检索结果-南通市图书馆

Light carbon isotope events of foraminifera attributed to methane release from gas hydrates on the continental slope, northeastern South China Sea

引用

Science China Earth Sciences 2016年第10期59卷 1981-1995页

作者： ZHUANG Chang CHEN Fang CHENG SiHai LU HongFeng WU Cong CAO Jun DUAN Xiao key laboratory of marine Mineral resources Ministry of Land and ResourceGuangzhou Marine Geological Survey

In 2013, the China geological Survey and Guangzhou marine geological Survey conducted the second Chinese gas hydrate expedition in the northern South China Sea （SCS） and successfully obtained visible gas hydrate samples. Five of the thirteen drilling sites were cored for further research. In this work, Site GMGS2-08 is selected for the stable isotopic analy- sis of foraminifera present in the boreholes in order to reveal the carbon isotopic characteristics of the foraminifera and their response to methane release in the gas hydrate geological system. Our results show that the methane content at Site GMGS2-08 is extremely high, with headspace methane concentrations up to 39300 μmol L^-1. The hydrocarbon δ^13C values, ranging from -69.4%o to -72.3‰ PDB, distinctly indicate biogenic generation. Based on the δD analytical results （-183‰ to -185‰ SMOW）, headspace methane is further discriminated to be microbial gas, derived from CO2 reduction. By isotopic measurement, five light δ^13C events are found in the boreholes from Site GMGS2-08, with foraminiferal δ^13C values being ap- parently lower than the normal variation range found in the glacial-interglacial cycles of the SCS. The δ^13C values of benthic Uvigerina peregrina are extremely depleted （as low as -15.85‰ PDB）, while those of planktonic Globigerinoides ruber reach -5.68‰ PDB. Scanning electron micrograph （SEM） studies show that foraminiferal tests have experienced post-depositional alteration, infilled with authigenic carbonate, and the diagenetic mineralization is unlikely to be related to the burial depths. The correlation calculation suggests that the anaerobic oxidation of organic matter has only weak influences on the δ^13C com- position of benthic foraminifera. This means that the anomalous δ^13C depletions are predominantly attributed to the overprint- ing of secondary carbonates derived from the anaerobic oxidation of methane （AOM）. Furthermore, the negative δ^13C anoma- lies, coupled with the positive

关键词： Gas hydrates Carbon isotopes Foraminifera South China Sea Taixinan Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comprehensive Investigation of Submarine Slide Zones and Mass Movements at the Northern Continental Slope of South China Sea

引用

Journal of Ocean University of China 2018年第1期17卷 101-117页

作者： CHEN Hongjun LIANG Jin GONG Yuehua key laboratory of marine Mineral resources Ministry of Land and ResourcesGuangzhou Marine Geological Survey

Multi-beam bathymetry and seismic sequence surveys in the northern slope of the South China Sea reveal detailed geomorphology and seismic stratigraphy characteristics of canyons, gullies, and mass movements. Modern canyons and gullies are roughly elongated NNW–SSW with U-shaped cross sections at water depths of 400–1000 m. Mass movements include slide complexes, slide scars, and debris/turbidity flows. Slide complexes and slide scars are oriented in the NE–SW direction and cover an area of about 1790 and 926 km^2, respectively. The debris/turbidity flows developed along the lower slope. A detailed facies analysis suggests that four seismic facies exist, and the late Cenozoic stratigraphy above the acoustic basement can be roughly subdivided into three sequences separated by regional unconformities in the study area. The occurrence of gas hydrates is marked by seismic velocity anomalies, bottom-simulating reflectors, gas chimneys, and pockmarks in the study area. Seismic observations suggest that modern canyons and mass movements formed around the transition between the last glacial period and the current interglacial period. The possible existence and dissociation of gas hydrates and the regional tectonic setting may trigger instability and mass movements on the seafloor. Canyons may be the final result of gas hydrate dissociation. Our study aims to contribute new information that is applicable to engineering construction required for deep-water petroleum exploration and gas hydrate surveys along any marginal sea.

关键词： South China Sea submarine slide zones mass movements continental slope

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Water discharge variability of Changjiang(Yangtze) and Huanghe(Yellow) Rivers and its response to climatic changes

引用

Chinese Journal of Oceanology and Limnology 2014年第6期32卷 1392-1405页

作者：张喜林范德江王厚杰杨作升 key laboratory of Submarine Geosciences and Technology of Ministry of Education Ocean University of China key laboratory of marine Hydrocarbon resources and environment Geology China Geological SurveyMinistry of Land and Resources Qingdao Institute of marine Geology China Geological Survey

Influences of large-scale climatic phenomena, such as the E1Nifio/La Nifia-Southem Oscillation （ENSO） and the Pacific Decadal Oscillation （PDO）, on the temporal variations of the annual water discharge at the Lijin station in the Huanghe （Yellow） River and at the Datong station in the Changjiang （Yangtze） River were examined. Using the empirical mode decomposition-maximum entropy spectral analysis （EMD- MESA） method, the 2- to 3-year, 8- to 14-year, and 23-year cyclical variations of the annual water discharge at the two stations were discovered. Based on the analysis results, the hydrological time series on the inter- annual to interdecadal scales were constructed. The results indicate that from 1950 to 2011, a significant downward trend occurred in the natural annual water discharge in Huanghe River. However, the changes in water discharge in Changjiang River basin exhibited a slightly upward trend. It indicated that the changes in the river discharge in the Huanghe basin were driven primarily by precipitation. Other factors, such as the precipitation over the Changjiang River tributaries, ice melt and evaporation contributed much more to the increase in the Changjiang River basin. Especially, the impacts of the inter-annual and inter-decadal climate oscillations such as ENSO and PDO could change the long-term patterns of precipitation over the basins of the two major rivers. Generally, low amounts of basin-wide precipitation on interannual to interdecadal scales over the two rivers corresponded to most of the warm ENSO events and the warm phases of the PDO, and vice versa. The positive phases of the PDO and ENSO could lead to reduced precipitation and consequently affect the long-term scale water discharges at the two rivers.

关键词： water discharge Changjiang (Yangtze) River Huanghe (Yellow) River empirical modedecomposition maximum entropy spectral analysis large-scale climate factor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Characteristic Patterns of Macrofaunal Fouling Assemblages in Nearshore Waters of the South China Sea

引用

Journal of Ocean University of China 2018年第5期17卷 1142-1148页

作者： CHEN Xin LIU Qiuyu ZHUO Wen LIU Wenjuan LI Ziwei TANG Min State key laboratory of South China Sea marine resources Utilization Hainan University College of Materials and Chemical Engineering Hainan University College of environment and Plant Protection Hainan University

The spatio-temporal patterns of macrofaunal fouling assemblages were quantitatively investigated in the nearshore waters of the South China *** work was undertaken by deploying seasonal panels at two sites(H-site,L-site) for one year,and the fouling communities on the panels were examined and *** results indicated that species composition of assemblages was obviously different between the two *** both sites the assemblages were characteristic with solitary dominant species throughout the year,with Amphibalanus reticulates dominating at H-site and Hydroides elegans at *** index and biomass of the assemblages varied with depth and season at both *** H-site the total biomass in summer and autumn were significantly higher than those in spring and winter,while at L-site the assemblage biomass also differed significantly among the four seasons,and the greatest biomass occurred at the depth of 2.0 m in *** abundance of all seasonal samples in non-metric multidimensional scaling was clustered as one group at L-site and three groups at *** environmental factors were more likely to be related to the variation of fouling ***,it also suggests that in tropical seas the integrated adaptability would qualify a species for dominating a fouling assemblage despite its short life cycle,rather than the usually assumed only species with long life *** study reveals the complexity and characteristic dynamics of macrofaunal fouling assemblages in the tropical habitats,and the results would provide valuable knowledge for biodiversity and antifouling research.

关键词： fouling macrofaunal assemblages dominant species non-metric multidimensional scaling the South China Sea

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Horizontal Normal Force on Buried Rigid Pipelines in Fluctuant Liquefied Silty Soil

引用

Journal of Ocean University of China 2019年第1期18卷 1-8页

作者： XU Xingbei XU Guohui REN Yupeng LIU Zhiqin CHEN Changyun key laboratory of marine environment and Ecology Ministry of Education Ocean University of China Shandong Provincial key laboratory of marine environment and geological Engineering Ocean University of China First Institute of Oceanography Ministry of Natural Resources

The submarine pipelines that are buried in the Yellow River subaqueous delta can be subject to fluctuant local-liquefied soil caused by storm wave action, possibly causing pipeline damage. An experimental investigation was carried out in a wave flume to study the horizontal normal force on buried rigid pipelines in fluctuant liquefied soil. In this experiment, the soil bed was made of silt from the Yellow River Delta, whereas a steel pipe served as pipeline. Under the experimental conditions, the normal force range on the pipeline in fluctuant liquefied soil was several times higher than that in stable soil, specifically on the side of the pipeline exposed to the wave direction. The resultant force of the horizontal normal forces on the buried pipeline grew by about one order of magnitude after soil liquefaction.

关键词： wave flume experiment fluctuant liquefied soil buried pipeline normal force

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Formation of the Zengmu and Beikang Basins,and West Baram Line in the southwestern South China Sea margin

引用

Journal of Oceanology and Limnology 2023年第2期41卷 592-611页

作者： Bing HAN Zhongxian ZHAO Xiaofang WANG Zhen SUN Fucheng LI Benduo ZHU Yongjian YAO Liqiang LIU Tianyue PENG Genyuan LONG key laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 511458China key laboratory of marine Mineral resources Ministry of Natural ResourcesGuangzhou 511458China Southern marine Science and Engineering Guangdong laboratory(Guangzhou) Guangzhou 511458China Guangzhou marine geological Survey China Geological SurveyMinistry of Natural ResourcesGuangzhou 511458China University of Chinese Academy of Sciences Beijing 100049China hainan key laboratory of marine geological resources and environment Haikou 570206China

The Zengmu and Beikang basins,separated by the West Baram Line(WBL)in the southwestern South China Sea margin,display distinct geological and geophysical ***,the nature of the basins and the WBL are *** we explore this issue by conducting the stratigraphic and structural interpretation,faults and subsidence analysis,and lithospheric finite extension modelling using seismic *** show that the WBL is a trans-extensional fault zone comprising normal faults and flower structures mainly active in the Late Eocene to Early *** Zengmu Basin,to the southwest of the WBL,shows an overall synformal geometry,thick folded strata in the Late Eocene to Late Miocene(40.4-5.2 Ma),and pretty small normal faults at the basin edge,which imply that the Zengmu Basin is a foreland basin under the Luconia and Borneo collision in the Sarawak since the ***,the basin exhibits two stages of subsidence(fast in 40.4-30 Ma and slow in 30-0 Ma);but the amount of observed subsidence and heat flow are both greater than that predicted by crustal *** Beikang Basin,to the NE of the WBL,consists of the syn-rift faulted sub-basins(45-16.4 Ma)and the post-rift less deformed sequences(16.4-0 Ma).The heat flow(~60 mW/m2)is also consistent with that predicted based on crustal thinning,inferring that it is a rifted ***,the basin shows three stages of subsidence(fast in 45-30 Ma,uplift in 30-16.4 Ma,and fast in 16.4-0 Ma).In the uplift stage,the strata were partly folded in the Late Oligocene and partly eroded in the Early Miocene,which is probably caused by the flexural bulging in response to the paleo-South China Sea subduction and the subsequent Dangerous Grounds and Borneo collision in the Sabah to the east of the WBL.

关键词： tectonic subsidence foreland basin West Baram Line Zengmu Basin Beikang Basin South China Sea

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatial distribution and inventory of natural gas hydrate in the Qiongdongnan Basin,northern South China Sea

引用

Journal of Oceanology and Limnology 2023年第2期41卷 729-739页

作者： Zhongxian ZHAO Ning QIU Zhen SUN Wen YAN Genyuan LONG Pengchun LI Haiteng ZHUO key laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 511458China Southern marine Science and Engineering Guangdong laboratory(Guangzhou) Guangzhou 511458China hainan key laboratory of marine geological resources and environment Haikou 570206China marine geological Institute of hainan Province Haikou 570206China School of marine Sciences Sun Yat-sen UniversityZhuhai 519082China

Natural gas hydrate is a potential clean energy source and is related to submarine geohazard,climate change,and global carbon *** investigations have revealed the occurrence of hydrate in the Qiongdongnan Basin,northern South China ***,the spatial distribution,controlling factors,and favorable areas are not well *** we use the available high-resolution seismic lines,well logging,and heat flow data to explore the issues by calculating the thickness of gas hydrate stability zone(GHSZ)and estimating the *** show that the GHSZ thickness ranges between mostly~200 and 400 m at water depths>500 *** gas hydrate inventory is~6.5×109-t carbon over an area of~6×104 *** areas including the lower uplift to the south of the Lingshui sub-basin,the Songnan and Baodao sub-basins,and the Changchang sub-basin have a thick GHSZ of~250-310 m,250-330 m,and 350-400 m,respectively,where water depths are~1000-1600 m,1000-2000 m,and2400-3000 m,*** these deep waters,bottom water temperatures vary slightly from~4 to 2℃.However,heat flow increases significantly with water depth and reaches the highest value of~80-100 mW/m2 in the deepest water area of Changchang *** heat flow tends to reduce GHSZ thickness,but the thickest GHSZ still occurs in the Changchang sub-basin,highlighting the role of water depth in controlling *** lower uplift to the south of the Lingshui sub-basin has high deposition rate(~270-830 m/Ma in 1.8-0 Ma);the thick Cenozoic sediment,rich biogenic and thermogenic gas supplies,and excellent transport systems(faults,diapirs,and gas chimneys)enables it a promising area of hydrate accumulation,from which hydrate-related bottom simulating reflectors,gas chimneys,and active cold seeps were widely revealed.

关键词： gas hydrate stability zone gas hydrate inventory Qiongdongnan Basin South China Sea

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Source identification of aluminum in surface sediments of the Yellow Sea off the Shandong Peninsula

引用

Acta Oceanologica Sinica 2015年第12期34卷 147-153页

作者： XU Gang LIU Jian PEI Shaofeng KONG Xianghuai HU Gang GAO Maosheng Qingdao Institute of marine Geology Ministry of Land and Natural laboratory for marine Geology Qingdao National Laboratory for Marine Science and Technology key laboratory of Ministry of Land and Natural resources for marine Hydrocarbon resources and environment Geology key laboratory of China geological Survey Bureau for Coastal Wetland Biogeosciences

Surface sediment samples in the near shore area of the north Shandong Peninsula are collected for grain size and element analyses. The results indicate that the surface sediments in the study area are primarily composed of the silt-sized components similar to the Huanghe River. The total concentration of aluminum varies from 5.57% to7.37%（average（6.33 ± 0.40）%）, and its spatial distribution is mainly controlled by the grain size. Correlations between the ratio of aluminum to titanium concentration and aluminum concentration, titanium concentration and the mean grain size indicate that aluminum in the near shore surface sediments is affected majorly by the terrigenous source, and partially by the anthropogenic source. The ratios of aluminum to titanium concentrations are larger than the background value of loess matter at some stations due to the existence of excess aluminum associated with human activities. Thus, the sources of aluminum should be identified firstly when aluminum is used as an index of terrigenous matter even in the near shore area dominated by terrigenous deposits.

关键词： aluminum source identification surface sediments Shandong Peninsula Yellow Sea

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The failure propagation of weakly stable sediment:A reason for the formation of high-velocity turbidity currents in submarine canyons

引用

Journal of Oceanology and Limnology 2023年第1期41卷 100-117页

作者： Yupeng REN Yi ZHANG Guohui XU Xingbei XU Houjie WANG Zhiyuan CHEN Shandong Provincial key laboratory of marine environment and geological Engineering Qingdao 266100China Shandong Provincial key laboratory of marine environment and geological Engineering Ocean University of ChinaQingdao 266100China key laboratory of marine environment and Ecology Ocean University of ChinaMinistry of EducationQingdao 266100China

The long-distance movement of turbidity currents in submarine canyons can transport large amounts of sediment to deep-sea *** studies show obvious differences in the turbidity current velocities derived from the multiple cables damage events ranging from 5.9 to 28.0 m/s and those of field observations between 0.15 and 7.2 m/***,questions remain regarding whether a turbid fluid in an undersea environment can flow through a submarine canyon for a long distance at a high speed.A new model based on weakly stable sediment is proposed(proposed failure propagation model for weakly stable sediments,WS S-PFP model for short)to explain the high-speed and long-range motion of turbidity currents in submarine canyons through the combination of laboratory tests and numerical *** model is based on two mechanisms:1)the original turbidity current triggers the destabilization of the weakly stable sediment bed and promotes the destabilization and transport of the soft sediment in the downstream direction and 2)the excitation wave that forms when the original turbidity current moves into the canyon leads to the destabilization and transport of the weakly stable sediment in the downstream *** proposed model will provide dynamic process interpretation for the study of deep-sea deposition,pollutant transport,and optical cable damage.

关键词： turbidity current excitation wave dense basal layer velocity WSS-PFP model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Propagating subduction initiation of the Caroline Plate at the Mussau Trench

引用

Science China Earth Sciences 2025年第1期 253-269页

作者： Chun-Feng LI Yongkang DENG Tao WU Dongdong DONG Guoliang ZHANG Jiazheng ZHANG Yutao LIU Yaqing LI Fugui TANG Lulu ZHANG Department of marine Sciences Zhejiang University laboratory of marine Mineral resources Laoshan Laboratory key Lab of marine Geology and environment Institute of Oceanology Chinese Academy of Sciences key Lab of Ocean and Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Science & Technology on Integrated Information System Lab Institute of Software Chinese Academy of Sciences

New seismic imaging from the Mussau Trench confirms that, under horizontal compression on an oceanic plate boundary, it is within the young and weak oceanic plate that a trench will develop, and it is the young plate, not so long after its birth, that starts to subduct toward the old plate. The Mesozoic Pacific Plate cannot easily bend, under the joint horizontal compression and vertical gravity pull, even with a pre-existing weak zone in place and with a large age offset across the plate boundary. The bending of the Caroline Plate near the northern end of the Mussau Trench started only after a long-time span of trench migration, and/or after a prolonged transition from initial compression to trench development. Highly contrasting trench deformation and sedimentary accretion between two parallel seismic sections support an evident migration of underthrusting or significant longitudinal heterogeneity along the trench. The swift transition from underthrusting to non-thrusting can be explained by a counter-clockwise rotation of the Caroline Plate. That miniature accretionary wedges develop even before the subduction initiates imply strong compression and uplifting before the underthrusting can kick-start. Rotation of the Caroline Plate have been halted as the Mussau Trench is seismically rather quiet and the Lyra Trough to the east shows relaxational extension.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：