Organic carbon and nitrogen isotopes in surface sediments from the western Arctic Ocean and their implications for sedimentary environments   总被引：2，自引：1，他引：1  

CHEN Zhihu  SHI Xuef  CAI Deling  HAN Yibing  YANG Zuosheng 《海洋学报(英文版)》2006,25(5):39-54

1 IntroductionFor several reasons, the Arctic Ocean and itsmarginal seas are key areas for understanding ocean-ic circulation and global climate system ( Clark,1982; Hansen et al., 1983; Walsh et al., 1996;Overpeck et al., 1997). First, the Arctic Ocean i…  相似文献   

Tide‐modulated hyperpycnal flows off the Huanghe (Yellow River) mouth,China     

Houjie Wang  Naishuang Bi  Yan Wang  Yoshiki Saito  Zuosheng Yang 《地球表面变化过程与地形》2010,35(11):1315-1329

Few hyperpycnal flows have ever been observed in marine environments although they are believed to play a critical role in sediment dispersal within estuarine and deltaic depositional systems. The paper describes hyperpycnal flows observed in situ off the Huanghe (Yellow River) mouth, their relationship to tidal cycles, and the mechanisms that drive them. Simultaneous observations at six mooring stations during a cruise off the Huanghe mouth in the flood season of 1995 suggest that hyperpycnal flows observed at the river mouth are initiated by high concentrations of sediment input from river and modulated by tides. Hyperpycnal flows started near the end of ebb tides, when near‐bottom suspended sediment concentration (SSC) increased rapidly and salinity decreased drastically (an inverse salt wedge). The median grain size of suspended particles within the hyperpycnal layer increased, causing strong stratification of the suspended sediments in the water column. Towards the end of flood tides, the hyperpycnal flow attenuated due to frictions at the upper and lower boundaries of the flow and tidal mixing, which collapsed the stratification of the water column. Both sediment concentration and median grain size of suspended particles within the bottom layer significantly decreased. The coarser sediment particles were deposited and the hyperpycnal flows stopped. The intra‐tidal behaviors of hyperpycnal flows are closely associated with the variations of SSC, salinity, and stratification of the water column. As nearly 90% of riverine sediment is delivered to the sea during the flood seasons when hyperpycnal flows are active, hyperpycnal flows at the Huanghe mouth and the river's high sediment loads have caused rapid accretion of the Huanghe delta. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

NUMERICAL MODELING OF THE SEABED MORPHOLOGY OF THE SUBAQUEOUS YELLOW RIVER DELTA     

WANG Hou-jie  YANG Zuo-sheng  LI Rui-jie  ZHANG Jun  and CHANG Rui-fang Estuarine & Coastal Studies  Ocean University of Qingdao  Qingdao  China Traffic  Ocean Engineering College  Hohai University  Nanjing  China corresponding 《国际泥沙研究》2001,16(4)

1 wrsoorCnoxThe Yenow mver delta is ereated by the river transponing sediment bom the Loess Plateau to the shallOWBOhai Gulf during the paSt l45 years. lh recent years, the water discharge and sediment load enedg thesea have bein ched dramacaily The river end chann shital northeastWed hom QingshulgOuN to qngshulgou-Chah chaDnel in 1996, resulting in a new regfor of sedimenboon and erosion ofthe subaqucous delta.,A nUInerial model for river sediInen dispersion and seabed mOrPhofogy of t…  相似文献   

GRAIN SIZE DISTRIBUTION OF SEDIMENT IN THE NORTHERN EAST CHINA SEA AND THE RELATIONSHIP WITH THE SEA CURRENTS     

LEI Kun    YANG Zuosheng  GUO Zhigang Doctoral student  College of marine geosciences  Ocean University of Qingdao    Qingdao  China Assistant prof.  the Chinese Research Acad 《国际泥沙研究》2002,17(2)

1 INTRODUCTION The East China Sea, one of the largest continental marginal seas in the world, receives large amount of suspended sediment from the land annually (Milliman and Meade, 1983; Shen, 1999). Since late Pleistocene, the deposition of the suspended sediment over the relict sandy sediment induces the complicated distribution of surface sediment (Fig. 1). Many studies have been done on the surface sediment distribution, sedimentation rate, concentration and dispersion of suspen…  相似文献   

A preliminary comparative study of the productivity of three economic seaweeds   总被引：1，自引：0，他引：1  

Wu Chaoyuan  Wen Zongcun  Peng Zuosheng  Zhang Jingpu 《中国海洋湖沼学报》1984,2(1):97-101

The rates of photosynthesis and respiration ofPorphyra, Laminaria andUndaria were determined with an oxygenmeter at different temperatures in an enclosed continuous-flow system. The temperature coefficients of respiration and the net primary productivities for the three species were calculated. The spectacular rates of primary production were found to be as high as 270 g C m⁻² forP. yezoensis, 2200 g C m⁻² forL. japonica and 160 g C m⁻² forU. pinnatifida annually. The low respiratory rates of these three species as well as low light compensation points especially at low temperatures are considered as a reason to save heat energy, resulting in a high productivity, especially in case ofLaminaria. Contribution No. 945 from the Institute of Oceanology, Academia Sinica. The paper was presented at the International Phycological Society Meeting, 19–22 Aug. 1980, Glasgow, UK.  相似文献   

利用输沙量预测现代黄河三角洲的面积增长   总被引：7，自引：0，他引：7  

孙效功  杨作升 《海洋与湖沼》1995,26(1):76-82

依据１９７６－１９８９年黄河亚三角洲的面积数据及其相应年份的利津站黄河来沙量，利用单输入，单输出的线性系模型对黄河三角洲的面积增长进行动态预测研究。结果表明，这一线性系统模型能较好地反映黄河三角洲的面积增长规律，且优于灰色系统的ＧＭ（１，１）模型。  相似文献   

现代黄河水下三角洲底坡的不稳定性   总被引：8，自引：3，他引：8  

林振宏  杨作升 《海洋地质与第四纪地质》1995,15(3):11-23

高分辨率声学系统在黄河口区记录到水下河道、埋藏沟谷、塌陷坑、陡缘洼地、滑块体、断层和浅层气等特征。水下三角洲可划分为浅水台地平整区、斜坡低隆起区、斜坡浅沟坑区、斜坡深沟坑区和斜坡前缘低角度平坦区五个底坡稳定性不同的微地貌单元。研究表明，水下三角洲的沉积－地貌格局受控于黄河汛期的巨量输沙、河口区的快速沉积和重力再搬运以及波浪和余环流因素。对影响底坡不稳定性的沉积物力学性质、自然地震和风暴潮因素也作了  相似文献   

黄河口泥沙异重流的数值模拟   总被引：2，自引：0，他引：2  

庞重光  杨作升 《中国海洋大学学报(自然科学版)》2001,31(5):762-768

将已被广泛应用的一维泥沙异重流控制方程推广到平面二维情形 ,构成一组四方程模型 ,并对方程中重要参数的取值作了讨论。而后针对黄河口泥沙异重流的发生和演变受潮相控制的特殊性对其进行数值模拟。在泥沙异重流的基本控制方程中加入了潮汐影响项 ,采用 ADI法对黄河口的潮流控制方程与有潮汐影响的泥沙异重流控制方程进行半耦合求解。模拟结果与实测结果基本吻合  相似文献   

长江、黄河河口沉积物中生物标志化合物组成的初步研究   总被引：5，自引：1，他引：5  

毛登  范德江  郭志刚  杨作升 《中国海洋大学学报(自然科学版)》2001,31(5):747-754

该文对长江口、黄河口以及废黄河口现代沉积物中生物标志化合物组成进行分析。结果表明 :长江与黄河沉积物中的生物标志化合物组成有较大的差别 ,长江沉积物中具明显奇偶优势的高碳数正构烷烃以及 C2 9甾烷的相对含量较高 ,Pr/Ph值较大 ,受陆生高等植物的影响明显 ;黄河低碳数正构烷烃和 C2 7甾烷的相对含量较高 ,Pr/Ph值较小 ,受陆生高等植物的影响较弱。甾烷、萜烷的成熟度指数显示长江高于黄河、现代黄河高于废黄河。这些差异主要受流域环境背景和流域内人文过程两大不同因素的影响  相似文献   

Benthic foraminiferal distribution in surface sediments along continental slope of the southern Okinawa Trough: dependance on water masses and food supply     

Xiang Rong  Li Tiegang  Yang Zuosheng  Yan Jun  Cao Qiyuan 《海洋学报(英文版)》2003,22(1):133-143

Benthic foraminiferal analysis of 29 samples in surface sediments from the southern Okinawa Trough is carried out.The results indicate that benthic foraminiferal abundance decreases rapidly with increasing water depth.Percentage frequencies of agglutinated foraminifera further confirm the modern shallow carbonate lysocline in the southern Okinawa Trough.From continental shelf edge to the bottom of Okinawa Trough,benthic foraminiferal fauna in the surface sediments can be divided into 5 assemblages:(1) Continental shelf break assemblage,dominated by Cibicides pseudoungerianus,corresponds to subsurface water mass of the Kuroshio Current;(2) upper continental slope assemblage,dominated by Cassidulina carinata,Globocassidulina subglobosa,corresponds to intermediate water mass of the Kuroshio Current;(3) intermediate continental slope assemblage,dominated by Uvigerina hispida,corresponds to the Okinawa Trough deep water mass above the carbonate lysocline.  相似文献