East China Sea were revealed.

  8. Frost flowers and sea-salt aerosols over seasonal sea-ice areas in northwestern Greenland during winter–spring

    Directory of Open Access Journals (Sweden)

    K. Hara

    2017-07-01

    Full Text Available Sea salts and halogens in aerosols, frost flowers, and brine play an important role in atmospheric chemistry in polar regions. Simultaneous sampling and observations of frost flowers, brine, and aerosol particles were conducted around Siorapaluk in northwestern Greenland during December 2013 to March 2014. Results show that water-soluble frost flower and brine components are sea-salt components (e.g., Na+, Cl−, Mg2+, K+, Ca2+, Br−, and iodine. Concentration factors of sea-salt components of frost flowers and brine relative to seawater were 1.14–3.67. Sea-salt enrichment of Mg2+, K+, Ca2+, and halogens (Cl−, Br−, and iodine in frost flowers is associated with sea-salt fractionation by precipitation of mirabilite and hydrohalite. High aerosol number concentrations correspond to the occurrence of higher abundance of sea-salt particles in both coarse and fine modes, and blowing snow and strong winds. Aerosol number concentrations, particularly in coarse mode, are increased considerably by release from the sea-ice surface under strong wind conditions. Sulfate depletion by sea-salt fractionation was found to be limited in sea-salt aerosols because of the presence of non-sea-salt (NSS SO42−. However, coarse and fine sea-salt particles were found to be rich in Mg. Strong Mg enrichment might be more likely to proceed in fine sea-salt particles. Magnesium-rich sea-salt particles might be released from the surface of snow and slush layer (brine on sea ice and frost flowers. Mirabilite-like and ikaite-like particles were identified only in aerosol samples collected near new sea-ice areas. From the field evidence and results from earlier studies, we propose and describe sea-salt cycles in seasonal sea-ice areas.

  9. Frost flowers and sea-salt aerosols over seasonal sea-ice areas in northwestern Greenland during winter-spring

    Science.gov (United States)

    Hara, Keiichiro; Matoba, Sumito; Hirabayashi, Motohiro; Yamasaki, Tetsuhide

    2017-07-01

    Sea salts and halogens in aerosols, frost flowers, and brine play an important role in atmospheric chemistry in polar regions. Simultaneous sampling and observations of frost flowers, brine, and aerosol particles were conducted around Siorapaluk in northwestern Greenland during December 2013 to March 2014. Results show that water-soluble frost flower and brine components are sea-salt components (e.g., Na+, Cl-, Mg2+, K+, Ca2+, Br-, and iodine). Concentration factors of sea-salt components of frost flowers and brine relative to seawater were 1.14-3.67. Sea-salt enrichment of Mg2+, K+, Ca2+, and halogens (Cl-, Br-, and iodine) in frost flowers is associated with sea-salt fractionation by precipitation of mirabilite and hydrohalite. High aerosol number concentrations correspond to the occurrence of higher abundance of sea-salt particles in both coarse and fine modes, and blowing snow and strong winds. Aerosol number concentrations, particularly in coarse mode, are increased considerably by release from the sea-ice surface under strong wind conditions. Sulfate depletion by sea-salt fractionation was found to be limited in sea-salt aerosols because of the presence of non-sea-salt (NSS) SO42-. However, coarse and fine sea-salt particles were found to be rich in Mg. Strong Mg enrichment might be more likely to proceed in fine sea-salt particles. Magnesium-rich sea-salt particles might be released from the surface of snow and slush layer (brine) on sea ice and frost flowers. Mirabilite-like and ikaite-like particles were identified only in aerosol samples collected near new sea-ice areas. From the field evidence and results from earlier studies, we propose and describe sea-salt cycles in seasonal sea-ice areas.

  10. Decadal variations in diatoms and dinoflagellates on the inner shelf of the East China Sea, China

    Science.gov (United States)

    Abate, Rediat; Gao, Yahui; Chen, Changping; Liang, Junrong; Mu, Wenhua; Kifile, Demeke; Chen, Yanghang

    2017-11-01

    Diatoms and dinoflagellates are two major groups of phytoplankton that flourish in the oceans, particularly in coastal zone and upwelling systems, and their contrasting production have been reported in several world seas. However, this information is not available in the coastal East China Sea (ECS). Thus, to investigate and compare the decadal trends in diatoms and dinoflagellates, a sediment core, 47 cm long, was collected from the coastal zone of the ECS. Sediment chlorophyll- a (Chl- a), phytoplankton-group specific pigment signatures of diatoms and dinoflagellates, and diatom valve concentrations were determined. The sediment core covered the period from 1961 to 2011 AD. The chlorophyll- a contents ranged from 2.32 to 73 µg/g dry sediment (dw) and averaged 9.81 µg/g dw. Diatom absolute abundance ranged from 29152 to 177501 valve/gram (v/g) dw and averaged 72137 v/g dw. Diatom valve and diatom specific pigment marker concentrations were not significantly correlated. Peridinin increased after the 1980s in line with intensified use of fertilizer and related increases in nutrient inputs into the marine environment. The increased occurrence of dinoflagellate dominance after the 1980s can be mostly explained by the increase in nutrients. However, the contribution of dinoflagellates to total phytoplankton production (Chl- a) decreased during the final decade of this study, probably because of the overwhelming increase in diatom production that corresponded with the construction of the Three Gorges Dam (TGD) and related light availability. Similarly, the mean ratio of fucoxanthin/peridinin for the period from 1982 to 2001 was 6% less than for 1961 to 1982, while the ratio for 2001 to 2011 was 45.3% greater than for 1982 to 2001. The decadal variation in the fucoxanthin/peridinin ratio implies that dinoflagellate production had been gradually increasing until 2001. We suggest that the observed changes can be explained by anthropogenic impacts, such as nutrient

  11. Dynamics of macrozoobenthos in the Southern Bulgarian Black Sea coastal and open-sea areas

    Directory of Open Access Journals (Sweden)

    S. STOYKOV

    2001-06-01

    Full Text Available The paper presents results of analysis of 96 macrozoobenthic samples, collected on a seasonal basis in Bourgas Bay and in open-sea areas offshore Cape Emine (Bulgarian Black Sea in 1996 and 1998. In total 96 taxa were established, distributed in four groups: Polychaeta, Mollusca, Crustacea and “Diversa”. The average density of populations was 1756 ind.m-2 with a predominating abundance of Polychaeta species. The average biomass estimated was 183.02 g.m-2, formed mainly by representatives of Mollusca. The latter species were measured together with the shells, which appraised their individual weights. Seven of the species found had a coefficient of constancy more than 50%. These were the most adapted species to the environmental conditions of the investigated areas. The quantitative and qualitative assessments in this study demonstrate an increasing tendency in the parameters obtained (density, biomass, species diversity in comparison with previous investigations in the early 1990-s, when intensive anthropogenic influence was widely perceived to misbalance the Black Sea ecosystem. The method of Warwick (1986 applied to characterize the water quality of the studied areas allowed us to define them as rather clean or moderately polluted aquatories.

  12. Classifying Vessels Operating in the South China Sea by Origin with the Automatic Identification System

    Science.gov (United States)

    2018-03-01

    p. 5) means to track voyage and safety related information in real time. Over time, massive amounts of information related to maritime operations... safety related messages from land based stations, navigation aids, and search and rescue (SAR) crews. All AIS messages are intended to encourage open...United States is the South China Sea. Eight countries, China, Taiwan, the Philippines, Brunei, Indonesia, Malaysia , Singapore, and Vietnam

  13. Recent advances in research on the aeolian geomorphology of China's Kumtagh Sand Sea

    Science.gov (United States)

    Dong, Z.; Lv, P.

    2014-02-01

    The Kumtagh Sand Sea in the hyper-arid region of northwestern China remained largely unexplored until the last decade. It deserves study due to its significance in understanding the evolution of the arid environments in northwestern China, and even central Asia. Aeolian geomorphology in the sand sea has received unprecedented study in the last decade. Encouraging advances have been made in types of aeolian landforms, geological outlines, wind systems, the formation of aeolian landforms, several unique aeolian landforms, aeolian geomorphic regionalization, aeolian geomorphological heritages and tourism development, and aeolian sand hazards and their control. These advances expand our knowledge of aeolian geomorphology.

  14. Occurrence and dry deposition of organophosphate esters in atmospheric particles over the northern South China Sea.

    Science.gov (United States)

    Lai, Senchao; Xie, Zhiyong; Song, Tianli; Tang, Jianhui; Zhang, Yingyi; Mi, Wenying; Peng, Jinhu; Zhao, Yan; Zou, Shichun; Ebinghaus, Ralf

    2015-05-01

    Nine organophosphate esters (OPEs) in airborne particles were measured during a cruise campaign over the northern South China Sea (SCS) from September to October 2013. The concentration of the total OPEs (∑OPEs) was 47.1-160.9 pg m(-3), which are lower than previous measurements in marine atmosphere environments. Higher OPE concentrations were observed in terrestrially influenced samples, suggesting that OPE concentrations were significantly influenced by air mass transport. Chlorinated OPEs were the dominant OPEs, accounting for 65.8-83.7% of the ∑OPEs. Tris-(2-chloroethyl) phosphate (TCEP) was the predominant OPE compound in the samples (45.0±12.1%), followed by tris-(1-chloro-2-propyl) phosphates (TCPPs) (28.8±8.9%). Dry particle-bound deposition fluxes ranged from 8.2 to 27.8 ng m(-2) d(-1) for the ∑OPEs. Moreover, the dry deposition input of the ∑OPEs was estimated to be 4.98 ton y(-1) in 2013 in a vast area of northern SCS. About half of the input was found to relate to air masses originating from China. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Sea Urchin Embryogenesis as Bioindicators of Marine Pollution in Impact Areas of the Sea of Japan/East Sea and the Sea of Okhotsk.

    Science.gov (United States)

    Lukyanova, Olga N; Zhuravel, Elena V; Chulchekov, Denis N; Mazur, Andrey A

    2017-08-01

    The embryogenesis of the sea urchin sand dollar Scaphechinus mirabilis was used as bioindicators of seawater quality from the impact areas of the Sea of Japan/East Sea (Peter the Great Bay) and the Sea of Okhotsk (northwestern shelf of Sakhalin Island and western shelf of Kamchatka Peninsula). Fertilization membrane formation, first cleavage, blastula formation, gastrulation, and 2-armed and 4-armed pluteus formation have been analyzed and a number of abnormalities were calculated. Number of embryogenesis anomalies in sand dollar larvae exposed to sea water from different stations in Peter the Great Bay corresponds to pollution level at each area. The Sea of Okhotsk is the main fishing area for Russia. Anthropogenic impact on the marine ecosystem is caused by fishing and transport vessels mainly. But two shelf areas are considered as "hot spots" due to oil and gas drilling. Offshore oil exploitation on the northeastern Sakhalin Island has been started and at present time oil is being drill on oil-extracting platforms continuously. Significant reserves of hydrocarbons are prospected on western Kamchatka shelf, and exploitation drilling in this area was intensified in 2014. A higher number of abnormalities at gastrula and pluteus stages (19-36%) were detected for the stations around oil platforms near Sakhalin Island. On the western Kamchatka shelf number of abnormalities was 7-21%. Such anomalies as exogastrula, incomplete development of pairs of arms were not observed at all; only the delay of development was registered. Eggs, embryos, and larvae of sea urchins are the suitable bioindicators of early disturbances caused by marine pollution in impact ecosystems.

  16. Expansion of the South China Sea basin: Constraints from magnetic anomaly stripes, sea floor topography, satellite gravity and submarine geothermics

    Directory of Open Access Journals (Sweden)

    Xuezhong Yu

    2017-01-01

    Full Text Available The widely distributed E–W-trending magnetic anomaly stripes in the central basin and the N–E-trending magnetic anomaly stripes in the southwest sub-basin provide the most important evidence for Neogene expansion of the South China Sea. The expansion mechanism remains, however, controversial because of the lack of direct drilling data, non-systematic marine magnetic survey data, and irregular magnetic anomaly stripes with two obvious directions. For example, researchers have inferred different ages and episodes of expansion for the central basin and southwest sub-basin. Major controversy centers on the order of basinal expansion and the mechanism of expansion for the entire South China Sea basin. This study attempts to constrain these problems from a comprehensive analysis of the seafloor topography, magnetic anomaly stripes, regional aeromagnetic data, satellite gravity, and submarine geothermics. The mapped seafloor terrain shows that the central basin is a north-south rectangle that is relatively shallow with many seamounts, whereas the southwest sub-basin is wide in northeast, gradually narrows to the southwest, and is relatively deeper with fewer seamounts. Many magnetic anomaly stripes are present in the central basin with variable dimensions and directions that are dominantly EW-trending, followed by the NE-, NW- and NS-trending. Conversely such stripes are few in the southwest sub-basin and mainly NE-trending. Regional magnetic data suggest that the NW-trending Ailaoshan-Red River fault extends into the South China Sea, links with the central fault zone in the South China Sea, which extends further southward to Reed Tablemount. Satellite gravity data show that both the central basin and southwest sub-basin are composed of oceanic crust. The Changlong seamount is particularly visible in the southwest sub-basin and extends eastward to the Zhenbei seamount. Also a low gravity anomaly zone coincides with the central fault zone in the sub

  17. CONTRIBUTION OF SATELLITE ALTIMETRY DATA IN GEOLOGICAL STRUCTURE RESEARCH IN THE SOUTH CHINA SEA

    Directory of Open Access Journals (Sweden)

    T. D. Tran

    2016-06-01

    Full Text Available The study area is bordered on the East China Sea, the Philippine Sea, and the Australian-Indo plate in the Northeast, in the East and in the South, respectively. It is a large area with the diversely complicated conditions of geological structure. In spite of over the past many years of investigation, marine geological structure in many places have remained poorly understood because of a thick seawater layer as well as of the sensitive conflicts among the countries in the region. In recent years, the satellite altimeter technology allows of enhancement the marine investigation in any area. The ocean surface height is measured by a very accurate radar altimeter mounted on a satellite. Then, that surface can be converted into marine gravity anomaly or bathymetry by using the mathematical model. It is the only way to achieve the data with a uniform resolution in acceptable time and cost. The satellite altimetry data and its variants are essential for understanding marine geological structure. They provide a reliable opportunity to geologists and geophysicists for studying the geological features beneath the ocean floor. Also satellite altimeter data is perfect for planning the more detailed shipboard surveys. Especially, it is more meaningful in the remote or sparsely surveyed regions. In this paper, the authors have effectively used the satellite altimetry and shipboard data in combination. Many geological features, such as seafloor spreading ridges, fault systems, volcanic chains as well as distribution of sedimentary basins are revealed through the 2D, 3D model methods of interpretation of satellite-shipboard-derived data and the others. These results are improved by existing boreholes and seismic data in the study area.

  18. Reef coral δ18O thermometer in Hainan island waters, south China sea

    International Nuclear Information System (INIS)

    He Xuexian; Peng Zicheng; Wang Zhaorong; Huo Weiguo; Tan Jun; Nie Baofu; Chen Tegu; Zhong Jinliang

    2000-01-01

    An 18-year-long (1981-1998) study was conducted in Hainan Island waters (22 degree 22'N, 110 degree 39'E) to determine the relationship between δ 18 O in skeletal aragonite carbonate and sea surface temperature (SST) in porites lutea of reef-building corals. δ 18 O values in skeletal aragonite carbonate were measured by means of mass spectrometry. Coral samples grew at 5 m depth at Longwan Bay. Monthly measurements of the SST from 1960 to 1998 were taken at Qinglan Bay adjacent to the place of the collected samples. The thermometer shows that SST = -4.16 δ 18 O PDB + 4.9 (r = 0.80) and dδ 18 O/dT = -0.24 per mil/degree C. The δ 18 O thermometer is strongly influenced by the rainfall and runoff. Using the thermometer, the SST in the past hundred years with monthly resolution will be reconstructed and the climatic change in the northern area of South China Sea will be hind cast

  19. Species composition and assemblages of ichthyoplankton during summer in the East China Sea

    Science.gov (United States)

    Lin, Han-Yang; Chiu, Mei-Yun; Shih, Yu-Ming; Chen, I.-Shiung; Lee, Ming-An; Shao, Kwang-Tsao

    2016-09-01

    The East China Sea (ECS) is one of the most important fish spawning and nursery grounds in the north Pacific. Even though summer is an important spawning season for many fishes in the region, large-scale molecular identification studies on ichthyoplankton during this season are few. In this study, we sampled 8,933 fish eggs and 12,161 fish larvae from 25 stations during the summer of 2009. Using DNA barcoding, a number of the fish eggs and larvae were identified and classified into 45 and 124 taxa, respectively. Principal component analysis (PCA) categorized the inshore stations of the Changjiang Diluted Water area as having the hydrographic features of low sea surface temperature (SST), salinity (SSS) and high chlorophyll a (SSC) contents, whereas the continental shelf and offshore stations under the influence of the Kuroshio Current displayed the opposite results. Ichthyoplankton was more abundant at the inshore stations than the offshore stations, but species diversity was lower at the former locations. Species compositions of both fish eggs and fish larvae at the 25 stations were categorized into three different assemblages based on a non-metric multidimensional scaling analysis. Combining the assemblage patterns of ichthyoplankton with the results of the PCA and satellite images of SST and SSC showed that the assemblage patterns of fish eggs were correlated with water mass, while those of the fish larvae were not.

  20. Elemental mercury in coastal seawater of Yellow Sea, China: Temporal variation and air-sea exchange

    Science.gov (United States)

    Ci, Zhijia; Zhang, Xiaoshan; Wang, Zhangwei

    2011-01-01

    Dissolved gaseous mercury (DGM, largely Hg(0)) in coastal seawater and gaseous elemental mercury (GEM or Hg(0)) in the atmosphere were simultaneously measured on the coast of the Yellow Sea, China in four different seasons (2008-09). Mean concentrations (±SD) of DGM and GEM over the study period were 34.0 ± 26.1 pg L -1 and 2.55 ± 0.98 ng m -3, respectively. DGM concentrations and the degree of DGM saturation ( Sa) exhibited distinct seasonal variation with the order of summer (DGM: 69.0 ± 23.3 pg L -1, Sa: 11.00 ± 5.92) > fall (27.0 ± 16.4 pg L -1, 3.50 ± 2.60) > spring (23.0 ± 8.7 pg L -1, 2.00 ± 0.98) > winter (16.0 ± 6.0 pg L -1, 0.96 ± 0.39). Under typical meteorological condition with low wind speed and intensive solar radiation in warm seasons, DGM usually exhibited the clear diurnal variation with elevated levels around noon and low levels in morning and afternoon. The diurnal and seasonal variation of DGM indicated the importance of photochemical DGM formation in the seawater. A consistent low DGM levels in high wind speed condition suggested that the biological activity probably influenced the DGM formation. There was no significant correlation between DGM and total mercury (THg), reactive mercury (RHg), dissolved organic carbon (DOC) in the seawater, indicating that THg/RHg and DOC might be not the controlling factors for the DGM formation in our study region. Based on the data of DGM and GEM and a two-layer gas exchange model, Hg(0) fluxes (in the unit of ng m -2 h -1) at air-sea interface were 0.51 ± 1.29 over the entire study period with 0.89 ± 1.84 in fall, 0.88 ± 1.38 in summer, 0.32 ± 0.71 in spring, and -0.06 ± 0.64, a slightly net Hg(0) deposition rate, in winter, respectively.

  1. The Greenlandic sea areas and activity level up to 2025

    DEFF Research Database (Denmark)

    Jakobsen, Uffe; í Dali, Birita

    2016-01-01

    , petroleum activity, tourism and research/government activity. The last chapter is devoted to summarizing findings about the current developed activity level in the High North sea and coastal regions and the estimated activity level up to 2025. Possible implications for the preparedness system in the High....... It includes an overview of types of vessels and other objects involved in different activities, and the volume of traffic connected to different types of activities, such as fisheries, petroleum, tourism, navy and research. Furthermore, this report estimates the maritime activity level in the area the next...

  2. A numerical study of the South China Sea Warm Current during winter monsoon relaxation

    Science.gov (United States)

    Zhang, Cong; Ding, Yang; Bao, Xianwen; Bi, Congcong; Li, Ruixiang; Zhang, Cunjie; Shen, Biao; Wan, Kai

    2018-03-01

    Using a Finite-Volume Community Ocean Model, we investigated the dynamic mechanism of the South China Sea Warm Current (SCSWC) in the northern South China Sea (NSCS) during winter monsoon relaxation. The model reproduces the mean surface circulation of the NSCS during winter, while model-simulated subtidal currents generally capture its current pattern. The model shows that the current over the continental shelf is generally southwestward, under a strong winter monsoon condition, but a northeastward counter-wind current usually develops between 50-and 100-m isobaths, when the monsoon relaxes. Model experiments, focusing on the wind relaxation process, show that sea level is elevated in the northwestern South China Sea (SCS), related to the persistent northeasterly monsoon. Following wind relaxation, a high sea level band builds up along the mid-shelf, and a northeastward current develops, having an obvious vertical barotropic structure. Momentum balance analysis indicates that an along-shelf pressure gradient provides the initial driving force for the SCSWC during the first few days following wind relaxation. The SCSWC subsequently reaches a steady quasi-geostrophic balance in the cross-shelf direction, mainly linked to sea level adjustment over the shelf. Lagrangian particle tracking experiments show that both the southwestward coastal current and slope current contribute to the northeastward movement of the SCSWC during winter monsoon relaxation.

  3. Antibiotics in the offshore waters of the Bohai Sea and the Yellow Sea in China: Occurrence, distribution and ecological risks

    International Nuclear Information System (INIS)

    Zhang, Ruijie; Tang, Jianhui; Li, Jun; Zheng, Qian; Liu, Di; Chen, Yingjun; Zou, Yongde; Chen, Xiaoxiang; Luo, Chunling; Zhang, Gan

    2013-01-01

    The ocean is an important sink of land-based pollutants. Previous studies showed that serious antibiotic pollution occurred in the coastal waters, but limited studies focused on their presence in offshore waters. In this study, eleven antibiotics in three different categories were investigated in offshore waters of the Bohai Sea and the Yellow Sea in China. The results indicated that three antibiotics dehydration erythromycin, sulfamethoxazole and trimethoprim occurred throughout the offshore waters at concentrations of 0.10–16.6 ng L −1 and they decreased exponentially from the rivers to the coastal and offshore waters. The other antibiotics all presented very low detection rates ( −1 ). Although the concentrations were very low, risk assessment based on the calculated risk quotients (RQs) showed that sulfamethoxazole, dehydration erythromycin and clarithromycin at most of sampling sites posed medium or low ecological risks (0.01 −1 . ► Their concentrations decreased exponentially from the rivers to the offshore waters. ► Some antibiotics in the offshore water posed medium or low risks to some organisms. -- Some antibiotics were ubiquitous in the offshore waters of the Bohai Sea and the Yellow Sea in China and posed medium or low ecological risks to some sensitive organisms

  4. Assessment on vulnerability of coastal wetlands to sea level rise in the Yangtze Estuary, China

    Science.gov (United States)

    Cui, L.; Ge, Z.; Zhang, L.

    2013-12-01

    The Yangtze Delta in China is vital economic hubs in terms of settlement, industry, agriculture, trade and tourism as well as of great environmental significance. In recent decades, the prospect of climate change, in particular sea level rise and its effects on low lying coastal areas have generated worldwide attention to coastal ecosystems. Coastal wetlands, as important parts of coastal ecosystem, are particularly sensitive to sea level rise. To study the responses of coastal wetlands to climate change, assess the impacts of climate change on coastal wetlands and formulate feasible and practical mitigation strategies are the important prerequisites for securing the coastal zone ecosystems. In this study, taking the coastal wetlands in the Yangtze Estuary as a case study, the potential impacts of sea-level rise to coastal wetlands habitat were analyzed by the Source-Pathway-Receptor-Consequence (SPRC) model. The key indicators, such as the sea-level rise rate, subsidence rate, elevation, daily inundation duration of habitat and sedimentation rate, were selected to build a vulnerability assessment system according to the IPCC definition of vulnerability, i.e. the aspects of exposure, sensitivity and adaptation. A quantitatively spatial assessment method on the GIS platform was established by quantifying each indicator, calculating the vulnerability index and grading the vulnerability. The vulnerability assessment on the coastal wetlands in the Yangtze Estuary under the sea level rise rate of the present trend and IPCC A1F1 scenario were performed for three sets of projections of short-term (2030s), mid-term (2050s) and long-term (2100s). The results showed that at the present trend of sea level rise rate of 0.26 cm/a, 92.3 % of the coastal wetlands in the Yangtze Estuary was in the EVI score of 0 in 2030s, i.e. the impact of sea level rise on habitats/species of coastal wetlands was negligible. While 7.4 % and 0.3 % of the coastal wetlands were in the EVI score of

  5. Case studies: Application of SEA in provincial level expressway infrastructure network planning in China - Current existing problems

    International Nuclear Information System (INIS)

    Zhou Kaiyi; Sheate, William R.

    2011-01-01

    Since the Law of the People's Republic of China on Environmental Impact Assessment was enacted in 2003 and Huanfa 2004 No. 98 was released in 2004, Strategic Environmental Assessment (SEA) has been officially being implemented in the expressway infrastructure planning field in China. Through scrutinizing two SEA application cases of China's provincial level expressway infrastructure (PLEI) network plans, it is found that current SEA practice in expressway infrastructure planning field has a number of problems including: SEA practitioners do not fully understand the objective of SEA; its potential contributions to strategic planning and decision-making is extremely limited; the employed application procedure and prediction and assessment techniques are too simple to bring objective, unbiased and scientific results; and no alternative options are considered. All these problems directly lead to poor quality SEA and consequently weaken SEA's effectiveness.

  6. Longtime variation of phytoplankton in the South China Sea from the perspective of carbon fixation

    Science.gov (United States)

    Li, Teng; Bai, Yan; Chen, Xiaoyan; Zhu, Qiankun; Gong, Fang; Wang, Difeng

    2017-10-01

    The ocean is a huge carbon pool in the earth, and about half of the anthropogenic emissions of carbon dioxide are absorbed by the ocean each year. By converting inorganic carbon into organic carbon, the photosynthesis process of phytoplankton affords an important way for carbon sequestration in the ocean. According to previous researches, primary production (NPP) and the structure of phytoplankton community are important in regulate the efficiency of biological carbon pump. This study examined the spatiotemporal variability of satellite remote sensing derived chlorophyll a concentration (Chla), phytoplankton carbon biomass (Carbon), composition ratio of micro-, nano- and pico- phytoplankton, NPP and integrated particulate organic carbon (IPOC) during 1998-2007 in the South China Sea (SCS). Micro-, nano-phytoplankton and NPP showed similar seasonal variation with highest values in winter (January) (especially in the western ocean of Luzon Strait) and lowest values in summer (July) in SCS. Chla, phytoplankton carbon biomass, and IPOC showed different seasonal trends with one peak values occurred in winter and lowest in spring. Two sampling areas (A, N:17-21°, E:117.5-120° and B, N:12.5-15°, E:112-119°) in SCS were selected based on spatial distribution of the standard deviation of research parameters mentioned above. Compared to Chla, phytoplankton carbon biomass, NPP and IPOC, the interannual changes of phytoplankton community structure were remarkable in the two areas. The fraction of micro- and nano- phytoplankton in SCS tend to rise when La Nina events occur. Our results contribute to an understanding of the response of phytoplankton to climate change in the marginal sea. To quantify the efficiency of biological carbon pump in this area, more attention should be paid to the development of remote sensing algorithms of export NPP (or POC export flux) as well as the regulate mechanism of export NPP.

  7. Temperature profile and water depth data collected from COCHRANE in the South China Sea and other seas from 09 January 1987 to 22 February 1987 (NODC Accession 8700095)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and water depth data were collected using BT and XBT from the COCHRANE in the South China and other seas. Data were collected from 09 January...

  8. Spatial variation of biogenic sulfur in the south Yellow Sea and the East China Sea during summer and its contribution to atmospheric sulfate aerosol.

    Science.gov (United States)

    Zhang, Sheng-Hui; Yang, Gui-Peng; Zhang, Hong-Hai; Yang, Jian

    2014-08-01

    Spatial distributions of biogenic sulfur compounds including dimethylsulfide (DMS), dissolved and particulate dimethylsulfoniopropionate (DMSPd and DMSPp) were investigated in the South Yellow Sea (SYS) and the East China Sea (ECS) in July 2011. The concentrations of DMS and DMSPp were significantly correlated with the levels of chlorophyll a in the surface water. Simultaneously, relatively high ratio values of DMSP/chlorophyll a and DMS/chlorophyll a occurred in the areas where the phytoplankton community was dominated by dinoflagellates. The DMSPp and chlorophyll a size-fractionation showed that larger nanoplankton (5-20 μm) was the most important producer of DMSPp in the study area. The vertical profiles of DMS and DMSP were characterized by a maximum at the upper layer and the bottom concentrations were also relatively higher compared with the overlying layer of the bottom. In addition, a positive linear correlation was observed between dissolved dimethylsulfoxide (DMSOd) and DMS concentrations in the surface waters. The sea-to-air fluxes of DMS in the study area were estimated to be from 0.03 to 102.35 μmol m(-2) d(-1) with a mean of 16.73 μmol m(-2) d(-1) and the contribution of biogenic non-sea-salt SO4(2-) (nss-SO4(2-)) to the measured total nss-SO4(2-) in the atmospheric aerosol over the study area varied from 1.42% to 30.98%, with an average of 8.2%. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. A new species of the genus Linuparus White, from the South China Sea (Crustacea Decapoda)

    NARCIS (Netherlands)

    Bruce, A.J.

    1965-01-01

    The palinurid genus Linuparus White, 1847, has been represented by a single recent species, Linuparus trigonus (Von Siebold). The trawl survey of the northern shelf region of the South China Sea at present being carried out by the R.V. "Cape St. Mary" of the Fisheries Research Station, Hong Kong,

  10. Thermoluminescence dating of abyssal deposits in the north region of the South China Sea

    International Nuclear Information System (INIS)

    Peng Xiaoxian

    1988-01-01

    The ages of abyssal deposits have been studied by TL dating. The ages of the deposits from the wells Weima 1, 5 and 6 at the slope in the north of the South China Sea are 36,100 and 128 thousand years respectively

  11. New species of the genus Sinularia (Octocorallia: Alcyonacea) from Nha Trang Bay, South China Sea, Vietnam

    NARCIS (Netherlands)

    Dautova, T.N.; Ofwegen, van L.P.; Savinkin, O.V.

    2010-01-01

    A total of eight Sinularia species is described and depicted, all from Nha Trang Bay, Vietnam (South China Sea). Six are new to science: S. capricornis, S. multiflora, S. pumila, S. sarmentosa, S. torta, and S. uva. Two other ones represent just new records for Vietnam: S. rigida (Dana, 1846) and S.

  12. Nannastacidae (Crustacea: Cumacea) from the Malayan shallow waters (South China Sea)

    NARCIS (Netherlands)

    Petrescu, Iorgu

    1997-01-01

    Four new species from the South China Sea are described: Nannastacus muelleri n.sp., Nannastacus wisseni n.sp., Scherocumella fagei n.sp. and Scherocumella malayensis n.sp. The descriptions of further 15 known species are complemented with new information ( Campylaspis amblyoda Gamo, 1960, Cumella

  13. CNA Maritime Asia Project. Workshop One: The Yellow and East China Seas

    Science.gov (United States)

    2012-05-01

    in 2011.8 In October, South Korean Coast Guard forces used tear gas and rubber bullets to subdue Chinese fishermen wielding clubs and shovels.9 An...tation Disputes in the East China Sea,” NBR Special Report No.35 (December 2011): 135 and 141. 39 CNA Maritime Asia Project Workshop One: The Yellow

  14. Numerical Forecasting Experiment of the Wave Energy Resource in the China Sea

    Directory of Open Access Journals (Sweden)

    Chong Wei Zheng

    2016-01-01

    Full Text Available The short-term forecasting of wave energy is important to provide guidance for the electric power operation and power transmission system and to enhance the efficiency of energy capture and conversion. This study produced a numerical forecasting experiment of the China Sea wave energy using WAVEWATCH-III (WW3, the latest version 4.18 wave model driven by T213 (WW3-T213 and T639 (WW3-T639 wind data separately. Then the WW3-T213 and WW3-T639 were verified and compared to build a short-term wave energy forecasting structure suited for the China Sea. Considering the value of wave power density (WPD, “wave energy rose,” daily and weekly total storage and effective storage of wave energy, this study also designed a series of short-term wave energy forecasting productions. Results show that both the WW3-T213 and WW3-T639 exhibit a good skill on the numerical forecasting of the China Sea WPD, while the result of WW3-T639 is much better. Judging from WPD and daily and weekly total storage and effective storage of wave energy, great wave energy caused by cold airs was found. As there are relatively frequent cold airs in winter, early spring, and later autumn in the China Sea and the surrounding waters, abundant wave energy ensues.

  15. Stability of submarine slopes in the northern South China Sea: a numerical approach

    Science.gov (United States)

    Zhang, Liang; Luan, Xiwu

    2013-01-01

    Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained ( Φ=0) cases. Results show that submarine slopes are stable when the slope is 13° with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes >10°, and >3° for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.

  16. Sources of new nitrogen in the Vietnamese upwelling region of the South China Sea

    DEFF Research Database (Denmark)

    Bombar, Deniz; Dippner, Joachim W.; Doan, Hai Nhu

    2010-01-01

    In the South China Sea, the southwest monsoon between June and September induces upwelling off the southern central Vietnamese coast. During field campaigns in July 2003 and 2004 we evaluated the importance of nitrate and nitrogen fixation as sources of new nitrogen for phytoplankton primary...

  17. Biogeochemical Impact of Long-Range Transported Dust over Northern South China Sea

    Science.gov (United States)

    Tsay, Si-Chee; Wang, S. H.; Hsu, N. C.

    2011-01-01

    Transpacific transport and impact of Asian dust aerosols have been well documented (e.g., results from ACE-Asia and regional follow-on campaigns), but little is known about dust invasion to the South China Sea (SCS). On 19-21 March 2010, a fierce Asian dust storm affected large areas from the Gobi deserts to the West Pacific, including Taiwan and Hong Kong. As a pilot study of the 7-SEAS (Seven South East Asian Studies) in the northern SCS, detailed characteristics of long-range transported dust aerosols were first observed by a comprehensive set of ground-based instruments deployed at the Dongsha islands (20deg42'52" N, 116deg43'51" E). Aerosol measurements such as particle mass concentrations, size distribution, optical properties, hygroscopicity, and vertical profiles help illustrate the evolution of this dust outbreak. Our results indicate that these dust particles were mixed with anthropogenic and marine aerosols, and transported near the surface. Satellite assessment of biogeochemical impact of dust deposition into open oceans is hindered by our current inability in retrieving areal dust properties and ocean colors over an extensive period of time, particularly under the influence of cloudy conditions. In this paper, we analyze the changes of retrieved Chlorophyll-a (Chl-a) concentration over the northern SCS, considered as oligotophic waters in the spring, from long-term SeaWiFS measurements since 1997. Over the past decade, six long-range transported dust events are identified based on spatiotemporal evolutions of PM10 measurements from regional monitoring stations, with the aid of trajectory analysis. Multi-year composites of Chl-a imagery for dust event and non-dust background during March-April are applied to overcome insufficient retrievals of Chl-a due to cloudy environment. Due to anthropogenic modification within a shallow boundary layer off the densely populated and industrial southeast coast of China, the iron ion activation of deliquescent dust

  18. Chinese Assertiveness in the South China Sea and Southeast Asian Responses

    Directory of Open Access Journals (Sweden)

    Carlyle A. Thayer

    2011-01-01

    Full Text Available This article reviews Chinese assertive behaviour towards the Philippines and Vietnam over South China Sea issues in 2011. The article compares and contrasts Chinese diplomatic behaviour in the period before and after the adoption by ASEAN member states and China of Guidelines for the Implementation the Declaration on Conduct of Parties in the South China Sea in July. In the first period China aggressively asserted its claims to sovereignty by interfering with commercial fishing and oil exploration activities of vessels operating in the Exclusive Economic Zones of Vietnam and the Philippines. Both states resisted Chinese actions. The Philippines allocated increased funding for defence modernization, lobbied ASEAN states and shored up its alliance with the United States. Vietnam too protested Chinese action and undertook symbolic steps to defend national sovereignty. In the second period all states moved to contain South China Sea tensions from affecting their larger bilateral relations. It remains to be seen, however, if proposed confidence building measures will ameliorate Chinese assertiveness.

  19. Detection of Total and Pathogenic Vibrio parahaemolyticus in Shellfish Growing along the South Yellow Sea and the East China Sea.

    Science.gov (United States)

    Han, Feng; Gu, Run-Run; Shen, Xiao-Sheng; Chen, Yuan-Ge; Tian, Liang-Liang; Zhou, Wei-Feng; Cai, You-Qiong

    2017-10-17

    This study was conducted to monitor the densities of total and pathogenic Vibrio parahaemolyticus in 300 samples of nine shellfish species harvested from the coasts of the South Yellow Sea and the East China Sea (N 23° to 34°, E 116° to 124°), People's Republic of China, between May and October 2015. Total V. parahaemolyticus densities were measured, and V. parahaemolyticus isolates were biochemically identified with probes for the thermostable direct hemolysin gene (tdh) and the thermostable direct hemolysin-related hemolysin gene (trh). We found that 202 of the 300 samples were positive for V. parahaemolyticus from all the sites: 58 of the 100 samples from the Fujian province, 71 of the 100 samples from the Zhejiang province, and 73 of the 100 samples from the Jiangsu province. In most (170) of the 300 samples, V. parahaemolyticus densities were 0.3 to 10 most probable number (MPN)/g; five lots exceeded 110 MPN/g, and two lots were estimated at 110 MPN/g. Among the 202 V. parahaemolyticus strains, only one was trh positive. Densities of V. parahaemolyticus in these shellfish were temperature dependent, with highest densities in June and July. Among the nine mollusk species, V. parahaemolyticus was most abundant in the agemaki clam (Sinonovacula constricta). The highest and lowest V. parahaemolyticus prevalences were found in oriental cyclina (Cyclina sinensis, 93.8%) and mussels (Mytilus edulis, 28.1%), respectively. Overall, although V. parahaemolyticus is widely distributed in marine environments, the density of V. parahaemolyticus was low and the prevalence of the main virulence factor was very low in shellfish along the coasts of the South Yellow Sea and East China Sea, which is important from a public health perspective. Data presented here will be useful for correlational research and can be utilized for developing risk management plans that establish food safety guidelines for V. parahaemolyticus in Chinese shellfish.

  20. Energy audit data for a resort island in the South China Sea

    Science.gov (United States)

    Basir Khan, M. Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

    2015-01-01

    The data consists of actual generation-side auditing including the distribution of loads, seasonal load profiles, and types of loads as well as an analysis of local development planning of a resort island in the South China Sea. The data has been used to propose an optimal combination of hybrid renewable energy systems that able to mitigate the diesel fuel dependency on the island. The resort island selected is Tioman, as it represents the typical energy requirements of many resort islands in the South China Sea. The data presented are related to the research article “Optimal Combination of Solar, Wind, Micro-Hydro and Diesel Systems based on Actual Seasonal Load Profiles for a Resort Island in the South China Sea” [1]. PMID:26900590

  1. Data from renewable energy assessments for resort islands in the South China Sea

    Science.gov (United States)

    Basir Khan, M. Reyasudin; Jidin, Razali; Pasupuleti, Jagadeesh

    2015-01-01

    Renewable energy assessments for resort islands in the South China Sea were conducted that involves the collection and analysis of meteorological and topographic data. The meteorological data was used to assess the PV, wind and hydropower system potentials on the islands. Furthermore, the reconnaissance study for hydro-potentials were conducted through topographic maps in order to determine the potential sites suitable for development of run-of-river hydropower generation. The stream data was collected for 14 islands in the South China Sea with a total of 51 investigated sites. The data from this study are related to the research article “Optimal combination of solar, wind, micro-hydro and diesel systems based on actual seasonal load profiles for a resort island in the South China Sea” published in Energy (Khan et al., 2015) [1]. PMID:26779562

  2. China’s Energy Insecurity and the South China Sea Dispute

    Science.gov (United States)

    2011-03-24

    Policy Since 1938 (New York, NY: Penguin Books, 1997), 123-126. 32 Ian Bremmer, “Gathering Storm: America and China in 2020,” World Affairs, 58. 32...from-the- asean-china- fta / (accessed March 21, 2020). 35 73 Jing-dong Yuan, China-ASEAN Relations: Perspectives, Prospects, and Implications for

  3. Preliminary numerical simulation for shallow strata stability of coral reef in South China Sea

    Science.gov (United States)

    Tang, Qinqin; Zhan, Wenhuan; Zhang, Jinchang

    2017-04-01

    Coral reefs are the geologic material and special rock and soil, which live in shallow water of the tropic ocean and are formed through biological and geological action. Since infrastructure construction is being increasingly developed on coral reefs during recent years, it is necessary to evaluate the shallow strata stability of coral reefs in the South China Sea. The paper is to study the borehole profiles for shallow strata of coral reefs in the South China Sea, especially in the hydrodynamic marine environment?, and to establish a geological model for numerical simulation with Geo-Studio software. Five drilling holes show a six-layer shallow structure of South China Sea, including filling layer, mid-coarse sand, coral sand gravel, fine sand, limestone debris and reef limestone. The shallow coral reef profile next to lagoon is similar to "layers cake", in which the right side close to the sea is analogous to "block cake". The simulation results show that coral reef stability depends on wave loads and earthquake strength, as well as the physical properties of coral reefs themselves. The safety factor of the outer reef is greater than 10.0 in the static condition, indicating that outer reefs are less affected by the wave and earthquake. However, the safety factor next to lagoon is ranging from 0.1 to 4.9. The main reason for the variations that the strata of coral reefs close to the sea are thick. For example, the thickness of reef limestone is more than 10 m and equivalent to the block. When the thickness of inside strata is less than 10 m, they show weak engineering geological characteristics. These findings can provide useful information for coral reef constructions in future. This work was funded by National Basic Research Program of China (contract: 2013CB956104) and National Natural Science Foundation of China (contract: 41376063).

  4. Primary production in the Sulu Sea

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    its remotely sensed values from OCTS (Ocean Colour Temperature Scanner) are found to be in ... Although the Sulu Sea is more productive than the adjacent South China Sea, the central area ... surrounding ocean by a chain of islands.

  5. Morphodynamics of Wadden Sea Areas – Field Measurements and Modeling

    Directory of Open Access Journals (Sweden)

    Thorsten Albers

    2010-09-01

    Full Text Available The Wadden Sea areas of the German North Sea coast are affected by intense morphodynamics. Especially in the mouths of the estuaries sedimentation and erosion occur on different temporal and spatial scales and therefore challenge the decision-makers. To satisfy the requirements, which modern maritime traffic demands, a sustainable concept for sediment management has to be developed to grant an economic and ecologic balanced system. To evaluate different actions and their effects, e.g. by means of numerical models, an improved knowledge of morphodynamic processes on tidal flats is required. The Institute of River and Coastal Engineering at the Hamburg University of Technology runs detailed measurements to collect hydrodynamic and morphodynamic data of tidal flats in the estuary Elbe, that is the approach to the port of Hamburg. Water levels, flow and wave parameters and concentrations of suspended sediments are recorded in high resolution. Furthermore, the bathymetry is determined in frequent intervals with a multi-beam echo sounder.

  6. Sources and accumulation of plutonium in a large Western Pacific marginal sea: The South China Sea.

    Science.gov (United States)

    Wu, Junwen; Dai, Minhan; Xu, Yi; Zheng, Jian

    2018-01-01

    In order to examine the sources of plutonium (Pu) and elaborate its scavenging and accumulation processes, 240 Pu/ 239 Pu atom ratios and 239+240 Pu activities in the water column of the South China Sea (SCS) were determined and compared with our previously reported data for the sediments. Consistently high 240 Pu/ 239 Pu atom ratios that ranged from 0.184-0.250 (average=0.228±0.015), indicative of non-global fallout Pu sources were observed both in the surface water and at depth during 2012-2014. The spatial distribution of the 240 Pu/ 239 Pu atom ratio in the SCS showed a decreasing trend away from the Luzon Strait, which was very consistent with the introduction pathway of the Kuroshio Current. The Kuroshio had an even heavier Pu isotopic ratio ranging from 0.250-0.263 (average=0.255±0.006), traceable to the non-global fallout Pu signature from the Pacific Proving Grounds (PPG). Using a simple two end-member mixing model, we further revealed that this PPG source contributed 41±17% of the Pu in the SCS water column. The 239+240 Pu activities in the SCS surface seawater varied from 1.59 to 2.94mBqm -3 , with an average of 2.34±0.38mBqm -3 . Such an activity level was ~40% higher than that in the Kuroshio. The distribution of 239+240 Pu in the surface seawater further showed a general trend of increase from the Kuroshio to the SCS basin, suggesting significant accumulation of Pu within the SCS. The 239+240 Pu inventory of the water column in the SCS basin at the SEATS station with a total depth of ~3840m was estimated to be ~29Bqm -2 , which was substantially higher than the sediment core estimates made for the SCS basin (3.75Bqm -2 ) but much lower than the sediment core estimates made for the shelf of the northern SCS (365.6Bqm -2 ). Such differences were determined by the lower scavenging efficiency of Pu in the SCS basin compared to the northern SCS shelf. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Sediment compaction and pore pressure prediction in deepwater basin of the South China Sea: Estimation from ODP and IODP drilling well data

    Science.gov (United States)

    Xie, Yangbing; Wu, Tuoyu; Sun, Jin; Zhang, Hanyu; Wang, Jiliang; Gao, Jinwei; Chen, Chuanxu

    2018-02-01

    Overpressure in deepwater basins not only causes serious soft sediment deformation, but also significantly affects the safety of drilling operations. Therefore, prediction of overpressure in sediments has become an important task in deepwater oil exploration and development. In this study, we analyze the drilling data from ODP Leg 184 Sites 1144, 1146, and 1148, and IODP Leg 349 Sites U1431, U1432, U1433, and U1435 to study the sediment compaction and controls in the northern South China Sea. Sedimentation rate, sediment content, distribution area, and buried depth are the factors that influence sediment compaction in the deepwater basin of the South China Sea. Among these factors, the sediment content is the most important. The fitted normal compacted coefficients and mudline porosity for an interval of 50 m shows disciplinary variation versus depth. The pore pressure predicted from different fitted results shows varying overpressure situations. The normal compaction trend from Site 1144 reflects the porosity variation trend in stable deposition basins in the northern South China Sea. The predicted pore pressure shows overpressure at Site 1144, which is attributed to compaction disequilibrium. Nevertheless, the mixed lithology column may influence the predicted over-pressure at Site 1148, which is responsible for the confusing result. Above all, we find that sediment compaction should serve as a proxy for pore pressure in the deepwater basin of the South China Sea.

  8. Isotopic composition and distribution of plutonium in northern South China Sea sediments revealed continuous release and transport of Pu from the Marshall Islands.

    Science.gov (United States)

    Wu, Junwen; Zheng, Jian; Dai, Minhan; Huh, Chih-An; Chen, Weifang; Tagami, Keiko; Uchida, Shigeo

    2014-03-18

    The (239+240)Pu activities and (240)Pu/(239)Pu atom ratios in sediments of the northern South China Sea and its adjacent Pearl River Estuary were determined to examine the spatial and temporal variations of Pu inputs. We clarified that Pu in the study area is sourced from a combination of global fallout and close-in fallout from the Pacific Proving Grounds in the Marshall Islands where above-ground nuclear weapons testing was carried out during the period of 1952-1958. The latter source dominated the Pu input in the 1950s, as evidenced by elevated (240)Pu/(239)Pu atom ratios (>0.30) in a dated sediment core. Even after the 1950s, the Pacific Proving Grounds was still a dominant Pu source due to continuous transport of remobilized Pu from the Marshall Islands, about 4500 km away, along the North Equatorial Current followed by the transport of the Kuroshio current and its extension into the South China Sea through the Luzon Strait. Using a simple two end-member mixing model, we have quantified the contributions of Pu from the Pacific Proving Grounds to the northern South China Sea shelf and the Pearl River Estuary are 68% ± 1% and 30% ± 5%, respectively. This study also confirmed that there were no clear signals of Pu from the Fukushima Daiichi Nuclear Power Plant accident impacting the South China Sea.

  9. Sensitivity of sediment magnetic records to climate change during Holocene for the northern South China Sea

    Science.gov (United States)

    Ouyang, Tingping; Li, Mingkun; Zhao, Xiang; Zhu, Zhaoyu; Tian, Chengjing; Qiu, Yan; Peng, Xuechao; Hu, Qiao

    2016-05-01

    Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS 14C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: 1) Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; 2) XARM/SIRM was more sensitive to detrital magnetite particles and SIRM/X was more effective to biogenic magnetite particles. Variations of XARM/SIRM and SIRM/X are corresponding to precipitation and temperature, respectively; 3) the Holocene Megathermal in the study area was identified as 7.5-3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1 to 3.9 cal. ka BP; 4) The 8 ka cold event was characterized as cold and dry during 8.55 to 8.25 cal. ka BP; 5) During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka BP.

  10. Sensitivity of sediment magnetic records to climate change during Holocene for the northern South China Sea

    Directory of Open Access Journals (Sweden)

    Tingping eOuyang

    2016-05-01

    Full Text Available Magnetic property has been proved to be a sensitive proxy to climate change for both terrestrial and marine sediments. Based on the schedule frame established by AMS 14C dating of foraminifera, detail magnetic analyses were performed for core PC24 sediments at sampling intervals of 2 cm to discuss magnetic sensitivity of marine sediment to climate during Holocene for the northern South China Sea. The results indicated that: 1 Concentration dependent magnetic parameters are positive corresponding to variation of temperature. The frequency dependent susceptibility coefficient basically reflected the variation in humidity; 2 XARM/SIRM was more sensitive to detrital magnetite particles and SIRM/X was more effective to biogenic magnetite particles. Variations of XARM/SIRM and SIRM/X are corresponding to precipitation and temperature, respectively; 3 the Holocene Megathermal in the study area was identified as 7.5-3.4 cal. ka BP. The warmest stage of Holocene for the study area should be during 6.1 to 3.9 cal. ka BP; 4 The 8 ka cold event was characterized as cold and dry during 8.55 to 8.25 cal. ka BP; 5 During early and middle Holocene, the climate combinations were warm dry and cold wet. It turned to warm and wet after 2.7 cal. ka BP.

  11. China National Scenic Area and Its Planning Characteristics

    Institute of Scientific and Technical Information of China (English)

    Jia Jianzhong; Deng Wugong; Li Caige

    2016-01-01

    Thirty years since the foundation of China's scenic area system,a comparatively comprehensive structural system,legal system,and management system have been established in this field,which has protected precious landscape resources and made remarkable achievements.The planning of scenic areas has its own attributes and technical characteristics,which attaches great importance to establishing a functional structure that combines the three systems of sightseeing,tourism services,and social management of local residents.Moreover,with the development of scenic areas,the planning will lay more emphasis on the connection between different levels,give full play to the comprehensive function of scenic areas,pay attention to the research on village and town planning within the area,and learn from the experience of national parks in foreign countries.

  12. Income and managing problems of the protected areas in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    n 2000, the authors collected a great quantity of relevant data by investigating more than 50 nature reserves. Based on the analysis of development and management situation of the protected areas in China, the main problems were put forward, such as, no unified management for income and managing activities, lack of special guideline and effective supervision, lack of income and investment, investing financial difference in different provinces. All these problems caused the lack of funds for construction, as well as the damage of resources and environment. Furthermore the conserving activities have to transmit to the profits in many protected areas. Combined with these problems, the primary solution programmers also were put forward.

  13. Population genetic structure and genetic diversity of Chinese pomfret at the coast of the East China Sea and the South China Sea.

    Science.gov (United States)

    Sun, Peng; Tang, Baojun; Yin, Fei

    2018-05-01

    The Chinese pomfret Pampus chinensis is one of the most economic and ecological important marine fish species in China. In the present study, the population genetic structure and genetic diversity of P. chinensis were evaluated from a total sample size of 180 individuals representing six populations from the East China Sea and the South China Sea using mitochondrial cytochrome c oxidase subunit I (COI) gene. A total of 24 variable sites (including 3 singleton sites and 21 parsimony information sites) were observed, and 18 haplotypes were defined. The haplotype diversity (Hd) of the populations ranged from 0.559 to 0.775, and the nucleotide diversity (π) ranged from 0.330 to 1.090%. Analysis of molecular variance (AMOVA) reveals that the main variation (66.02%) was among individuals within populations. The average pairwise differences and ϕ ST values indicated significant genetic differentiation between Dongxing population and the other populations. The results of the present study are helpful for the sustainable management and utilization of this species.

  14. Seasonal atmospheric deposition and air-sea gaseous exchange of polycyclic aromatic hydrocarbons over the Yangtze River Estuary, East China Sea: Implication for the source-sink processes

    Science.gov (United States)

    Jiang, Y.; Guo, Z.

    2017-12-01

    As the home of the largest port in the world, the Yangtze River Estuary (YRE) in the East China Sea (ECS) is adjacent to the largest economic zone in China with more than 10% of Chinese population and provides one-fifth of national GDP. The YRE is under the path of contaminated East Asian continental outflow. These make the YRE unique for the pollutant biogeochemical cycling in the world. In this work, 94 pairs of air samples and 20 surface seawater samples covering four seasons were collected from a remote receptor site in the YRE from March 2014 to January 2015, in order to explore the seasonal fluxes of air-sea gaseous exchange and atmospheric dry and wet deposition of 15 polycyclic aromatic hydrocarbons (PAHs) and their source-sink processes at the air-sea interface. The average dry and wet deposition fluxes of 15 PAHs were estimated as 879 ± 1393 ng m-2 d-1 and 755 ± 545 ng m-2 d-1, respectively. The gaseous PAHs were released from seawater to atmosphere during the whole year with an average of 3039 ± 2030 ng m-2 d-1. The gaseous exchange of PAHs was referred as the dominant process at the air-sea interface in the YRE as the magnitude of volatilization flux of PAHs exceeded that of the total dry and wet deposition. The gaseous PAH exchange flux was dominated by 3-ring PAHs, with the highest value in summer while lowest in winter, depicting a strong seasonal variation due to temperature, wind speed and air-sea concentration gradient difference among seasons. Based on the simplified mass balance estimation, net 9.6 tons/y of PAHs was volatilized from seawater to atmosphere with an area of approximately 20000 km2 in the YRE. Apart from Yangtze River input and ocean ship emissions in the entire year, the selective release of low molecular weight PAHs from sediments in winter due to re-suspension triggered by the East Asian winter monsoon could be another possible source for dissolved PAHs. This work suggests that the source-sink processes of PAHs at air-sea

  15. Reconciling late Quaternary transgressions in the Bohai Sea, China to the global sea level changes, and new linkage of sedimentary records to three astronomical rhythms

    Science.gov (United States)

    Yi, Liang

    2013-04-01

    The Bohai Sea in China was formed by subsidence during the Cenozoic. Some 2000-3000 m of fluvial, lacustrine and marine sediments has been deposited in the basin (IOCAS 1985), and these sediments have great potentials in high-/low-latitude interaction, environmental impacts on ancient human activities, and other important issues (Liu, 2009; Yi et al. 2012a), because it is influenced by the Siberian-Mongolian Highs and the ITCZ, and is close to the Nihewan basin and the Zhoukoudian site which are both world-renowned for the discovery of Homo erectus. Since the 1970s, hundreds of studies have been conducted around the Bohai Sea and the major results could be summarized as follows (Zhao et al., 1978; IOCAS, 1985; Liu, 2009, and references therein): (1) constrained by radiocarbon dating, TL/OSL or geomagnetic excursion, three transgressions (T1, T2, T3) developed during the Holocene, marine isotopic stage (MIS) 3 and MIS 5, respectively; and (2) regressions occurred at the beginning of glacial stages, i.e. MIS2 and MIS4. However, apparent inconsistency could be found between T2 and T3, and the question is that in the context that MIS 3 is an inter-stadial stage with a global sea level of 60~80 m lower than the present (Chappell et al. 1996), how did T2 occur in the Bohai Sea, and why did T2 have much larger influence than T3 which occurred at the beginning of MIS 5? To correlate regional environmental changes with global pattern and thus to detect the potential interaction between various driving factors on orbital timescales, three cores with a high recovery rate were drilled in the south Bohai Sea. This study was conducted following three perspectives: chronology (Yi et al. 2012b), sea-level change (Yi et al. 2012c) and paleoclimatology (Yi et al. 2012a), and the main results are as follows: 1. Chronology. Luminescence and radiocarbon dating methods were applied in dating these coastal/marine sediments: (1) For Holocene samples, most of the radiocarbon dates agree

  16. Digitisation of Scenic and Historic Interest Areas in China

    Science.gov (United States)

    Yang, C.; Lawson, G.; Sim, J.

    2015-08-01

    Digital documents have become the major information source for heritage conservation practice. More heritage managers today use electronic maps and digital information systems to facilitate management and conservation of cultural heritage. However, the social aspects of digital heritage have not been sufficiently recognised. The aim of this paper is to examine China's `Digital Scenic Area' project, a national program started in 2004, to reveal the political and economic powers behind digital heritage practice. It was found that this project was only conducted within the most popular tourist destinations in China. Tourism information was the main object but information about landscape cultures were neglected in this project. This project also demonstrated that digital management was more like a political or economic symbol rather than a tool for heritage conservation. However, using digital technologies are still considered by the local government as a highly objective way of heritage management. Selected as a typical Scenic Area in China, Slender West Lake in Yangzhou was investigated to identify heritage stakeholder's attitudes toward digital management and the request from local management practice.

  17. Total Lightning Flash Activity Response to Aerosol over China Area

    Directory of Open Access Journals (Sweden)

    Pengguo Zhao

    2017-01-01

    Full Text Available Twelve years of measurements of aerosol optical depth (AOD, cloud fraction, cloud top height, ice cloud optical thickness and lightning flash density from 2001 to 2012 have been analyzed to investigate the effect of aerosols on electrical activity over an area of China. The results show that increasing aerosol loading inspires the convective intensity, and then increases the lightning flash density. The spatial distribution of the correlation between aerosol loading and electrical activity shows a remarkable regional difference over China. The high-correlation regions embody the positive aerosol microphysical effect on the intensity of the electrical activity, while the large-scale processes may play the main role in convection development and producing lightning in low-correlation regions.

  18. Opening of the South China Sea and Upwelling of the Hainan Plume

    Science.gov (United States)

    Yu, Mengming; Yan, Yi; Huang, Chi-Yue; Zhang, Xinchang; Tian, Zhixian; Chen, Wen-Huang; Santosh, M.

    2018-03-01

    Opening of the South China Sea and upwelling of the Hainan Plume are among the most challenging issues related to the tectonic evolution of East Asia. However, when and how the Hainan Plume affected the opening of the South China Sea remains unclear. Here we investigate the geochemical and isotopic features of the 25 Ma mid-ocean ridge basalt (MORB) in the Kenting Mélange, southern Taiwan, 16 Ma MORB drilled by the IODP Expedition 349, and 9 Ma ocean island basalt-type dredged seamount basalt. The 25 Ma MORBs reveal a less metasomatic depleted MORB mantle-like source. In contrast, the Miocene samples record progressive mantle enrichment and possibly signal the contribution of the Hainan Plume. We speculate that MORBs of the South China Sea which could have recorded plume-ridge source mixing perhaps appear since 23.8 Ma. On the contrary, the Paleocene-Eocene ocean island basalt-type intraplate volcanism of the South China continental margin is correlated to decompression melting of a passively upwelling fertile asthenosphere due to continental rifting.

  19. High occurrence of Bathyarchaeota (MCG) in the deep-sea sediments of South China Sea quantified using newly designed PCR primers.

    Science.gov (United States)

    Yu, Tiantian; Liang, Qianyong; Niu, Mingyang; Wang, Fengping

    2017-08-01

    The archaeal phylum Bathyarchaeota, which is composed of a large number of diverse lineages, is widespread and abundant in marine sediments. Environmental factors that control the distribution, abundance and evolution of this largely diversified archaeal phylum are currently unclear. In this study, a new pair of specific primers that target the major marine subgroups of bathyarchaeotal 16S rRNA genes was designed and evaluated to investigate the distribution and abundance of Bathyarchaeota in marine sediments. The abundance of Bathyarchaeota along two sediment cores from the deep-sea sediments of South China Sea (SCS, each from the Dongsha and Shenhu area) was determined. A strong correlation was found between the bathyarchaeotal abundance and the content of total organic carbon (TOC), suggesting an important role of Bathyarchaeota in organic matter remineralisation in the sediments of SCS. Furthermore, diversity analysis revealed that subgroups Bathy-2, Bathy-8 and Bathy-10 were dominant bathyarchaeotal members of the deep-sea sediments in the SCS. Bathy-8 was found predominantly within the reducing and deeper sediment layers, while Bathy-10 occurred preferentially in the oxidizing and shallower sediment layers. Our study lays a foundation for the further understanding of the ecological functions and niche differentiation of the important but not well-understood sedimentary archaeal group. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  20. Phytoplankton diversity in the East China Sea and Yellow Sea measured by PCR-DGGE and its relationships with environmental factors

    Science.gov (United States)

    Sun, Jing; Yu, Zhigang; Gao, Yahui; Zhou, Qianqian; Zhen, Yu; Chen, Hongtao; Zhao, Liyuan; Yao, Qingzhen; Mi, Tiezhu

    2010-03-01

    Relationships between phytoplankton community composition and environmental variables in the East China Sea (ECS) and Yellow Sea (YS) were investigated using geochemical and molecular microbiology methods. The diversity of phytoplankton was characterized using cultivation-independent PCR-based denaturing gradient gel electrophoresis (DGGE). Groups resulting from unweighted pair-group method with arithmetic averages clustering of the DGGE profiles showed good consistency with the eco-environmental characteristics of the sea area they belonged to. Additionally, the clustering results based on DGGE fingerprinting and those based on morphological compositions were practically identical. The relationship of phytoplankton diversity to environmental factors was statistically analyzed. Temperature, dissolved inorganic nitrogen (DIN), and silicate-Si were found significantly related to the phytoplankton community composition. Canonical correspondence analysis (CCA) was performed to reveal the relationship between community composition and these three environmental factors. Generally, values of the ECS are clearly separated from those of the YS in the CCA biplot, due to mainly the effect of temperature and DIN.

  1. Spatial distribution of per- and polyfluoroalkyl compounds in coastal waters from the East to South China Sea

    International Nuclear Information System (INIS)

    Cai Minghong; Zhao Zhen; Yang Haizhen; Yin Zhigao; Hong Qingquan; Sturm, Renate; Ebinghaus, Ralf; Ahrens, Lutz; Cai Minggang; He, Jianfeng; Xie Zhiyong

    2012-01-01

    The spatial distribution of per- and polyfluoroalkyl compounds (PFCs) were investigated in coastal waters collected onboard research vessel Snow Dragon from the East to South China Sea in 2010. All samples were prepared by solid-phase extraction and analyzed using high performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(−)ESI-MS/MS). Concentrations of 9 PFCs, including C 4 and C 8 (PFBS, PFOS) perfluoroalkyl sulfonate (PFSAs), C 5 –C 9 and C 13 (PFPA, PFHxA, PFHpA, PFOA, PFNA, PFTriDA) perfluoroalkyl carboxylates (PFCAs), and N-ethyl perfluorooctane sulfonamide (EtFOSA) were quantified. The ΣPFC concentrations ranged from 133 pg/L to 3320 pg/L, with PFOA (37.5–1541 pg/L), PFBS (23.0–941 pg/L) and PFHpA (0–422 pg/L) as dominant compounds. Concentrations of PFCs were greater in coastal waters along Shanghai, Ningbo, Taizhou, Xiamen and along coastal cities of the Guangdong province compared to less populated areas along the east Chinese coast. Additionally, the comparison with other seawater PFC measurements showed lower levels in this study. - Highlights: ► Concentrations of various ionic PFCs were firstly quantified in coastal waters of China Sea for the first time. ► PFOA and PFBS, PFHxA, PFNA, PFOS, PFHpA were positively correlated which indicates that the same sources. ► The result of this study is useful for global transport models of PFCs. - Concentrations of 9 PFCs were quantified in coastal waters from the East to South China Sea for the first time.

  2. Occurrence and inputs of perfluoroalkyl substances (PFASs) from rivers and drain outlets to the Bohai Sea, China.

    Science.gov (United States)

    Chen, Hong; Wang, Xiaomeng; Zhang, Can; Sun, Ruijun; Han, Jianbo; Han, Gengchen; Yang, Wenchao; He, Xin

    2017-02-01

    Concentrations of 19 PFASs in riverwater, coastal wastewater and effluents from WWTPs which were directly discharged into the Bohai Sea of China were measured and their inputs to this sea area were calculated accordingly. For riverwater samples, the total PFAS concentrations ranged from 13.1 to 69 238 ng/L. PFAS levels in riverwater collected from Liaoning Province were comparable to those from Shandong Province, while they were two orders of magnitude greater than those from Hebei Province and the city of Tianjin. The dominant PFAS patterns were spatially different. PFBS and PFOA were the predominant PFASs in riverwater samples at sites where fluorochemical industry parks are located in Liaoning Province and Shandong Province, respectively. For other sites, PFOA and PFOS were the most abundant PFASs. In contrast, the total PFAS concentrations in coastal wastewater and effluent samples ranged from 16.7 to 7 522 ng/L and from 13.1 to 319 ng/L, respectively. PFOA was dominant in these samples. Inputs of PFASs to the Bohai Sea via riverine flow, discharge of coastal wastewater and effluents were estimated to be 87.3 tons per year. As compared with coastal wastewater and effluent discharge, riverine input was a major source for the PFAS pollution in the Bohai Sea except for PFBS. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Monitoring of chlorophyll-a and sea surface silicate concentrations in the south part of Cheju island in the East China sea using MODIS data

    Science.gov (United States)

    Zhang, Yuanzhi; Huang, Zhaojun; Fu, Dongyang; Tsou, Jin Yeu; Jiang, Tingchen; Liang, X. San; Lu, Xia

    2018-05-01

    Continually supplied with nutrients, phytoplankton maintains high productivity under ideal illumination and temperature conditions. Data in the south part of Cheju Island in the East China Sea (ECS), which has experienced a spring bloom since the 2000s, were acquired during a research cruise in the spring of 2007. Compared with in-situ measurements, MODIS chlorophyll-a measurements showed high stability in this area. Excluding some invalid stations data, the relationships between nutrients and chlorophyll-a concentrations in the study area were examined and compared with the results in 2015. A high positive correlation between silicate and chlorophyll-a concentration was identified, and a regression relationship was proposed. MODIS chlorophyll-a measurements and sea surface temperature were utilized to determine surface silicate distribution. The silicate concentration retrieved from MODIS exhibited good agreement with in-situ measurements with R2 of 0.803, root mean square error (RMSE) of 0.326 μmol/L (8.23%), and mean absolute error (MAE) of 0.925 μmol/L (23.38%). The study provides a new solution to identify nutrient distributions using satellite data such as MODIS for water bodies, but the method still needs to be refined to determine the relationship of chlorophyll-a and nutrients during other seasons to monitor water quality in this and other areas.

  4. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    Directory of Open Access Journals (Sweden)

    Rui Chang

    2015-01-01

    Full Text Available Using accurate inputs of wind speed is crucial in wind resource assessment, as predicted power is proportional to the wind speed cubed. This study outlines a methodology for combining multiple ocean satellite winds and winds from WRF simulations in order to acquire the accurate reconstructed offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS. The wind roses from the Navy Operational Global Atmospheric Prediction System (NOGAPS and ASCAT agree well with these observations from the corresponding in situ measurements. The statistical results comparing in situ wind speed and SAR-based (ASCAT-based wind speed for the whole co-located samples show a standard deviation (SD of 2.09 m/s (1.83 m/s and correlation coefficient of R 0.75 (0.80. When the offshore winds (i.e., winds directed from land to sea are excluded, the comparison results for wind speeds show an improvement of SD and R, indicating that the satellite data are more credible over the open ocean. Meanwhile, the validation of satellite winds against the same co-located mast observations shows a satisfactory level of accuracy which was similar for SAR and ASCAT winds. These satellite winds are then assimilated into the Weather Research and Forecasting (WRF Model by WRF Data Assimilation (WRFDA system. Finally, the wind resource statistics at 100 m height based on the reconstructed winds have been achieved over the study area, which fully combines the offshore wind information from multiple satellite data and numerical model. The findings presented here may be useful in future wind resource assessment based on satellite data.

  5. Origins of terrestrial organic matter in surface sediments of the East China Sea shelf

    Science.gov (United States)

    Zhang, Hailong; Xing, Lei; Zhao, Meixun

    2017-10-01

    Terrestrial organic matter (TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea (ECS) is important for understanding regional carbon cycle. A novel approach combining molecular proxies and compound-specific carbon isotopes is used to quantitatively constrain the origins and transport mechanisms of TOM in surface sediments from the ECS shelf. The content of terrestrial biomarkers of (C27+C29+C31) n-alkanes (52 to 580 ng g-1) revealed a seaward decreasing trend, the δ13CTOC values (-20.6‰ to -22.7‰) were more negative near the coast, and the TMBR (terrestrial and marine biomarker ratio) values (0.06 to 0.40) also revealed a seaward decreasing trend. These proxies all indicated more TOM (up to 48%) deposition in the coastal areas. The Alkane Index, the ratio of C29/(C29+C31) n-alkanes indicated a higher proportion of grass vegetation in the coastal area; While the δ13C values of C29 n-alkane (-29.3‰ to -33.8‰) indicated that terrestrial plant in the sediments of the ECS shelf were mainly derived from C3 plants. Cluster analysis afforded detailed estimates of different-sourced TOM contributions and transport mechanisms. TOM in the Zhejiang-Fujian coastal area was mostly delivered by the Changjiang River, and characterized by higher %TOM (up to 48%), higher %C3 plant OM (68%-85%) and higher grass plant OM (56%-61%); TOM in the mid-shelf area was mostly transported by aerosols, and characterized by low %TOM (less than 17%), slightly lower C3 plant OM (56%-72%) and lower grass plant OM (49%-55%).

  6. Statistics of Acoustic Pulse Signals Through Nonlinear Internal Waves on the Continental Shelf of the Northeastern South China Sea

    National Research Council Canada - National Science Library

    Reeves, Justin M

    2008-01-01

    ...) was conducted from 13 - 15 April 2005 on the continental shelf in the northeast portion of the South China Sea to study the effects of nonlinear internal waves on the transmission of a 400-Hz signal...

  7. Antifouling phenyl ethers and other compounds from the invertebrates and their symbiotic fungi collected from the South China Sea

    KAUST Repository

    Wang, Chao-Yi; Wang, Kai-Ling; Ghosheh, Yanal; Xu, Ying; Chen, Min; Zheng, Juan-Juan; Liu, Min; Shao, Chang-Lun; Wang, Chang-Yun

    2016-01-01

    for their antifouling activities and security. These compounds include 44 natural products isolated from marine invertebrates and their symbiotic microorganisms collected from the South China Sea and 11 structural modified products derived from the isolated compounds

  8. Connectivity of larval cod in the transition area between North Sea and Baltic Sea and potential implications for fisheries management

    DEFF Research Database (Denmark)

    Huwer, Bastian; Hinrichsen, H.-H.; Hüssy, Karin

    2016-01-01

    in the transition area between North Sea and Baltic were investigated to (i) determine long-term trends and variability in advective transport of larvae from spawning grounds to juvenile nursery areas, (ii) estimate the degree of exchange between different management areas, and (iii) compare the results...

  9. Offshore Wind Resources Assessment from Multiple Satellite Data and WRF Modeling over South China Sea

    DEFF Research Database (Denmark)

    Chang, Rui; Rong, Zhu; Badger, Merete

    2015-01-01

    offshore winds which can be used for offshore wind resource assessment. First, wind speeds retrieved from Synthetic Aperture Radar (SAR) and Scatterometer ASCAT images were validated against in situ measurements from seven coastal meteorological stations in South China Sea (SCS). The wind roses from...... (SD) of 2.09 m/s (1.83 m/s) and correlation coefficient of R 0.75 (0.80). When the offshore winds (i.e., winds directed from land to sea) are excluded, the comparison results for wind speeds show an improvement of SD and R, indicating that the satellite data are more credible over the open ocean...

  10. Seasonal variability of thermal fronts in the northern South China Sea from satellite data

    Science.gov (United States)

    Wang, Dongxiao; Liu, Yun; Qi, Yiquan; Shi, Ping

    The 8-year (1991-1998) Pathfinder sea surface temperature data have been applied here to produce the objectively derived seasonality of the oceanic thermal fronts in the northern South China Sea from 17°N to 25°N. Several fronts have been clearly distinguished, namely, Fujian and Guangdong Coastal Water, Pear River Estuary Coastal, Taiwan Bank, Kuroshio Intrusion, Hainan Island East Coast and Tonkin Gulf Coastal fronts. The frontal patterns in winter, spring and summer are quite similar, whereas individual fronts display different modes of seasonal variability due to different mechanisms favoring those fronts.

  11. Persistent and energetic bottom-trapped topographic Rossby waves observed in the southern South China Sea

    Science.gov (United States)

    Shu, Yeqiang; Xue, Huijie; Wang, Dongxiao; Chai, Fei; Xie, Qiang; Cai, Shuqun; Chen, Rongyu; Chen, Ju; Li, Jian; He, Yunkai

    2016-01-01

    Energetic fluctuations with periods of 9–14 days below a depth of 1400 m were observed in the southern South China Sea (SCS) from 5 years of direct measurements. We interpreted such fluctuations as topographic Rossby waves (TRWs) because they obey the dispersion relation. The TRWs persisted from May 24, 2009 to August 23, 2013, and their bottom current speed with a maximum of ~10 cm/s was one order of magnitude greater than the mean current and comparable to the tidal currents near the bottom. The bottom-trapped TRWs had an approximate trapping depth of 325 m and reference wavelength of ~82 km, which were likely excited by eddies above. Upper layer current speed that peaked approximately every 2 months could offer the energy sources for the persistent TRWs in the southern SCS. Energetic bottom-trapped TRWs may have a comparable role in deep circulation to tides in areas with complex topography. PMID:27075644

  12. Spatiotemporal variation characteristics and related affecting factors of dissolved carbohydrates in the East China Sea

    Science.gov (United States)

    He, Zhen; Wang, Qi; Yang, Gui-Peng; Gao, Xian-Chi; Wu, Guan-Wei

    2015-10-01

    Carbohydrates are the largest identified fraction of dissolved organic carbon and play an important role in biogeochemical cycling in the ocean. Seawater samples were collected from the East China Sea (ECS) during June and October 2012 to study the spatiotemporal distributions of total dissolved carbohydrates (TCHOs) constituents, including dissolved monosaccharides (MCHOs) and polysaccharides (PCHOs). The concentrations of TCHOs, MCHOs and PCHOs showed significant differences between summer and autumn 2012, and exhibited an evident diurnal variation, with high values occurring in the daytime. Phytoplankton biomass was identified as the primary factor responsible for seasonal and diurnal variations of dissolved carbohydrates in the ECS. The TCHOs, MCHOs and PCHOs distributions in the study area displayed similar distribution patterns, with high concentrations appearing in the coastal water. The influences of chlorophyll-a, salinity and nutrients on the distributions of these carbohydrates were examined. A carbohydrate enrichment in the near-bottom water was found at some stations, implying that there might be an important source of carbohydrate in the deep water or bottom sediment.

  13. [Feeding habits of Trichiurus lepturus in Beibu Gulf of South China Sea].

    Science.gov (United States)

    Yan, Yun-Rong; Chen, Jun-Lan; Hou, Gang; Lu, Huo-Sheng; Jin, Xian-Shi

    2010-03-01

    From August 2008 to September 2009, the feeding habits of Trichurus lepturus L. in Beibu Gulf of South China Sea were studied by monthly sampling and stomach content analysis. In study area, T. lepturus was euryphagous, which fed on fish, cephalopoda, benthic crustacean, and zooplankton, etc., among which, Bregmaceros rarisquamosu, Decapterus maruadsi, and Acetes chinensis were the main prey components, accounting for 37.99%, 16.42%, and 10.03%, respectively. D. maruadsi and Anchoviella heteroloba appeared throughout the Beibu Gulf all year round, and could be served as the index species for the migration and fishing ground distribution of T. lepturus. The indices feeding intensity and stomach fullness differed significantly among seasons (P 0.05), which peaked in autumn and had an annual average value of 1.97. Cluster analysis revealed that when the preanal length of T. lepturus was 190 mm, i. e., at 50% of maturity length, a clear diet shift happened, from small zooplankton, pelagic fishes, and crustacean for the juveniles to predominantly larger fish and cephalopoda for the adults.

  14. Marine Geoid Undulation Assessment Over South China Sea Using Global Geopotential Models and Airborne Gravity Data

    Science.gov (United States)

    Yazid, N. M.; Din, A. H. M.; Omar, K. M.; Som, Z. A. M.; Omar, A. H.; Yahaya, N. A. Z.; Tugi, A.

    2016-09-01

    Global geopotential models (GGMs) are vital in computing global geoid undulations heights. Based on the ellipsoidal height by Global Navigation Satellite System (GNSS) observations, the accurate orthometric height can be calculated by adding precise and accurate geoid undulations model information. However, GGMs also provide data from the satellite gravity missions such as GRACE, GOCE and CHAMP. Thus, this will assist to enhance the global geoid undulations data. A statistical assessment has been made between geoid undulations derived from 4 GGMs and the airborne gravity data provided by Department of Survey and Mapping Malaysia (DSMM). The goal of this study is the selection of the best possible GGM that best matches statistically with the geoid undulations of airborne gravity data under the Marine Geodetic Infrastructures in Malaysian Waters (MAGIC) Project over marine areas in Sabah. The correlation coefficients and the RMS value for the geoid undulations of GGM and airborne gravity data were computed. The correlation coefficients between EGM 2008 and airborne gravity data is 1 while RMS value is 0.1499.In this study, the RMS value of EGM 2008 is the lowest among the others. Regarding to the statistical analysis, it clearly represents that EGM 2008 is the best fit for marine geoid undulations throughout South China Sea.

  15. A 700-year record of mercury in avian eggshells of Guangjin Island, South China Sea

    International Nuclear Information System (INIS)

    Xu Liqiang; Liu Xiaodong; Sun Liguang; Chen Qianqian; Yan Hong; Liu Yi; Luo Yuhan; Huang Jing

    2011-01-01

    Ancient eggshells over the past 700 years were extracted from an ornithogenic sediment profile on Guangjin Island, South China Sea. Based on SEM and nitrogen isotope analyses, we determined that neither post-depositional processes nor seabirds' dietary changes had a large influence on eggshell Hg levels. The historical change of Hg in these eggshells was reconstructed. Eggshell Hg was a marker for past Hg deposition in marine environment. The eggshell Hg showed three small peaks at around 1300AD, 1600 AD and 1700-1750AD and rapid increase since 1800 AD. Before 1970 AD the Hg deposition in the Xisha area had global distribution characteristics, with increased Hg emissions due to global anthropogenic activities in industrial times. However, after 1970 AD, a further sharp increase up to present day occurred, implying that the Hg production center had gradually shifted from Europe and America to Asia. - Research highlights: → Eggshell Hg is a marker for past mercury deposition in marine environment. → This is a Hg record from ancient sequential eggshell samples. → The 700-year record of eggshell Hg is closely related to human activities. → Eggshell Hg suggests the increase of Hg production in Asia over the past decades. - Our work provides a potential use of ancient sequential eggshells to reconstruct past mercury deposition in marine ecosystems.

  16. A 700-year record of mercury in avian eggshells of Guangjin Island, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Xu Liqiang [Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Center, Suzhou, Jiangsu 215123 (China); Liu Xiaodong, E-mail: ycx@ustc.edu.cn [Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026 (China); Sun Liguang, E-mail: slg@ustc.edu.cn [Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026 (China); Chen Qianqian; Yan Hong; Liu Yi; Luo Yuhan; Huang Jing [Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2011-04-15

    Ancient eggshells over the past 700 years were extracted from an ornithogenic sediment profile on Guangjin Island, South China Sea. Based on SEM and nitrogen isotope analyses, we determined that neither post-depositional processes nor seabirds' dietary changes had a large influence on eggshell Hg levels. The historical change of Hg in these eggshells was reconstructed. Eggshell Hg was a marker for past Hg deposition in marine environment. The eggshell Hg showed three small peaks at around 1300AD, 1600 AD and 1700-1750AD and rapid increase since 1800 AD. Before 1970 AD the Hg deposition in the Xisha area had global distribution characteristics, with increased Hg emissions due to global anthropogenic activities in industrial times. However, after 1970 AD, a further sharp increase up to present day occurred, implying that the Hg production center had gradually shifted from Europe and America to Asia. - Research highlights: > Eggshell Hg is a marker for past mercury deposition in marine environment. > This is a Hg record from ancient sequential eggshell samples. > The 700-year record of eggshell Hg is closely related to human activities. > Eggshell Hg suggests the increase of Hg production in Asia over the past decades. - Our work provides a potential use of ancient sequential eggshells to reconstruct past mercury deposition in marine ecosystems.

  17. Assessment of Light Pollution Impact on Protected Areas in China

    Science.gov (United States)

    Jiang, W.; He, G.; Ni, Y.

    2017-09-01

    The Protected Areas (PAs) with natural, ecological and cultural value play important role in biological processes, biodiversity and ecosystem service. During the past years of rapid urban expansion in China, the spatial range and intensity of light pollution unprecedented increase. Historically, optical remote sensing and field survey data had been used to reveal that human activities impacted on PAs for individual areas and few papers documented the issue of light pollution impact on PAs at national scale. Here, time series night-time light satellite images of Defense Meteorological Satellite Program Operational Linescan System (DMSP-OLS) were selected to assess the light pollution impacted on PAs in China. The method we proposed can be effectively applied to assess the impact of light pollution on PAs and the percent of dark PAs decreased by 35.38 % from 1992 to 2012 at nationwide. The trend of light pollution of most PAs in stable, however, light pollution of the local area is increase significantly, especially in northern Xinjiang, Gansu, Xizang, Yunnan, Jiangsu and Shandong. Considering the current status of light pollution encroach into PAs, two strategies of appropriate buffer zone and wide measured for light pollution are also recommend.

  18. Did opening of the South China Sea impact development of the Asian Monsoon? Results from Oligocene microfossils, IODP Site U1435, northern South China Sea

    Science.gov (United States)

    Kulhanek, Denise K.; Su, Xin; Li, Qianyu; Gregory, Mitch; Warny, Sophie; Clift, Peter D.

    2016-04-01

    Development of the Asian Monsoon is linked to uplift of the Himalayas and Tibetan Plateau in the Cenozoic, with good evidence for a strong monsoon system by the late Oligocene to early Miocene (e.g., Guo et al., 2002; Clift et al., 2008). However, Licht et al. (2014) suggested the presence of an Asian Monsoon in the late Eocene. Recent scientific ocean drilling in the Indian Ocean and surrounding marginal seas gives us the opportunity to test this hypothesis with newly recovered Paleogene sediment cores. International Ocean Discovery Program Expedition 349 to the South China Sea recovered a 30 m section of primarily lower Oligocene nannofossil-rich claystone at Site U1435, located near the northern continent/ocean boundary. A thick sandstone unit devoid of typical marine microfossils underlies the marine claystone. The sandstone is interpreted as a deltaic or restricted marine deposit and is dated to the Eocene based on the presence of organic-walled palynomorphs, suggesting that a hiatus of several million years likely separates the sandstone below from the Oligocene marine claystone. This hiatus is interpreted as the breakup unconformity, with paleodepths in the South China Sea increasing during the Oligocene. Thus, this claystone should record if opening of the South China Sea during the early Oligocene influenced development of the Asian Monsoon. Combined calcareous nannofossil and planktonic foraminifer biostratigraphy indicates that the 30 m section is primarily early Oligocene in age (~33.5-30 Ma) and was deposited on the middle slope, with paleodepths >500 m. Stable oxygen isotopes from planktonic foraminifers become heavier up-hole, suggestive of cooling/deepening in the region, whereas carbon isotopes record variable conditions with no distinct maxima or minima. Calcareous nannoplankton primarily live in the upper 50 m of the ocean and are sensitive to sea-surface temperature and nutrient conditions, thus making them useful recorders of paleoceanographic

  19. Environment-Dependent Distribution of the Sediment nifH-Harboring Microbiota in the Northern South China Sea

    Science.gov (United States)

    Yang, Jinying; Li, Jing; Luan, Xiwu; Zhang, Yunbo; Gu, Guizhou; Xue, Rongrong; Zong, Mingyue; Klotz, Martin G.

    2013-01-01

    The South China Sea (SCS), the largest marginal sea in the Western Pacific Ocean, is a huge oligotrophic water body with very limited influx of nitrogenous nutrients. This suggests that sediment microbial N2 fixation plays an important role in the production of bioavailable nitrogen. To test the molecular underpinning of this hypothesis, the diversity, abundance, biogeographical distribution, and community structure of the sediment diazotrophic microbiota were investigated at 12 sampling sites, including estuarine, coastal, offshore, deep-sea, and methane hydrate reservoirs or their prospective areas by targeting nifH and some other functional biomarker genes. Diverse and novel nifH sequences were obtained, significantly extending the evolutionary complexity of extant nifH genes. Statistical analyses indicate that sediment in situ temperature is the most significant environmental factor influencing the abundance, community structure, and spatial distribution of the sediment nifH-harboring microbial assemblages in the northern SCS (nSCS). The significantly positive correlation of the sediment pore water NH4+ concentration with the nifH gene abundance suggests that the nSCS sediment nifH-harboring microbiota is active in N2 fixation and NH4+ production. Several other environmental factors, including sediment pore water PO43− concentration, sediment organic carbon, nitrogen and phosphorus levels, etc., are also important in influencing the community structure, spatial distribution, or abundance of the nifH-harboring microbial assemblages. We also confirmed that the nifH genes encoded by archaeal diazotrophs in the ANME-2c subgroup occur exclusively in the deep-sea methane seep areas, providing for the possibility to develop ANME-2c nifH genes as a diagnostic tool for deep-sea methane hydrate reservoir discovery. PMID:23064334

  20. Effect of Ocean Interannual Variability on Acoustic Propagation in the Philippine Sea and South China Sea

    Science.gov (United States)

    2017-06-01

    depth in order to analyze the Deep Water (Figure 12). The maximum values are found in the Philippine Sea, eastern part of the Mindanao Island in May...the water column stability. The seasonal variability is modulated by interannual and decadal modes of variability. The same effects were found ...ABSTRACT (maximum 200 words ) Effect of interannual variability of temperature and salinity on acoustic propagation in the Philippine Sea and South

  1. Airborne geoid mapping of land and sea areas of East Malaysia

    Science.gov (United States)

    Jamil, H.; Kadir, M.; Forsberg, R.; Olesen, A.; Isa, M. N.; Rasidi, S.; Mohamed, A.; Chihat, Z.; Nielsen, E.; Majid, F.; Talib, K.; Aman, S.

    2017-02-01

    This paper describes the development of a new geoid-based vertical datum from airborne gravity data, by the Department of Survey and Mapping Malaysia, on land and in the South China Sea out of the coast of East Malaysia region, covering an area of about 610,000 square kilometres. More than 107,000 km flight line of airborne gravity data over land and marine areas of East Malaysia has been combined to provide a seamless land-to-sea gravity field coverage; with an estimated accuracy of better than 2.0 mGal. The iMAR-IMU processed gravity anomaly data has been used during a 2014-2016 airborne survey to extend a composite gravity solution across a number of minor gaps on selected lines, using a draping technique. The geoid computations were all done with the GRAVSOFT suite of programs from DTU-Space. EGM2008 augmented with GOCE spherical harmonic model has been used to spherical harmonic degree N = 720. The gravimetric geoid first was tied at one tide-gauge (in Kota Kinabalu, KK2019) to produce a fitted geoid, my_geoid2017_fit_kk. The fitted geoid was offset from the gravimetric geoid by +0.852 m, based on the comparison at the tide-gauge benchmark KK2019. Consequently, orthometric height at the six other tide gauge stations was computed from HGPS Lev = hGPS - Nmy_geoid2017_.t_kk. Comparison of the conventional (HLev) and GPS-levelling heights (HGPS Lev) at the six tide gauge locations indicate RMS height difference of 2.6 cm. The final gravimetric geoidwas fitted to the seven tide gauge stations and is known as my_geoid2017_fit_east. The accuracy of the gravimetric geoid is estimated to be better than 5 cm across most of East Malaysia land and marine areas

  2. Projections of wind-waves in South China Sea for the 21st century

    Science.gov (United States)

    Mohammed, Aboobacker; Dykyi, Pavlo; Zheleznyak, Mark; Tkalich, Pavel

    2013-04-01

    IPCC-coordinated work has been completed within Fourth Assessment Report (AR4) to project climate and ocean variables for the 21st century using coupled atmospheric-ocean General Circulation Models (GCMs). GCMs are not having a wind-wave variable due to a poor grid resolution; therefore, dynamical downscaling of wind-waves to the regional scale is advisable using well established models, such as Wave Watch III (WWIII) and SWAN. Rectilinear-coordinates WWIII model is adapted for the far field comprising the part of Pacific and Indian Oceans centered at the South China Sea and Sunda Shelf (90 °E-130 °E, 10 °S - 26.83 °N) with a resolution of 10' (about 18 km). Near-field unstructured-mesh SWAN model covers Sunda Shelf and centered on Singapore Strait, while reading lateral boundary values from WWIII model. The unstructured grid has the coarsest resolution in the South China Sea (6 to 10 km), medium resolution in the Malacca Strait (1 to 2 km), and the finest resolution in the Singapore Strait (400 m) and along the Singapore coastline (up to 100 m). Following IPCC methodology, the model chain is validated climatologically for the past period 1961-1990 against Voluntary Observing Ship (VOS) data; additionally, the models are validated using recent high-resolution satellite data. The calibrated model chain is used to project waves to 21st century using WRF-downscaled wind speed output of CCSM GCM run for A1FI climate change scenario. To comply with IPCC methodology the entire modeling period is split into three 30-years periods for which statistical parameters are computed individually. Time series of significant wave height at key points near Singapore and on ship sea routes in the SCS are statistically analysed to get probability distribution functions (PDFs) of extreme values. Climatological maps of mean and maximum significant wave height (SWH) values, and mean wave period are built for Singapore region for each 30-yrs period. Linear trends of mean SWH values

  3. Dynamics of the water circulations in the southern South China Sea and its seasonal transports

    DEFF Research Database (Denmark)

    Daryabor, Farshid; Ooi, See Hai Ooi; Samah, Azizan Abu

    2016-01-01

    -analysis data of the Simple Ocean Data Assimilation. It is found that the seasonal water circulations are mainly driven by the monsoonal wind stress and influenced by the water outflow/inflow and associated currents of the entire South China Sea. The intrusion of the strong current along the East Coast......A three-dimensional Regional Ocean Modeling System is used to study the seasonal water circulations and transports of the Southern South China Sea. The simulated seasonal water circulations and estimated transports show consistency with observations, e.g., satellite altimeter data set and re...... of Peninsular Malaysia and the eddies at different depths in all seasons are due to the conservation of the potential vorticity as the depth increases. Results show that the water circulation patterns in the northern part of the East Coast of Peninsular Malaysia are generally dominated by the geostrophic...

  4. Detection and temporal variation of (60)Co in the digestive glands of the common octopus, Octopus vulgaris, in the East China Sea.

    Science.gov (United States)

    Morita, Takami; Otosaka, Shigeyoshi; Fujimoto, Ken; Nishiuchi, Kou; Kimoto, Katsunori; Yamada, Haruya; Kasai, Hiromi; Minakawa, Masayuki; Yoshida, Katsuhiko

    2010-08-01

    (60)Co were detected in common octopus specimens collected in the East China Sea in 1996-2005. The source of (60)Co has remained unclear yet. Stable isotope analyses showed that there was no difference in stable Co concentrations between octopus samples with (60)Co and without (60)Co. This result showed that the stable Co in the digestive gland of octopus potentially did not include a trace amount of (60)Co and the source of (60)Co existed independently. Furthermore, investigations of octopus in other area and other species indicated that the origin of the source of (60)Co occurred locally in the restricted area in the East China Sea and not in the coastal area of Japan. Concentrations of (60)Co have annually decreased with shorter half-life than the physical half-life. This decrease tendency suggests that the sources of (60)Co were identical and were temporary dumped into the East China Sea as a solid waste. Copyright 2010 Elsevier Ltd. All rights reserved.

  5. Boron isotopic compositions in growing corals from the South China Sea

    Science.gov (United States)

    Xiao, Jun; Xiao, Yingkai; Jin, Zhangdong; Liu, Congqiang; He, Maoyong

    2013-01-01

    In order to determine incorporation of boron species, boron isotopic fractionation, and influence of trace elements on isotopic compositions of boron in corals (δ11Bcoral), concentrations of Mg, Sr, Na, B and δ11Bcoral in growing corals from the South China Sea were measured. Relative to seawater, Sr enriched while Mg depleted in corals in the South China Sea. Although the δ11Bcoral values were different from various species and were not closely correlated with the element concentrations in corals in the South China Sea, Mg(OH)2 existed in corals can result in high δ11Bcoral. Thus, it is necessary to examine the existence of Mg(OH)2 and to choose the same species when δ11Bcoral is used in the δ11B-pH proxy. Based on the measured δ11B values of corals and coexisting seawater as well as the seawater pH in the South China Sea, a new isotopic fractionation factor a4-3 between B(OH)4- and B(OH)3 was determined to be 0.979. Besides B(OH)4- into corals, our results showed that B(OH)3 may also be incorporated into corals with variable proportions. The incorporation of B(OH)3 into corals may challenge the hypothesis of δ11Bcoral = δ11B4, resulting in increasing uncertainty to the calculated seawater pH values to the δ11B-pH proxy. We suggested that a best-fit empirical equation between δ11B of bio-carbonates and seawater pH needs to be established by the precipitation experiments of inorganic carbonates or culture experiments of corals or foraminifera.

  6. Numerical assessment of factors affecting nonlinear internal waves in the South China Sea

    Science.gov (United States)

    Li, Qiang

    2014-02-01

    Nonlinear internal waves in the South China Sea exhibit diverse characteristics, which are associated with the complex conditions in Luzon Strait, such as the double ridge topography, the Earth’s rotation, variations in stratification and the background current induced by the Kuroshio. These effects are individually assessed using the MITgcm. The performance of the model is first validated through comparison with field observations. Because of in-phased ray interaction, the western ridge in Luzon Strait intensifies the semidiurnal internal tides generated from the eastern ridge, thus reinforcing the formation of nonlinear internal waves. However, the ray interaction for K1 forcing becomes anti-phased so that the K1 internal tide generation is reduced by the western ridge. Not only does the rotational dispersion suppress internal tide generation, it also inhibits nonlinear steepening and consequent internal solitary wave formation. As a joint effect, the double ridges and the rotational dispersion result in a paradoxical phenomenon: diurnal barotropic tidal forcing is dominant in Luzon Strait, but semidiurnal internal tides prevail in the deep basin of the South China Sea. The seasonal variation of the Kuroshio is consistent with the seasonal appearance of nonlinear internal waves in the South China Sea. The model results show that the westward inflow due to the Kuroshio intrusion reduces the amplitude of internal tides in the South China Sea, causing the weakening or absence of internal solitary waves. Winter stratification cannot account for the significant reduction of nonlinear internal waves, because the amplitude growth of internal tides due to increased thermocline tilting counteracts the reduced nonlinearity caused by thermocline deepening.

  7. Why Gas Hydrate Occurrenced Over Topographic Highs in Shenhu Area Northern South China Sea?

    Science.gov (United States)

    Liao, J.

    2015-12-01

    Methane gas hydrate has been drilled by China Geological Survey in shenhu area northern south china sea in 2007 .Shenhu area is located in the middle-lower continental slope and 17 submarine canyons are incised into the shelf,gas hydrtae was observed in boreholes over topographic highs,but origin of the hydrate is controversial.Accumulation of gas hydrate is depending on temperature-pressure field and supply quantities of methane and some other factors,in the same depth of the shallow sediments there is the same press,so temperature field and supply quantities of methane become the most important factors.Lachenbruch(1968) calculated the topographic disturbance to geothermal gradients,in shenhu area consistent local variations were observed, notably low heat flow values over prominent topographic highs and high heat flow values over the flanks of the topographic highs. At some localities over a horizontal distance of 2.5 km, heat flow increased by as much as 50%, from typical values of 65 to 100 mW/m2 .Some vertical fractures were observed beneath topographic highs in previous studies.Based on the profile across borehole SH7,we designed four experiments:A,uniform distribution of heat flux with no vertical fractures;B,Uniform distribution of heat flux with vertical fractures beneath geographic highs;C,uneven distribution of heat flux with no vertical fractures;D,uneven distribution of heat flux with vertical fractures beneath geographic highs.According to previous studies,we restored Palaeobathymetry,abundance of organic matters, sandstone-madstone ratio ,porosity and permeability of each,and parameters of vertical fractures.The result of experiment D shows the similar distribution characteristic with the drilling result,so We believe that low heat flux and Vertical fractures are the most important factors . This work was supported by the National Science Foundation of China(grant no. 41406080).

  8. Island building in the South China Sea: detection of turbidity plumes and artificial islands using Landsat and MODIS data

    Science.gov (United States)

    Barnes, Brian B.; Hu, Chuanmin

    2016-01-01

    The South China Sea is currently in a state of intense geopolitical conflict, with six countries claiming sovereignty over some or all of the area. Recently, several countries have carried out island building projects in the Spratly Islands, converting portions of coral reefs into artificial islands. Aerial photography and high resolution satellites can capture snapshots of this construction, but such data are lacking in temporal resolution and spatial scope. In contrast, lower resolution satellite sensors with regular repeat sampling allow for more rigorous assessment and monitoring of changes to the reefs and surrounding areas. Using Landsat-8 data at ≥15-m resolution, we estimated that over 15 km2 of submerged coral reef area was converted to artificial islands between June 2013 and December 2015, mostly by China. MODIS data at ≥250-m resolution were used to locate previously underreported island building activities, as well as to assess resulting in-water turbidity plumes. The combined spatial extent of observed turbidity plumes for island building activities at Mischief, Subi, and Fiery Cross Reefs was over 4,300 km2, although nearly 40% of this area was only affected once. Together, these activities represent widespread damage to coral ecosystems through physical burial as well as indirect turbidity effects. PMID:27628096

  9. Island building in the South China Sea: detection of turbidity plumes and artificial islands using Landsat and MODIS data.

    Science.gov (United States)

    Barnes, Brian B; Hu, Chuanmin

    2016-09-15

    The South China Sea is currently in a state of intense geopolitical conflict, with six countries claiming sovereignty over some or all of the area. Recently, several countries have carried out island building projects in the Spratly Islands, converting portions of coral reefs into artificial islands. Aerial photography and high resolution satellites can capture snapshots of this construction, but such data are lacking in temporal resolution and spatial scope. In contrast, lower resolution satellite sensors with regular repeat sampling allow for more rigorous assessment and monitoring of changes to the reefs and surrounding areas. Using Landsat-8 data at ≥15-m resolution, we estimated that over 15 km(2) of submerged coral reef area was converted to artificial islands between June 2013 and December 2015, mostly by China. MODIS data at ≥250-m resolution were used to locate previously underreported island building activities, as well as to assess resulting in-water turbidity plumes. The combined spatial extent of observed turbidity plumes for island building activities at Mischief, Subi, and Fiery Cross Reefs was over 4,300 km(2), although nearly 40% of this area was only affected once. Together, these activities represent widespread damage to coral ecosystems through physical burial as well as indirect turbidity effects.

  10. Population genetics of Thamnaconus hypargyreus (Tetraodontiformes: Monacanthidae) in the South China Sea.

    Science.gov (United States)

    Li, Yufang; Chen, Guobao; Yu, Jie; Wu, Shuiqing; Xiong, Dan; Li, Xia; Cui, Ke; Li, Yongzhen

    2016-01-01

    Knowledge of population structure is particularly important for long-term fisheries management and conservation. Lesser-spotted leatherjacket Thamnaconus hypargyreus is an economically important fish species in the South China Sea. Fish specimens (totally 158 individuals) used in this study were collected from five geographical locations in the north of the South China Sea and the southwestern Nansha Islands. The results were as follows: a total of 636 nucleotides of the mitochondrial DNA (mtDNA) control region (CR) of T. hypargyreus were amplified by polymerase chain reaction (PCR) technology. Both 103 mutations of nucleotide acids without inserting or deleting one and 91 haplotypes were found among the examined CR fragment. High haplotype diversity (0.9419 ± 0.0151) and nucleotide diversity (0.0095 ± 0.00506) relatively together with a recent and sudden population expansion which characterizes the genetic population structure of this species. Analysis of molecular variance (AMOVA) and the fixation indices (Fst) of five groups showed that the genetic variance mainly came from individuals within groups, and there was no genetic differentiation between groups. The phylogenetic trees including maximum likelihood (ML) and Bayesian inference (BI) proved no phylogeographic differentiation structure in five groups. The mtDNA marker suggested the five groups should be genetic homogeneity, which implied T. hypargyreus in the north and southwest continental shelf of the South China Sea belongs to one population.

  11. Bioprospecting of Novel and Bioactive Compounds from Marine Actinomycetes Isolated from South China Sea Sediments.

    Science.gov (United States)

    Yang, Na; Song, Fuhang

    2018-02-01

    Marine actinomycetes are less investigated compared to terrestrial strains as potential sources of natural products. To date, few investigations have been performed on culturable actinomycetes associated with South China Sea sediments. In the present study, twenty-eight actinomycetes were recovered from South China Sea sediments after dereplication by traditional culture-dependent method. The 16S rRNA gene sequences analyses revealed that these strains related to five families and seven genera. Twelve representative strains possessed at least one of the biosynthetic genes coding for polyketide synthase I, II, and nonribosomal peptide synthetase. Four strains had anti-Mycobacterium phlei activities and five strains had activities against methicillin-resistant Staphylococcus aureus. 10 L-scale fermentation of strains Salinispora sp. NHF45, Nocardiopsis sp. NHF48, and Streptomyces sp. NHF86 were carried out for novel and bioactive compounds discovery. Finally, we obtained a novel α-pyrone compound from marine Nocardiopsis sp. NHF48, an analogue of paulomenol from marine Streptomyces sp. NHF86 and a new source of rifamycin B, produced by Salinispora sp. NHF45. The present study concluded that marine actinomycetes, which we isolated from South China Sea sediments, will be a suitable source for the development of novel and bioactive compounds.

  12. Molecular approach to the identification of fish in the South China Sea.

    Directory of Open Access Journals (Sweden)

    Junbin Zhang

    Full Text Available BACKGROUND: DNA barcoding is one means of establishing a rapid, accurate, and cost-effective system for the identification of species. It involves the use of short, standard gene targets to create sequence profiles of known species against sequences of unknowns that can be matched and subsequently identified. The Fish Barcode of Life (FISH-BOL campaign has the primary goal of gathering DNA barcode records for all the world's fish species. As a contribution to FISH-BOL, we examined the degree to which DNA barcoding can discriminate marine fishes from the South China Sea. METHODOLOGY/PRINCIPAL FINDINGS: DNA barcodes of cytochrome oxidase subunit I (COI were characterized using 1336 specimens that belong to 242 species fishes from the South China Sea. All specimen provenance data (including digital specimen images and geospatial coordinates of collection localities and collateral sequence information were assembled using Barcode of Life Data System (BOLD; www.barcodinglife.org. Small intraspecific and large interspecific differences create distinct genetic boundaries among most species. In addition, the efficiency of two mitochondrial genes, 16S rRNA (16S and cytochrome b (cytb, and one nuclear ribosomal gene, 18S rRNA (18S, was also evaluated for a few select groups of species. CONCLUSIONS/SIGNIFICANCE: The present study provides evidence for the effectiveness of DNA barcoding as a tool for monitoring marine biodiversity. Open access data of fishes from the South China Sea can benefit relative applications in ecology and taxonomy.

  13. Variation of Synechococcus Pigment Genetic Diversity Along Two Turbidity Gradients in the China Seas.

    Science.gov (United States)

    Xia, Xiaomin; Liu, Hongbin; Choi, Donghan; Noh, Jae Hoon

    2018-01-01

    Synechococcus are important and widely distributed picocyanobacteria that encompass a high pigment diversity. In this study, we developed a primer set (peBF/peAR) for amplifying the cpeBA operon sequence from Synechococcus genomic DNA to study Synechococcus pigment diversity along two turbidity gradients in the China seas. Our data revealed that all previously reported pigment types occurred in the South (SCS) and East (ECS) China Seas. In addition, a novel pigment genetic type (type 3f), represented by the high phycourobilin Synechococcus sp. strain KORDI-100 (Exc495:545 = 2.35), was detected. This pigment genetic type differs from the 3c/3d types not only for a very high PUB/PEB ratio but also for a different intergenic spacer sequence and gene organization of the phycobilisome. Synechococcus of different pigment types exhibited clear niche differentiation. Type 2 dominated in the coastal waters, whereas type 3c/3d and 3f were predominant in oceanic waters of the SCS in summer. In the ECS, however, type 3a was the major pigment type throughout the transect. We suggest that in marine environment, various pigment types often co-occur but with one type dominant and PUB/PEB ratio is related to geographic distribution of Synechococcus pigment types. The two marginal seas of China have markedly different Synechococcus pigment compositions.

  14. Interannual variation of the South China Sea circulation during winter: intensified in the southern basin

    Science.gov (United States)

    Zu, Tingting; Xue, Huijie; Wang, Dongxiao; Geng, Bingxu; Zeng, Lili; Liu, Qinyan; Chen, Ju; He, Yunkai

    2018-05-01

    Surface geostrophic current derived from altimetry remote sensing data, and current profiles observed from in-situ Acoustic Doppler Current Profilers (ADCP) mooring in the northern South China Sea (NSCS) and southern South China Sea (SSCS) are utilized to study the kinetic and energetic interannual variability of the circulation in the South China Sea (SCS) during winter. Results reveal a more significant interannual variation of the circulation and water mass properties in the SSCS than that in the NSCS. Composite ananlysis shows a significantly reduced western boundary current (WBC) and a closed cyclonic eddy in the SSCS at the mature phase of El Niño event, but a strong WBC and an unclosed cyclonic circulation in winter at normal or La Niña years. The SST is warmer while the subsurface water is colder and fresher in the mature phase of El Niño event than that in the normal or La Niña years in the SSCS. Numerical experiments and energy analysis suggest that both local and remote wind stress change are important for the interannual variation in the SSCS, remote wind forcing and Kuroshio intrusion affect the circulation and water mass properties in the SSCS through WBC advection.

  15. Wind energy for water pumping in rural areas of China

    International Nuclear Information System (INIS)

    Dechang, S.

    1991-01-01

    After 1980, as the supply of conventional energy has not been able to follow the tremendous increase of the production demand in rural areas of China, a renewed interest for the application of wind energy was shown in many places. Therefore, the Chinese government began to pay more attention to wind energy utilization in rural areas. During the last ten years, several R ampersand D tasks for new modern wind pumps were carried out. Among them, three projects are the developments of wind energy screw pump systems (FDG-5 wind pump, FDG-7 wind pump and TFS-5 wind pump). At present, 50 of these wind pumps are working successfully in the rural areas for farmland drainage, salt ponds water lifting and aquatic product breeding, etc. The field tests show that these wind energy screw pump systems are suitable for low lifting head (< 3 meter) and large water flow (50 m/hr to 120 m/hr) operation in the coastal areas. Because the wind energy resource in many rural areas is sufficient for attractive application of wind pumps, and the supply of electricity as well as fuels is insufficient in these areas, the wind pumps will be spread on a rather large scale in the near future. 7 figs., 2 tabs., 3 refs

  16. The potential of wave and offshore wind energy in around the coastline of Malaysia that face the South China Sea

    International Nuclear Information System (INIS)

    Chiang, E.P.; Zainal, Z.A.; Aswatha Narayana, P.A.; Seetharamu, K.N.

    2006-01-01

    The world wide estimated wave resource is more than 2 TW. Offshore wind speeds are generally higher than wind speeds over land, hence higher available energy resource. The estimated offshore wind potential in European waters alone is in excess of 2500 TWh/annum. Offshore area also provides larger area for deploying wind energy devices. In recent year efforts to promote these two types of renewable and green energy sources have been intensify. Using the data obtained from the Malaysia Meteorological Service (MMS) analysis was conducted for the potential of wave energy and wind energy along the coastline of Malaysia facing the South China Sea. Maps of wave power potential were produced. The mean vector wind speed and direction were tabulated

  17. Solar Lighting Technologies for Highway Green Rest Areas in China: Energy Saving Economic and Environmental Evaluation

    Directory of Open Access Journals (Sweden)

    Xiaochun Qin

    2015-01-01

    Full Text Available In this paper, taking Lushan West Sea highway green rest area in Jiangxi Province of China as the case study, the suitable types, applicability, advantages, and effective methods of solar lighting technologies for highway rest area were determined based on the analysis of characteristics of highway green rest area. It was proved that solar lighting technologies including the natural light guidance system, solar LED lighting, and maximizing natural light penetration were quite suitable for highway rest area in terms of lighting effects and energy and economic efficiency. The illuminance comparison of light guidance system with electrical lighting was made based on the on-site experiment. Also, the feasibility of natural light guidance system was well verified in terms of the lighting demand of the visitor centre in the rest area by the illuminance simulation analysis. The evaluation of the energy saving, economic benefits, and environmental effects of solar lighting technologies for highway rest area was, respectively, made in detail. It was proved that the application of solar technology for green lighting of highway rest facilities not only could have considerable energy saving capacity and achieve high economic benefits, but also make great contributions to the reduction of environment pollution.

  18. Organic walled dinoflagellate cysts from the Tarim Basin, western China: Implications for the retreat of the Paratethys Sea

    NARCIS (Netherlands)

    Grothe, A.; Houben, A.J.P.; Bosboom, R.E.; Dupont-Nivet, G.; Brinkhuis, H.

    2011-01-01

    Paleogene sediments of the Tarim basin in western China hold the easternmost extent of the Paratethys Sea, an epicontinental sea that covered a large part of Eurasia and probably extended to the Mediterranean Tethys in the west. The late Cretaceous and Paleogene sedimentary record of the

  19. Decadal Shift in West China Autumn Precipitation and its Association With Sea Surface Temperature

    Science.gov (United States)

    Wei, Ting; He, Shengping; Yan, Qing; Dong, Wenjie; Wen, Xiaohang

    2018-01-01

    West China autumn precipitation (WCAP) is the final stage of the rainy season in mainland China and is characterized as the secondary peak in annual cycle of precipitation in West China. This study reveals that WCAP experienced a significant interdecadal shift around the mid-1980s, with greatly reduced precipitation after this shift. Features related to the decrease in WCAP include the weakening of warm, wet southerlies prevailing from the oceans to inland China, the weakened Eurasian pattern, and the southward displacement of the East Asian jet stream (EAJS). Further analysis indicates that the interdecadal changes in WCAP may be attributed to the interdecadal increasing of sea surface temperature (SST) in the Indo-Pacific warm pool (SSTIOP), North Pacific (SSTNP), and central equatorial Pacific (SSTCEP) after the 1980s. The warmer SSTIOP contributes to a weaker meridional land-sea thermal contrast, which inducts an anomalous local meridional circulation and northerly. The warmer SSTNP stimulates a Rossby wave train that leads to weakened West Pacific subtropical high and accompanying cyclonic circulation anomaly, hindering the transport of water vapor inland from the oceans. The increased SSTCEP leads to the southward displacement of the EAJS and its secondary circulation, generating an anomalous descending branch and reduced WCAP. Numerical simulations further support the conclusions derived from the diagnostic analysis that the decadal warming of the SSTIOP, SSTNP, and SSTCEP synergistically contributes to the reduction of WCAP after the 1980s.

  20. ASEAN - China Free Trade Area : A quantitative study of Trade diversion and Trade creation effects on ASEAN - China trade flows

    OpenAIRE

    Duong Xuan, Vinh

    2011-01-01

    The Association of South-East Asian Nations (ASEAN) and China have a long history of trading with each other. They are economic partners as well as competitors for many years. In order to push their economic relationship to a higher level, in November 2002, ASEAN and China signed the initial framework agreement, determined on establishing the ASEAN - China Free Trade Area (ACFTA) among the eleven countries by 2010 for the ASEAN-6 (Brunei, Indonesia, Malaysia, Philippines, Singapore, Thailand)...

  1. Difference of nitrogen-cycling microbes between shallow bay and deep-sea sediments in the South China Sea.

    Science.gov (United States)

    Yu, Tiantian; Li, Meng; Niu, Mingyang; Fan, Xibei; Liang, Wenyue; Wang, Fengping

    2018-01-01

    In marine sediments, microorganisms are known to play important roles in nitrogen cycling; however, the composition and quantity of microbes taking part in each process of nitrogen cycling are currently unclear. In this study, two different types of marine sediment samples (shallow bay and deep-sea sediments) in the South China Sea (SCS) were selected to investigate the microbial community involved in nitrogen cycling. The abundance and composition of prokaryotes and seven key functional genes involved in five processes of the nitrogen cycle [nitrogen fixation, nitrification, denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and anaerobic ammonia oxidation (anammox)] were presented. The results showed that a higher abundance of denitrifiers was detected in shallow bay sediments, while a higher abundance of microbes involved in ammonia oxidation, anammox, and DNRA was found in the deep-sea sediments. Moreover, phylogenetic differentiation of bacterial amoA, nirS, nosZ, and nrfA sequences between the two types of sediments was also presented, suggesting environmental selection of microbes with the same geochemical functions but varying physiological properties.

  2. New species of the giant deep-sea isopod genus Bathynomus (Crustacea, Isopoda, Cirolanidae) from Hainan Island, South China Sea.

    Science.gov (United States)

    Kou, Qi; Chen, Jun; Li, Xinzheng; He, Lisheng; Wang, Yong

    2017-07-01

    Several specimens of the giant deep-sea isopod genus Bathynomus were collected by a deep-sea lander at a depth of 898 m near Hainan Island in the northern South China Sea. After careful examination, this material and the specimens collected from the Gulf of Aden, north-western Indian Ocean, previously reported as Bathynomus sp., were identified to be the same as a new species to the genus. Bathynomus jamesi sp. nov. can be distinguished from the congeners by: the distal margin of pleotelson with 11 or 13 short straight spines and central spine not bifid; uropodal endopod and exopod with distolateral corner slightly pronounced; clypeus with lateral margins concave; and antennal flagellum extending when extended posteriorly reaches the pereonite 3. In addition, Bathynomus jamesi sp. nov. is also supported by molecular analyses based on mitochondrial COI and 16S rRNA gene sequences. The distribution range of the new species includes the western Pacific and north-western Indian Ocean. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

  3. Sea level rise, surface warming, and the weakened buffering ability of South China Sea to strong typhoons in recent decades.

    Science.gov (United States)

    Sun, Jingru; Oey, Leo; Xu, F-H; Lin, Y-C

    2017-08-07

    Each year, a number of typhoons in the western North Pacific pass through the Luzon Strait into South China Sea (SCS). Although the storms remain above a warm open sea, the majority of them weaken due to atmospheric and oceanic environments unfavorable for typhoon intensification in SCS, which therefore serves as a natural buffer that shields the surrounding coasts from potentially more powerful storms. This study examines how this buffer has changed over inter-decadal and longer time scales. We show that the buffer weakens (i.e. greater potential for more powerful typhoons) in negative Pacific Decadal Oscillation (PDO) years, as well as with sea-level-rise and surface warming, caused primarily by the deepening of the ocean's 26 °C isotherm Z 26 . A new Intensity Change Index is proposed to describe the typhoon intensity change as a function of Z 26 and other environmental variables. In SCS, the new index accounts for as high as 75% of the total variance of typhoon intensity change.

  4. With Strings Attached: Chinas Economic Policy in the South China Sea

    Science.gov (United States)

    2016-06-01

    10 million toward the relief efforts. The Swedish corporation Ikea even pledged $2.7 million through a customer-match campaign.140 China’s initial...142 Associated Press, “Typhoon Haiyan: China Gives Less Aid to Philippines than Ikea ,” The Guardian, November 14, 2013, http://www.theguardian.com...world/2013/nov/14/typhoon-haiyan-china- aid-philippines- ikea . 143 Daniel Baltrusaitis, “China’s Revealing Typhoon Haiyan Response,” The Diplomat

  5. Prevention of US-China Armed Conflict Over South China Sea Territorial Disputes

    Science.gov (United States)

    2013-03-01

    States, and the global community as they pertain to the disputed islands. This will include an analysis of China’s constitutional philosophy of the...Publishing. October 22, 2012, 21. 11 its regional competitors , China ratified the UNCLOS soon thereafter despite disagreements with how various...support United Nations Security 2 CNBC, “ Toyota China Sales Tank as Islands Row Hits Japan Inc.,” CNBC

  6. Spatial diversity of bacterioplankton communities in surface water of northern South China Sea.

    Science.gov (United States)

    Li, Jialin; Li, Nan; Li, Fuchao; Zou, Tao; Yu, Shuxian; Wang, Yinchu; Qin, Song; Wang, Guangyi

    2014-01-01

    The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS). Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones) and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.

  7. Spatial diversity of bacterioplankton communities in surface water of northern South China Sea.

    Directory of Open Access Journals (Sweden)

    Jialin Li

    Full Text Available The South China Sea is one of the largest marginal seas, with relatively frequent passage of eddies and featuring distinct spatial variation in the western tropical Pacific Ocean. Here, we report a phylogenetic study of bacterial community structures in surface seawater of the northern South China Sea (nSCS. Samples collected from 31 sites across large environmental gradients were used to construct clone libraries and yielded 2,443 sequences grouped into 170 OTUs. Phylogenetic analysis revealed 23 bacterial classes with major components α-, β- and γ-Proteobacteria, as well as Cyanobacteria. At class and genus taxon levels, community structure of coastal waters was distinctively different from that of deep-sea waters and displayed a higher diversity index. Redundancy analyses revealed that bacterial community structures displayed a significant correlation with the water depth of individual sampling sites. Members of α-Proteobacteria were the principal component contributing to the differences of the clone libraries. Furthermore, the bacterial communities exhibited heterogeneity within zones of upwelling and anticyclonic eddies. Our results suggested that surface bacterial communities in nSCS had two-level patterns of spatial distribution structured by ecological types (coastal VS. oceanic zones and mesoscale physical processes, and also provided evidence for bacterial phylogenetic phyla shaped by ecological preferences.

  8. Realized niches explain spatial gradients in seasonal abundance of phytoplankton groups in the South China Sea

    Science.gov (United States)

    Xiao, Wupeng; Wang, Lei; Laws, Edward; Xie, Yuyuan; Chen, Jixin; Liu, Xin; Chen, Bingzhang; Huang, Bangqin

    2018-03-01

    A basic albeit elusive goal of ocean science is to predict the structure of biological communities from the multitude of environmental conditions they experience. Estimates of the realized niche-based traits (realized traits) of phytoplankton species or functional groups in temperate seas have shown that response traits can help reveal the mechanisms responsible for structuring phytoplankton communities, but such approaches have not been tested in tropical and subtropical marginal seas. Here, we used decadal-scale studies of pigment-based phytoplankton groups and environmental conditions in the South China Sea to test whether realized traits could explain the biogeographic patterns of phytoplankton variability. We estimated the mean and breadth of the phytoplankton realized niches based on responses of the group-specific phytoplankton composition to key environmental factors, and we showed that variations of major phytoplankton groups in this system can be explained by different adaptive trade-offs to constraints imposed by temperature, irradiance, and nutrient concentrations. Differences in the patterns of trade-offs clearly separated the dominant groups from one another and generated four sets of realized traits that mirrored the observed biogeographic distribution patterns. The phytoplankton realized niches and their associated traits that we characterized in the present study could help to predict responses of phytoplankton to changes in environmental conditions in the South China Sea and could be incorporated into global biogeochemical models to anticipate shifts in community structure under future climate scenarios.

  9. HELIUM, PARTICULATE ORGANIC CARBON and other data from HEIYO, KAIYO and other platforms in the NW Pacific, Philippine Sea and East China Sea from 1939-08-17 to 1988-09-27 (NODC Accession 9000197)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A tape containing part of the annual exchange of chemical data from the Japan Oceanographic Data Center collected from East China Sea (Tung Hai), Philippine Sea, NW...

  10. A parabolic model of drag coefficient for storm surge simulation in the South China Sea

    Science.gov (United States)

    Peng, Shiqiu; Li, Yineng

    2015-01-01

    Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models. PMID:26499262

  11. A parabolic model of drag coefficient for storm surge simulation in the South China Sea

    Science.gov (United States)

    Peng, Shiqiu; Li, Yineng

    2015-10-01

    Drag coefficient (Cd) is an essential metric in the calculation of momentum exchange over the air-sea interface and thus has large impacts on the simulation or forecast of the upper ocean state associated with sea surface winds such as storm surges. Generally, Cd is a function of wind speed. However, the exact relationship between Cd and wind speed is still in dispute, and the widely-used formula that is a linear function of wind speed in an ocean model could lead to large bias at high wind speed. Here we establish a parabolic model of Cd based on storm surge observations and simulation in the South China Sea (SCS) through a number of tropical cyclone cases. Simulation of storm surges for independent Tropical cyclones (TCs) cases indicates that the new parabolic model of Cd outperforms traditional linear models.

  12. International cooperation on wind energy for rural areas in China

    International Nuclear Information System (INIS)

    Pengfei, Shi

    1991-01-01

    An overview of the recent wind energy activities in China is given. China has a long history in harnessing the wind; modern development started during the late seventies. The Chinese wind potential is mainly in the coastal regions (North East and South East) and in Inner Mongolia. The actual total installed wind power is estimated to be 15 MW. For low lift (within 2 meters), high volume applications, e.g. salt making in salt pans along the coast, of mechanical windmills coupled to screw pumps have been developed. In Inner Mongolia, small portable wind generators (50-200 MW) charging car batteries are supplying some 100,000 farmer and herdsman families with electricity for television and lighting. The average energy consumption is between 200 and 300 kWh per year and the corresponding kWh price 0.40 to 0.50 US$. Since 1988 the demand for small wind generators declined due to the lower wool prices on the world market, affecting the income of the herdsman, and due to the fact that the machines have to be marketed in remote, less accesible rural areas. Various demonstration projects have been set up, f.e. a decentralized energy system on Dachen Island, including a wind diesel hybrid system. On Kongdon Island a 60 kW wind turbine and a 60 kW diesel generator were installed. With several foreign wind turbine manufacturers cooperations have been set up for licensed production in China. Also wind farms have been installed. The largest Chinese prototype at the moment is a 32 meter diameter, 200 kW machine. Western organizations or manufacturers are involved in most of the cooperatives. For the next five years the focus is on development of a large 150 and 200 kW machine and a windmill coupled to a centrifugal pump for lifting heads between 2 and 5 meter. 1 fig., 3 refs

  13. Satellite based wind resource assessment over the South China Sea

    DEFF Research Database (Denmark)

    Badger, Merete; Astrup, Poul; Hasager, Charlotte Bay

    2014-01-01

    variations are clearly visible across the domain; for instance sheltering effects caused by the land masses. The satellite based wind resource maps have two shortcomings. One is the lack of information at the higher vertical levels where wind turbines operate. The other is the limited number of overlapping...... years of WRF data – specifically the parameters heat flux, air temperature, and friction velocity – are used to calculate a long-term correction for atmospheric stability effects. The stability correction is applied to the satellite based wind resource maps together with a vertical wind profile...... from satellite synthetic aperture radar (SAR) data are particularly suitable for offshore wind energy applications because they offer a spatial resolution up to 500 m and include coastal seas. In this presentation, satellite wind maps are used in combination with mast observations and numerical...

  14. Characteristics of surface O{sub 3} over Qinghai Lake area in Northeast Tibetan Plateau, China

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Zhenxing, E-mail: zxshen@mail.xjtu.edu.cn [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Cao, Junji [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Leiming [Air Quality Research Division, Environment Canada, Toronto (Canada); Zhao, Zhuzi [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Dong, Jungang [School of Architecture, Xi' an University of Architecture and Technology, Xi' an 710055 (China); Wang, Linqing [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China); Wang, Qiyuan; Li, Guohui; Liu, Suixin [Key Lab of Aerosol, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi' an (China); Zhang, Qian [Department of Environmental Sciences and Engineering, Xi' an Jiaotong University, Xi' an (China)

    2014-12-01

    Surface O{sub 3} was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O{sub 3} ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O{sub 3} followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O{sub 3} showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O{sub 3}. It was found that O{sub 3} was poorly correlated with solar radiation due to the insufficient NO{sub x} in the ambient air, thus limiting O{sub 3} formation under strong solar radiation. In contrast, high O{sub 3} levels always coincided with strong winds, suggesting that stratospheric O{sub 3} and long range transport might be the main sources of O{sub 3} in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O{sub 3} was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O{sub 3} chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O{sub 3} and transport might be the main sources of O{sub 3} in this area.

  15. Characteristics of surface O3 over Qinghai Lake area in Northeast Tibetan Plateau, China

    International Nuclear Information System (INIS)

    Shen, Zhenxing; Cao, Junji; Zhang, Leiming; Zhao, Zhuzi; Dong, Jungang; Wang, Linqing; Wang, Qiyuan; Li, Guohui; Liu, Suixin; Zhang, Qian

    2014-01-01

    Surface O 3 was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3200 m above sea level) in Qinghai Lake area (36°58′37″N, 99°53′56″E) in Northeast Tibetan Plateau, China. Daily average O 3 ranged from 21.8 ppbv to 65.3 ppbv with an annual average of 41.0 ppbv. Seasonal average of O 3 followed a decreasing order of summer > autumn > spring > winter. Diurnal variations of O 3 showed low concentrations during daytime and high concentrations during late night and early morning. An intensive campaign was also conducted during Aug. 13–31, 2010 to investigate correlations between meteorological or chemical conditions and O 3 . It was found that O 3 was poorly correlated with solar radiation due to the insufficient NO x in the ambient air, thus limiting O 3 formation under strong solar radiation. In contrast, high O 3 levels always coincided with strong winds, suggesting that stratospheric O 3 and long range transport might be the main sources of O 3 in this rural area. Back-trajectory analysis supported this hypothesis and further indicated the transport of air masses from northwest, northeast and southeast directions. - Highlights: • Surface O 3 was measured in Qinghai Lake area in Northeast Tibetan Plateau, China. • The O 3 chemical formation was under a strong NOx-limited in Qinghai Lake areas. • Stratospheric O 3 and transport might be the main sources of O 3 in this area

  16. Drought reconstruction in eastern Hulun Buir steppe, China and its linkages to the sea surface temperatures in the Pacific Ocean

    Science.gov (United States)

    Liu, Na; Liu, Yu; Bao, Guang; Bao, Ming; Wang, Yanchao; Zhang, Lizhi; Ge, Yuxiang; Bao, Wurigen; Tian, Heng

    2016-01-01

    A tree-ring width chronology covering the period 1780-2013 AD was developed from Pinus sylvestris var. mongolica for the eastern Hulun Buir steppe, a region located on the edge of the eastern Mongolian Plateau, China. Climate-growth response analysis revealed drought stress to be the primary limiting factor for tree growth. Therefore, the mean February-July standardized precipitation evapotranspiration index (SPEI) was reconstructed over the period 1819-2013, where the reconstruction could account for 32.8% of the variance in the instrumental record over the calibration period 1953-2011. Comparison with other tree-ring-based moisture sequences from nearby areas confirmed a high degree of confidence in our reconstruction. Severe drought intervals since the late 1970s in our study area consisted with the weakening East Asian summer monsoon, which modulating regional moisture conditions in semi-arid zone over northern China. Drought variations in the study area significantly correlated with sea surface temperatures (SSTs) in North Pacific Ocean, suggesting a possible connection of regional hydroclimatic variations to the Pacific Decadal Oscillation (PDO). The potential influence associated with El Niño-Southern Oscillation (ENSO) was primarily analyzed.

  17. Assessment of tsunami hazard for coastal areas of Shandong Province, China

    Science.gov (United States)

    Feng, Xingru; Yin, Baoshu

    2017-04-01

    Shandong province is located on the east coast of China and has a coastline of about 3100 km. There are only a few tsunami events recorded in the history of Shandong Province, but the tsunami hazard assessment is still necessary as the rapid economic development and increasing population of this area. The objective of this study was to evaluate the potential danger posed by tsunamis for Shandong Province. The numerical simulation method was adopted to assess the tsunami hazard for coastal areas of Shandong Province. The Cornell multi-grid coupled tsunami numerical model (COMCOT) was used and its efficacy was verified by comparison with three historical tsunami events. The simulated maximum tsunami wave height agreed well with the observational data. Based on previous studies and statistical analyses, multiple earthquake scenarios in eight seismic zones were designed, the magnitudes of which were set as the potential maximum values. Then, the tsunamis they induced were simulated using the COMCOT model to investigate their impact on the coastal areas of Shandong Province. The numerical results showed that the maximum tsunami wave height, which was caused by the earthquake scenario located in the sea area of the Mariana Islands, could reach up to 1.39 m off the eastern coast of Weihai city. The tsunamis from the seismic zones of the Bohai Sea, Okinawa Trough, and Manila Trench could also reach heights of >1 m in some areas, meaning that earthquakes in these zones should not be ignored. The inundation hazard was distributed primarily in some northern coastal areas near Yantai and southeastern coastal areas of Shandong Peninsula. When considering both the magnitude and arrival time of tsunamis, it is suggested that greater attention be paid to earthquakes that occur in the Bohai Sea. In conclusion, the tsunami hazard facing the coastal area of Shandong Province is not very serious; however, disasters could occur if such events coincided with spring tides or other

  18. Seasonal Dynamics of Dissolved Organic Carbon Under Complex Circulation Schemes on a Large Continental Shelf: The Northern South China Sea

    Science.gov (United States)

    Meng, Feifei; Dai, Minhan; Cao, Zhimian; Wu, Kai; Zhao, Xiaozheng; Li, Xiaolin; Chen, Junhui; Gan, Jianping

    2017-12-01

    We examined the distribution and seasonality of dissolved organic carbon (DOC) based on a large data set collected from the northern South China Sea (NSCS) shelf under complex circulation schemes influenced by river plume, coastal upwelling, and downwelling. The highest surface values of ˜117 μmol L-1 were observed nearshore in summer suggesting high DOC supplies from the river inputs, whereas the lowest surface values of ˜62 μmol L-1 were on the outer shelf in winter due to entrainment of DOC-poor subsurface water under strengthened vertical mixing. While the summer coastal upwelling brought lower DOC from offshore depth to the nearshore surface, the winter coastal downwelling delivered higher surface DOC to the midshelf deep waters from the inner shelf fueled by the China Coastal Current (CCC) transporting relatively high DOC from the East China Sea to the NSCS. The intensified winter downwelling generated a cross-shelf DOC transport of 3.1 × 1012 g C over a large shelf area, which induced a significant depression of the NSCS DOC inventory in winter relative to in autumn. In addition to the variable physical controls, net biological production of DOC was semiquantified in both the river plume (2.8 ± 3.0 μmol L-1) and coastal upwelling (3.1 ± 1.3 μmol L-1) in summer. We demonstrated that the NSCS shelf had various origins of DOC including riverine inputs, inter-shelf transport and in situ production. Via cross-shelf transport, the accumulated DOC would be exported to and stored in the deep ocean, suggesting that continental shelves are a potentially effective carbon sink.

  19. Air-sea exchange of gaseous mercury in the tropical coast (Luhuitou fringing reef) of the South China Sea, the Hainan Island, China.

    Science.gov (United States)

    Ci, Zhijia; Zhang, Xiaoshan; Wang, Zhangwei

    2016-06-01

    The air-sea exchange of gaseous mercury (mainly Hg(0)) in the tropical ocean is an important part of the global Hg biogeochemical cycle, but the related investigations are limited. In this study, we simultaneously measured Hg(0) concentrations in surface waters and overlaying air in the tropical coast (Luhuitou fringing reef) of the South China Sea (SCS), Hainan Island, China, for 13 days on January-February 2015. The purpose of this study was to explore the temporal variation of Hg(0) concentrations in air and surface waters, estimate the air-sea Hg(0) flux, and reveal their influencing factors in the tropical coastal environment. The mean concentrations (±SD) of Hg(0) in air and total Hg (THg) in waters were 2.34 ± 0.26 ng m(-3) and 1.40 ± 0.48 ng L(-1), respectively. Both Hg(0) concentrations in waters (53.7 ± 18.8 pg L(-1)) and Hg(0)/THg ratios (3.8 %) in this study were significantly higher than those of the open water of the SCS in winter. Hg(0) in waters usually exhibited a clear diurnal variation with increased concentrations in daytime and decreased concentrations in nighttime, especially in cloudless days with low wind speed. Linear regression analysis suggested that Hg(0) concentrations in waters were positively and significantly correlated to the photosynthetically active radiation (PAR) (R (2) = 0.42, p sea Hg(0) fluxes were estimated to be 1.73 ± 1.25 ng m(-2) h(-1) with a large range between 0.01 and 6.06 ng m(-2) h(-1). The high variation of Hg(0) fluxes was mainly attributed to the greatly temporal variation of wind speed.

  20. Phytoplankton pigment patterns and community composition in the northern South China Sea during winter

    Science.gov (United States)

    Zhai, Hongchang; Ning, Xiuren; Tang, Xuexi; Hao, Qiang; Le, Fengfeng; Qiao, Jing

    2011-03-01

    Phytoplankton pigment patterns and community composition were investigated in the northern South China Sea using high-performance liquid chromatography and the CHEMTAX software from February 11 to 23, 2009. We recognized four different vertical distribution patterns of pigments: chlorophyll a (Chi a)-like type, divinyl chlorophyll a (DV Chi a) type, even distribution type, and surface type. The average value of ratios of accessory photo-protective pigments (APP) to accessory photo-synthetic pigments was 0.89±0.63 in the upper 50 m and 0.16±0.06 below 50 m depth. With increasing depth, APP decreased and photo-synthetically active radiation was attenuated. There was an obvious succession in the phytoplankton community from inshore to the open sea. Diatoms were dominant in the inshore region, while pelagophytes, Prochlorococcus, cyanobacteria and prymnesiophytes were dominant in the open sea. The vertical distribution of phytoplankton also differed greatly from inshore to the open sea. In the coastal and shelf region, diatoms were important components in the whole water column. Cyanobacteria also had a high abundance at the Subsurface Chlorophyll a Maxima (SCM) in the shelf region. In the slope and open sea, Prochlorococcus and cyanobacteria were important groups above the SCM, while pelagophytes dominated below the SCM.

  1. Relationship Between Sea Surface Salinity from L-Band Radiometer and Optical Features in the East China Sea

    Science.gov (United States)

    2014-01-01

    bounded on the east by Japan and on the west by mainland China from which it receives the huge outflow from the Changjiang River (CR). Because of its large...particles (a^, i.e. detritus) have similar spectral curves *, under highly turbid conditions detritus can significantly affect, or even dominate the...biased in this region due to persistent low levels of Radio Frequency Interference (RFI) from the coastal areas (e.g. North Atlantic and Asia-Pacific

  2. Recent Multidisciplinary Research Initiatives and IODP Drilling in the South China Sea

    Science.gov (United States)

    Lin, J.; Li, C. F.; Wang, P.; Kulhanek, D. K.

    2016-12-01

    The South China Sea (SCS) is the largest low-latitude marginal sea in the world. Its formation and evolution are linked to the complex continental-oceanic tectonic interaction of the Eurasian, Pacific, and Indo-Australian plates. Despite its relatively small size and short history, the SCS has undergone nearly a complete Wilson cycle from continental break-up to seafloor spreading to subduction, serving as a natural laboratory for studying the linkages between tectonic, volcanic, and oceanic processes. The last several years have witnessed significant progress in investigation of the SCS through comprehensive research programs using multidisciplinary approaches and enhanced international collaboration. The International Ocean Discovery Program (IODP) Expedition 349 drilled and cored five sites in the SCS in 2014. The expedition successfully obtained the first basaltic rock samples of the SCS relict spreading center, discovered large and frequent deep-sea turbidity events, and sampled multiple seamount volcaniclastic layers. In addition, high-resolution near-seafloor magnetic surveys were conducted in the SCS with survey lines passing near some of the IODP drilling sites. Together the IODP drilling and deep-tow magnetic survey results confirmed, for the first time, that the entire SCS basin might have stopped seafloor spreading at similar ages in early Miocene, providing important constraints on marginal sea geodynamic models. In 2007, IODP Expeditions 367 and 368 will drill the northern margin of the SCS to investigate the mechanisms of rifting to spreading processes. Meanwhile, major progress in studying the SCS processes has also been made through comprehensive multidisciplinary programs, for example, the eight-year-long "South China Sea Deep" initiative, which also supports and encourages strong international collaboration. This presentation will highlight the recent multidisciplinary research initiatives in investigation of the SCS and the important role of

  3. Human exposure to polybrominated diphenyl ethers at production area, China.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian

    2010-05-01

    The concentrations of polybrominated diphenyl ethers (PBDEs) were detected in air and aquatic products in PBDEs production areas which are located at the south coast area of Laizhou Bay, Shandong province, China in this study. Concentrations of SigmaPBDEs in the air ranged from 0.47 ng/m3 to 161 ng/m3. In aquatic products, concentrations of SigmaPBDEs ranged from 2.7 ng/g wet weight to 42 ng/g wet weight. The mean dietary intake of SigmaPBDEs via aquatic products consumption in this study was 218 ng/day. Daily intake of SigmaPBDEs via inhalation in this study was 612 ng for men and 455 ng for women. With a contribution of 80%, BDE-209 was predominant in the total intake. Dietary intake and breathing inhalation contributed 29 and 71%, respectively, to the total PBDEs intake. The results indicate that breathing inhalation also plays a very significant pathway for the population of the PBDEs production area. Compared with similar studies in other countries, human exposure to PBDEs via diet and inhalation in this study was the highest in the world. Copyright (c) 2010 SETAC.

  4. Karst collapse in cities and mining areas, China

    International Nuclear Information System (INIS)

    Jian Chen

    1988-01-01

    Karst collapse is a dynamic geological phenomenon, in which the rock mass or deposits overlying the karstified zone subsides down along the karst cavity, resulting in a collapse pit or sinkhole. After discussing the typical examples of collapse emerging in the karst cities and mines in provinces and regions of South China, such as Guangdong, Guangxi, Hunan, Hubei, Zhejiang, Yunnan, Guizhou, and Jiangxi, it is considered that human activities of economy and production have become a major effect in causing karst collapse. Man-made collapses make 66.4 percent of the total, whereas natural ones 33.6 percent. Most of the collapses occurred to the area with soil overburden (96.7 percent), only a few in areas of bedrock overburden (3.3 percent). The karst collapses have a close relationship with the extent of karst development, the character and the thickness of overburden, and the dynamic condition of underground water. Collapse usually occurs in those parts of an area that are more intensely karstified, with soil thickness less than 5 m and a high amplitude of water table fluctuation. Many kinds of mechanical effects are caused by pumping or draining on the over-burden and destroying its equilibrium, leading to the collapse. These effects included the support loss and load-added effect, penetrating suffusion, gas explosion, water-hammer, suction pressure erosion, and liquefaction effects. The collapses are the result of varied comprehensive effects, particularly the support loss and load-added, and penetrating suffusion

  5. Occurrence of marine algal toxins in oyster and phytoplankton samples in Daya Bay, South China Sea.

    Science.gov (United States)

    Jiang, Tao; Liu, Lei; Li, Yang; Zhang, Jing; Tan, Zhijun; Wu, Haiyan; Jiang, Tianjiu; Lu, Songhui

    2017-09-01

    The occurrence and seasonal variations of marine algal toxins in phytoplankton and oyster samples in Daya Bay (DYB), South China Sea were investigated. Two Dinophysis species, namely, D. caudata and D. acuminata complex, were identified as Okadaic acid (OA)/pectenotoxin (PTX) related species. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis demonstrated that 2.04-14.47 pg PTX2 per cell was the predominant toxin in single-cell isolates of D. caudata. D. acuminata was not subjected to toxin analysis. The occurrence of OAs in phytoplankton concentrates of net-haul sample coincided with the presence of D. accuminata complex, suggesting that this species is most likely an OA producer in this sea area. OA, dinophysistoxins-1 (DTX1), PTX2, PTX2sa, gymnodimine (GYM), homoyessotoxin (homoYTX), and domoic acid (DA) demonstrated positive results in net haul samples. To our best knowledge, this paper is the first to report the detection of GYM, DA, and homoYTX in phytoplankton samples in Chinese coastal waters. Among the algal toxins, GYM demonstrated the highest frequency of positive detections in phytoplankton concentrates (13/17). Five compounds of algal toxins, including OA, DTX1, PTX2, PTX2sa, and GYM, were detected in oyster samples. DA and homoYTX were not detected in oysters despite of positive detections for both in the phytoplankton concentrates. However, neither the presence nor absence of DA in oysters can be determined because extraction conditions with 100% methanol used to isolate toxins from oysters (recommended by the EU-Harmonised Standard Operating Procedure, 2015) would likely be unsuitable for this water-soluble toxin. In addition, transformation of DA during the digestion process of oysters may also be involved in the negative detections of this toxin. GYM exhibited the highest frequency of positive results in oysters (14/17). OAs were only detected in the hydrolyzed oyster samples. The detection rates of PTX and PTX2sa in

  6. Assessment of Wave Energy in the South China Sea Based on GIS Technology

    Directory of Open Access Journals (Sweden)

    Gang Lin

    2017-01-01

    Full Text Available China is now the world’s largest user of coal and also has the highest greenhouse gas emissions associated with the mining and use of coal. Under today’s enormous pressures of the growing shortage of conventional energy sources and the need for emission reductions, the search for clean energy is the most effective strategy to address the energy crisis and global warming. This study utilized satellite remote sensing technology, geographic information system (GIS technology, and simulated wave data for the South China Sea. The characteristic features of the wave energy were obtained by analysis through the wave resource assessment formula and the results were stored in a GIS database. Software for the evaluation of wave energy in the South China Sea was written. The results should provide accurate, efficient references for wave energy researchers and decision-makers. Based on a 24-year WW3 model simulation wave data and GIS technology, this study presented the characteristic of the wave energy in the SCS; results demonstrated that the SCS has the feasibility and viability for wave energy farming.

  7. Nitrogen Losses in Sediments of the East China Sea: Spatiotemporal Variations, Controlling Factors, and Environmental Implications

    Science.gov (United States)

    Lin, Xianbiao; Liu, Min; Hou, Lijun; Gao, Dengzhou; Li, Xiaofei; Lu, Kaijun; Gao, Juan

    2017-10-01

    Global reactive nitrogen (N) has increased dramatically in coastal marine ecosystems over the past decades and caused numerous eco-environmental problems. Coastal marine sediment plays a critical role in N losses via denitrification and anaerobic ammonium oxidation (anammox) and release of nitrous oxide (N2O). However, both the magnitude and contributions of denitrification, anammox, and N2O production in sediments still remain unclear, causing uncertainty in defining the N budget for coastal marine ecosystems. Here potential rates of N losses, and their contributions and controlling factors, were investigated in surface sediments during six cruises from 429 sites of the East China Sea. The potential rates of denitrification, anammox, and N2O production varied both spatially and seasonally, but the contribution of anammmox to total N2 production (%anammox) and N2O:N2 ratio only varied spatially. Both organic carbon and nitrate (NO3-) were important factors controlling N losses, N2O:N2 ratio, and %anammox. Our results also showed that marine organic carbon induced by eutrophication plays an important role in stimulating reactive N removal and increasing N2O production in warm seasons. The sediment N loss caused by denitrification, anammox, and N2O production in the study area were estimated at 2.2 × 106 t N yr-1, 4.6 × 105 t N yr-1, and 8 × 103 t N yr-1, respectively. Although sediments remove large quantities of reactive N, they act as an important source of N2O in this region influenced by NO3--laden rivers.

  8. Diversity and abundance of nitrate assimilation genes in the northern South china sea.

    Science.gov (United States)

    Cai, Haiyuan; Jiao, Nianzhi

    2008-11-01

    Marine heterotrophic microorganisms that assimilate nitrate play an important role in nitrogen and carbon cycling in the water column. The nasA gene, encoding the nitrate assimilation enzyme, was selected as a functional marker to examine the nitrate assimilation community in the South China Sea (SCS). PCR amplification, restriction fragment length polymorphism (RFLP) screening, and phylogenetic analysis of nasA gene sequences were performed to characterize in situ nitrate assimilatory bacteria. Furthermore, the effects of nutrients and other environmental factors on the genetic heterogeneity of nasA fragments from the SCS were evaluated at the surface in three stations, and at two other depths in one of these stations. The diversity indices and rarefaction curves indicated that the nasA gene was more diverse in offshore waters than in the Pearl River estuary. The phylotype rank abundance curve showed an abundant and unique RFLP pattern in all five libraries, indicating that a high diversity but low abundance of nasA existed in the study areas. Phylogenetic analysis of environmental nasA gene sequences further revealed that the nasA gene fragments came from several common aquatic microbial groups, including the Proteobacteria, Cytophaga-Flavobacteria (CF), and Cyanobacteria. In addition to the direct PCR/sequence analysis of environmental samples, we also cultured a number of nitrate assimilatory bacteria isolated from the field. Comparison of nasA genes from these isolates and from the field samples indicated the existence of horizontal nasA gene transfer. Application of real-time quantitative PCR to these nasA genes revealed a great variation in their abundance at different investigation sites and water depths.

  9. Spectral Interpretation of Wave-vortex Duality in Northern South China Sea

    Science.gov (United States)

    Cao, H.; Jing, Z.; Yan, T.

    2017-12-01

    The mesoscale to submesocale oceanic dynamics are characterized by a joint effect of vortex and wave component, which primarily declares the partition between geostrophic balanced and unbalanced flows. The spectral method is a favorable approach that can afford the muti-scale analysis. This study investigates the characteristics of horizontal wavenumber spectra in Nothern South China Sea using orbital altimeter data (SARA/AltiKa), 13-yr shipboard ADCP (Acoustic Doppler Current Profiler) measurements (2014-2016), and a high-resolution numerical simulation (llc4320 Mitgcm). The observed SSH (sea surface height) spectrum presents a conspicuous transition at scales of 50-100 km, which clearly shows the inconsistency with geostrophic balance. The Helmholtz decomposition separating the wave and vortex energy for the spectra of ADCP and numerical model data shows that ageostrophic flows should be responsible for the spectral discrepancy with the QG (qusi-geostrophic) turbulence theory. Generally, it is found that inertia-gravity waves (including internal tides) govern the significant kinetic energy in the submesoscale range in Northern South China Sea. More specific analysis suggests that the wave kinetic energy can extend to a large scale of 500 km or more from the zonal velocity spectra at the left-center of Luzon Strait, which appears to be dominated by inertia-gravity waves likely emitted by the intrusion of the west pacific at Luzon Strait. Instead, the development of eddy kinetic energy at this place is strictly constrained by the width of the strait.

  10. Tracking an Oil Tanker Collision and Spilled Oils in the East China Sea Using Multisensor Day and Night Satellite Imagery

    Science.gov (United States)

    Sun, Shaojie; Lu, Yingcheng; Liu, Yongxue; Wang, Mengqiu; Hu, Chuanmin

    2018-04-01

    Satellite remote sensing is well known to play a critical role in monitoring marine accidents such as oil spills, yet the recent SANCHI oil tanker collision event in January 2018 in the East China Sea indicates that traditional techniques using synthetic aperture radar or daytime optical imagery could not provide timely and adequate coverage. In this study, we show the unprecedented value of Visible Infrared Imaging Radiometer Suite (VIIRS) Nightfire product and Day/Night Band data in tracking the oil tanker's drifting pathway and locations when all other means are not as effective for the same purpose. Such pathway and locations can also be reproduced with a numerical model, with root-mean-square error of days of the tanker's sinking reveals much larger oil spill area (>350 km2) than previous reports, the impact of the spilled condensate oil on the marine environment requires further research.

  11. Sustainable development of agriculture in karst areas, South China

    Directory of Open Access Journals (Sweden)

    Linhua Song

    1999-01-01

    Full Text Available The exposed carbonate rocks aged from Sinian to Mid-Triassic Periods cover an area of 500,000 Km2 in south-west China. In karst areas with spectacular landscapes characterized by magnificent tower karst and conical karst, rare surface drainage systems and prevalent subsurface drainage systems, the environment is ecologically very fragile. The rapid increase of population, over deforested and cultivated lands, worsted the ecological system, causing a higher frequency of draught, flood and various disasters, backward economic development, low living standard of the people. In order to improve the sustainability of the agriculture the experience shows that the following operations should be adopted: (1 serious control of the population increase, emigration, extra labours and improvement of the environmental education of the local inhabitants; (2 terracing of the slopes (shi jala di as to improve the cultivated land quality, to preserve the water, soil and fertiliser and ameliorate the effective utilisation of the land; (3 development of new rural energies such as the solar energy and gas energy, and expansion of the saving-fuel stoves to reduce the load of bio-energy; (4 reforestation and bounding the hills and mountains; the ecological, economic and fuel forests model has been developed in fengcong-depression areas: the tree species with high ecological, economical and energetic characteristics, should be chosen, such as the bamboo, wild grapes, Sapium rotundifolium etc.; (5 better utilisation of the ram water and karst water resource to solve the water supply problems. The karst landscape is well developed in the 500,000 km2 carbonate terrain in Yunnan, Guizhou, Guangxi, west Hunan and south Sichuan provinces in south-west China, where 100 million habitants live (Song, 1997. The large population and its high density, serious deforestation, over-cultivation and fragile ecological system make the environmental problems very serious and about 30

  12. A review of the green tides in the Yellow Sea, China.

    Science.gov (United States)

    Liu, Xiangqing; Wang, Zongling; Zhang, Xuelei

    2016-08-01

    The recurrent green tide of Ulva prolifera caused serious ecological problems in the Yellow Sea and attached substantial scientific study. The bloom originated in the Subei Shoal area and drifted to the coast of Shandong Province during the period from May to July, driven by a series of physical processes. Here we reviewed advances in the understanding of green tides in the Yellow Sea and elucidate the developmental model of this phenomenon. This knowledge will help resource managers to take reasonable measures to mitigate the impacts to the Yellow Sea. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Steering a Steady Course in the South China Sea

    Science.gov (United States)

    2017-10-27

    NUMBER (Include area code ) 401-841-3556 Standard Form 298 (Rev. 8-98) Prescribed by ANSI-Std Z39-18 Steering a Steady Course in the South...minor features claimed by a Filipino civilian in the SCS are not worth US blood, talent , or treasure defending against the PRC. The PRC, on the other

  14. Linkages between the spatial toxicity of sediments and sediment dynamics in the Yangtze River Estuary and neighboring East China Sea.

    Science.gov (United States)

    Gao, Jinjuan; Shi, Huahong; Dai, Zhijun; Mei, Xuefei; Zong, Haibo; Yang, Hongwei; Hu, Lingling; Li, Shushi

    2018-02-01

    Anthropogenic activities are driving an increase in sediment contamination in coastal areas. This poses significant challenges for the management of estuarine ecosystems and their adjacent seas worldwide. However, few studies have been conducted on how dynamic mechanisms affect the sediment toxicity in the estuarine environment. This study was designed to investigate the linkages between sediment toxicity and hydrodynamics in the Yangtze River Estuary (YRE) area. High sediment toxicity was found in the Yangtze River mouth (Region I), the depocenter of the Yangtze River Delta (Region II), and the southeastern area of the adjacent sea (Region III), while low sediment toxicity was found in the northeastern offshore region (Region IV). A spatial comparison analysis and regression model indicated that the distributed pattern of sediment toxicity was likely related to hydrodynamics and circumfluence in the East China Sea (ECS) shelf. Specifically, high sediment toxicity in Region I may be affected by the Yangtze River Pump (YRP) and the low hydrodynamics there, and high toxicity in Region II can be influenced by the low sediment dynamics and fine sediment in the depocenter. The high sediment toxicity in Region III might be related to the combination of the YRP and Taiwan Warm Current, while the low toxicity in Region IV may be influenced by the local coarse-grained relict sand with strong sediment dynamics there. The present research results further suggest that it is necessary to link hydrodynamics and the spatial behavior of sediment and sediment-derived pollutants when assessing the pollution status of estuarine environments, especially for those mega-estuaries and their neighboring ocean environments with complex waves, tides and ocean currents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Seasonal and spatial variations of macro- and megabenthic community characteristics in two sections of the East China Sea

    Science.gov (United States)

    Xu, Yong; Li, Xinzheng; Ma, Lin; Dong, Dong; Kou, Qi; Sui, Jixing; Gan, Zhibin; Wang, Hongfa

    2017-09-01

    In spring and summer 2011, the macro- and megabenthic fauna in two sections of the East China Sea were investigated using an Agassiz net trawl to detect the seasonal and spatial variations of benthic community characteristics and the relation to environmental variables. The total number of species increased slightly from spring (131 species) to summer (133) whereas the percentage of Mollusca decreased significantly. The index of relative importance (IRI) indicated that the top five important species changed completely from spring to summer. Species number, abundance and biomass in summer were significantly higher than in spring, but no significant difference was observed among areas (coastal, transitional and oceanic areas, divided basically from inshore to offshore). Species richness ( d), diversity ( H') and evenness ( J') showed no significant seasonal or spatial variations. Cluster analysis and nMDS ordination identified three benthic communities from inshore to offshore, corresponding to the three areas. Analysis of Similarity (ANOSIM) indicated the overall significant difference in community structure between seasons and among areas. K-dominance curves revealed the high intrinsic diversity in the offshore area. Canonical correspondence analysis showed that the coastal community was positively correlated to total nitrogen and total organic carbon in spring, but negatively in summer; oceanic community was positively correlated to total nitrogen and total organic carbon in both seasons. Species such as Coelorhynchus multispinulosus, Neobythites sivicola, Lepidotrigla alata, Solenocera melantho, Parapenaeus fissuroides, Oratosquilla gonypetes and Spiropagurus spiriger occurred exclusively in the offshore oceanic area and their presence may reflect the influence of the offshore Kuroshio Current.

  16. Depositional setting analysis using seismic sedimentology: Example from the Paleogene Lishagang sequence in the Fushan depression, South China Sea

    Directory of Open Access Journals (Sweden)

    Yuan Li

    2017-09-01

    Full Text Available The Fushan depression is a classic lacustrine rifted sub-basin in the Beibuwan Basin, South China Sea. The Paleogene Liushagang sequence is the main hydrocarbon-bearing stratigraphic unit in the depression. Using three-dimensional (3-D seismic data and logging data, we analyzed depositional setting of the Liushagang sequence. We use wave impedance inversion to describe progradational directions of provenance and the general distribution of sand body. The seismic facies was analyzed by using the seismic sedimentology approach based on 3-D seismic data, and summed into eight types of seismic facies which could be well related to sedimentary facies. Seismic attributes with six objective sequence boundaries were extracted. Consequently, four provenance system of Liushagang sequence in the study area were confirmed by the corresponding relationship between the geologic information and the warm color and higher value area of seismic attributes: (i the Hainan uplift provenance area in the south, (ii the Linggao uplift provenance area in the west, (iii the Yunlong uplift provenance area in the east and (iv the northern provenance area. The seismic sedimentology used in this study may provide new insights into a better understanding of depositional setting in continental lacustrine rifted basins.

  17. Global Warming: The Instability of Desert Climate is Enhancing in the Northwest Area in China: A Case Study in the Desert Area in Northwestern China

    OpenAIRE

    Zhao-Feng Chang; Shu-Juan Zhu; Fu-Gui Han; Sheng-Nnian Zhong; Qiang-Qiang Wang; Jian-Hui Zhang

    2013-01-01

    To disclose the relation between the sandstorms change and the temperature changes, a case study in the desert area in northwestern china is investigated. The results showed that: the instability of climate in Minqin desert area is enhancing in the arid desert region in northwest China. Mainly as follows: Variation the annual extreme maximum temperature increasing. Variation of extreme minimum temperature also an increasing trend. Average visibility of sandstorms significantly reduced and the...

  18. Effect of climate and environmental changes on plankton biodiversity and bigeochemical cycles of the Dongsha (Pratas) Atoll, South China Sea

    Science.gov (United States)

    Lo, Wen-tseng; Hsu, Pei-Kai; Hunag, Jia-Jang; Wang, Yu-Huai

    2013-04-01

    Dongsha (Pratas) Atoll, the so called "Pearl Crown of South China Sea", is a well-developed atoll with a total area of 80000 hectares. It possesses various ecosystems and has very high biodiversity, but it is very sensitive to climate change and physical processes. According to our investigation within the shallow semi-enclosed atoll in April, July, and October, 2011 (i.e., spring, summer, and autumn, respectively), we found that plankton assemblages and hydrographical conditions exhibited clear seasonal and spatial variations. Colder and higher salinity water was observed in April, while warmer water in July and lower salinity water in October, respectively. Nutrient concentration within the atoll was similar to that of the oligotrophic South China Sea waters and seemed to be in nitrogen-limit situation, while the distribution pattern of DOC and POC was mainly attributed to Chla and imported detritus matters. Carbon deposition flux also showed significant seasonal changes, but POC/PN value was near Redfield ratio, implying mostly due to biogenic factors; however it could still be classified as a typical coral ecosystem, since CaCO3 sinking flux generally was 30 times higher than that of organic matter. Plankton biodiversity was quite high in the atoll, and preformed apparent seasonal succession; in total, 82 phytoplankton species and 67 copepod species were recorded; furthermore, crab zoea (17.3% of the total zooplankton by number), fish eggs (12.5%), and shrimp larvae (4.2%), were relatively abundant in zooplankton community, revealed that atoll might be a good hatching ground. We deduced that the seasonal patterns of chemical and biological variables were mainly influenced by monsoons and precipitation, while small scales of temporal and spatial variations could be ascribed to internal wave and tide in this study area.

  19. Spatial variability in the abundance, composition, and age of organic matter in surficial sediments of the East China Sea

    Science.gov (United States)

    Wu, Ying; Eglinton, Timothy; Yang, Liyang; Deng, Bing; Montluçon, Daniel; Zhang, Jing

    2013-12-01

    the sources and fate of organic matter (OM) sequestered in continental margin sediments is of importance because the mode and efficiency of OM burial impact the carbon cycle and the regulation of atmospheric CO2 over long time scales. We carried out molecular (lignin-derived phenols from CuO oxidation), elemental, isotopic (δ13C, Δ14C), and sedimentological (grain size and mineral surface area) analyses in order to examine spatial variability in the abundance, source, age of surface sediments of the East China Sea. Higher terrigenous organic matter values were found in the main accumulating areas of fluvial sediments, including the Changjiang (Yangtze) Estuary and Zhejiang-Fujian coastal zone. Isotopic and biomarker data suggest that the sedimentary OM in the inner shelf region was dominated by aged (Δ14C = -423 ± 42‰) but relatively lignin-rich OM (Λ = 0.94 ± 0.57 mg/100 mg OC) associated with fine-grained sediments, suggesting important contributions from soils. In contrast, samples from the outer shelf, while of similar age (Δ14 C = -450 ± 99‰), are lignin poor (Λ = 0.25 ± 0.14 mg/100 mg OC) and associated with coarse-grained material. Regional variation of lignin phenols and OM ages indicates that OM content is fundamentally controlled by hydrodynamic sorting (especially, sediment redistribution and winnowing) and in situ primary production. Selective sorption of acid to aldehyde in clay fraction also modified the ratios of lignin phenols. The burial of lignin in East China Sea is estimated to be relatively efficient, possibly as a consequence of terrigenous OM recalcitrance and/or relatively high sedimentation rates in the Changjiang Estuary and the adjacent Zhejing-Fujian mud belt.

  20. The research of modern He discharge in volcanic and tectonically active areas of China's continent

    International Nuclear Information System (INIS)

    Shangguan, Z.G.

    1999-01-01

    The realising features of modern helium in volcanic and tectonically active areas of China's continent are here discussed, presenting that the current escaped He in volcanic areas are mainly the mantle-derived He. The 3 He/ 4 He ratios of crustal gases in Eastern China are relatively higher than those gases in Middle-Western China. The author considers difficult to interpret this phenomenon by means of the differences of tectonic activity in those areas: it may be related to the variation of crustal thickness of China's continent from East to West

  1. Estimating Remineralized Phosphate and Its Remineralization Rate in the Northern East China Sea During Summer 1997: A Snapshot Study Before Three-Gorges Dam Construction

    Directory of Open Access Journals (Sweden)

    Hyun-Cheol Kim

    2016-01-01

    Full Text Available The northern East China Sea (a.k.a., “The South Sea” is a dynamic zone that exerts a variety of effects on the marine ecosystem due to Three-Gorges Dam construction. As the northern East China Sea region is vulnerable to climate forcing and anthropogenic impacts, it is important to investigate how the remineralization rate in the northern East China Sea has changed in response to such external forcing. We used an historical hydrographic dataset from August 1997 to obtain a baseline for future comparison. We estimate the amount of remineralized phosphate by decomposing the physical mixing and biogeochemical process effect using water column measurements (temperature, salinity, and phosphate. The estimated remineralized phosphate column inventory ranged from 0.8 to 42.4 mmol P m-2 (mean value of 15.2 ± 12.0 mmol P m-2. Our results suggest that the Tsushima Warm Current was a strong contributor to primary production during the summer of 1997 in the study area. The estimated summer (June - August remineralization rate in the region before Three-Gorges Dam construction was 18 ± 14 mmol C m-2 d-1.

  2. 50 CFR Table 6 to Part 679 - Steller Sea Lion Protection Areas Atka Mackerel Fisheries Restrictions

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Steller Sea Lion Protection Areas Atka Mackerel Fisheries Restrictions 6 Table 6 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 6 Table 6 to Part 679—Steller Sea Lion...

  3. 50 CFR Table 5 to Part 679 - Steller Sea Lion Protection Areas Pacific Cod Fisheries Restrictions

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Steller Sea Lion Protection Areas Pacific Cod Fisheries Restrictions 5 Table 5 to Part 679 Wildlife and Fisheries FISHERY CONSERVATION AND... THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 5 Table 5 to Part 679—Steller Sea Lion...

  4. Cooperation from Strength: The United States, China and the South China Sea

    Science.gov (United States)

    2012-01-01

    powers, such as Brazil and India) maintains that coastal rights can restrict foreign military activities within the EEZ, even though most other...Argentina, Austro-Hungary, Belgium, Bolivia, Brazil , Chile, China, Colombia, Costa Rica, Cuba, Denmark, Dominican Republic, Ecuador, El Salvador...address this challenge, Vietnam is trying to save the coastal mangrove forests that offer natural protection from coastal storm surges – something

  5. China’s Use of Peoples War Theory in the South China Sea

    Science.gov (United States)

    2017-05-25

    Fishing Industry, in which he expounded on the importance of fishing China’s vast marine territories to meet the challenges of the rising demand for food ...conflicts with the claims of Taiwan, Malaysia, Brunei, Indonesia, Philippines’ and Vietnam. Although all these countries, in addition to China, are...owned Baosha fishing corporation, provides an example of Mao’s concept of employing the population in a people’s war when he stated, “Vietnam seems like

  6. The Arab Spring and South China Sea Tensions: Analyzing China's Drive to Energy Security

    OpenAIRE

    Sevilla, Henelito A.

    2015-01-01

    The Arab Spring has brought significant changes to the political landscape in many Middle Eastern and North African (MENA) countries since early 2011. It has also affected the geo strategic and economic interests of powerful emerging Asian states, especially China and other net-energy consuming countries. One immediate result of the Arab Spring is its highly disrupted impact (a ' Black Swan') on the production and supply of crude oil to the economies in Asia due to their high degree...

  7. Temporal and Spatial Diversity of Bacterial Communities in Coastal Waters of the South China Sea

    Science.gov (United States)

    Du, Jikun; Xiao, Kai; Li, Li; Ding, Xian; Liu, Helu; Lu, Yongjun; Zhou, Shining

    2013-01-01

    Bacteria are recognized as important drivers of biogeochemical processes in all aquatic ecosystems. Temporal and geographical patterns in ocean bacterial communities have been observed in many studies, but the temporal and spatial patterns in the bacterial communities from the South China Sea remained unexplored. To determine the spatiotemporal patterns, we generated 16S rRNA datasets for 15 samples collected from the five regularly distributed sites of the South China Sea in three seasons (spring, summer, winter). A total of 491 representative sequences were analyzed by MOTHUR, yielding 282 operational taxonomic units (OTUs) grouped at 97% stringency. Significant temporal variations of bacterial diversity were observed. Richness and diversity indices indicated that summer samples were the most diverse. The main bacterial group in spring and summer samples was Alphaproteobacteria, followed by Cyanobacteria and Gammaproteobacteria, whereas Cyanobacteria dominated the winter samples. Spatial patterns in the samples were observed that samples collected from the coastal (D151, D221) waters and offshore (D157, D1512, D224) waters clustered separately, the coastal samples harbored more diverse bacterial communities. However, the temporal pattern of the coastal site D151 was contrary to that of the coastal site D221. The LIBSHUFF statistics revealed noticeable differences among the spring, summer and winter libraries collected at five sites. The UPGMA tree showed there were temporal and spatial heterogeneity of bacterial community composition in coastal waters of the South China Sea. The water salinity (P=0.001) contributed significantly to the bacteria-environment relationship. Our results revealed that bacterial community structures were influenced by environmental factors and community-level changes in 16S-based diversity were better explained by spatial patterns than by temporal patterns. PMID:23785512

  8. Methylmercury in fish from the South China Sea: Geographical distribution and biomagnification

    International Nuclear Information System (INIS)

    Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

    2013-01-01

    Highlights: • A large-scale investigation of MeHg in 46 species of marine wild fish from South China Sea. • Log 10 MeHg concentration was significantly related to their length and wet weight. • Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. • Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic species. • Biomagnification of MeHg was site-specific. -- Abstract: We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ 15 N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log 10 MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log 10 (MeHg) and δ 15 N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea

  9. Investigation of Spatial and Temporal Trends in Water Quality in Daya Bay, South China Sea

    Science.gov (United States)

    Wu, Mei-Lin; Wang, You-Shao; Dong, Jun-De; Sun, Cui-Ci; Wang, Yu-Tu; Sun, Fu-Lin; Cheng, Hao

    2011-01-01

    The objective is to identify the spatial and temporal variability of the hydrochemical quality of the water column in a subtropical coastal system, Daya Bay, China. Water samples were collected in four seasons at 12 monitoring sites. The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on water quality in Daya Bay. In the spatial pattern, two groups have been identified, with the help of multidimensional scaling analysis and cluster analysis. Cluster I consisted of the sites S3, S8, S10 and S11 in the west and north coastal parts of Daya Bay. Cluster I is mainly related to anthropogenic activities such as fish-farming. Cluster II consisted of the rest of the stations in the center, east and south parts of Daya Bay. Cluster II is mainly related to seawater exchange from South China Sea. PMID:21776234

  10. Hygroscopic behavior of water-soluble matter in marine aerosols over the East China Sea.

    Science.gov (United States)

    Yan, Yu; Fu, Pingqing; Jing, Bo; Peng, Chao; Boreddy, S K R; Yang, Fan; Wei, Lianfang; Sun, Yele; Wang, Zifa; Ge, Maofa

    2017-02-01

    In this study, we investigated hygroscopic properties of water-soluble matter (WSM) in marine aerosols over the East China Sea, which were collected during a Natural Science Foundation of China (NSFC) sharing cruise in 2014. Hygroscopic growth factors (g) of WSM were measured by a hygroscopicity tandem differential mobility analyzer (H-TDMA) with an initial dry particle mobility diameter of 100nm. The observed g at 90% relative humidity (RH), g(90%) WSM , defined as the ratio of the particle diameter at 90% RH to that at RHsea water was likely due to the transport of anthropogenic aerosols, chemical aging of dust particles, the contribution of biomass burning products, and the aerosol hygroscopic growth inhibition of organics. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Arctic sea ice, Eurasia snow, and extreme winter haze in China.

    Science.gov (United States)

    Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

    2017-03-01

    The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction.

  12. Gauging The Potential For Armed Conflict Between China And Indonesia In The South China Sea

    Science.gov (United States)

    2017-12-01

    strong belief in Marxism. Based on class struggle theory, nationalism is only a short - term objective before achieving the long - term objective of...were victims of the atrocities themselves or saw the atrocities first hand. Naturally, all those memories were passed to their children and...be any effort from the Chinese government to educate its public about the Law of the Sea in the short term , it is better to understand, how the

  13. Bothid larvae (Pleuronectiformes - Pisces) of the Gulf of Thailand and South China Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Devi, C.B.L.

    , Paralichthidae and Bothidae). Kaiyo Kagaku, 11 (2): 100-110 (in Japanese). Amaoka, K., 1984. Bothidae in The fishes of the Japanese Archipelago edited by H. Masuda et al. Tokai Univ. Press. Tokyo. 347-350. 70 LALITHAMBIKA DEVI i Amaoka, K. and E. Yamamoto..., with notes on the species of genus Bothus in Japanese waters. J. Oceanogr. Soc. Jap., 1 (1-2) : 133-140. Kyusin, K., Amaoka, K., Nakaya, K., Ida., H., Tanino, Y. and Senta, T. 1982. Fishes of the S outh China Sea. Japan Fish. Reso. Res. Center, Tokyo 333 pp...

  14. Briarane Diterpenes from the South China Sea Gorgonian Coral, Junceella gemmacea

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    2014-01-01

    Full Text Available Four new briarane diterpenoids, junceellolides M–P (1–4, were isolated together with seven known analogs (5–11 from the South China Sea gorgonian, Junceella gemmacea. The structures of these compounds were elucidated by detailed spectroscopic analysis and comparison with the reported data. The absolute configuration of compounds 1–3 were determined based on an ECD experiment, while the absolute configuration of compound 4 was genetically determined. All the compounds were isolated for the first time from J. gemmacea. These compounds showed no growth inhibitory activity against A549, MG63 and SMMC-7721 cell lines in an in vitro bioassay.

  15. Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo

    Science.gov (United States)

    Gao, Cheng-Hai; Wang, Yi-Fei; Li, Shen; Qian, Pei-Yuan; Qi, Shu-Hua

    2011-01-01

    Five zoanthoxanthin alkaloids (1–5) and four sesquiterpenes (6–9) were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (1–2), 8-hydroxy-6β-methoxy-14- oxooplop-6,12-olide (6) and 3β-methoxyguaian-10(14)-en-2β-ol (7) were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae. PMID:22163197

  16. A new species of Eunice (Polychaeta: Eunicidae) from Hainan Island, South China Sea

    Science.gov (United States)

    Wu, Xuwen; Sun, Ruiping; Liu, Ruiyu

    2013-01-01

    A taxonomic survey of benthic marine animals from coastal regions of Hainan Island, South China Sea, revealed specimens of a new species of Eunice (Polychaeta: Eunicida: Eunicidae), Eunice uschakovi n. sp., collected from the intertidal zone. The species belongs to the group of Eunice that has yellow tridentate subacicular hooks and branchiae scattered over an extensive region of the body. It resembles E. miurai and E. havaica in having both bidentate and tridentate falcigers, but can be readily distinguished by branchial features. Comparisons between E. uschakovi and the two related species are presented.

  17. Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

    KAUST Repository

    Wang, Chang Yun

    2011-08-01

    Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1-10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite. © 2011 Elsevier Ltd.

  18. Jaspiferin A and B: Two New Secondary Metabolites from the South China Sea Sponge Jaspis stellifera

    Directory of Open Access Journals (Sweden)

    Shengan Tang

    2012-07-01

    Full Text Available A chemical investigation of marine sponge Jaspis stellifera, collected from South China Sea, led to the isolation of two new compounds, Jaspiferin A and B (1-2, and six known compounds, gibepyrone F (3 , p- hydroxy benzaldehyde (4 , 3-Indole-3-aldehyde (5 , Thymine (6 , 24(28-dehydroaplysterol (7 , (25s-26- methylene-cholest-4-en-3-one (8. Their structures were determined by extensive spectroscopic analysis in association with physical and chemical properties, as well as comparison of their spectral data with these reported in literatures. The biogenetic transformation of compound 2 was also speculated.

  19. Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo

    Directory of Open Access Journals (Sweden)

    Shu-Hua Qi

    2011-11-01

    Full Text Available Five zoanthoxanthin alkaloids (1–5 and four sesquiterpenes (6–9 were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (1–2, 8-hydroxy-6β-methoxy-14-oxooplop-6,12-olide (6 and 3β-methoxyguaian-10(14-en-2β-ol (7 were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae.

  20. Chemical constituents of soft coral Sarcophyton infundibuliforme from the South China Sea

    KAUST Repository

    Wang, Chang Yun; Chen, An Na; Shao, Chang Lun; Li, Liang; Xu, Ying; Qian, Pei Yuan

    2011-01-01

    Chemical investigation on soft coral Sarcophyton infundibuliforme collected from the South China Sea led to the isolation and identification of 14 secondary metabolites, including ten cembrene diterpenoids (1-10), one α-tocopheryl quinone derivative (11), one prostaglandin (12), one lipid (13) and one carotinoid (14). Their structures were determined by extensive analysis of their spectroscopic data. All of these metabolites were isolated from this species for the first time. Diterpenoids 1, 2, 7 and 10 showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite. © 2011 Elsevier Ltd.

  1. Annual and interannual variability of scatterometer ocean surface wind over the South China Sea

    DEFF Research Database (Denmark)

    Zhang, GS; Xu, Q.; Gong, Z.

    2014-01-01

    To investigate the annual and interannual variability of ocean surface wind over the South China Sea (SCS), the vector empirical orthogonal function (VEOF) method and the Hilbert-Huang transform (HHT) method were employed to analyze a set of combined satellite scatterometer wind data during.......3% of the total variance and represents the East Asian monsoon features. The second mode of VEOF corresponds to a spring-autumn oscillation which accounts for 8.3% of the total variance. To analyze the interannual variability, the annual signal was removed from the wind data set and the VEOFs of the residuals...

  2. Sources and distribution of polychlorinated-dibenzo-p-dioxins and -dibenzofurans in soil and sediment from the Yellow Sea region of China and Korea

    International Nuclear Information System (INIS)

    Naile, Jonathan E.; Khim, Jong Seong; Wang Tieyu; Wan Yi; Luo Wei; Hu Wenyou; Jiao Wentao; Park, Jinsoon; Ryu, Jongseong; Hong, Seongjin; Jones, Paul D.; Lu Yonglong

    2011-01-01

    Polychlorinated-dibenzo-p-dioxins and -dibenzofurans (PCDD/Fs) were measured in soils and sediments from the Yellow Sea region. Korean soils and sediments mostly contained detectable PCDD/Fs and showed a widespread distribution among locations. Soil and sedimentary PCDD/Fs from China were comparable to or less than those in Korea. The patterns of relative concentrations of individual congeners in soils were different between the two countries, but similar in sediments. Sources of PCDD/Fs in China and Korea were found to be independent of each other and their distributions reflected matrix-dependent accumulation. Spatial distribution indicated some point sources in Korea while Chinese sources were more widespread and diffuse. PCDD/Fs measured in the coastal areas of the Yellow Sea were comparable to or less than those previously reported in for eastern Asia. However, ΣTEQs in soils and sediments were near to or, in some cases exceeded environmental quality guidelines. - Research highlights: → PCDDs were comparable or greater than PCDFs for Yellow Sea soils and sediments. → PCDD/Fs congener patterns in soils were different but similar in sediments. → PCDD/Fs congener patterns varied among regions reflecting regional activities. → Sources of PCDD/Fs in China and Korea were mainly independent of each other. → ΣTEQs in Yellow Sea soils and sediments often exceeded corresponding guidelines. - PCDD/Fs in soils and sediments along the Yellow Sea indicated both point and non-point sources and their contribution to total TEQs differed among land uses and by regional activities.

  3. Occurrence and seasonal variations of per- and polyfluoroalkyl substances (PFASs) including fluorinated alternatives in rivers, drain outlets and the receiving Bohai Sea of China.

    Science.gov (United States)

    Chen, Hong; Han, Jianbo; Zhang, Can; Cheng, Jiayi; Sun, Ruijun; Wang, Xiaomeng; Han, Gengchen; Yang, Wenchao; He, Xin

    2017-12-01

    A simultaneous sampling campaign was undertaken to study the pollution by 21 per- and polyfluoroalkyl substances (PFASs) in rivers, drain outlets and their receiving Bohai Sea of China. Chlorinated polyfluoroalkyl ether sulfonic acids (Cl-PFESAs) are being used as fluorinated alternatives and they were included in this study. In comparison with other regions and countries, high concentrations of ∑ 21 PFASs in seawater samples from the Bohai Sea, ranging from 5.03 to 41 700 ng/L (median: 64.8 ng/L), were observed. The spatial distribution of PFAS levels in this sea area was in the ranking of Laizhou Bay > Liaodong Bay > Bohai Bay > other sea areas. By comparing the levels and composition profiles of PFASs in the seawater and their sources (rivers and drain outlets), it was concluded that rivers and drain outlets are the primary sources of PFAS contamination to the Bohai Sea. These PFAS levels varied seasonally among the rivers and drain outlets, but statistically significant changes were not observed. Levels of 6:2 and 8:2 Cl-PFESAs in rivers, drain outlets and receiving sea were firstly reported in the present study. Relatively high concentrations of 6:2 Cl-PFESA were found in drain outlets, ranging from below method limits of quantification (MLQ) to 7600 ng/L, but 8:2 Cl-PFAES detection was infrequent and all median concentration below MLQ. Mass discharges to the sea of 6:2 Cl-PFESA from rivers and drain outlets to the sea were estimated to be 37 and 17 kg/y, respectively. Copyright © 2017. Published by Elsevier Ltd.

  4. Biogeographical distribution and diversity of bacterial communities in surface sediments of the South China Sea.

    Science.gov (United States)

    Li, Tao; Wang, Peng

    2013-05-01

    This paper aims at an investigation of the features of bacterial communities in surface sediments of the South China Sea (SCS). In particular, biogeographical distribution patterns and the phylogenetic diversity of bacteria found in sediments collected from a coral reef platform, a continental slope, and a deep-sea basin were determined. Bacterial diversity was measured by an observation of 16S rRNA genes, and 18 phylogenetic groups were identified in the bacterial clone library. Planctomycetes, Deltaproteobacteria, candidate division OP11, and Alphaproteobacteria made up the majority of the bacteria in the samples, with their mean bacterial clones being 16%, 15%, 12%, and 9%, respectively. By comparison, the bacterial communities found in the SCS surface sediments were significantly different from other previously observed deep-sea bacterial communities. This research also emphasizes the fact that geographical factors have an impact on the biogeographical distribution patterns of bacterial communities. For instance, canonical correspondence analyses illustrated that the percentage of sand weight and water depth are important factors affecting the bacterial community composition. Therefore, this study highlights the importance of adequately determining the relationship between geographical factors and the distribution of bacteria in the world's seas and oceans.

  5. Empirical prediction of the onset dates of South China Sea summer monsoon

    Science.gov (United States)

    Zhu, Zhiwei; Li, Tim

    2017-03-01

    The onset of South China Sea summer monsoon (SCSSM) signifies the commencement of the wet season over East Asia. Predicting the SCSSM onset date is of significant importance. In this study, we establish two different statistical models, namely the physical-empirical model (PEM) and the spatial-temporal projection model (STPM) to predict the SCSSM onset. The PEM is constructed from the seasonal prediction perspective. Observational diagnoses reveal that the early onset of the SCSSM is preceded by (a) a warming tendency in middle and lower troposphere (850-500 hPa) over central Siberia from January to March, (b) a La Niña-like zonal dipole sea surface temperature pattern over the tropical Pacific in March, and (c) a dipole sea level pressure pattern with negative center in subtropics and positive center over high latitude of Southern Hemisphere in January. The PEM built on these predictors achieves a cross-validated reforecast temporal correlation coefficient (TCC) skill of 0.84 for the period of 1979-2004, and an independent forecast TCC skill of 0.72 for the period 2005-2014. The STPM is built on the extended-range forecast perspective. Pentad data are used to predict a zonal wind index over the South China Sea region. Similar to PEM, the STPM is constructed using 1979-2004 data. Based on the forecasted zonal wind index, the independent forecast of the SCSSM onset dates achieves a TCC skill of 0.90 for 2005-2014. The STPM provides more detailed information for the intraseasonal evolution during the period of the SCSSM onset (pentad 25-35). The two models proposed herein are expected to facilitate the real-time prediction of the SCSSM onset.

  6. 50 CFR Table 12 to Part 679 - Steller Sea Lion Protection Areas, 3nm No Groundfish Fishing Sites

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Steller Sea Lion Protection Areas, 3nm No... EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 12 Table 12 to Part 679—Steller Sea Lion Protection Areas, 3nm No Groundfish Fishing Sites Steller Sea Lion Protection Areas, 3nm No Groundfish Fishing Sites...

  7. Forecasters Handbook for Japan and Adjacent Sea Areas

    Science.gov (United States)

    1988-06-01

    marginal seas by the Tsushima (Korea) Strait, and La Perouse ( Soya ) and Tartar straits respectively. Only the Tsushima (Korea) Strait has a sill depth...northward along the west side of Hokkaido and then splits. One branch turns eastward through the Soya ( La Perouse) Strait and returns southward as the...islands of Honshu and Hokkaido, the Soya ( La Perouse) Strait between Hokkaido and Sakhalin Island, and the Tartar Strait between Sakhalin Island and

  8. Designing Local-Scale Marine Protected Area Networks in the Central Saudi Arabian Red Sea

    KAUST Repository

    Khalil, Maha T.

    2015-01-01

    Coral reefs around the world are at risk from overexploitation and climate change, and coral reefs of the Red Sea are no exception. Science-based designation of marine protected areas (MPAs), within which human activities are restricted, has become

  9. Fishers and Territorial Anxieties in China and Vietnam: Narratives of the South China Sea Beyond the Frame of the Nation

    Directory of Open Access Journals (Sweden)

    Edyta Roszko

    2016-12-01

    Full Text Available In the geopolitical conflict over the South China Sea (SCS, fishers are at the center of Chinese and Vietnamese cartographic imaginations that define the sea as either “Chinese” or “Vietnamese” and hence tied to the disputed territories of the Paracel and Spratly Islands. While their historical presence and customary fishing rights in the SCS have been much publicized in the context of this territorial dispute, the long-standing Cham seafaring trade networks and legacy are ignored by both countries. The ethnic and national categories of Cham, Việt, and Han intersect with occupational categories such as those of fisher, trader, shipbuilder, sailor, and pirate, which in the past represented shifting, relational, and situational activities by the same people. The contemporary use of such professional and national labels produces particular political effects by projecting recent closures and enclosures onto the past, in spite of the common historical, cultural, and ethnic flows that always existed in the SCS. Rather than aiming to legitimize or delegitimize Vietnam’s or China’s territorial claims to the SCS, this article argues that seafaring narratives should be liberated from abstract, anachronistic discourses of sovereignty, territoriality, and territorial anxieties that separate the interconnected histories of the Cham, Vietnamese, and Chinese.

  10. Satellite remote sensing of a low-salinity water plume in the East China Sea

    Directory of Open Access Journals (Sweden)

    Y. H. Ahn

    2008-07-01

    Full Text Available With the aim to map and monitor a low-salinity water (LSW plume in the East China Sea (ECS, we developed more robust and proper regional algorithms from large in-situ measurements of apparent and inherent optical properties (i.e. remote sensing reflectance, Rrs, and absorption coefficient of coloured dissolved organic matter, aCDOM determined in ECS and neighboring waters. Using the above data sets, we derived the following relationships between visible Rrs and absorption by CDOM, i.e. Rrs (412/Rrs (555 vs. aCDOM (400 (m−1 and aCDOM (412 (m−1 with a correlation coefficient R2 0.67 greater than those noted for Rrs (443/Rrs (555 and Rrs (490/Rrs (555 vs. aCDOM (400 (m−1 and aCDOM (412 (m−1. Determination of aCDOM (m−1 at 400 nm and 412 nm is particularly necessary to describe its absorption as a function of wavelength λ using a single exponential model in which the spectral slope S as a proxy for CDOM composition is estimated by the ratio of aCDOM at 412 nm and 400 nm and the reference is explained simply by aCDOM at 412 nm. In order to derive salinity from the absorption coefficient of CDOM, in-situ measurements of salinity made in a wide range of water types from dense oceanic to light estuarine/coastal systems were used along with in-situ measurements of aCDOM at 400 nm, 412 nm, 443 nm and 490 nm. The CDOM absorption at 400 nm was better inversely correlated (R2=0.86 with salinity than at 412 nm, 443 nm and 490 nm (R2=0.85–0.66, and this correlation corresponded best with an exponential (R2=0.98 rather than a linear function of salinity measured in a variety of water types from this and other regions. Validation against a discrete in-situ data set showed that empirical algorithms derived from the above relationships could be successfully applied to satellite data over the range of water types for which they have been developed. Thus, we applied these algorithms to a series of SeaWiFS images for the derivation of CDOM and salinity

  11. China’s Near Seas Combat Capabilities (China Maritime Study, Number 11)

    Science.gov (United States)

    2014-02-01

    include FY- 2G and -2H in 2014, FY-3D/PM1 and FY-4 M in 2015, FY-3E/AM1 in 2017, FY-3F/PM2 in 2019, china’s near seas combat capabilities 97 FY- 3G ...on ASCMs. This is indicated by the display of land-based, mobile YJ-62 transporter-erector-launchers (TELs) during the 1 October 2009 National Day...air defenses and a supporting targeting system that can detect fleeting mobile targets and rapidly relay the data underwater, submarines would

  12. SEAWIFS Analysis of the Japan and East China Sea Air/Sea Environment

    National Research Council Canada - National Science Library

    Rocha, James

    2001-01-01

    ... characteristics and distribution, the effects of both ocean turbidity and various aerosols on the radiance received from the top of the atmosphere, and develop algorithms designed to identify areas of airborne dust and high ocean turbidity...

  13. The status of coastal oceanography in heavily impacted Yellow and East China Sea: Past trends, progress, and possible futures

    Science.gov (United States)

    Wang, Xiao Hua; Cho, Yang-Ki; Guo, Xinyu; Wu, Chau-Ron; Zhou, Junliang

    2015-09-01

    Coastal environments are a key location for transport, commercial, residential and defence infrastructure, and have provided conditions suitable for economic growth. They also fulfil important cultural, recreational and aesthetic needs; have intrinsic ecosystem service values; and provide essential biogeochemical functions such as primary productivity, nutrient cycling and water filtration. The rapid expansion in economic development and anticipated growth of the population in the coastal zones along the Yellow and East China Sea basin has placed this region under intense multiple stresses. Here we aim to: 1) synthesize the new knowledge/science in coastal oceanography since 2010 within the context of the scientific literature published in English; 2) report on a citation analysis that assesses whether new research topics have emerged and integrated over time, indicate the location of modelling and field-based studies; and 3) suggest where the new research should develop for heavily impacted estuaries and coastal seas of East Asia. The conclusions of the synthesis include: 1) China has emerged as a dominant force in the region in producing scientific literature in coastal oceanography, although the area of publications has shifted from its traditional fields such as physical oceanography; 2) there has been an increasing number of publications with cross-disciplinary themes between physical oceanography and other fields of the biological, chemical, and geological disciplines, but vigorous and systematic funding mechanisms are still lacking to ensure the viability of large scale multi-disciplinary teams and projects in order to support trans-disciplinary research and newly emerging fields; 3) coastal oceanography is responding to new challenges, with many papers studying the impacts of human activities on marine environment and ecology, but so far very few studying management and conservation strategies or offering policy solutions.

  14. Persistent organic pollutants in marine fish from Yongxing Island, South China Sea: levels, composition profiles and human dietary exposure assessment.

    Science.gov (United States)

    Sun, Yu-Xin; Hao, Qing; Xu, Xiang-Rong; Luo, Xiao-Jun; Wang, Shuai-Long; Zhang, Zai-Wang; Mai, Bi-Xian

    2014-03-01

    Little data is available on the bioaccumulation of persistent organic pollutants (POPs) in marine organisms from South China Sea (SCS). Five marine fish species were collected from Yongxing Island, SCS to investigate the presence of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). PBDEs, PCBs, and DDTs concentrations ranged from 2.0-117, 6.3-199, and 9.7-5831 ng g(-1) lw, respectively. In general, contaminants measured in this study were at the lower end of the global range. Concentrations of PBDEs and PCBs were significantly correlated in fish samples, implying that PBDEs are as prevalent as PCBs in Yongxing Island. Among the five fish species studied, yellow striped goatfish had the highest concentrations of PBDEs, PCBs, and DDTs, probably attributed to its different living and feeding habits. The contaminant distribution pattern indicated that agrochemical source is more important than industrial source in Yongxing Island, SCS. The average estimated daily intakes of PBDEs, PCBs, and DDTs via fish consumption by local residents in the coastal areas of South China ranged from 1.42-5.91, 3.20-13.3, and 8.08-33.6 ng d(-1), which were lower than those in previous studies, suggesting that consumption of marine fish in Yongxing Island, SCS, might not subject local residents to significant health risk as far as POPs are concerned. This is the first study to report the occurrence of POPs in marine biota from SCS. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. [Mercury concentration of fish in Tokyo Bay and the surrounding sea area].

    Science.gov (United States)

    Zhang, R; Kashima, Y; Matsui, M; Okabe, T; Doi, R

    2001-07-01

    Total mercury in the muscles of three fish species was analyzed in fish caught in Tokyo Bay and the surrounding sea areas, Sagami Bay and Choshi. Tokyo Bay is a semi-closed sea area surrounded by Tokyo, Kanagawa and Chiba prefectures. Sagami Bay and Choshi are open to the Pacific Ocean. A total of 412 fish consisting of northern whiting (Sillago japonica), flatfish (Limanda yokohamae) and sardine (Sardinops melanosticta) were caught in these areas over a 6 months period from November 1998 to April 1999. Total mercury concentration ranged from 0.008-0.092 microgram/g (wet wt.) in northern whiting, 0.006-0.065 microgram/g in flatfish and 0.001-0.045 microgram/g in sardine. All concentrations were below the restriction limit of fish mercury in Japan, 0.4 microgram/g of total mercury concentration. A significant correlation was found between mercury concentrations and body length or body weight in northern whiting and flatfish, irrespective of the sea area. A correlation was also found between mercury concentration in fish and their feeding habits: among the 3 species caught in the same area, crustacean feeding northern whiting had the highest, polychaete feeding flatfish moderate, and plankton feeding sardine had the lowest mercury concentration. In a comparison of mercury concentration in the same species caught in different sea areas, a higher concentration was noted in fish caught in the semi-closed sea area of Tokyo Bay, than in fish caught in the open sea areas of Sagami Bay and Choshi. This difference was most marked in fish caught at the bottom of Tokyo Bay and we considered that the mercury concentration of seawater and sediment in these areas was the cause of mercury accumulation in fish. These findings suggest that improved water quality control and environmental monitoring is necessary in semi-closed sea areas such as Tokyo Bay.

  16. Coastal surface sediment quality assessment in Leizhou Peninsula (South China Sea) based on SEM-AVS analysis.

    Science.gov (United States)

    Li, Feng; Lin, Jin-qin; Liang, Yan-yan; Gan, Hua-yang; Zeng, Xiang-yun; Duan, Zhi-peng; Liang, Kai; Liu, Xing; Huo, Zhen-hai; Wu, Chang-hua

    2014-07-15

    Surface sediments from the coastal area of the Leizhou Peninsula in the South China Sea were collected and analyzed and the potential ecological risks in the area were assessed based on acid-volatile sulfide (AVS) model. The AVS levels are between 0.109 and 55.6 μmol g(-1), with the average at 4.45 μmol g(-1). The high AVS-concentration zones include the aquaculture areas of Liusha Bay and the densely populated areas of Zhanjiang Bay. The simultaneously extracted metals (SEM) range from 0.026 μmol g(-1) to 8.61 μmol g(-1), with the average at 0.843 μmol g(-1). Most of high SEM-concentration stations were located in ports or aquaculture zones. Most of the coastal surface sediments of the Leizhou Peninsula (90%) had no adverse biological effects according to the criterion proposed by USEPA (2005); while adverse effects were uncertain in some stations (8%); even in 2 stations (2%) adverse biological effects may be expected. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Thinned crustal structure and tectonic boundary of the Nansha Block, southern South China Sea

    Science.gov (United States)

    Dong, Miao; Wu, Shi-Guo; Zhang, Jian

    2016-12-01

    The southern South China Sea margin consists of the thinned crustal Nansha Block and a compressional collision zone. The Nansha Block's deep structure and tectonic evolution contains critical information about the South China Sea's rifting. Multiple geophysical data sets, including regional magnetic, gravity and reflection seismic data, reveal the deep structure and rifting processes. Curie point depth (CPD), estimated from magnetic anomalies using a windowed wavenumber-domain algorithm, enables us to image thermal structures. To derive a 3D Moho topography and crustal thickness model, we apply Oldenburg algorithm to the gravity anomaly, which was extracted from the observed free air gravity anomaly data after removing the gravity effect of density variations of sediments, and temperature and pressure variations of the lithospheric mantle. We found that the Moho depth (20 km) is shallower than the CPD (24 km) in the Northwest Borneo Trough, possibly caused by thinned crust, low heat flow and a low vertical geothermal gradient. The Nansha Block's northern boundary is a narrow continent-ocean transition zone constrained by magnetic anomalies, reflection seismic data, gravity anomalies and an interpretation of Moho depth (about 13 km). The block extends southward beneath a gravity-driven deformed sediment wedge caused by uplift on land after a collision, with a contribution from deep crustal flow. Its southwestern boundary is close to the Lupar Line defined by a significant negative reduction to the pole (RTP) of magnetic anomaly and short-length-scale variation in crustal thickness, increasing from 18 to 26 km.

  18. Kinematic parameters of internal waves of the second mode in the South China Sea

    Directory of Open Access Journals (Sweden)

    O. Kurkina

    2017-10-01

    Full Text Available Spatial distributions of the main properties of the mode function and kinematic and non-linear parameters of internal waves of the second mode are derived for the South China Sea for typical summer conditions in July. The calculations are based on the Generalized Digital Environmental Model (GDEM climatology of hydrological variables, from which the local stratification is evaluated. The focus is on the phase speed of long internal waves and the coefficients at the dispersive, quadratic and cubic terms of the weakly non-linear Gardner model. Spatial distributions of these parameters, except for the coefficient at the cubic term, are qualitatively similar for waves of both modes. The dispersive term of Gardner's equation and phase speed for internal waves of the second mode are about a quarter and half, respectively, of those for waves of the first mode. Similarly to the waves of the first mode, the coefficients at the quadratic and cubic terms of Gardner's equation are practically independent of water depth. In contrast to the waves of the first mode, for waves of the second mode the quadratic term is mostly negative. The results can serve as a basis for expressing estimates of the expected parameters of internal waves for the South China Sea.

  19. Occurrence of persistent organic pollutants in marine fish from the Natuna Island, South China Sea.

    Science.gov (United States)

    Hao, Qing; Sun, Yu-Xin; Xu, Xiang-Rong; Yao, Zi-Wei; Wang, You-Shao; Zhang, Zai-Wang; Luo, Xiao-Jun; Mai, Bi-Xian

    2014-08-15

    Five marine fish species were collected from the Natuna Island, South China Sea to investigate the occurrence of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs in marine fish ranged from 2.85 to 7.82, 14.3 to 48.1, and 7.99 to 40.3 ng/g lipid weight, respectively. Higher concentrations of PBDEs, PCBs, and DDTs were observed in Snakefish (Trachinocephalus myops), which might be attributed to their different feeding and living habits. PCBs were the predominant POPs in all marine fish, followed by DDTs and PBDEs. BDE 47 and PCB 153 were the predominant congener of PBDEs and PCBs, respectively. Compositional distribution of DDTs indicated the possible presence of fresh input sources around the Natuna Island. The ratios of o,p'-DDT/p,p'-DDT being less than 1 in fish samples suggested that DDT contributions from dicofol seemed considerably low. New input sources of DDT in South China Sea are worth further research. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Methylmercury in fish from the South China Sea: geographical distribution and biomagnification.

    Science.gov (United States)

    Zhu, Aijia; Zhang, Wei; Xu, Zhanzhou; Huang, Liangmin; Wang, Wen-Xiong

    2013-12-15

    We conducted a large-scale investigation of methylmercury (MeHg) in a total of 628 marine wild fish covering 46 different species collected from the South China Sea between 2008 and 2009. Biological and ecological characteristics such as size (length and wet weight), feeding habit, habitat, and stable isotope (δ(15)N) were examined to explain MeHg bioaccumulation in marine fish and their geographical distribution. MeHg levels in the muscle tissues of the 628 individuals ranged from 0.010 to 1.811 μg/g dry wt. Log10MeHg concentration was significantly related to their length and wet weight. Feeding habit and habitat were the primary factors influencing MeHg bioaccumulation. Demersal fish were more likely to be contaminated with MeHg than the epipelagic and mesopelagic varieties. Linear relationships were obtained between Log10(MeHg) and δ(15)N only for one location, indicating that biomagnification was site-specific. Results from this study suggest that dietary preference and trophic structure were the main factors affecting MeHg bioaccumulation in marine fish from the South China Sea. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Acceleration of modern acidification in the South China Sea driven by anthropogenic CO2

    Science.gov (United States)

    Liu, Yi; Peng, Zicheng; Zhou, Renjun; Song, Shaohua; Liu, Weiguo; You, Chen-Feng; Lin, Yen-Po; Yu, Kefu; Wu, Chung-Che; Wei, Gangjian; Xie, Luhua; Burr, George S.; Shen, Chuan-Chou

    2014-01-01

    Modern acidification by the uptake of anthropogenic CO2 can profoundly affect the physiology of marine organisms and the structure of ocean ecosystems. Centennial-scale global and regional influences of anthropogenic CO2 remain largely unknown due to limited instrumental pH records. Here we present coral boron isotope-inferred pH records for two periods from the South China Sea: AD 1048–1079 and AD 1838–2001. There are no significant pH differences between the first period at the Medieval Warm Period and AD 1830–1870. However, we find anomalous and unprecedented acidification during the 20th century, pacing the observed increase in atmospheric CO2. Moreover, pH value also varies in phase with inter-decadal changes in Asian Winter Monsoon intensity. As the level of atmospheric CO2 keeps rising, the coupling global warming via weakening the winter monsoon intensity could exacerbate acidification of the South China Sea and threaten this expansive shallow water marine ecosystem. PMID:24888785

  2. New record of Japanese snake blenny Xiphasia matsubarai (Perciformes: Blenniidae) from South China Sea

    Science.gov (United States)

    Yi, Murong; Zhao, Chunxu; Su, Xin; Tao, Yajin; Yan, Yunrong

    2017-11-01

    Specimens belonging to the family Blenniidae were collected in a fishery resource investigation from the coastal waters of Xisha Islands and Hainan Island, South China Sea in 2016. Combining morphological results with sequence analysis, we identified one specimen as Xiphasia matsubarai Okada & Suzuki, 1952. This represents a new record in the South China Sea. In morphology, the specimen has the following traits: body elongated, eel-like or ribbon-like in shape; flanks medium flat; the head small bluntly rounded anteriorly and without a moustache; eyes is slightly smaller, on upper lateral position of head, which is about equal to 1/5 of the length of the head; body without scales, lateral line has been degraded; both sides of the upper and lower jaws with a canine; gill is opening at the top of the pectoral fin base, approximately equal to the length of eye diameter. Dorsal fin XI, 96; pectoral fin 10; anal fin II, 95. Head and body grey-brown, including 26 dark grey-brown bands; abdomen and lower operculum yellowish grey and colour lighter; and dorsal base long with dark grey. Origin of dorsal is located over the anterior margin of pupil; black blotch on dorsal fin between 8th and 10th dorsal spine; anal and caudal fins dark grey, pectoral and ventral fins pale yellow. Sequence analysis of cytochrome oxidase subunit I gene (COI) strongly supports the identity of the specimen as X. matsubarai.

  3. Performance Calculation of Floating Wind Turbine Tension Leg Platform in the South China Sea

    Directory of Open Access Journals (Sweden)

    Hai Feng Wang

    2015-10-01

    Full Text Available The harvesting of wind energy is expected to increase greatly in the future because of its stability, abundance, and renewability in large coastal states such as China. The floating support structure will likely become the major structural form for wind turbines in the future due to its cost advantages when the water depth reaches 50 m. The 5MW wind turbine model from National Renewable Energy Lab (NREL and the modified tension leg platform model proposed by Harbin Institute of Technology (HIT were applied to certain sea conditions in the South China Sea in order to consider the effects of external load coupling actions. In this study, the internal force, mooring system force, as well as the acceleration, displacement and velocity of the floating structure of the modified HIT Tension Leg Platform (HIT-TLP were calculated. During this process, the physical parameters of its tension leg structure at a specific frequency domain were obtained to find the technical reserves for its practical application in the future.

  4. Response of internal solitary waves to tropical storm Washi in the northwestern South China Sea

    Directory of Open Access Journals (Sweden)

    Z. H. Xu

    2011-11-01

    Full Text Available Based on in-situ time series data from an array of temperature sensors and an acoustic Doppler current profiler on the continental shelf of the northwestern South China Sea, a sequence of internal solitary waves (ISWs were observed during the passage of tropical storm Washi in the summer of 2005, which provided a unique opportunity to investigate the ISW response to the tropical cyclone. The passing tropical storm is found to play an important role in affecting the stratification structure of the water column, and consequently leading to significant variability in the propagating features of the ISWs, such as the polarity reversal and amplitude variations of the waves. The response of the ISWs to Washi can be divided into two stages, direct forcing by the strong wind (during the arrival of Washi and remote forcing via the near-inertial internal waves induced by the tropical storm (after the passage of Washi. The field observations as well as a theoretical analysis suggest that the variations of the ISWs closely coincide with the changing stratification structure and shear currents in accompanied by the typhoon wind and near-inertial waves. This study presents the first observations and analysis of the ISW response to the tropical cyclone in the South China Sea.

  5. Mean relative sea level rise along the coasts of the China Seas from mid-20th to 21st centuries

    Science.gov (United States)

    Chen, Nan; Han, Guoqi; Yang, Jingsong

    2018-01-01

    Mean relative sea level (MRSL) rise has caused more frequent flooding in many parts of the world. The MRSL rise varies substantially from place to place. Here we use tide-gauge data and satellite measurements to examine past MRSL trends for the coasts of the China Seas. We then combine climate model output and satellite observations to provide MRSL projections in the 21st century. The MRSL trend based on tide-gauge data shows substantial regional variations, from 1 to 5 mm/yr. The vertical land motion (VLM) based on altimetry and tide-gauge (ATG) data indicates large land subsidence at some tide-gauge locations, consistent with the Global Positioning Systems (GPS)-based VLM but different significantly from small uplift estimated by a Glacial Isostatic Adjustment (GIA) model, which suggests other important factors causing the VLM instead of the GIA process. When GPS- or ATG-based VLM estimates are used, the projected MRSL rise between 1986-2005 and 2081-2100 at tide-gauge sites varies from 60 to 130 cm under the Representative Concentration Pathway 8.5 (RCP8.5) scenario of the Intergovernmental Panel on Climate Change (IPCC). Our projections are significantly larger than those of IPCC and other literature, as a result of accounting for the land subsidence derived from observations. Steric and dynamic ocean effects and land-ice melt effects are comparable (about 30 cm each) and do not vary much over the tide-gauge locations. The VLM effect varies from -10 to 60 cm. The projections between 1986-2005 and 2081-2100 under RCP4.5 show a similar spatial distribution to that under RCP8.5, with a smaller amount of rise by 18 cm on average for this region.

  6. Validation and Variation of Upper Layer Thickness in South China Sea from Satellite Altimeter Data

    Directory of Open Access Journals (Sweden)

    Nan-Jung Kuo

    2008-06-01

    Full Text Available Satellite altimeter data from 1993 to 2005 has been used to analyze the seasonal variation and the interannual variability of upper layer thickness (ULT in the South China Sea (SCS. Base on in-situ measurements, the ULT is defined as the thickness from the sea surface to the depth of 16°C isotherm which is used to validate the result derived from satellite altimeter data. In comparison with altimeter and in-situ derived ULTs yields a correlation coefficient of 0.92 with a slope of 0.95 and an intercept of 6 m. The basin averaged ULT derived from altimeter is 160 m in winter and 171 m in summer which is similar to the in-situ measurements of 159 m in winter and 175 m in summer. Both results also show similar spatial patterns. It suggests that the sea surface height data derived from satellite sensors are usable for study the variation of ULT in the semi-closed SCS. Furthermore, we also use satellite derived ULT to detect the development of eddy. Interannual variability of two meso-scale cyclonic eddies and one anticyclonic eddy are strongly influenced by El Niño events. In most cases, there are highly positive correlations between ULT and sea surface temperature except the periods of El Niño. During the onset of El Niño event, ULT is deeper when sea surface temperature is lower.

  7. Impacts of South East Biomass Burning on local air quality in South China Sea

    Science.gov (United States)

    Wai-man Yeung, Irene; Fat Lam, Yun; Eniolu Morakinyo, Tobi

    2016-04-01

    Biomass burning is a significant source of carbon monoxide and particulate matter, which is not only contribute to the local air pollution, but also regional air pollution. This study investigated the impacts of biomass burning emissions from Southeast Asia (SEA) as well as its contribution to the local air pollution in East and South China Sea, including Hong Kong and Taiwan. Three years (2012 - 2014) of the Hybrid Single Particle Lagrangian-Integrated Trajectory (HYSPLIT) with particles dispersion analyses using NCEP (Final) Operational Global Analysis data (FNL) data (2012 - 2014) were analyzed to track down all possible long-range transport from SEA with a sinking motion that worsened the surface air quality (tropospheric downwash from the free troposphere). The major sources of SEA biomass burning emissions were first identified using high fire emissions from the Global Fire Emission Database (GFED), followed by the HYSPLIT backward trajectory dispersion modeling analysis. The analyses were compared with the local observation data from Tai Mo Shan (1,000 msl) and Tap Mun (60 msl) in Hong Kong, as well as the data from Lulin mountain (2,600 msl) in Taiwan, to assess the possible impacts of SEA biomass burning on local air quality. The correlation between long-range transport events from the particles dispersion results and locally observed air quality data indicated that the background concentrations of ozone, PM2.5 and PM10 at the surface stations were enhanced by 12 μg/m3, 4 μg/m3 and 7 μg/m3, respectively, while the long-range transport contributed to enhancements of 4 μg/m3, 4 μg/m3 and 8 μg/m3 for O3, PM2.5 and PM10, respectively at the lower free atmosphere.

  8. Flux, Budget and Sources of Black Carbon (BC) in the Continental Shelf of the Bohai and Yellow Seas, China

    Science.gov (United States)

    Fang, Y.; Chen, Y.; Tian, C.

    2015-12-01

    Black carbon (BC) derived from incomplete combustion of fossil fuels and biomass has received increasing attention due to their potential importance in a wide range of biogeochemical processes. China has been generally considered as the world's largest BC emitter. Due to a combination of the prevailing East Asia monsoon and large amounts of riverine outflow, BC released from China can be transported to the adjacent continental shelf seas, the Bohai Sea (BS) and Yellow Sea (YS). Based on measurements of BC in 191 surface sediments, 36 riverine water, and 2 seawater samples, as well as the reported BC data set of the aerosol samples in the Bohai Rim, the concentration, flux, and budget of BC in the BS and YS were investigated. The spatial distribution of the BC concentration in surface sediments was largely influenced by the regional hydrodynamic conditions, with high values mainly occurring in the central mud areas. The BC burial flux in the BS and YS ranged from 4 to 1100 μg/cm2/yr, and averaged 166 ± 200 μg/cm2/yr. The area-integrated sedimentary BC sink flux in the entire BS and YS was ~325 Gg/yr. The BC budget calculated in the BS showed that atmospheric deposition and riverine discharge played comparable importance in delivering BC to the BS, and sequestration to bottom sediments was the major BC output pattern, accounting for ~88% of the total input BC. Besides, we attempted to apportion the BC sources in the BS and YS surface sediments using PAHs (organic molecular proxies cogenerated with BC) and BC as an input data to the Positive Matrix Factorization (PMF) receptor model. Results showed that ~83% of the sediment BC was attributed to the combustion of fossil fuels, and the remaining ~17% was from biomass burning. Due to the differences in their production mechanisms and therefore physicochemical properties, the above distinction and quantification would help us better understand their different environmental behaviors in the complex continental shelf

  9. Correlation and SVD Analysis of Anomalous Spring Precipitation in Northwest China and Sea Surface Temperature in Key Region in Recent 50 Years

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to study the relationship between spring precipitation anomaly in Northwest China and sea surface temperature anomaly (SSTA) in Key region in recent 50 years. [Method] Based on monthly average precipitation in Northwest China and global monthly sea surface temperature (SST) grid data, the effects of SSTA in equatorial central and eastern Pacific on spring precipitation in Northwest China were discussed by means of correlation and SVD analysis. [Result] For spring precipitation in Nor...

  10. Plutonium activities and 240Pu/ 239Pu atom ratios in sediment cores from the east China sea and Okinawa Trough: Sources and inventories

    Science.gov (United States)

    Wang, Zhong-liang; Yamada, Masatoshi

    2005-05-01

    Plutonium concentrations and 240Pu/ 239Pu atom ratios in the East China Sea and Okinawa Trough sediment cores were determined by isotope dilution inductively coupled plasma mass spectrometry after separation using ion-exchange chromatography. The results showed that 240Pu/ 239Pu atom ratios in the East China Sea and Okinawa Trough sediments, ranging from 0.21 to 0.33, were much higher than the reported value of global fallout (0.18). The highest 240Pu/ 239Pu ratios (0.32-0.33) were observed in the deepest Okinawa Trough sediment samples. These ratios suggested the US nuclear weapons tests in the early 1950s at the Pacific Proving Grounds in the Marshall Islands were a major source of plutonium in the East China Sea and Okinawa Trough sediments, in addition to the global fallout source. It was proposed that close-in fallout plutonium was delivered from the Pacific Proving Grounds test sites via early direct tropospheric fallout and transportation by the North Pacific Equatorial Circulation system and Kuroshio Current into the Okinawa Trough and East China Sea. The total 239 + 240 Pu inventories in the cores were about 150-200% of that expected from direct global fallout; about 46-67% of the total inventories were delivered from the Pacific Proving Grounds. Much higher 239 + 240 Pu inventories were observed in the East China Sea sediments than in sediments of the Okinawa Trough, because in the open oceans, part of the 239 + 240 Pu was still retained in the water column, and continued Pu scavenging was higher over the margin than the trough. According to the vertical distributions of 239 + 240 Pu activities and 240Pu/ 239Pu atom ratios in these cores, it was concluded that sediment mixing was the dominant process in controlling profiles of plutonium in this area. Faster mixing in the coastal samples has homogenized the entire 240Pu/ 239Pu ratio record today; slightly slower mixing and less scavenging in the Okinawa Trough have left the surface sediment ratios closer

  11. Characterization of aerosol over the Northern South China Sea during two cruises in 2003

    Science.gov (United States)

    Zhang, Xingying; Zhuang, Guoshun; Guo, Jinghua; Yin, Kedong; Zhang, Peng

    Atmospheric transport of trace elements has been found to be an important pathway for their input to the ocean. TSP, PM10, and PM2.5 aerosol samples were collected over the Northern South China Sea in two cruises in 2003 to estimate the input of aerosol from continent to the ocean. About 23 elements and 14 soluble ions in aerosol samples were measured. The average mass concentration of TSP in Cruise I in January (78 μg m -3) was ˜twice of that in Cruise II in April (37 μg m -3). Together with the crustal component, heavy metals from pollution sources over the land (especially from the industry and automobiles in Guangzhou) were transported to and deposited into the ocean. The atmospheric MSA concentrations in PM2.5 (0.048 μg m -3 in Cruise I and 0.043 μg m -3 in Cruise II) over Northern South China Sea were comparable to those over other coastal regions. The ratio of non-sea-salt (NSS)-sulfate to MSA is 103-655 for Cruise I and 15-440 for Cruise II in PM2.5 samples, which were much higher than those over remote oceans. The estimated anthropogenic sulfate accounts for 83-98% in Cruise I and 63-95% in Cruise II of the total NSS-sulfate. Fe (II) concentration in the aerosols collected over the ocean ranged from 0.1 to 0.9 μg m -3, accounting for 16-82% of the total iron in the aerosol, which could affect the marine biogeochemical cycle greatly.

  12. Dongsha Atoll: A potential thermal refuge for reef-building corals in the South China Sea.

    Science.gov (United States)

    Tkachenko, Konstantin S; Soong, Keryea

    2017-06-01

    Dongsha Atoll (also known as the Pratas Islands), the northernmost atoll in the South China Sea, experiences two contrasting physical phenomena: repetitive anomalies of the sea surface temperature exceeding the coral bleaching threshold and regular effects of the world's strongest internal waves resulting in the rhythmic upwelling of cold deep waters at the outer reef slopes of the atoll. This unique combination may result in significant differences in coral species composition and structure between the lagoon and forereef. Surveys conducted in August-September 2016 at 12 study sites in the 2-15 m depth range at Dongsha Atoll revealed a clear spatial separation between 'thermally-susceptible' stony coral genera, including Acropora, Pocillopora and Montipora, which mainly inhabited the forereef, and 'thermally-resistant' genera, including massive Porites, foliaceous Echinopora, Pavona and Turbinaria, which mainly resided in the lagoon. The mean coral cover and species richness on the forereef were respectively 1.8 and 1.4 times higher than those in the lagoon (61.3% and 98 species on the forereef vs. 34.2% and 69 species in the lagoon). Coral mortality rates, expressed as the ratio of dead to live stony corals, showed the same pattern (0.4 in the lagoon vs. 0.009 on the forereef). Furthermore, in a laboratory experiment, 'thermally-susceptible' taxa from the lagoon, (e.g. Pocillopora verrucosa and P. damicornis), exhibited higher resistance to bleaching than did their counterparts from the forereef. The present findings indicate that Dongsha Atoll is a potential thermal refuge for reef-building corals in the northern South China Sea and reveal the development of resilience and resistance to bleaching in coral communities of the lagoon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Application Of Multi-grid Method On China Seas' Temperature Forecast

    Science.gov (United States)

    Li, W.; Xie, Y.; He, Z.; Liu, K.; Han, G.; Ma, J.; Li, D.

    2006-12-01

    Correlation scales have been used in traditional scheme of 3-dimensional variational (3D-Var) data assimilation to estimate the background error covariance for the numerical forecast and reanalysis of atmosphere and ocean for decades. However there are still some drawbacks of this scheme. First, the correlation scales are difficult to be determined accurately. Second, the positive definition of the first-guess error covariance matrix cannot be guaranteed unless the correlation scales are sufficiently small. Xie et al. (2005) indicated that a traditional 3D-Var only corrects some certain wavelength errors and its accuracy depends on the accuracy of the first-guess covariance. And in general, short wavelength error can not be well corrected until long one is corrected and then inaccurate first-guess covariance may mistakenly take long wave error as short wave ones and result in erroneous analysis. For the purpose of quickly minimizing the errors of long and short waves successively, a new 3D-Var data assimilation scheme, called multi-grid data assimilation scheme, is proposed in this paper. By assimilating the shipboard SST and temperature profiles data into a numerical model of China Seas, we applied this scheme in two-month data assimilation and forecast experiment which ended in a favorable result. Comparing with the traditional scheme of 3D-Var, the new scheme has higher forecast accuracy and a lower forecast Root-Mean-Square (RMS) error. Furthermore, this scheme was applied to assimilate the SST of shipboard, AVHRR Pathfinder Version 5.0 SST and temperature profiles at the same time, and a ten-month forecast experiment on sea temperature of China Seas was carried out, in which a successful forecast result was obtained. Particularly, the new scheme is demonstrated a great numerical efficiency in these analyses.

  14. Middle-Holocene sea-level fluctuations interrupted the developing Hemudu culture in the lower Yangtze River, China

    Science.gov (United States)

    He, Keyang; Lu, Houyuan; Zheng, Yunfei; Zhang, Jianping; Xu, Deke; Huan, Xiujia; Wang, Jiehua; Lei, Shao

    2018-05-01

    The eastern coastal zone of China is densely populated and widely recognized as a center of rice domestication, which has undergone dramatic sea-level fluctuation during the Holocene epoch. Hemudu culture is distributed mainly in the eastern coastal area and was once presumed as a mature agricultural economy based on rice, making it an ideal case for examining the remarkable human-environment interaction in the Lower Yangtze River. Though numerous studies have been conducted on the cultural evolution, ecological environment, and rice domestication of Hemudu culture, the impact of sea-level fluctuation on human settlement and food production remains controversial. In this study, we report high-resolution pollen, phytolith, and diatom records, and accurately measured elevation from the Yushan site, which is the closest site of Hemudu culture to the modern coastline. Based on the data gathered, we suggest that the Hemudu culture and subsequent Liangzhu culture developed in the context of regression and were interrupted by two transgressions that occurred during 6300-5600 BP and 5000-4500 BP. The regional ecological environment of the Yushan site alternated between intertidal mudflat and freshwater wetlands induced by sea-level fluctuations in the mid-late Holocene. Though rice was cultivated in the wetland as early as 6700 BP, this cultivation was subsequently discontinued due to the transgression; thus, full domestication of rice did not occur until 5600 BP in this region. Comprehensive analysis of multiple proxies in this study promote the understanding of the relationship between environmental evolution, cultural interruption, and rice domestication.

  15. Late Quaternary climatic changes in the Ross Sea area, Antarctica

    International Nuclear Information System (INIS)

    Brambati, A.; Melis, R.; Quaia, T.; Salvi, G.

    2002-01-01

    Ten cores from the Ross Sea continental margin were investigated to detect Late Quaternary climatic changes. Two main climatic cycles over the last 300,000 yr (isotope stages 1-8) were recognised in cores from the continental slope, whereas minor fluctuations over the last 30,000 yr were found in cores from the continental shelf. The occurrence of calcareous taxa within the Last Glacial interval and their subsequent disappearance reveal a general raising of the CCD during the last climatic cycle. In addition, periodical trends of c. 400, c. 700, and c. 1400 yr determined on calcareous foraminifers from sediments of the Joides Basin, indicate fluctuations of the Ross Ice Shelf between 15 and 30 ka BP. (author). 24 refs., 5 figs

  16. Yellowfin Tuna (Thunnusalbacares Fishing Ground Forecasting Model Based On Bayes Classifier In The South China Sea

    Directory of Open Access Journals (Sweden)

    Zhou Wei-feng

    2017-08-01

    Full Text Available Using the yellowfin tuna (Thunnusalbacares,YFTlongline fishing catch data in the open South China Sea (SCS provided by WCPFC, the optimum interpolation sea surface temperature (OISST from CPC/NOAA and multi-satellites altimetric monthly averaged product sea surface height (SSH released by CNES, eight alternative options based on Bayes classifier were made in this paper according to different strategies on the choice of environment factors and the levels of fishing zones to classify the YFT fishing ground in the open SCS. The classification results were compared with the actual ones for validation and analyzed to know how different plans impact on classification results and precision. The results of validation showed that the precision of the eight options were 71.4%, 75%, 70.8%, 74.4%, 66.7%, 68.5%, 57.7% and 63.7% in sequence, the first to sixth among them above 65% would meet the practical application needs basically. The alternatives which use SST and SSH simultaneously as the environmental factors have higher precision than which only use single SST environmental factor, and the consideration of adding SSH can improve the model precision to a certain extent. The options which use CPUE’s mean ± standard deviation as threshold have higher precision than which use CPUE’s 33.3%-quantile and 66.7%-quantile as the threshold

  17. Slow Warming of the Northern South China Sea during the Last Deglaciation

    Directory of Open Access Journals (Sweden)

    Tomoya Shintani

    2008-01-01

    Full Text Available We have generated a record of alkenone sea surface temperatures (SSTs during the last 28000 years from Core MD97-2146 for the northern South China Sea (SCS. The SST record showed a typical pattern for change in the northern SCS SST. The SST during the LGM was ~25 C, this decreased to ~24 C to 17 ka, increased to ~25.5 C to 14.5 ka, decreased again to ~24.5 C to 11.8 ka, increased gradually to ~27 C to 6 ka, and then increased more gradually to reach ~27.5 C at present. The SST difference ( SSTNSCS = SSTMD97-2146 - SSTMD97-2141 between Cores MD97-2146 (the northern SCS; this study and MD97-2141 (the Sulu Sea; Rosenthal et al. 2003 was used to characterize the SST changes in the northern SCS relative to changes in the adjacent WTPregion. The SSTNSCS decreased from 21 to 11.8 ka and increased after 11.8 ka, indicating slower warming of the northern SCS during the last deglaciation than that of the adjacent western tropical Pacific region.We infer that the slow warming of the northern SCS was principally a result of stronger winter monsoon during the last deglaciation and early Holocene. In addition, the cool water inflow through the Taiwan Strait after 13 ka and the warm water inflow through the Sunda Shelf after 11 ka could influence the SST in the northern SCS.

  18. Arctic and Antarctic Oscillation signatures in tropical coral proxies over the South China Sea

    Directory of Open Access Journals (Sweden)

    D.-Y. Gong

    2009-05-01

    Full Text Available Arctic Oscillation (AO and Antarctic Oscillation (AAO are the leading modes of atmospheric circulation in mid-high latitudes. Previous studies have revealed that the climatic influences of the two modes are dominant in extra-tropical regions. This study finds that AO and AAO signals are also well recorded in coral proxies in the tropical South China Sea. There are significant interannual signals of AO and AAO in the strontium (Sr content, which represents the sea surface temperature (SST. Among all the seasons, the most significant correlation occurs during winter in both hemispheres: the strongest AO-Sr and AAO-Sr coral correlations occur in January and August, respectively. This study also determined that the Sr content lags behind AO and AAO by 1–3 months. Large-scale anomalies in sea level pressure and horizontal wind at 850 hPa level support the strength of AO/AAO-coral teleconnections. In addition, a comparison with oxygen isotope records from two coral sites in neighboring oceans yields significant AO and AAO signatures with similar time lags. These results help to better understand monsoon climates and their teleconnection to high-latitude climate changes.

  19. Transport of terrigenous polycyclic aromatic hydrocarbons affected by the coastal upwelling in the northwestern coast of South China Sea.

    Science.gov (United States)

    Ya, Miaolei; Wu, Yuling; Li, Yongyu; Wang, Xinhong

    2017-10-01

    Coastal upwelling prevails in the coast of Hainan Island, the northern South China Sea (SCS) during summer. We studied the influences of the upwelling on the horizontal and vertical transport of terrigenous polycyclic aromatic hydrocarbons (PAHs). PAHs in dissolved and suspended particulate phase of water samples were determined in the upper (depth  10 m). PAH levels decreased sharply from inshore to offshore to open sea. The results showed that terrestrial input was the main source of coastal PAHs. Perylene, an important indicator of land plant-derived PAH, showed the significant correlation with PAHs (p sea. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Assessment of sea water inundation along Daboo creek area in Indus Delta Region, Pakistan

    Science.gov (United States)

    Zia, Ibrahim; Zafar, Hina; Shahzad, Muhammad I.; Meraj, Mohsin; Kazmi, Jamil H.

    2017-12-01

    Indus Deltaic Region (IDR) in Pakistan is an erosion vulnerable coast due to the high deep water wave energy. Livelihood of millions of people depends on the fisheries and mangrove forests in IDR. IDR consists of many creeks where Daboo is a major creek located at southeast of the largest city of Pakistan, Karachi. Unfortunately, there has been no detailed study to analyze the damages of sea water intrusion at a large temporal and spatial scale. Therefore, this study is designed to estimate the effects of sea water inundation based on changing sea water surface salinity and sea surface temperature (SST). Sea surface salinity and SST data from two different surveys in Daboo creek during 1986 and 2010 are analyzed to estimate the damages and extent of sea water intrusion. Mean salinity has increased 33.33% whereas mean SST decreased 13.79% from 1987 to 2010. Spatio-temporal analysis of creek area using LANDSAT 5 Thematic mapper (TM) data for the years 1987 and 2010 shows significant amount of erosion at macro scale. Creek area has increased approximately 9.93% (260.86 m2 per year) which is roughly equal to 60 extensive sized shrimp farms. Further Land Use Land Cover (LULC) analyses for years 2001 and 2014 using LANDSAT 7 Enhanced Thematic Mapper Plus (ETM+) has indicated 42.3% decrease in cultivated land. Wet mud flats have spread out at the inner mouth of creek with enormous increase of 123.3%. Significant sea water intrusion has increased the area of barren land by 37.9%. This also resulted in overall decrease of 6.7% in area covered by mangroves. Therefore, this study recorded a significant evidence of sea water intrusion in IDR that has caused serious damages to community living in the area, economical losses. Additionally, it has also changed the environment by reducing creek biological productivity as reported by earlier studies over other regions of the world.

  1. [Monitoring "green tide" in the Yellow Sea and the East China Sea using multi-temporal and multi-source remote sensing images].

    Science.gov (United States)

    Xing, Qian-Guo; Zheng, Xiang-Yang; Shi, Ping; Hao, Jia-Jia; Yu, Ding-Feng; Liang, Shou-Zhen; Liu, Dong-Yan; Zhang, Yuan-Zhi

    2011-06-01

    Landsat-TM (Theme Mapper) and EOS (Earth Observing System)-MODIS (MODerate resolution Imaging Spectrora-diometer) Terra/Aqua images were used to monitor the macro-algae (Ulva prolifera) bloom since 2007 at the Yellow Sea and the East China Sea. At the turbid waters of Northern Jiangsu Shoal, there is strong spectral mixing behavior, and satellite images with finer spatical resolution are more effective in detection of macro-algae patches. Macro-algae patches were detected by the Landsat images for the first time at the Sheyang estuary where is dominated by very turbid waters. The MODIS images showed that the macro-algae from the turbid waters near the Northern Jiangsu Shoal drifted southwardly in the early of May and affected the East China Sea waters; with the strengthening east-asian Summer Monsoon, macro-algae patches mainly drifted in a northward path which was mostly observed at the Yellow Sea. Macro-algae patches were also found to drift eastwardly towards the Korea Peninsular, which are supposed to be driven by the sea surface wind.

  2. Research on Cold Core Eddy Change and Phytoplankton Bloom Induced by Typhoons: Case Studies in the South China Sea

    Directory of Open Access Journals (Sweden)

    Xiao-dong Shang

    2015-01-01

    Full Text Available The effects of 8 typhoons which passed by coldcore eddy (CCE areas in the South China Sea (SCS from 1997 to 2009 were observed and evaluated. The changes in the preexisting CCE acted upon by typhoons were described by eddy kinetic energy (EKE and eddy available gravitational potential energy (EAGPE. The mechanical energy of CCE was estimated from a two-layer reduced gravity model. Comparing with the scenario that typhoon passes by the region without CCEs, the preexisting CCE area plays an important role in the increase of chlorophyll-a (chl-a concentration in the CCEs impacted by the typhoons. The preexisting chl-a in CCE is about 25%~45% (8%~25% of postexisting chl-a in CCE for higher (slower transit speed typhoons. If the EAGPE of CCE increases greatly after typhoon passing by with slow transit speed, so does the chl-a in the CCE area. The EKE (EAGPE changes of the preexisting CCE are in the order of O(1014~1015 J. EKE and EAGPE of CCE are dominantly enhanced by typhoon with slow transit speed (<3 m/s and the posttyphoon EAGPE is always larger than posttyphoon EKE for 8 cases. The maximum EAGPE change of the preexisting CCE reaches 5.11×1015 J, which was induced by typhoon Hagibis.

  3. Perception of Air Pollution in the Jinchuan Mining Area, China : A Structural Equation Modeling Approach

    NARCIS (Netherlands)

    Li, Zhengtao; Folmer, Henk; Xue, Jianhong

    2016-01-01

    Studies on the perception of air pollution in China are very limited. The aim of this paper is to help to fill this gap by analyzing a cross-sectional dataset of 759 residents of the Jinchuan mining area, Gansu Province, China. The estimations suggest that perception of air pollution is

  4. On Financial Support System for Compulsory Education in China's Western Minority Areas

    Science.gov (United States)

    Jinyu, Qi

    2008-01-01

    China's Western Development is a policy adopted to boost its less developed Western regions, that is, a systematic project and a longterm and arduous task. The development of compulsory education in China's minority areas is the key to it. This paper attempts to use the beneficial experience of developing compulsory education support system of…

  5. Deep-sea genetic resources: New frontiers for science and stewardship in areas beyond national jurisdiction

    Science.gov (United States)

    Harden-Davies, Harriet

    2017-03-01

    The deep-sea is a large source of marine genetic resources (MGR), which have many potential uses and are a growing area of research. Much of the deep-sea lies in areas beyond national jurisdiction (ABNJ), including 65% of the global ocean. MGR in ABNJ occupy a significant gap in the international legal framework. Access and benefit sharing of MGR is a key issue in the development of a new international legally-binding instrument under the United Nations Convention on the Law of the Sea (UNCLOS) for the conservation and sustainable use of marine biological diversity in ABNJ. This paper examines how this is relevant to deep-sea scientific research and identifies emerging challenges and opportunities. There is no internationally agreed definition of MGR, however, deep-sea genetic resources could incorporate any biological material including genes, proteins and natural products. Deep-sea scientific research is the key actor accessing MGR in ABNJ and sharing benefits such as data, samples and knowledge. UNCLOS provides the international legal framework for marine scientific research, international science cooperation, capacity building and marine technology transfer. Enhanced implementation could support access and benefit sharing of MGR in ABNJ. Deep-sea scientific researchers could play an important role in informing practical new governance solutions for access and benefit sharing of MGR that promote scientific research in ABNJ and support deep-sea stewardship. Advancing knowledge of deep-sea biodiversity in ABNJ, enhancing open-access to data and samples, standardisation and international marine science cooperation are significant potential opportunity areas.

  6. Accessing the Impact of Sea-Salt Emissions on Aerosol Chemical Formation and Deposition Over Pearl River Delta, China

    Science.gov (United States)

    Fan, Q.; Wang, X.; Liu, Y.; Wu, D.; Chan, P. W.; Fan, S.; Feng, Y.

    2015-12-01

    Sea-salt aerosol (SSA) emissions have a significant impact on aerosol pollution and haze formation in the coastal areas. In this study, Models-3/CMAQ modeling system was utilized to access the impact of SSA emissions on aerosol chemical formation and deposition over Pearl River Delta (PRD), China in July 2006. More SSAs were transported inland from the open-ocean under the southeast wind in summertime. Two experiments (with and without SSA emissions in the CMAQ model) were set up to compare the modeling results with each other. The results showed that the increase of sulfate concentrations were more attributable to the primary emissions of coarse SO42- particles in SSA, while the increase of nitrate concentrations were more attributable to secondary chemical formations, known as the mechanisms of chloride depletion in SSA. In the coastal areas, 17.62 % of SO42-, 26.6% of NO3- and 38.2% of PM10 were attributed to SSA emissions, while those portions were less than 1% in the inland areas. The increases of PM10 and its components due to SSA emissions resulted in higher deposition fluxes over PRD, particularly in the coastal areas, except for the wet deposition of nitrate. Nitrate was more sensitive to SSA emissions in chemical formations than sulfate and dry deposition of aerosol was also more sensitive than that for wet deposition. Process analysis of sulfate and nitrate was applied to find out the difference of physical and chemical mechanisms between Guangzhou (the inland areas) and Zhuhai (the coastal areas). The negative contributions of dry deposition process to both sulfate and nitrate concentrations increased if SSA emissions were taken into account in the model, especially for Zhuhai. The negative contributions of cloud process also increased due to cloud scavenging and wet deposition process. In the coastal area, the gas-to-particle conversions became more active with high contributions of aerosol process to nitrate concentrations.

  7. Diagnosing the leading mode of interdecadal covariability between the Indian Ocean sea surface temperature and summer precipitation in southern China

    Science.gov (United States)

    Liu, Jingpeng; Ren, Hong-Li; Li, Weijing; Zuo, Jinqing

    2018-03-01

    Precipitation in southern China during boreal summer (June to August) shows a substantial interdecadal variability on the timescale longer than 8 years. In this study, based on the analysis of singular value decomposition, we diagnose the leading mode of interdecadal covariability between the observational precipitation in southern China and the sea surface temperature (SST) in the Indian Ocean. Results indicate that there exist a remarkable southern China zonal dipole (SCZD) pattern of interdecadal variability of summer precipitation and an interdecadal Indian Ocean basin mode (ID-IOBM) of SST. It is found that the SCZD is evidently covaried with the ID-IOBM, which may induce anomalous inter-hemispheric vertical circulation and atmospheric Kelvin waves. During the warm phase of the ID-IOBM, an enhanced lower-level convergence and upper-level divergence exist over the tropical Indian Ocean, which is a typical Gill-Matsuno-type response to the SST warming. Meanwhile, the accompanied upper-level outflow anomalies further converge over the Indo-China peninsula, resulting in a lower-level anticyclone that contributes to reduction of the eastward moisture transport from the Bay of Bengal to the west part of southern China. In addition, the Kelvin wave-like pattern, as a response of the warm ID-IOBM phase, further induces the lower-level anticyclonic anomaly over the South China Sea-Philippines. Such an anticyclonic circulation is favorable for more water vapor transport from the East China Sea into the east part of southern China. Therefore, the joint effects of the anomalous inter-hemispheric vertical circulation and the Kelvin wave-like pattern associated with the ID-IOBM may eventually play a key role in generating the SCZD pattern.

  8. Hydrodynamic patterns favouring sea urchin recruitment in coastal areas: A Mediterranean study case.

    Science.gov (United States)

    Farina, S; Quattrocchi, G; Guala, I; Cucco, A

    2018-05-11

    In invertebrate fisheries, sea urchin harvesting continues to grow with dramatic consequences for benthic ecosystems. The identification of areas with a marked natural recruitment and the mechanisms regulating it is crucial for the conservation of benthic communities and for planning the sustainable harvesting. This study evaluates the spatial distribution and density of recruits of the edible sea urchin Paracentrotus lividus along the Sinis + Peninsula (Sardinia) and explores its significant relationships with the local oceanographic features. Our results reveal that recruitment is favoured in areas with slow currents and high levels of confinement and trapping of the water masses. Analysis of the residual circulation indicates that the presence of local standing circulation structures promotes the sea urchin recruitment process. Our findings emphasize the importance of managing local sea urchin harvesting as a system of populations with their demographic influence mainly dependent on the most important ecological driver that is the recruitment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Bacterial community composition of South China Sea sediments through pyrosequencing-based analysis of 16S rRNA genes.

    Science.gov (United States)

    Zhu, Daochen; Tanabe, Shoko-Hosoi; Yang, Chong; Zhang, Weimin; Sun, Jianzhong

    2013-01-01

    Subseafloor sediments accumulate large amounts of organic and inorganic materials that contain a highly diverse microbial ecosystem. The aim of this study was to survey the bacterial community of subseafloor sediments from the South China Sea. Pyrosequencing of over 265,000 amplicons of the V3 hypervariable region of the 16S ribosomal RNA gene was performed on 16 sediment samples collected from multiple locations in the northern region of the South China Sea from depths ranging from 35 to 4000 m. A total of 9,726 operational taxonomic units (OTUs; between 695 and 2819 unique OTUs per sample) at 97% sequence similarity level were generated. In total, 40 bacterial phyla including 22 formally described phyla and 18 candidate phyla, with Proteobacteria, Firmicutes, Planctomycetes, Actinobacteria and Chloroflexi being most diverse, were identified. The most abundant phylotype, accounting for 42.6% of all sequences, belonged to Gammaproteobacteria, which possessed absolute predominance in the samples analyzed. Among the 18 candidate phyla, 12 were found for the first time in the South China Sea. This study provided a novel insight into the composition of bacterial communities of the South China Sea subseafloor. Furthermore, abundances and community similarity analysis showed that the compositions of the bacterial communities are very similar at phylum level at different depths from 35-4000 m.

  10. Phenotypic and genetic characterization of bacteria isolated from diseased cultured sea cucumber (Apostichopus japonicus) in Northeastern China

    Science.gov (United States)

    During the winter–spring from 2004 to 2006 in northeastern China cultured Japanese sea cucumber Apostichopus japonicus suffered from a serious disease. Clinical signs included swollen mouth, skin ulceration and massive mortality. Clinical samples taken during this period were studied. Thirty-one bac...

  11. Bacterial community composition of South China Sea sediments through pyrosequencing-based analysis of 16S rRNA genes.

    Directory of Open Access Journals (Sweden)

    Daochen Zhu

    Full Text Available BACKGROUND: Subseafloor sediments accumulate large amounts of organic and inorganic materials that contain a highly diverse microbial ecosystem. The aim of this study was to survey the bacterial community of subseafloor sediments from the South China Sea. METHODOLOGY/PRINCIPAL FINDINGS: Pyrosequencing of over 265,000 amplicons of the V3 hypervariable region of the 16S ribosomal RNA gene was performed on 16 sediment samples collected from multiple locations in the northern region of the South China Sea from depths ranging from 35 to 4000 m. A total of 9,726 operational taxonomic units (OTUs; between 695 and 2819 unique OTUs per sample at 97% sequence similarity level were generated. In total, 40 bacterial phyla including 22 formally described phyla and 18 candidate phyla, with Proteobacteria, Firmicutes, Planctomycetes, Actinobacteria and Chloroflexi being most diverse, were identified. The most abundant phylotype, accounting for 42.6% of all sequences, belonged to Gammaproteobacteria, which possessed absolute predominance in the samples analyzed. Among the 18 candidate phyla, 12 were found for the first time in the South China Sea. CONCLUSIONS: This study provided a novel insight into the composition of bacterial communities of the South China Sea subseafloor. Furthermore, abundances and community similarity analysis showed that the compositions of the bacterial communities are very similar at phylum level at different depths from 35-4000 m.

  12. Dry well analysis of well 6407/10-5 at 793 area, Norwegian Sea.

    OpenAIRE

    Qamar, Javeria

    2017-01-01

    Master's thesis in Petroleum Geosciences Engineering. The region of investigation is located in the Norwegian Sea, which is an area of high hydrocarbon activity. Many reservoirs have been successfully identified, drilled, and now they are producing in large oil & gas fields. However, the Norwegian Sea has a complex geology as it resulted from Permian to Late Jurassic crustal extension, which created rift basins and several horst and graben structures. Most of the important hydrocarbon rese...

  13. Geochemical nature of sub-ridge mantle and opening dynamics of the South China Sea

    Science.gov (United States)

    Zhang, Guo-Liang; Luo, Qing; Zhao, Jian; Jackson, Matthew G.; Guo, Li-Shuang; Zhong, Li-Feng

    2018-05-01

    The Indian-type mantle (i.e., above the north hemisphere reference line on the plot of 208Pb/204Pb vs. 206Pb/204Pb) has been considered as a "Southern Hemisphere" geochemical signature, whose origin remains enigmatic. The South China Sea is an extensional basin formed after rifting of the Euro-Asia continent in the Northern Hemisphere, however, the geochemical nature of the igneous crust remains unexplored. For the first time, IODP Expedition 349 has recovered seafloor basalts covered by the thick sediments in the Southwest sub-basin (Sites U1433 and U1434) and the East sub-basin (Site U1431). The Southwest sub-basin consists of enriched (E)-MORB type basalts, and the East sub-basin consists of both normal (N)-MORB-type and E-MORB-type basalts based on trace element compositions. The basalts of the two sub-basins are Indian-type MORBs based on Sr-Nd-Pb-Hf isotope compositions, and the Southwest sub-basin basalts show isotopic compositions (i.e., 206Pb/204Pb of 17.59-17.89) distinctly different from the East sub-basin (i.e., 206Pb/204Pb of 18.38-18.57), suggesting a sub-basin scale mantle compositional heterogeneity and different histories of mantle compositional evolution. Two different enriched mantle end-members (EM1 and EM2) are responsible for the genesis of the Indian-type mantle in the South China Sea. We have modeled the influences of Hainan mantle plume and lower continental crust based on Sr-Nd-Pb-Hf isotope compositions. The results indicate that the influence of Hainan plume can explain the elevated 206Pb/204Pb of the East sub-basin basalts, and the recycling of lower continental crust can explain the low 206Pb/204Pb of the Southwest sub-basin basalts. Based on the strong geochemical imprints of Hainan plume in the ridge magmatism, we propose that the Hainan plume might have promoted the opening of the South China Sea, during which the Hainan plume contributed enriched component to the sub-ridge mantle and caused thermal erosion and return of lower

  14. Mercury profiles in sediments of the Pearl River Estuary and the surrounding coastal area of South China

    International Nuclear Information System (INIS)

    Shi Jianbo; Ip, Carman C.M.; Zhang Gan; Jiang Guibin; Li Xiangdong

    2010-01-01

    The spatial and temporal variations of mercury (Hg) in sediments of the Pearl River Estuary (PRE) and the surrounding coastal area (South China Sea) were studied. In surface sediments, the concentrations of Hg ranged from 1.5 to 201 ng/g, with an average of 54.4 ng/g, displaying a decreasing trend with the distance from the estuary to the open sea. This pattern indicates that the anthropogenic emissions from the Pearl River Delta (PRD) region are probably the main sources of Hg in this coastal region. Using the 210 Pb dating technique, the historical changes in the concentrations and influxes of Hg in the last 100 years were also investigated. The variations in Hg influxes in sediment cores obviously correlate with the economic development and urbanization that has occurred the PRD region, especially in the last three decades. - The spatial and historical changes of Hg in sediment reflect the industrial development and urbanization of the region in south China.

  15. Distribution profiles of per- and poly fluoroalkyl substances (PFASs) and their re-regulation by ocean currents in the East and South China Sea.

    Science.gov (United States)

    Zheng, Hongyuan; Wang, Feng; Zhao, Zhen; Ma, Yuxin; Yang, Haizhen; Lu, Zhibo; Cai, Minggang; Cai, Minghong

    2017-12-15

    We investigated the distribution of 17 individual per- and polyfluoroalkyl substances (PFASs) in 42 surface water samples collected from the East and South China Seas (7.0-36.0°N, 110.0°N-123.0°E). Concentrations of 7 individual PFASs, including perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluoropentanoic acid (PFPA), perfluorohexanoate (PFHxA), perfluoroheptanoate (PFHpA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonamide (FOSA), were quantified in the East China Sea, but only concentrations of PFOA and FOSA were quantified in the South China Sea. The total concentrations of the 17 PFASs ranged from 181 to 2658pg/L in the East China Sea and from 62 to 494pg/L in the South China Sea. We also show that river fluxes and ocean currents had a strong influence on the distribution of PFASs in the East China Sea. Using ArcGIS 10.1, we show how ocean currents control the spatial distribution of PFOA in the central South China Sea. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Errors of Mean Dynamic Topography and Geostrophic Current Estimates in China's Marginal Seas from GOCE and Satellite Altimetry

    DEFF Research Database (Denmark)

    Jin, Shuanggen; Feng, Guiping; Andersen, Ole Baltazar

    2014-01-01

    and geostrophic current estimates from satellite gravimetry and altimetry are investigated and evaluated in China's marginal seas. The cumulative error in MDT from GOCE is reduced from 22.75 to 9.89 cm when compared to the Gravity Recovery and Climate Experiment (GRACE) gravity field model ITG-Grace2010 results......The Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) and satellite altimetry can provide very detailed and accurate estimates of the mean dynamic topography (MDT) and geostrophic currents in China's marginal seas, such as, the newest high-resolution GOCE gravity field model GO......-CONS-GCF-2-TIM-R4 and the new Centre National d'Etudes Spatiales mean sea surface model MSS_CNES_CLS_11 from satellite altimetry. However, errors and uncertainties of MDT and geostrophic current estimates from satellite observations are not generally quantified. In this paper, errors and uncertainties of MDT...

  17. Magnetic Properties of the Rivers Feeding the South China Sea: a Critical Step for Understanding the Paleo-Marine Records.

    Science.gov (United States)

    Kissel, C.; Liu, Z.; Wandres, C.

    2014-12-01

    In order to use the magnetic properties of marine sediments as a tracer for past changes in the precipitation rate on land and in oceanic water masses transport and exchanges in the South China Sea, we identify and characterize the different sources of the detrital fraction among which the magnetic particles. This work is presently conducted in the framework of the Franco-Chinese LIA-MONOCL Thanks to the Westpac project, we had access to sediments collected in the deltas of the main rivers feeding the South China Sea from about 25°N to the equator. This is represented on the Asian continent by the Pearl river, the Red River, the Mekong river, by Malaysia, Sumatra and Borneo regions with minor rivers but also contributing to the South China Sea, and finally by Luzon and Taiwan. The geological formations contributing to the river sediment discharges are different from one catchment basin to another as well as the present climatic conditions. The magnetic analyses consist in the analysis of low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of 3-axes IRM, hysteresis parameters, and FORC diagrams. The obtained parameters all together allow us to define the nature of the magnetic grains and their grain size distribution when magnetite is dominant. Some degree of variability is observed at the river mouths, illustrating different geological sources at the local/regional scale. As an average, it appears that the Southern basin of the South China Sea is surrounded by regions richer in high coercivity magnetic minerals than the northern basin. This mineral is identified as hematite while magnetites (and sulfides) are more abundant in the north. These results are complementary to the clay mineral assemblages previously determined on the same samples. The first steps of a similar study conducted on marine core-tops well distributed in the South China Sea will also be illustrated.

  18. Modeled connectivity of Acropora millepora populations from reefs of the Spratly Islands and the greater South China Sea

    Science.gov (United States)

    Dorman, Jeffrey G.; Castruccio, Frederic S.; Curchitser, Enrique N.; Kleypas, Joan A.; Powell, Thomas M.

    2016-03-01

    The Spratly Island archipelago is a remote network of coral reefs and islands in the South China Sea that is a likely source of coral larvae to the greater region, but about which little is known. Using a particle-tracking model driven by oceanographic data from the Coral Triangle region, we simulated both spring and fall spawning events of Acropora millepora, a common coral species, over a 46-yr period (1960-2005). Simulated population biology of A. millepora included the acquisition and loss of competency, settlement over appropriate benthic habitat, and mortality based on experimental data. The simulations aimed to provide insights into the connectivity of reefs within the Spratly Islands, the settlement of larvae on reefs of the greater South China Sea, and the potential dispersal range of reef organisms from the Spratly Islands. Results suggest that (1) the Spratly Islands may be a significant source of A. millepora larvae for the Palawan reefs (Philippines) and some of the most isolated reefs of the South China Sea; and (2) the relatively isolated western Spratly Islands have limited source reefs supplying them with larvae and fewer of their larvae successfully settling on other reefs. Examination of particle dispersal without biology (settlement and mortality) suggests that larval connectivity is possible throughout the South China Sea and into the Coral Triangle region. Strong differences in the spring versus fall larval connectivity and dispersal highlight the need for a greater understanding of spawning dynamics of the region. This study confirms that the Spratly Islands are likely an important source of larvae for the South China Sea and Coral Triangle region.

  19. The Effect of ASEAN-China Free Trade Area (ACFTA on Indonesia Export

    Directory of Open Access Journals (Sweden)

    Indriyani Indriyani

    2016-10-01

    Full Text Available ASEAN-China Free Trade Area (ACFTA is an agreement between the members of ASEAN and China to create a free trade area by removing tariff and non-tariff barriers. This agreement begins with the signing of the agreement on November 5, 2002 in Phnom Penh. Implementation is done in phases beginning January 1, 2004. The purpose of this study determines the effect of the implementation of ACFTA on Indonesia's exports to the ASEAN countries and China. This study complements previous research regarding the ACFTA. The data used in this study are the data of Indonesian exports to ASEAN countries and China for 15 years from 2000 until 2014. The tests were conducted with a fixed effect panel data model with cross section SUR. The results of this study indicate that the ACFTA increase Indonesian exports to the ASEAN countries and China.DOI: 10.15408/etk.v15i2.3331

  20. Early interglacial carbonate-dilution events in the South China Sea: Implications for strengthened typhoon activities over subtropical East Asia

    Science.gov (United States)

    Huang, Enqing; Tian, Jun; Qiao, Peijun; Wan, Sui; Xie, Xin; Yang, Wenguang

    2015-10-01

    A compilation of many late Quaternary marine sediment records from the northern South China Sea (SCS) continental slope confirms 15-50% reductions in sedimentary calcium carbonate concentrations between 11.0 and 8.5 ka BP in the early Holocene. This low carbonate% event occurred at a time when the regional sea level rose from -50 m to -10 m, which drowned large areas of continental shelves especially those near and within the Taiwan Strait. This event is associated with a significant increase in bulk sedimentation rates on the upper continental slope and the relative abundance of fine-grained detritus. Sediment provenance analyses suggest a dominant terrigenous input from Taiwan and a minor contribution from Luzon during the low carbonate% event, similar to the background terrigenous deposition in other periods of the Holocene. Two comparable low carbonate% events, respectively from the beginning of marine isotope stages 5.5 and 7.3, have also been recognized, pointing to similar causal factors. While carbonate dissolution and carbonate accumulation rate should not have been responsible, increased terrigenous input and dilution is considered as the main cause for the recurrent low carbonate% events in early interglacials. We further hypothesize that, during early interglacials, fluvial sediment discharge from Taiwan and Luzon intensified due to stronger typhoon activities, and massive fine-grained sediments from these two end members may have been transported to the northern SCS continental slope via surface and deep ocean currents. The conjecture of strengthened typhoon activities over East Asia during the early Holocene is supported by high ocean heat contents in the West Pacific Warm Pool area with the prevailing La Niña-like conditions.

  1. Vulnerability of the Nile Delta coastal areas to inundation by sea level rise.

    Science.gov (United States)

    Hassaan, M A; Abdrabo, M A

    2013-08-01

    Sea level changes are typically caused by several natural phenomena, including ocean thermal expansion, glacial melt from Greenland and Antarctica. Global average sea level is expected to rise, through the twenty-first century, according to the IPCC projections by between 0.18 and 0.59 cm. Such a rise in sea level will significantly impact coastal area of the Nile Delta, consisting generally of lowland and is densely populated areas and accommodates significant proportion of Egypt's economic activities and built-up areas. The Nile Delta has been examined in several previous studies, which worked under various hypothetical sea level rise (SLR) scenarios and provided different estimates of areas susceptible to inundation due to SLR. The paper intends, in this respect, to identify areas, as well as land use/land cover, susceptible to inundation by SLR based upon most recent scenarios of SLR, by the year 2100 using GIS. The results indicate that about 22.49, 42.18, and 49.22 % of the total area of coastal governorates of the Nile Delta would be susceptible to inundation under different scenarios of SLR. Also, it was found that 15.56 % of the total areas of the Nile Delta that would be vulnerable to inundation due to land subsidence only, even in the absence of any rise in sea level. Moreover, it was found that a considerable proportion of these areas (ranging between 32.32 and 53.66 %) are currently either wetland or undeveloped areas. Furthermore, natural and/or man-made structures, such as the banks of the International Coastal Highway, were found to provide unintended protection to some of these areas. This suggests that the inundation impact of SLR on the Nile Delta is less than previously reported.

  2. Partial pressure (or fugacity) of carbon dioxide, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from RYOFU MARU in the Bismarck Sea, East China Sea and others from 1989-11-17 to 1995-03-07 (NODC Accession 0116982)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0116982 includes Surface underway data collected from RYOFU MARU in the Bismarck Sea, East China Sea (Tung Hai), North Pacific Ocean, Philippine Sea,...

  3. “Population Invasion” versus Urban Exclusion in the Tibetan Areas of Western China

    OpenAIRE

    Fischer, Andrew Martín

    2008-01-01

    textabstractThis article examines the confluence of local population transitions (demographic transition and urbanization) with non-local in-migration in the Tibetan areas of western China. The objective is to assess the validity of Tibetan perceptions of "population invasion" by Han Chinese and Chinese Muslims. The article argues that migration to Tibet from other regions in China has been concentrated in urban areas and has been counterbalanced by more rapid rates of natural increase in the...

  4. Antifouling briarane type diterpenoids from South China Sea gorgonians Dichotella gemmacea

    KAUST Repository

    Sun, Jian Fan; Han, Zhuang; Zhou, Xue Feng; Yang, Bin; Lin, Xiuping; Liu, Juan; Peng, Yan; Yang, Xian Wen; Liu, Yonghong

    2013-01-01

    Our continued investigation on the South China Sea gorgonian Dichotella gemmacea led to the isolation of 16 new briarane-type diterpenoids, dichotellides F-U (1-16), along with 18 known analogues (17-34). Their structures were determined by MS, 1D and 2D NMR spectra analyses and by comparison with those reported in literature. The absolute configuration of 15 was confirmed by single-crystal X-ray diffraction data. The antifouling test showed that compounds 3, 4, 6-11, 16, and 23 had potent antifouling activities at nontoxic concentrations with EC50 values of 4.1, 1.82, 6.3, 7.6, 4.6, 1.2, 5.6, 0.79, 2.0, and 0.2 μg/mL, respectively. © 2012 Elsevier Ltd. All rights reserved.

  5. A Study on Bottom Friction Coefficient in the Bohai, Yellow, and East China Sea

    Directory of Open Access Journals (Sweden)

    Daosheng Wang

    2014-01-01

    Full Text Available The adjoint tidal model based on the theory of inverse problem has been applied to investigate the effect of bottom friction coefficient (BFC on the tidal simulation. Using different schemes of BFC containing the constant, different constant in different subdomain, depth-dependent form, and spatial distribution obtained from data assimilation, the M2 constituent in the Bohai, Yellow, and East China Sea (BYECS is simulated by assimilating TOPEX/Poseidon altimeter data, respectively. The simulated result with spatially varying BFC obtained from data assimilation is better than others. Results and analysis of BFC in BYECS indicate that spatially varying BFC obtained from data assimilation is the best fitted one; meanwhile it could improve the accuracy in the simulation of M2 constituent. Through the analysis of the best fitted one, new empirical formulas of BFC in BYECS are developed with which the commendable simulated results of M2 constituent in BYECS are obtained.

  6. Chemical Constituents of the Sponge Mycale Sp ecies from South China Sea

    Directory of Open Access Journals (Sweden)

    Xuefeng Zhou

    2013-03-01

    Full Text Available Chemical investigation of the sponge Mycale species from the South China Sea afforded eleven known compounds, henicosanoic acid methyl ester (1 , hexadecyl ethers of glycerol ( 2 , N-docosanoyl-D-erythro-(2S,3R-16-methyl-heptadecasphing-4(E-enine ( 3 , dibutyl phthalate ( 4 , cholesterol ( 5 , 5α,8α-epidioxycholest-6,22-dien-3β-ol ( 6 , 5-hexadecyl-pyrrole-2-carboxaldehyde ( 7 , benzoic acid ( 8 , 4-hydroxybenzoic acid ( 9 , thymine ( 10 ,and uracil ( 11 . Compounds 1 – 4 , 6 – 9 were obtained from the sponge of the genus Mycale for the first time, and 4 and 6 showed toxicity in the brine shrimp lethality test with the LD 50 values at 2.9 μg/mL and 4. 7 μg/mL, respectively .

  7. Monomia lucida sp. nov., a new swimming crab (Crustacea: Decapoda: Portunidae) from the South China Sea.

    Science.gov (United States)

    Koch, Milan; ĎuriŠ, ZdenĚk

    2018-02-27

    A new species of the portunid genus, Monomia Gistel, 1848, is described from the South China Sea in Vietnam. Monomia lucida sp. nov. is morphologically most similar to M. argentata (A. Milne-Edwards, 1861), which was originally described from Sarawak, on the island of Borneo. In addition to the stout, forward-directed anterolateral teeth of the carapace, the subrectangular sixth segment of the male pleon, and the long and slender laterally bent first gonopods, adults of the new species reach a greater size, and can also be distinguished from M. argentata by the colour pattern on the natatory dactylus. The independent specific status of M. lucida sp. nov. is also supported by molecular evidence. Aside from a comparison of this new species with other known congeners, new photographs of the holotype of M. samoensis (Ward, 1939) are also provided.

  8. Diversity of marine planktonic ostracods in South China Sea: a DNA taxonomy approach.

    Science.gov (United States)

    Xu, Lei; Wang, Lianggen; Ning, Jiajia; Li, Hong; Ji, Yingying; Du, Feiyan

    2018-04-19

    Ostracods (Crustacea, Ostracoda) are small bivalved crustaceans, contributing over 200 described species to the marine zooplankton community. They are widely distributed and are relatively abundant components of the mesozooplankton, playing an important role in the transport of organic matter to deep layers. However, identification of ostracods based on micro-morphological characters is extremely difficult and time-consuming. Previous fragmentary taxonomic studies of ostracods in the South China Sea (SCA), were based solely on morphology. Here, by analysing the mitochondrial COI gene, we explore the taxa across the SCA using molecular tools for the first time. Our results show that sequence divergence among species varies within a large range, from 12.93% to 35.82%. Sixteen of the taxonomic units recovered by DNA taxonomy agree well with morphology, but Paraconchoecia oblonga, Conchoecia magna and Halocypris brevirostris split into two clades each, each of which contains cryptic species.

  9. Seismic, satellite, and site observations of internal solitary waves in the NE South China Sea

    Science.gov (United States)

    Tang, Qunshu; Wang, Caixia; Wang, Dongxiao; Pawlowicz, Rich

    2014-01-01

    Internal solitary waves (ISWs) in the NE South China Sea (SCS) are tidally generated at the Luzon Strait. Their propagation, evolution, and dissipation processes involve numerous issues still poorly understood. Here, a novel method of seismic oceanography capable of capturing oceanic finescale structures is used to study ISWs in the slope region of the NE SCS. Near-simultaneous observations of two ISWs were acquired using seismic and satellite imaging, and water column measurements. The vertical and horizontal length scales of the seismic observed ISWs are around 50 m and 1–2 km, respectively. Wave phase speeds calculated from seismic observations, satellite images, and water column data are consistent with each other. Observed waveforms and vertical velocities also correspond well with those estimated using KdV theory. These results suggest that the seismic method, a new option to oceanographers, can be further applied to resolve other important issues related to ISWs. PMID:24948180

  10. Spatial and vertical distribution of bacterial community in the northern South China Sea.

    Science.gov (United States)

    Sun, Fu-Lin; Wang, You-Shao; Wu, Mei-Lin; Sun, Cui-Ci; Cheng, Hao

    2015-10-01

    Microbial communities are highly diverse in coastal oceans and response rapidly with changing environments. Learning about this will help us understand the ecology of microbial populations in marine ecosystems. This study aimed to assess the spatial and vertical distributions of the bacterial community in the northern South China Sea. Multi-dimensional scaling analyses revealed structural differences of the bacterial community among sampling sites and vertical depth. Result also indicated that bacterial community in most sites had higher diversity in 0-75 m depths than those in 100-200 m depths. Bacterial community of samples was positively correlation with salinity and depth, whereas was negatively correlation with temperature. Proteobacteria and Cyanobacteria were the dominant groups, which accounted for the majority of sequences. The α-Proteobacteria was highly diverse, and sequences belonged to Rhodobacterales bacteria were dominant in all characterized sequences. The current data indicate that the Rhodobacterales bacteria, especially Roseobacter clade are the diverse group in the tropical waters.

  11. Heavy metal concentrations in wild fishes captured from the South China Sea and associated health risks.

    Science.gov (United States)

    Gu, Yang-Guang; Lin, Qin; Wang, Xue-Hui; Du, Fei-Yan; Yu, Zi-Ling; Huang, Hong-Hui

    2015-07-15

    Heavy metal concentrations were measured in 29 marine wild fish species from the South China Sea. Concentrations (wet weight) were 0.51-115.81 ng/g (Cd), 0.54-27.31 ng/g (Pb), 0.02-1.26 μg/g (Cr), 8.32-57.48 ng/g (Ni), 0.12-1.13 μg/g (Cu), 2.34-6.88 μg/g (Zn), 2.51-22.99 μg/g (Fe), and 0.04-0.81 μg/g (Mn), respectively. Iron concentrations in all and Mn in some fish species were higher than the acceptable daily upper limit, suggesting human consumption of these wild fish species may pose a health risk. Human health risk assessment, however, indicated no significant adverse health effects with consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Remote sensing reflectance simulation of coastal optical complex water in the East China Sea

    Science.gov (United States)

    He, Shuo; Lou, Xiulin; Zhang, Huaguo; Zheng, Gang

    2018-02-01

    In this work, remote sensing reflectance (Rrs) spectra of the Zhejiang coastal water in the East China Sea (ECS) were simulated by using the Hydrolight software with field data as input parameters. The seawater along the Zhejiang coast is typical Case II water with complex optical properties. A field observation was conducted in the Zhejiang coastal region in late May of 2016, and the concentration of ocean color constituents (pigment, SPM and CDOM), IOPs (absorption and backscattering coefficients) and Rrs were measured at 24 stations of 3 sections covering the turbid to clear inshore coastal waters. Referring to these ocean color field data, an ocean color model suitable for the Zhejiang coastal water was setup and applied in the Hydrolight. A set of 11 remote sensing reflectance spectra above water surface were modeled and calculated. Then, the simulated spectra were compared with the filed measurements. Finally, the spectral shape and characteristics of the remote sensing reflectance spectra were analyzed and discussed.

  13. Seismic, satellite, and site observations of internal solitary waves in the NE South China Sea.

    Science.gov (United States)

    Tang, Qunshu; Wang, Caixia; Wang, Dongxiao; Pawlowicz, Rich

    2014-06-20

    Internal solitary waves (ISWs) in the NE South China Sea (SCS) are tidally generated at the Luzon Strait. Their propagation, evolution, and dissipation processes involve numerous issues still poorly understood. Here, a novel method of seismic oceanography capable of capturing oceanic finescale structures is used to study ISWs in the slope region of the NE SCS. Near-simultaneous observations of two ISWs were acquired using seismic and satellite imaging, and water column measurements. The vertical and horizontal length scales of the seismic observed ISWs are around 50 m and 1-2 km, respectively. Wave phase speeds calculated from seismic observations, satellite images, and water column data are consistent with each other. Observed waveforms and vertical velocities also correspond well with those estimated using KdV theory. These results suggest that the seismic method, a new option to oceanographers, can be further applied to resolve other important issues related to ISWs.

  14. Laser induced fluorescence technique for detecting organic matter in East China Sea

    Science.gov (United States)

    Chen, Peng; Wang, Tianyu; Pan, Delu; Huang, Haiqing

    2017-10-01

    A laser induced fluorescence (LIF) technique for fast diagnosing chromophoric dissolved organic matter (CDOM) in water is discussed. We have developed a new field-portable laser fluorometer for rapid fluorescence measurements. In addtion, the fluorescence spectral characteristics of fluorescent constituents (e.g., CDOM, chlorophyll-a) were analyzed with a spectral deconvolution method of bi-Gaussian peak function. In situ measurements by the LIF technique compared well with values measured by conventional spectrophotometer method in laboratory. A significant correlation (R2 = 0.93) was observed between fluorescence by the technique and absorption by laboratory spectrophotometer. Influence of temperature variation on LIF measurement was investigated in lab and a temperature coefficient was deduced for fluorescence correction. Distributions of CDOM fluorescence measured using this technique in the East China Sea coast were presented. The in situ result demonstrated the utility of the LIF technique for rapid detecting dissolved organic matter.

  15. Climate modulates internal wave activity in the Northern South China Sea

    Science.gov (United States)

    DeCarlo, Thomas M.; Karnauskas, Kristopher B.; Davis, Kristen A.; Wong, George T. F.

    2015-02-01

    Internal waves (IWs) generated in the Luzon Strait propagate into the Northern South China Sea (NSCS), enhancing biological productivity and affecting coral reefs by modulating nutrient concentrations and temperature. Here we use a state-of-the-art ocean data assimilation system to reconstruct water column stratification in the Luzon Strait as a proxy for IW activity in the NSCS and diagnose mechanisms for its variability. Interannual variability of stratification is driven by intrusions of the Kuroshio Current into the Luzon Strait and freshwater fluxes associated with the El Niño-Southern Oscillation. Warming in the upper 100 m of the ocean caused a trend of increasing IW activity since 1900, consistent with global climate model experiments that show stratification in the Luzon Strait increases in response to radiative forcing. IW activity is expected to increase in the NSCS through the 21st century, with implications for mitigating climate change impacts on coastal ecosystems.

  16. Community composition of picoeukaryotes in the South China Sea during winter

    Science.gov (United States)

    Lin, Yun-Chi; Chiang, Kuo-Ping; Kang, Lee-Kuo

    2017-07-01

    Picoeukaryotes, the smallest protists, are highly diverse and abundant in the ocean. However, little information is available about their community composition in the tropical northwestern Pacific Ocean. This study collected surface and deep chlorophyll maximum (DCM) waters from the South China Sea (SCS) to study the picoeukaryotic composition by constructing clone libraries of the 18S rRNA gene. The libraries were dominated by the heterotrophic organisms, alveolates and Rhizaria, which accounted for 46% and 16% of total clones, respectively. MALV-I was the most abundant group in alveolates, and Rhizaria appears to be a key organism in the SCS, particularly within DCM layers. These results indicate that parasitism is significant in the oligotrophic and tropical SCS. Apart from core-dinoflagellates, chlorophytes, haptophytes, cryptophytes and pelagophytes were other important contributors to primary production in pico-sized fraction based on quantitative and qualitative data.

  17. Ecologically least vulnerable sites for exploration drilling in the Wadden Sea and the North Sea coastal area

    International Nuclear Information System (INIS)

    Lindeboom, H.J.; Bergman, M.J.N.; De Gee, A.

    1996-01-01

    The Dutch Oil Company (NAM, abbreviated in Dutch) applied for a number of exploration drilling in the Dutch part of the Wadden Sea and the North Sea coastal area. NAM is obliged to draft a so-called MER (environmental impact report) to indicate the most environment-friendly alternative for the test drilling. By order of NAM, NIOZ and the IBN-DLO (Institute for Research on Forests and Nature) analyzed samples of the animal life in all the potential sites. Based on the results of the analyses, literature and expert knowledge the ecologically least vulnerable sites and the ecologically least vulnerable season were selected during a workshop. In this report the results are given of the workshop, the field sample analyses and a sailing trip along the sites

  18. Annually recurrent macroalgal blooms (Ulva prolifera) resulting in the world's largest green-tides caused by expansion of coastal aquaculture in the Yellow Sea off China

    Science.gov (United States)

    Keesing, John; Liu, Dongyan

    2013-04-01

    The largest macroalgal blooms ever recorded occurred in the Yellow Sea of China in 2008 and 2009 and resulted in extensive green tides along the Shandong Province coastline, including at Qingdao. At their peak these Ulva prolifera blooms covered more than 4,000 km2 and affected 40,000 km2. A smaller bloom was recorded in 2007, but not earlier. Since then massive blooms have occurred annually in summer from 2008 to 2012. Using remote sensing methods, we tracked the source of the 2008 and 2009 blooms to an area along the Jiangsu Province coastline near Yancheng, over 200 km south of Qingdao, where there had been rapid expansion of Porphyra aquaculture to as much as 13 km offshore, prior to the appearance of the first bloom in 2007. Porphyra is grown on rafts which can become heavily fouled with U. prolifera which is disposed of into the sea when the Porphyra is harvested. The timing of the blooms occurred post the April harvest period when daily tidal ranges in this region can be in excess of 7 m. This provides the mechanism for transportation of the floating algae offshore and into the warm nutrient rich waters of the Yellow Sea where it grows rapidly forming large patches. As the patches of algae grow and join, they gradually move north, as a result of wind driven surface currents that prevail in the Yellow Sea in summer, ultimately washing ashore on the Shandong Peninsula. We present a range of oceanographic, biological, ecological and genetic data to support the hypothesis that Porphyra aquaculture provides the source biomass for the Yellow Sea green-tides. Improved aquaculture waste disposal methods in the southern area of Jiangsu Province are likely to reduce or prevent the Yellow Sea green tides and present a feasible solution to a recurrent problem.

  19. Structures within the oceanic crust of the central South China Sea basin and their implications for oceanic accretionary processes

    Science.gov (United States)

    Ding, Weiwei; Sun, Zhen; Dadd, Kelsie; Fang, Yinxia; Li, Jiabiao

    2018-04-01

    Internal structures in mature oceanic crust can elucidate understanding of the processes and mechanism of crustal accretion. In this study, we present two multi-channel seismic (MCS) transects across the northern flank of the South China Sea basin to reveal the internal structures related to Cenozoic tectono-magmatic processes during seafloor spreading. Bright reflectors within the oceanic crust, including the Moho, upper crustal reflectors, and lower crustal reflectors, are clearly imaged in these two transects. The Moho reflection displays varied character in continuity, shape and amplitude from the continental slope area to the abyssal basin, and becomes absent in the central part of the basin where abundant seamounts and seamount chains formed after the cessation of seafloor spreading. Dipping reflectors are distinct in most parts of the MCS data but generally confined to the lower crust above the Moho reflection. These lower crustal reflectors merge downward into the Moho without offsetting it, probably arising from shear zones between the crust and mantle characterized by interstitial melt, although we cannot exclude other possibilities such as brittle faulting or magmatic layering in the local area. A notable feature of these lower crustal reflector events is their opposite inclinations. We suggest the two groups of conjugate lower crustal reflector events observed between magnetic anomalies C11 and C8 were associated with two unusual accretionary processes arising from plate reorganizations with southward ridge jumps.

  20. Macrobioerosion in Porites corals in subtropical northern South China Sea: a limiting factor for high-latitude reef framework development

    Science.gov (United States)

    Chen, Tianran; Li, Shu; Yu, Kefu

    2013-03-01

    Bioerosion is an important limiting factor in carbonate accretion and reef framework development; however, few studies have quantified the direct impact of macroborers on high-latitude coral communities, which are viewed as potential refuge during a period of global warming. In this study, internal macrobioerosion of Porites corals was examined at Daya Bay, subtropical northern South China Sea. The principal borers were the bivalve Lithophaga spp. and the sponges Cliona spp. and Cliothosa spp. (≥80 %), while sipunculid and polychaete worms and barnacles accounted for small amounts of bioerosion (≤20 %). Porites corals were heavily bioeroded in areas impacted by aquacultural and urban activities (10.34-27.55 %) compared with corals in relatively unpolluted areas (2.18-6.76 %). High levels of bioerosion, especially boring bivalve infestation, significantly weaken the corals and increase their susceptibility to dislodgement and fragmentation in typhoons, limiting accumulation of limestone framework. This study implies that carbonate accretion and reef development for high-latitude coral communities may be limited in future high-CO2 and eutrophication-stressed environments.

  1. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas), Taiwan, in the South China Sea.

    Science.gov (United States)

    Keshavmurthy, Shashank; Tang, Kuo-Hsun; Hsu, Chia-Min; Gan, Chai-Hsia; Kuo, Chao-Yang; Soong, Keryea; Chou, Hong-Nong; Chen, Chaolun Allen

    2017-01-01

    Dongsha Atoll (also known as Pratas) in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park's scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1-5 m; and deep, 10-15 m) in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP) of 28S nuclear large subunit ribosomal DNA (nlsrDNA). Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5%) was higher compared to deep (14.9%). Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE) of internal transcribed spacer 2 (ITS2) in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population.

  2. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas, Taiwan, in the South China Sea

    Directory of Open Access Journals (Sweden)

    Shashank Keshavmurthy

    2017-01-01

    Full Text Available Dongsha Atoll (also known as Pratas in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park’s scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1–5 m; and deep, 10–15 m in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP of 28S nuclear large subunit ribosomal DNA (nlsrDNA. Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5% was higher compared to deep (14.9%. Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE of internal transcribed spacer 2 (ITS2 in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population.

  3. Design of a Data Distribution Core Model for Seafloor Observatories in East China Sea

    Science.gov (United States)

    Chen, H.; Qin, R.; Xu, H.

    2017-12-01

    High loadings of nutrients and pollutants from agriculture, industries and city waste waters are carried by Changjiang (Yangtze) River and transformed into the foodweb in the river freshwater plume. Understanding these transport and transformation processes is essential for the ecosystem protection, fisheries resources management, seafood safety and human health. As Xiaoqushan Seafloor Observatory and Zhujiajian Seafloor Observatory built in East China Sea, it is an opportunity and a new way for the research of Changjiang River plume. Data collected by seafloor observatory should be accessed conveniently by end users in real time or near real time, which can make it play a better role. Therefore, data distribution is one of major issues for seafloor observatory characterized by long term, real time, high resolution and continuous observation. This study describes a Data Distribution core Model for Seafloor Observatories in East China Sea (ESDDM) containing Data Acquisition Module (DAM), Data Interpretation Module (DIM), Data Transmission Module (DTM) and Data Storage Module (DTM), which enables acquiring, interpreting, transmitting and storing various types of data in real time. A Data Distribution Model Makeup Language (DDML) based on XML is designed to enhance the expansibility and flexibility of the system implemented by ESDDM. Network sniffer is used to acquire data by IP address and port number in DAM promising to release the operating pressure of junction boxes. Data interface, core data processing plugins and common libraries consist of DIM helping it interpret data in a hot swapping way. DTM is an external module in ESDDM transmitting designated raw data packets to Secondary Receiver Terminal. The technology of database connection pool used in DSM facilitates the efficiency of large volumes of continuous data storage. Given a successful scenario in Zhujiajian Seafloor Observatory, the protosystem based on ESDDM running up to 1500h provides a reference for

  4. Remediation of Legacy Arsenic Mining Areas in Yunnan Province, China

    Directory of Open Access Journals (Sweden)

    Ian H. von Lindern

    2011-01-01

    Conclusions. The success of the demonstration project was recognized and has provided direction and momentum for a wider effort by the Province to address mining pollution and water contamination challenges. It demonstrates the success of using known techniques for environmental remediation in the US, with local partners in China responding to their communities’ health and environmental problems.

  5. Study on the regional crust stability of Beishan area, Gansu province, NW China-the preselected area for China's high level radioactive waste repository

    International Nuclear Information System (INIS)

    Wang Ju; Xu Guoqing; Jin Yuanxin; Chen Weiming; Guo Yonghai; Yang Tianxiao

    2004-01-01

    This paper summarizes the research results on the crust stability of the Beishan area, Gansu province, NW China-the preselected area for China's high level radioactive waste repository. The studies include regional tectonic structure and its evolution, regional geophysical field, crust structure, regional deep-rooted faults, regional seismological activity, regional neo-tectonics, regional modern stress field and its numerical simulation, geological interpretation of TM satellite and its application in the study of crust stability, and the evaluation on crust stability. The research in the past years indicates that the west part of Gansu province (the area we studied) can be divided into 8 parts with different crust stability: (1) Beishan stable area; (2) East Huahai stable area; (3) Huahai sub-stable area; (4) Yumenzheng sub-unstable area; (5) Yumenshi sub-unstable area; (6) Daxueshan sub-unstable area; (7) Jiayuguan unstable area; and (8) Beiqilian unstable area. Among those parts, the Beishan area possess the best conditions, its crust stability accords with the demands on candidate site for HLW repositories, which are described in the International atomic energy agency's safety series No.111-G-4.1 Guidelines. Therefore, the Beishan area is suitable region for further work. (author)

  6. Projections of tsunami inundation area coupled with impacts of sea level rise in Banda Aceh, Indonesia

    Science.gov (United States)

    Tursina, Syamsidik, Kato, Shigeru

    2017-10-01

    In a long term, sea level rise is anticipated to give devastating effects on Banda Aceh, as one of the coastal cities in the northern tip of Sumatra. The growth of the population and buildings in the city has come to the stage where the coastal area is vulnerable to any coastal hazard. Some public facilities and settlements have been constructed and keep expanding in the future. According to TOPEX/POSEIDON satellite images, 7 mm/year the sea level has been risen between 1992 and 2015 in this area. It is estimated that in the next 100 years, there will be 700 mm additional sea level rise which will give a setback more over to a rather flat area around the coast. This research is aim at investigating the influence of sea level rise toward the tsunami inundation on the land area particularly the impacts on Banda Aceh city. Cornell Multigrid Coupled Tsunami Model (COMCOT) simulation numerically generated tsunami propagation. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Geological movement of the underwater fault was generated using Piatanesi and Lorito of 9.15 Mw 2004 multi-fault scenario. The inundation area produced by COMCOT revealed that the inundation area was expanded to several hundred meters from the shoreline. To investigate the impacts of tsunami wave on Banda Aceh, the inundation area were digitized and analyzed with Quantum GIS spatial tools. The Quantum GIS analyzed inundations area affected by the projected tsunami. It will give a new tsunami-prone coastal area map induced by sea level rise in 100 years.

  7. Rates and fluxes of centennial-scale carbon storage in the fine-grained sediments from the central South Yellow Sea and Min-Zhe belt, East China Sea

    Science.gov (United States)

    Wang, Jianghai; Xiao, Xi; Zhou, Qianzhi; Xu, Xiaoming; Zhang, Chenxi; Liu, Jinzhong; Yuan, Dongliang

    2018-01-01

    The global carbon cycle has played a key role in mitigating global warming and climate change. Long-term natural and anthropogenic processes influence the composition, sources, burial rates, and fluxes of carbon in sediments on the continental shelf of China. In this study, the rates, fluxes, and amounts of carbon storage at the centennial scale were estimated and demonstrated using the case study of three fine-grained sediment cores from the central South Yellow Sea area (SYSA) and Min-Zhe belt (MZB), East China Sea. Based on the high-resolution temporal sequences of total carbon (TC) and total organic carbon (TOC) contents, we reconstructed the annual variations of historical marine carbon storage, and explored the influence of terrestrial and marine sources on carbon burial at the centennial scale. The estimated TC storage over 100 years was 1.18×108 t in the SYSA and 1.45×109 t in the MZB. The corrected TOC storage fluxes at the centennial scale ranged from 17 to 28 t/(km2·a)in the SYSA and from 56 to 148 t/(km2·a) in the MZB. The decrease of terrestrial materials and the increase of marine primary production suggest that the TOC buried in the sediments in the SYSA and MZB was mainly derived from the marine autogenetic source. In the MZB, two depletion events occurred in TC and TOC storage from 1985 to 1987 and 2003 to 2006, which were coeval with the water impoundment in the Gezhouba and Three Gorges dams, respectively. The high-resolution records of the carbon storage rates and fluxes in the SYSA and MZB reflect the synchronous responses to human activities and provide an important reference for assessing the carbon sequestration capacity of the marginal seas of China.

  8. Can sediments at hydrocarbon seep sites represent a source for marine bioavailable iron? — A case study from the South China Sea

    Science.gov (United States)

    Li, N.; Feng, D.; Chen, D.

    2017-12-01

    Niu Li1, Dong Feng1,2, and Duofu Chen2,31CAS Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. 2Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China. 3Hadal Science and Technology Research Center, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China. Iron is an essential micronutrient and commonly considered to be one of the key-limiting factors for biological productivity in many ocean regions. Seafloor Fe supply should be most efficient in suboxic conditions. Recent studies shown that widely spread anoxic environments can develop in hydrocarbon seep sediment and local bottom water, owing to the occurrence of aerobic and/or anaerobic methane oxidation. Under this condition, the iron in sediment can be reduced to dissolved Fe2+ in the ocean. However, questions remain about whether the hydrocarbon seep sediment can represent a source for bioavailable iron to the ocean, and the control factor for the transformation of iron in the sediment remains largely unexplored. For a number of hydrocarbon seeps from the northern and southern South China Sea, the iron speciation, pyrite sulfur isotope, and iron isotope, as well as the major and trace elements are used to constrain the intensity of cold seep, and its impact on transformation of iron in sediment. Samples from both areas show sediment iron lost during the high methane flux conditions, owing to the suboxic conditions cause by aerobic methane oxidation. On the other hand, high sediment iron content accompanied by high sulfur content can be seen during the conditions of high methane flux without the occurrence of aerobic methane oxidation, which is possible ascribed to the anaerobic methane oxidation and the release of iron through seep activity. This study reveals the transformation of iron in the sediment is closely related to the

  9. Arctic Sea Ice, Eurasia Snow, and Extreme Winter Haze in China

    Science.gov (United States)

    Zou, Y.; Wang, Y.; Xie, Z.; Zhang, Y.; Koo, J. H.

    2017-12-01

    Eastern China is experiencing more severe haze pollution in winter during recent years. Though the environmental deterioration in this region is usually attributed to the high intensity of anthropogenic emissions and large contributions from secondary aerosol formation, the impact of climate variability is also indispensable given its significant influence on regional weather systems and pollution ventilation. Here we analyzed the air quality related winter meteorological conditions over Eastern China in the last four decades and showed a worsening trend in poor regional air pollutant ventilation. Such variations increased the probability of extreme air pollution events, which is in good agreement with aerosol observations of recent years. We further identified the key circulation pattern that is conducive to the weakening ventilation and investigated the relationship between synoptic circulation changes and multiple climate forcing variables. Both statistical analysis and numerical sensitivity experiments suggested that the poor ventilation condition is linked to boreal cryosphere changes including Arctic sea ice in preceding autumn and Eurasia snowfall in earlier winter. We conducted comprehensive dynamic diagnosis and proposed a physical mechanism to explain the observed and simulated circulation changes. At last, we examined future projections of winter extreme stagnation events based on the CMIP5 projection data.

  10. Red List of amphibians and reptiles of the Wadden Sea area

    Science.gov (United States)

    Fog, K.; Podloucky, R.; Dierking, U.; Stumpel, A. H. P.

    1996-10-01

    In the Wadden Sea, in total, 8 species of amphibians and 4 species of reptiles are threatened in at least one subregion. Of these, 7 species of amphibians and all 4 species of reptiles are threatened in the entire area and are therefore placed on the trilateral Red List. 1 species of the listed reptiles is (probably) extinct in the entire Wadden Sea area. The status of 1 species of amphibians is endangered, the status of (probably) 4 species of amphibians and 3 species of reptiles are vulnerable and of 2 species of amphibians susceptible.

  11. Thin Ice Area Extraction in the Seasonal Sea Ice Zones of the Northern Hemisphere Using Modis Data

    Science.gov (United States)

    Hayashi, K.; Naoki, K.; Cho, K.

    2018-04-01

    Sea ice has an important role of reflecting the solar radiation back into space. However, once the sea ice area melts, the area starts to absorb the solar radiation which accelerates the global warming. This means that the trend of global warming is likely to be enhanced in sea ice areas. In this study, the authors have developed a method to extract thin ice area using reflectance data of MODIS onboard Terra and Aqua satellites of NASA. The reflectance of thin sea ice in the visible region is rather low. Moreover, since the surface of thin sea ice is likely to be wet, the reflectance of thin sea ice in the near infrared region is much lower than that of visible region. Considering these characteristics, the authors have developed a method to extract thin sea ice areas by using the reflectance data of MODIS (NASA MYD09 product, 2017) derived from MODIS L1B. By using the scatter plots of the reflectance of Band 1 (620 nm-670 nm) and Band 2 (841 nm-876 nm)) of MODIS, equations for extracting thin ice area were derived. By using those equations, most of the thin ice areas which could be recognized from MODIS images were well extracted in the seasonal sea ice zones in the Northern Hemisphere, namely the Sea of Okhotsk, the Bering Sea and the Gulf of Saint Lawrence. For some limited areas, Landsat-8 OLI images were also used for validation.

  12. Regional air-sea coupled model simulation for two types of extreme heat in North China

    Science.gov (United States)

    Li, Donghuan; Zou, Liwei; Zhou, Tianjun

    2018-03-01

    Extreme heat (EH) over North China (NC) is affected by both large scale circulations and local topography, and could be categorized into foehn favorable and no-foehn types. In this study, the performance of a regional coupled model in simulating EH over NC was examined. The effects of regional air-sea coupling were also investigated by comparing the results with the corresponding atmosphere-alone regional model. On foehn favorable (no-foehn) EH days, a barotropic cyclonic (anticyclonic) anomaly is located to the northeast (northwest) of NC, while anomalous northwesterlies (southeasterlies) prevail over NC in the lower troposphere. In the uncoupled simulation, barotropic anticyclonic bias occurs over China on both foehn favorable and no-foehn EH days, and the northwesterlies in the lower troposphere on foehn favorable EH days are not obvious. These biases are significantly reduced in the regional coupled simulation, especially on foehn favorable EH days with wind anomalies skill scores improving from 0.38 to 0.47, 0.47 to 0.61 and 0.38 to 0.56 for horizontal winds at 250, 500 and 850 hPa, respectively. Compared with the uncoupled simulation, the reproduction of the longitudinal position of Northwest Pacific subtropical high (NPSH) and the spatial pattern of the low-level monsoon flow over East Asia are improved in the coupled simulation. Therefore, the anticyclonic bias over China is obviously reduced, and the proportion of EH days characterized by anticyclonic anomaly is more appropriate. The improvements in the regional coupled model indicate that it is a promising choice for the future projection of EH over NC.

  13. Crustal Stretching Style and Lower Crust Flow of the South China Sea Northern Margin

    Science.gov (United States)

    Bai, Y.; Dong, D.; Runlin, D.

    2017-12-01

    There is a controversy about crustal stretching style of the South China Sea (SCS) northern margin mainly due to considerable uncertainty of stretching factor estimation, for example, as much as 40% of upper crust extension (Walsh et al., 1991) would be lost by seismic profiles due to poor resolution. To discover and understand crustal stretching style and lower crustal flow on the whole, we map the Moho and Conrad geometries based on gravity inversion constrained by deep seismic profiles, then according to the assumption of upper and lower crust initial thickness, upper and lower crust stretching factors are estimated. According to the comparison between upper and lower crust stretching factors, the SCS northern margin could be segmented into three parts, (1) sediment basins where upper crust is stretched more than lower crust, (2) COT regions where lower crust is stretched more than upper crust, (3) other regions where the two layers have similar stretching factors. Stretching factor map shows that lower crust flow happened in both of COT and sediment basin regions where upper crust decouples with lower crust due to high temperature. Pressure contrast by sediment loading in basins and erosion in sediment-source regions will lead to lower crust flow away from sediment sink to source. Decoupled and fractured upper crust is stretched further by sediment loading and the following compensation would result in relatively thick lower crust than upper crust. In COT regions with thin sediment coverage, low-viscosity lower crust is easier to thin in extensional environment, also the lower crust tends to flow away induced by magma upwelling. Therefore, continental crust on the margin is not stretching in a constant way but varies with the tectonic setting changes. This work is supported by National Natural Science Foundation of China (Grant No. 41506055, 41476042) and Fundamental Research Funds for the Central Universities China (No.17CX02003A).

  14. Can Asian Dust Trigger Phytoplankton Blooms in the Oligotrophic Northern South China Sea?

    Science.gov (United States)

    Wang, Sheng Hsiang; Hsu, Nai-Yung Christina; Tsay, Si-Chee; Lin, Neng-Huei; Sayer, Andrew M.; Huang, Shih-Jen; Lau, William K. M.

    2012-01-01

    Satellite data estimate a high dust deposition flux (approximately 18 g m(exp-2 a(exp-1) into the northern South China Sea (SCS). However, observational evidence concerning any biological response to dust fertilization is sparse. In this study, we combined long-term aerosol and chlorophyll-a (Chl-a) measurements from satellite sensors (MODIS and SeaWiFS) with a 16-year record of dust events from surface PM10 observations to investigate dust transport, flux, and the changes in Chl-a concentration over the northern SCS. Our result revealed that readily identifiable strong dust events over this region, although relatively rare (6 cases since 1994) and accounting for only a small proportion of the total dust deposition (approximately 0.28 g m(exp-2 a(exp-1), do occur and could significantly enhance phytoplankton blooms. Following such events, the Chl-a concentration increased up to 4-fold, and generally doubled the springtime background value (0.15 mg m(exp-3). We suggest these heavy dust events contain readily bioavailable iron and enhance the phytoplankton growth in the oligotrophic northern SCS.

  15. Temperature shapes coral-algal symbiosis in the South China Sea

    Science.gov (United States)

    Tong, Haoya; Cai, Lin; Zhou, Guowei; Yuan, Tao; Zhang, Weipeng; Tian, Renmao; Huang, Hui; Qian, Pei-Yuan

    2017-01-01

    With the increase in sea surface temperature (SST), scleractinian corals are exposed to bleaching threats but may possess certain flexibilities in terms of their associations with symbiotic algae. Previous studies have shown a close symbiosis between coral the and Symbiodinium; however, the spatial variation of the symbiosis and the attribution underlying are not well understood. In the present study, we examined coral-algal symbiosis in Galaxea fascicularis and Montipora spp. from three biogeographic regions across ~10° of latitude in the South China Sea. Analysis of similarities (ANOSIM) indicated a highly flexible coral-algal symbiosis in both G. fascicularis and Montipora spp. and canonical correspondence analysis (CCA) showed that temperature explained 83.2% and 60.1% of the explanatory subclade variations in G. fascicularis and Montipora spp., respectively, which suggested that temperature was the main environmental factor contributing to the diversity of Symbiodinium across the three regions. The geographic specificity of the Symbiodinium phylogeny was identified, revealing possible environmental selection across the three regions. These results suggest that scleractinian corals may have the ability to regulate Symbiodinium community structures under different temperatures and thus be able to adapt to gradual climate change. PMID:28084322

  16. Acoustic impedance properties of seafloor sediments off the coast of Southeastern Hainan, South China Sea

    Science.gov (United States)

    Hou, Zhengyu; Chen, Zhong; Wang, Jingqiang; Zheng, Xufeng; Yan, Wen; Tian, Yuhang; Luo, Yun

    2018-04-01

    Geoacoustic parameters are essential inputs to sediment wave propagation theories and are vital to underwater acoustic environment and explorations of the sea bottom. In this study, 21 seafloor sediment samples were collected off the coast of southeastern Hainan in the South China Sea. The sound speed was measured using a portable WSD-3 digital sonic instrument and the coaxial differential distance measurement method. Based on the measured sound speed and physical properties, the acoustic impedance and the pore-water-independent index of impedance (IOI) were calculated in this study. Similar to the sound speed, the IOI values are closely related to the sediment physical properties and change gradually from the northwest to the southeast. The relations between IOI and physical properties were studied and compared to the relations between the sound speed and physical properties. IOI is better correlated to physical properties than sound speed. This study also uses an error norm method to analyze the sensitivity of IOI to the physical parameters in the double-parameter equations and finds that the most influential physical parameters are as follows: wet bulk density > porosity > clay content > mean particle size.

  17. Influence of the May Southern annular mode on the South China Sea summer monsoon

    Science.gov (United States)

    Liu, Ting; Li, Jianping; Li, YanJie; Zhao, Sen; Zheng, Fei; Zheng, Jiayu; Yao, Zhixiong

    2017-07-01

    The possible impact of the May Southern Hemisphere (SH) annular mode (SAM) on the following South China Sea (SCS) summer monsoon (SCSSM) is examined. A close inverse relationship between the two is revealed in the observations. The simultaneous South Pacific dipole (SPD), a dipole-like sea surface temperature anomaly pattern in the South Pacific, acts as the "oceanic bridge" to preserve the May SAM signal and prolong it into June-September. Observational evidence and numerical simulations both demonstrate that the SPD communicates its large thermal inertia signal to the atmosphere, regulating the Southern Pacific Subtropical Jet (SPSJ) variability over eastern Australia. Corresponding to the adjustment of circulation associated with the SPSJ is a prominent tripolar cross-Pacific teleconnection pattern stretching from the SH middle-high latitudes into the NH East Asia coastal region, referred to as the South-North Pacific (SNP) teleconnection pattern. Wave ray tracing analysis manifests that the SNP acts as the "atmospheric bridge" to propagate the related wave energy across the equator and into the Maritime Continent and SCS monsoon region, modulating the vertical motion and middle-lower tropospheric flows, and favoring the out-of-phase variation of the SCSSM. Therefore, the "coupled oceanic-atmospheric bridge" process and the related Rossby wave energy transmission are possible mechanisms for the significant influence of the May SAM on the variability of the following SCSSM. Therefore, the May SAM provides a fresh insight into the prediction of the SCSSM from the perspective of the SH high latitudes.

  18. First results from experiment in South China Sea using marine controlled source electromagnetic

    Science.gov (United States)

    Li, Yuan; Wang, Lipeng; Deng, Ming

    2016-04-01

    We concentrated on the use of marine controlled-source electromagnetic (CSEM) sounding with a horizontal electric dipole source towed close to the seafloor and receivers anchored on the seafloor. We applied the CSEM method in South China Sea for the first time in 2014, which not only test the application of our instrument, but also test our data processing method. Electromagnetic fields transmitted by a towed electric dipole source in deep sea were measured by a linear array of six seafloor receivers, positioned 600 meter (m) apart. Our results provided two highly resistivity layers beneath the survey line and the gas hydrate saturation profile associated with the anomalous resistivity. In the letter, we discussed some anomalous layers during the interpretation steps. The most plausible explanation of the first resistivity layer anomalies is that large amounts of gas hydrate have accumulated at 200 m depth below the seep sites, and the second layers is considerable volumes of gas hydrate have accumulated the seafloor at survey line according to the conceptual model, during the resistivity compared with other evidence like seismic and well data from the same survey. We should try other observation like heat flow, geochemical or other evidence to test the statement in the future.

  19. Factors driving the spatiotemporal variability in phytoplankton in the Northern South China Sea

    Science.gov (United States)

    Wei, Na; Satheeswaran, Thangaraj; Jenkinson, Ian R.; Xue, Bing; Wei, Yuqiu; Liu, Haijiao; Sun, Jun

    2018-06-01

    The influence of oceanographic processes on phytoplankton diversity and community structure was examined during a cruise conducted from July to August 2012 in the northern South China Sea (nSCS). One hundred ninety seven seawater samples were collected and analyzed from 41 stations in the nSCS. A total of 215 species were identified belonging to 67 genera, mostly dominated by diatoms (67.36%) followed by dinoflagellates (28.16%). The mean cell abundance of diatoms and dinoflagellates were 1.954 × 103 cells L-1 and 0.817 × 103 cells L-1, respectively. Diatoms mainly distributed in coastal region whereas dianoflaglletes in the open sea. Margalaf's species richness (dMa) was maximum (3.96) at SQD1 station (Depth 15 m), whereas it was minimum (0.07) at SS1 (Depth 200 m). Further, Box-Whisker plot displayed that dissolved inorganic nutrients incresed with depth. Nevertheless, redundacy analysis reveled that phytoplankton density has a negative relationship with nutrients. Overall the presesant study provides latest in-depth information about how the factors influencing the phytoplankton density and diversity in the (nSCS) during summer based on the cruise data which could serve as a reference for the similar study.

  20. Investigation of antibiotics in mollusks from coastal waters in the Bohai Sea of China

    International Nuclear Information System (INIS)

    Li Wenhui; Shi Yali; Gao Lihong; Liu Jiemin; Cai Yaqi

    2012-01-01

    This study focused on the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides in mollusks from the Bohai Sea of China. 190 samples of eleven species were collected in 2006, 2007 and 2009. Laboratory analyses revealed that antibiotics were widely distributed in the mollusks with quinolones as the major compounds with concentrations of 0.71∼1575.10 μg/kg, which were up to two orders of magnitude higher than those of sulfonamides (0∼76.75 μg/kg) and macrolides (0∼36.21 μg/kg). The contents of quinolones and macrolides did not show significant changes from 2006, 2007 to 2009, while sulfonamides decreased significantly from 2006 to 2009. Compared with other sites, the city of Dalian was more polluted with quinolones, while Beidaihe was more contaminated with erythromycin and sulfapyridine. In addition, Mactra veneriformis and Meretrix merehjgntrix Linnaeus contained higher concentrations of quinolones and sulfamonomethoxine, while Mytilus edulis had higher levels of erythromycin and sulfapyridine. - Highlights: ► Antibiotics widely existed in the mollusks from the Bohai Sea. ► Quinolones were the major antibiotics in the mollusks. ► The concentrations of sulfonamides decreased from 2006 to 2009. - Antibiotics were widely distributed in the mollusks with quinolones as the major compounds.

  1. The influence of ENSO on an oceanic eddy pair in the South China Sea

    Science.gov (United States)

    Chu, Xiaoqing; Dong, Changming; Qi, Yiquan

    2017-03-01

    An eddy pair off the Vietnam coast is one of the most important features of the summertime South China Sea circulation. Its variability is of interest due to its profound impact on regional climate, ecosystems, biological processes, and fisheries. This study examines the influence of the El Niño-Southern Oscillation (ENSO), a basin-scale climatic mode, on the interannual variability of this regional eddy pair using satellite observational data and historical hydrographic measurements. Over the last three decades, the eddy pair strengthened in 1994 and 2002, and weakened in 2006, 2007, and 2008. It was absent in 1988, 1995, 1998, and 2010, coinciding with strong El Nino-to-La Nina transitions. Composite analyses showed that the strong transition events of ENSO led to radical changes in the summer monsoon, through the forcing of a unique sea surface temperature anomaly structure over the tropical Indo-Pacific basin. With weaker zonal wind, a more northward wind direction, and the disappearance of a pair of positive and negative wind stress curls, the eastward current jet turns northward along the Vietnam coast and the eddy pair disappears.

  2. Pyrosequencing reveals diverse microbial community associated with the zoanthid Palythoa australiae from the South China Sea.

    Science.gov (United States)

    Sun, Wei; Zhang, Fengli; He, Liming; Li, Zhiyong

    2014-05-01

    Diverse sessile organisms inhabit the coral reef ecosystems, including corals, sponges, and sea anemones. In the past decades, scleractinian corals (Cnidaria, Anthozoa, Scleractinia) and their associated microorganisms have attracted much attention. Zoanthids (Cnidaria, Anthozoa, Zoanthidea) are commonly found in coral reefs. However, little is known about the community structure of zoanthid-associated microbiota. In this study, the microbial community associated with the zoanthid Palythoa australiae in the South China Sea was investigated by 454 pyrosequencing. As a result, 2,353 bacterial, 583 archaeal, and 36 eukaryotic microbial ribotypes were detected, respectively. A total of 22 bacterial phyla (16 formally described phyla and six candidate phyla) were recovered. Proteobacteria was the most abundant group, followed by Chloroflexi and Actinobacteria. High-abundance Rhizobiales and diverse Chloroflexi were observed in the bacterial community. The archaeal population was composed of Crenarchaeota and Euryarchaeota, with Marine Group I as the dominant lineage. In particular, Candidatus Nitrosopumilus dominated the archaeal community. Besides bacteria and archaea, the zoanthid harbored eukaryotic microorganisms including fungi and algae though their diversity was very low. This study provided the first insights into the microbial community associated with P. australiae by 454 pyrosequencing, consequently laid a basis for the understanding of the association of P. australiae-microbes symbioses.

  3. Five Dragons Stirring Up the Sea: Challenge and Opportunity in China’s Improving Maritime Enforcement Capabilities (China Maritime Study, Number 5)

    Science.gov (United States)

    2010-04-01

    is quite cognizant of globalization and the growing interdependence among nations. In this current of thinking, also amply evident in the Ningbo...occasions. In March, Unicorn Ace, with a crew of nineteen Chinese citizens, sank in the South China Sea. The Hong Kong Rescue Service, querying the...second major implication is that stronger Chinese coast guard entities are likely to give further impetus to China’s rapidly growing “soft power” both in

  4. Phytoplankton response to a plume front in the northern South China Sea

    Science.gov (United States)

    Li, Qian P.; Zhou, Weiwen; Chen, Yinchao; Wu, Zhengchao

    2018-04-01

    Due to a strong river discharge during April-June 2016, a persistent salinity front, with freshwater flushing seaward on the surface but seawater moving landward at the bottom, was formed in the coastal waters west of the Pearl River estuary (PRE) over the northern South China Sea (NSCS) shelf. Hydrographic measurements revealed that the salinity front was influenced by both the river plume and coastal upwelling. On shipboard nutrient-enrichment experiments with size-fractionation chlorophyll a measurements were taken on both sides of the front as well as in the frontal zone to diagnose the spatial variations of phytoplankton physiology across the frontal system. We also assessed the size-fractionated responses of phytoplankton to the treatment of plume water at the frontal zone and the sea side of the front. The biological impact of vertical mixing or upwelling was further examined by the response of surface phytoplankton to the addition of local bottom water. Our results suggested that there was a large variation in phytoplankton physiology on the sea side of the front, driven by dynamic nutrient fluxes, although P limitation was prevailing on the shore side of the front and at the frontal zone. The spreading of plume water at the frontal zone would directly improve the growth of microphytoplankton, while nano- and picophytoplankton growths could have become saturated at high percentages of plume water. Also, the mixing of bottom water would stimulate the growth of surface phytoplankton on both sides of the front by altering the surface N/P ratio to make it closer to the Redfield stoichiometry. In summary, phytoplankton growth and physiology could be profoundly influenced by the physical dynamics in the frontal system during the spring-summer of 2016.

  5. Size Resolved Measurements of Springtime Aerosol Particles over the Northern South China Sea

    Science.gov (United States)

    Atwood, Samuel A.; Reid, Jeffrey S.; Kreidenweis, Sonia M.; Cliff, Stephen S.; Zhao, Yongjing; Lin, Neng-Huei; Tsay, Si-Chee; Chu, Yu-Chi; Westphal, Douglas L.

    2012-01-01

    Large sources of aerosol particles and their precursors are ubiquitous in East Asia. Such sources are known to impact the South China Sea (henceforth SCS), a sometimes heavily polluted region that has been suggested as particularly vulnerable to climate change. To help elucidate springtime aerosol transport into the SCS, an intensive study was performed on the remote Dongsha (aka Pratas) Islands Atoll in spring 2010. As part of this deployment, a Davis Rotating-drum Uniform size-cut Monitor (DRUM) cascade impactor was deployed to collect size-resolved aerosol samples at the surface that were analyzed by X-ray fluorescence for concentrations of selected elements. HYSPLIT backtrajectories indicated that the transport of aerosol observed at the surface at Dongsha was occurring primarily from regions generally to the north and east. This observation was consistent with the apparent persistence of pollution and dust aerosol, along with sea salt, in the ground-based dataset. In contrast to the sea-level observations, modeled aerosol transport suggested that the westerly flow aloft (w700 hPa) transported smoke-laden air toward the site from regions from the south and west. Measured aerosol optical depth at the site was highest during time periods of modeled heavy smoke loadings aloft. These periods did not coincide with elevated aerosol concentrations at the surface, although the model suggested sporadic mixing of this free-tropospheric aerosol to the surface over the SCS. A biomass burning signature was not clearly identified in the surface aerosol composition data, consistent with this aerosol type remaining primarily aloft and not mixing strongly to the surface during the study. Significant vertical wind shear in the region also supports the idea that different source regions lead to varying aerosol impacts in different vertical layers, and suggests the potential for considerable vertical inhomogeneity in the SCS aerosol environment.

  6. The South China Sea Mesoscale Eddy Experiment (S-MEE) and Its Primary Findings

    Science.gov (United States)

    Zhang, Z.; Tian, J.; Zhao, W.; Qiu, B.

    2016-02-01

    South China Sea (SCS), the largest marginal sea in the northwestern Pacific, have strong eddy activities as revealed by both satellite and in situ observations. The 3D structures of the SCS mesoscale eddies and their lifecycles, including the generation and dissipation processes, are, however, still not well understood at present because of the lack of well-designed field observations. In order to address the above two scientific issues (3D structure and lifecycle of SCS mesoscale eddies), the SCS Mesoscale Eddy Experiment (S-MEE for short) was designed and conducted in the period from October 2013 to June 2014. As part of S-MEE, two bottom-anchored subsurface mooring arrays with one consisting of 10 moorings and the other 7 moorings, were deployed along the historical pathway of the mesoscale eddies in the northern SCS. All the moorings were equipped with ADCPs, RCMs, CTDs and temperature chains to make continues measurements of horizontal current velocity and temperature/salinity in the whole water column. During the S-MEE, a total of 5 distinct mesoscale eddies were observed to cross the mooring arrays, among which one anticyclonic and cyclonic eddy pair was fully captured by the mooring arrays. In addition to moored observations, we also conducted two transects across the center of the anticyclonic eddy and made high-resolution hydrographic and turbulent mixing measurements. Based on the data collected by the S-MEE and concurrent satellite-derived observations, we constructed the full-depth 3D structure of the eddy pair and analyzed its generation and dissipation mechanisms. We found that the eddies extend from the surface to the sea bottom and display prominent tilted structures in the vertical. By conducting an eddy energy budget analysis, we further identified that generation of submesoscale motions constitutes the dominant mechanism for the oceanic eddy dissipation.

  7. Ibsen's mermaid in China: adapting The lady from the sea for the traditional Yue theatre

    Directory of Open Access Journals (Sweden)

    Terry Siu-han Yip

    2015-02-01

    Full Text Available Ibsen has created Ellida Wangel in The Lady from the Sea as a “mermaid” stranded on land, feeling trapped in her marriage with Dr Wangel and suffocated by her restrictive gender roles as wife and step-mother. The play focuses on Ellida the dying mermaid’s process of individuation as she struggles to seek happiness, freedom and self-fulfilment in life. Through Ellida’s entangled relationship with the Stranger and her husband, Ibsen has created a living “mermaid”, who enables him to explore gender relations, individual freedom and choice, as well as the liberation of the self.             However, when The Lady from the Sea was transposed from Norway to China and adapted for the traditional Chinese theatre, the Chinese Yue theatre in this case, Ellida had undergone drastic changes in order to suit the traditional Yue theatregoers’ expectations and taste, as well as to fit the socio-cultural norm of traditional Yue opera.             Instead of examining those technical alterations such as rearrangement of scenes (Ye, 2011, 20, the use of symbols (Wu, 2011, 80, the setting (Wu, 2011, 78, or theatrical performance and devices (Qing Yun, 2010, 32 adopted in the Chinese operatic adaptation of The Lady from the Sea, this article focuses on the cultural re-presentation of Ellida and the re-constitution of her character, the purpose of which is to make her plausible as a Chinese woman on the traditional Yue stage. A close study of the cultural transformation of Ellida and her re-orientation on the traditional Yue stage adaptation will enable the reader to better understand the Chinese cultural emphasis on didacticism, Confucian morality and propriety in traditional drama and theatre, as well as the difficulties involved in transporting Ibsen’s mermaid to the Chinese traditional Yue stage.

  8. Fluxes of particulate organic carbon in the East China Sea in summer

    Directory of Open Access Journals (Sweden)

    C.-C. Hung

    2013-10-01

    Full Text Available To understand carbon cycling in marginal seas better, particulate organic carbon (POC concentrations, POC fluxes and primary production (PP were measured in the East China Sea (ECS in summer 2007. Higher concentrations of POC were observed in the inner shelf, and lower POC values were found in the outer shelf. Similar to POC concentrations, elevated uncorrected POC fluxes (720–7300 mg C m−2 d−1 were found in the inner shelf, and lower POC fluxes (80–150 mg C m−2 d−1 were in the outer shelf, respectively. PP values (~ 340–3380 mg C m−2 d−1 had analogous distribution patterns to POC fluxes, while some of PP values were significantly lower than POC fluxes, suggesting that contributions of resuspended particles to POC fluxes need to be appropriately corrected. A vertical mixing model was used to correct effects of bottom sediment resuspension, and the lowest and highest corrected POC fluxes were in the outer shelf (58 ± 33 mg C m−2 d−1 and the inner shelf (785 ± 438 mg C m−2 d−1, respectively. The corrected POC fluxes (486 to 785 mg C m−2 d−1 in the inner shelf could be the minimum value because we could not exactly distinguish the effect of POC flux from Changjiang influence with turbid waters. The results suggest that 27–93% of the POC flux in the ECS might be from the contribution of resuspension of bottom sediments rather than from the actual biogenic carbon sinking flux. While the vertical mixing model is not a perfect model to solve sediment resuspension because it ignores biological degradation of sinking particles, Changjiang plume (or terrestrial inputs and lateral transport, it makes significant progress in both correcting the resuspension problem and in assessing a reasonable quantitative estimate of POC flux in a marginal sea.

  9. What Controls Seasonal Variation of Phytoplankton Growth in the East China Sea?

    Science.gov (United States)

    Liu, K.; Chao, S.; Lee, H.; Gong, G.; Teng, Y.

    2009-05-01

    The seasonal variation of phytoplankton growth in the East China Sea (ECS) is simulated with a three- dimensional coupled physical-biogeochemical model, which includes discharges from Changjiang (aka the Yangtze River). The purpose is to determine the main control on the seasonality of primary productivity in the ECS shelf, which nurtures rich biological resources. The model has a horizontal resolution of 1/6 degree in the domain from 23N to 41N and from 116E to 134E, excluding the Japan/East Sea, and 33 layers in the vertical. The nitrogen-based biogeochemical model has four compartments: dissolved inorganic nitrogen (DIN), phytoplankton, zooplankton and detritus. The chlorophyll to phytoplankton ratio depends on light and DIN availability. The model is driven by monthly climatological winds with the sea surface temperature, salinity and DIN relaxed towards the climatological mean values. It successfully reproduces the observed seasonal variation of phytoplankton growth over the ECS shelf with a strong peak in later spring and summer. The modeled annual mean primary production over the entire ECS shelf is 439 mg C m-2 d-1, which falls within the reported range of 390-529 mg C m-2 d-1. It also reproduces the marked gradient of DIN across the shelf decreasing away from the Changjiang River plume. An alternative model run, Free-N, which deviates from the standard run by essentially removing nudging on DIN, generates the same seasonal pattern of primary productivity but somewhat reduced productivity. In yet another alternative run, Fix-PAR, which deviates from Free-N by removing the seasonal cycle of photosynthetically active radiation, the seasonality of primary productivity almost vanishes. These model results demonstrate that light availability is the major control on the seasonality of primary productivity. However, nutrient supply from vertical nutrient pumping and from Changjiang discharges is still important. It is the insufficient nutrient pumping that leads

  10. Seismic investigation on the Littoral Faults Zone in the northern continental margin of South China Sea

    Science.gov (United States)

    Sun, J.; Xu, H.; Xia, S.; Cao, J.; Wan, K.

    2017-12-01

    The continental margin of the northern South China Sea (SCS) had experienced continuous evolution from an active continental margin in the late Mesozoic to a passive continental margin in the Cenozoic. The 1200km-long Littoral Faults Zone (LFZ) off the mainland South China was suggested to represent one of the sub-plate boundaries and play a key role during the evolution. Besides, four devastating earthquakes with magnitude over 7 and another 11 destructive events with M>6 were documented to have occurred along the LFZ. However, its approximity to the shoreline, the shallow water depth, and the heavy fishing activities make it hard to conduct a marine seismic investigation. As a result, understandings about the LFZ before 2000 were relatively poor and mostly descriptive. After two experiments of joint onshore-offshore wide-angle seismic surveys in the 1st decade of this century, several cruses aiming to unveil the deep structure of the LFZ were performed in the past few years, with five joint onshore-offshore wide-angle seismic survey profiles completed. Each of these profiles is perpendicular to the shoreline, with four to five seismometers of campaign mode deployed on the landside and over ten Ocean Bottom Seismometers (OBSs) spacing at 20km deployed on the seaside. Meanwhile, multi-channel seismic (MCS) data along these profiles were obtained simultaneously. Based on these data, velocity models from both forward modeling and inversion were obtained. According to these models, the LFZ was imaged to be a low-velocity fractured zone dipping to the SSE-SE at a high-angle and cutting through the thinned continental crust at some locations. Width of the fractured zone varies from 6km to more than 10km from site to site. With these results, it is suggested that the LFZ accommodates the stresses from both the east side, where the Eurasia/Philippine Sea plate converging and mountain building is ongoing, and the west side, where a strike-slip between the Indochina

  11. Magnetic minerals in three Asian rivers draining into the South China Sea: Pearl, Red, and Mekong Rivers

    Science.gov (United States)

    Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

    2016-05-01

    The use of the marine sedimentary magnetic properties, as tracers for changes in precipitation rate and in oceanic water masses transport and exchanges, implies to identify and to characterize the different sources of the detrital fraction. This is of particular importance in closed and/or marginal seas such as the South China Sea. We report on the magnetic properties of sedimentary samples collected in three main Asian rivers draining into the South China Sea: the Pearl, Red, and Mekong Rivers. The geological formations as well as the present climatic conditions are different from one catchment to another. The entire set of performed magnetic analyses (low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis parameters, FORC diagrams, and low-temperature magnetic measurements) allow us to identify the magnetic mineralogy and the grain-size distribution when magnetite is dominant. Some degree of variability is observed in each basin, illustrating different parent rocks and degree of weathering. On average it appears that the Pearl River is rich in magnetite along the main stream while the Mekong River is rich in hematite. The Red River is a mixture of the two. Compared to clay mineral assemblages and major element contents previously determined on the same samples, these new findings indicate that the magnetic fraction brings complementary information of great interest for environmental reconstructions based on marine sediments from the South China Sea.

  12. MODELING OF OIL POLLUTION OF ARTIC SEA COASTAL AREAS

    Directory of Open Access Journals (Sweden)

    2017-01-01

    Full Text Available This article studies the elastic filtration oil drive of oil in a layer based on the estimation of risks of environmental oil pollution because of accidental releases. The model of oil spillage and resorption by the precoat is based on continuity equation and Darcy rule as well as on equations of state taking into account fluid compressibility due to pressure. Filtering area is a line between the precoat and air. Oil filtering area is limited by soil surface below and by free surface above, its equation is known beforehand and is to be defined. The case of soil pollution from the point source, which is the point of fracture of pipeline or borehole, is considered. Upper and approximate estimates of the oil pollution radius due to different types of underlying terrains and to oil characteristics as well as to environmental conditions. The dynamics of oil free sur- face depending on spillage radii is calculated and presented. The estimates of temporary duration of oil filtering by the pre- coat in terms of light ends and soil type are made. The thickness of the oil film and the square of the spill upon condition of constant speed of oil spillage, horizontal position of underlying terrain and the proximity of pressure to normal are deter- mined. For the numerical implementation of the model different cases of oil spillage were considered. Under given values of air temperature, soil porosity and filtration speed the pollution radii according to light end, the time from the moment of accident till the leakage suppression and the speed of oil spillage was calculated.

  13. Tectonic framework of the Hanoe Bay area, southern Baltic Sea

    International Nuclear Information System (INIS)

    Wannaes, K.O.; Floden, T.

    1994-06-01

    The tectonic framework and the general geologic development of the Hanoe Bay, from the Scanian coast in the west to south of Oeland in the east, has been investigated by means of reflection seismic methods. The Hanoe Bay is in this paper subdivided into four areas of different geologic settings. These are: 1) The Hanoe Bay slope, which forms a southward dipping continuation of the rigid Blekinge coastal plain. 2) The eastward dipping Kalmarsund Slope, which southwards from Oeland forms the western part of the Paleozoic Baltic Syneclise. 3) The Mesozoic Hanoe Bay Halfgraben, which forms the central and southern parts of the Hanoe Bay. The ongoing subsidence of the Halfgraben is estimated to be in the order of 20-60 m during the Quaternary. 4) The Yoldia Structural Element, which forms a deformed, tilted and possibly rotated block of Paleozoic bedrock located east of the Hanoe Bay Halfgraben. Two tectonic phases dominate the post-Paleozoic development of the Hanoe Bay, these are: 1) The Early Kimmerian phase, which initiated subsidence and reactivated older faults. 2) The Late Cretaceous phase, which is the main subsidence phase of the Hanoe Bay Halfgraben. The tectonic fault pattern of the Hanoe Bay is dominated by three directions, i.e. NW-SE, NE-SW and WNW-ESE. The two main tectonic elements of the area are the Kullen-Christiansoe Ridge System (NW-SE) and the Bornholm Gat Tectonic Zone (NE-SW). Sinistral strike-slip movements in order of 2-3 km are interpreted to have occurred along the Bornholm Gat Tectonic Zone during the late Cretaceous. 20 refs, 19 figs

  14. Arctic sea ice area changes in CMIP3 and CMIP5 climate models’ ensembles

    Directory of Open Access Journals (Sweden)

    V. A. Semenov

    2017-01-01

    Full Text Available The shrinking Arctic sea ice cover observed during the last decades is probably the clearest manifestation of ongoing climate change. While climate models in general reproduce the sea ice retreat in the Arctic during the 20th century and simulate further sea ice area loss during the 21st century in response to anthropogenic forcing, the models suffer from large biases and the results exhibit considerable spread. Here, we compare results from the two last generations of climate models, CMIP3 and CMIP5, with respect to total and regional Arctic sea ice change. Different characteristics of sea ice area (SIA in March and September have been analysed for the Entire Arctic, Central Arctic and Barents Sea. Further, the sensitivity of SIA to changes in Northern Hemisphere (NH temperature is investigated and dynamical links between SIA and some atmospheric variability modes are assessed.CMIP3 (SRES A1B and CMIP5 (RCP8.5 models not only simulate a coherent decline of the Arctic SIA but also depict consistent changes in the SIA seasonal cycle. The spatial patterns of SIC variability improve in CMIP5 ensemble, most noticeably in summer when compared to HadISST1 data. A better simulation of summer SIA in the Entire Arctic by CMIP5 models is accompanied by a slightly increased bias for winter season in comparison to CMIP3 ensemble. SIA in the Barents Sea is strongly overestimated by the majority of CMIP3 and CMIP5 models, and projected SIA changes are characterized by a high uncertainty. Both CMIP ensembles depict a significant link between the SIA and NH temperature changes indicating that a part of inter-ensemble SIA spread comes from different temperature sensitivity to anthropogenic forcing. The results suggest that, in general, a sensitivity of SIA to external forcing is enhanced in CMIP5 models. Arctic SIA interannual variability in the end of the 20th century is on average well simulated by both ensembles. To the end of the 21st century, September

  15. Heavy metals in the surface sediments of the northern portion of the South China Sea shelf: distribution, contamination, and sources.

    Science.gov (United States)

    Xu, Fangjian; Tian, Xu; Yin, Feng; Zhao, Yongfang; Yin, Xuebo

    2016-05-01

    The concentrations of seven heavy metals (Cr, Ni, Cu, Zn, As, Cd, and Pb) in the surface sediments of the northern portion of the South China Sea (SCS) shelf collected between 2012 and 2014 were measured to assess the potential contamination levels and determine the environmental risks that are associated with heavy metals in the area. The measured concentrations in the sediments were 12.4-72.5 mg kg(-1) for Cr, 4.4-29.2 mg kg(-1) for Ni, 7.1-38.1 mg kg(-1) for Cu, 19.3-92.5 mg kg(-1) for Zn, 1.3-12.1 mg kg(-1) for As, 0.03-0.24 mg kg(-1) for Cd, and 8.5-24.4 mg kg(-1) for Pb. These results indicate that the heavy metal concentrations in the sediments generally meet the China Marine Sediment Quality criteria and suggest that the overall sediment quality of the northern portion of the SCS shelf has not been significantly impacted by heavy metal pollution. However, the enrichment factor (EF) and geoaccumulation index (I geo) clearly show that elevated concentrations of Cd occur in the region. A Pearson's correlation analysis was performed, and the results suggest that Cr, Ni, Cu, and Zn have a natural origin; Cd is primarily sourced from anthropogenic activities, with partial lithogenic components, and As and Pb may be affected by factors such as varying input sources or pathways (i.e., coal burning activities and aerosol precipitation). Heavy metal contamination mostly occurred to the east of Hainan Island, mainly because of the rapid economic and social developments in the Hainan Island. The results of this study will be useful for marine environment managers for the remediation of pollution sources.

  16. Velocity structure around the 410 km discontinuity beneath the East China Sea based on the waveform modeling method

    Science.gov (United States)

    Li, W.; Cui, Q.; Gao, Y.; Wei, R.; Zhou, Y.; Yu, J.

    2017-12-01

    The 410 km discontinuity is the upper boundary of the mantle transition zone. Seismic detections on the structure and morphology of the 410 km discontinuity are helpful to understand the compositions of the Earth's interior and the relevant geodynamics. In this paper, we select the broadband P waveforms of an intermediate earthquake that occurred in the Ryukyu subduction zone and retrieved from the China Digital Seismograph Network, and study the fine velocity structure around the 410 km discontinuity by matching the observed triplicated waveforms with the theoretical ones. Our results reveal that (1) the 410 km discontinuity beneath the East China Sea is mostly a sharp boundary with a small-scale uplift of 8-15 km and a gradient boundary up to 20 km in the most southern part, and (2) there exist a low velocity layer atop the 410 km discontinuity with the thickness of 50-62 km and P-wave velocity decrease of 0.5%-1.5%, and (3) a high velocity anomaly with P-wave decrease of 1.0%-3.0% below 440 km. Combining with the previous topographic results in this area, we speculate that the high velocity anomaly is relevant to the stagnancy of the western Pacific slab in the mantle transition zone, the decomposition of phase E in the slab results in the increase of water content, which would cause the uplift of the 410 km discontinuity, and the low velocity layer atop the discontinuity should be related to the partial melting of the mantle peridotite induced by the dehydration of the hydrous minerals.

  17. Satellite remote sensing of a low-salinity water plume in the East China Sea

    Directory of Open Access Journals (Sweden)

    Y. H. Ahn

    2008-07-01

    Full Text Available With the aim to map and monitor a low-salinity water (LSW plume in the East China Sea (ECS, we developed more robust and proper regional algorithms from large in-situ measurements of apparent and inherent optical properties (i.e. remote sensing reflectance, Rrs, and absorption coefficient of coloured dissolved organic matter, aCDOM determined in ECS and neighboring waters. Using the above data sets, we derived the following relationships between visible Rrs and absorption by CDOM, i.e. Rrs (412/Rrs (555 vs. aCDOM (400 (m−1 and aCDOM (412 (m−1 with a correlation coefficient R2 0.67 greater than those noted for Rrs (443/Rrs (555 and Rrs (490/Rrs (555 vs. aCDOM (400 (m−1 and aCDOM (412 (m−1. Determination of aCDOM (m−1 at 400 nm and 412 nm is particularly necessary to describe its absorption as a function of wavelength λ using a single exponential model in which the spectral slope S as a proxy for CDOM composition is estimated by the ratio of aCDOM at 412 nm and 400 nm and the reference is explained simply by aCDOM at 412 nm. In order to derive salinity from the absorption coefficient of CDOM, in-situ measurements of salinity made in a wide range of water types from dense oceanic to light estuarine/coastal systems were used along with in-situ measurements of aCDOM at 400 nm, 412 nm, 443 nm and 490 nm. The CDOM absorption at 400 nm was better inversely correlated (R2=0.86 with salinity than at 412 nm, 443 nm and 490 nm (R2=0.85–0.66, and this correlation corresponded best with an exponential (R2=0

  18. Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China

    International Nuclear Information System (INIS)

    Wang Chen; Li Wei; Chen Jiwei; Wang Hongqijie; Li Tongchao; Shen Guofeng; Shen Huizhong; Huang Ye; Wang Rong; Wang Bin; Zhang Yanyan; Tang Jianhui; Liu Wenxin; Wang Xilong; Tao Shu

    2012-01-01

    High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 ± 72 pg/m 3 ) and other 13 PBDEs (16 ± 12 pg/m 3 ) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively. - Graphical abstract: Concentration of PBDEs at each site of the studied area. Highlights: ► High levels of PBDEs with BDE-209 domination were detected in air in northern China. ► PBDE concentrations in rural residential areas were significantly higher than those in rural open fields. ► Proportions of BDE-209 in urban areas were higher than those in rural areas. ► PBDE concentrations were correlated to local population density and Gross Domestic Production. - In northern China, PBDEs in air in rural residential areas were significantly higher than those in open fields.

  19. Anomalous Ba/Ca signals associated with low temperature stresses in Porites corals from Daya Bay, northern South China Sea

    Institute of Scientific and Technical Information of China (English)

    Tianran Chen; Kefu Yu; Shu Li; Tegu Chen; Qi Shi

    2011-01-01

    Barium to calcium (Ba/Ca) ratio in corals has been considered as a useful geochemical proxy for upwelling,river flood and other oceanic processes.However,recent studies indicated that additional environmental or biological factors can influence the incorporation of Ba into coral skeletons.In this study,Ba/Ca ratios of two Porites corals collected from Daya Bay,northern South China Sea were analyzed.Ba/Ca signals in the two corals were 'anomalous' in comparison with Ba behaviors seen in other near-shore corals influenced by upwelling or riverine runoff.Our Ba/Ca profiles displayed similar and remarkable patterns characterized by low and randomly fluctuating background signals periodically interrupted by sharp and large synchronous peaks,clearly indicating an environmental forcing.Further analysis indicated that the Ba/Ca profiles were not correlated with previously claimed environmental factors such as precipitation,coastal upwelling,anthropogenic activities or phytoplankton blooms in other areas.The maxima of Ba/Ca appeared to occur in the period of Sr/Ca maxima,coinciding with the winter minimum temperatures,which suggests that the anomalous high Ba/Ca signals were related to winter-time low sea surface temperature.We speculated that the Ba/Ca peaks in corals of the Daya Bay were most likely the results of enrichment of Ba-rich particles in their skeletons when coral polyps retracted under the stresses of anomalous winter low temperatures.In this case,Ba/Ca ratio in relatively high-latitude corals can be a potential proxy for tracing the low temperature stress.

  20. Concentration and characterization of dissolved organic matter in the surface microlayer and subsurface water of the Bohai Sea, China

    Science.gov (United States)

    Chen, Yan; Yang, Gui-Peng; Wu, Gua