南海北部及广东沿海新生代火山活动   总被引：17，自引：0，他引：17  

孙嘉诗 《海洋地质与第四纪地质》1991,11(3):45-66,T006

调查区新生代火山活动十分活跃。岩性以基性为主,少数属超基性Sr~(87/86)初始值最高0.706189,最低0.703178,陆区和海盆新生代火山岩均来自地幔。 K-Ar年龄最老62.86百万年,最新0.43百万年。从老至新可划分为8个活动期,分别为古新世早期、始新世早期、渐新世末期、中新世中期、中新世晚期、早更新世早期、早更新世晚期和中更新世中期。 海盆与陆区火山活动在岩性、同位素特征、活动时期、喷发方式以及岩浆来源等方面都十分相似,二者属统一的新生代火山岩区。  相似文献   

Relationship between biogeochemical features of biogenic elements and flocculation in the Changjiang Estuary   总被引：1，自引：3，他引：1  

Lin Yi''an  Tang Renyou  Li Yan  Dong Henglin  Guan Xuwei  Chen Yinzu 《海洋学报(英文版)》1995,14(2):225-234

ＲｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎｂｉｏｇｅｏｃｈｅｍｉｃａｌｆｅａｔｕｒｅｓｏｆｂｉｏｇｅｎｉｃｅｌｅｍｅｎｔｓａｎｄｆｌｏｃｃｕｌａｔｉｏｎｉｎｔｈｅＣｈａｎｇｊｉａｎｇＥｓｔｕａｒｙ￥ＬｉｎＹｉ＇ａｎ；ＴａｎｇＲｅｎｙｏｕ；ＬｉＹａｎ；Ｄｏ...  相似文献   

渤海南部海域年极值波浪和设计波浪的特征研究   总被引：1，自引：0，他引：1  

滕学春  吴秀杰 《海洋科学进展》1994,(3)

本文用统计计算和后报方法，获得了本海域不同海区多年年极值波高（Ｈ１／１０）资料。用Ｐ－Ⅲ型和短期测波资料频率分析方法，估算了各海区的设计波高，并依据文献［３］计算出对应的平均周期。用Ｋｏｌｍｏｇｏｒｏｆｆ适合度方法检验所得的结果表明，依Ｐ－Ⅲ型方法拟配的理论频率曲线与经验点十分吻合，从而确定了本海域不同海区最佳的设计波浪。分析本海域年极值波浪的基本特征表明，本海域除了渤海湾北部海区以外，主浪向一般为ＮＮＥ向，渤海海峡区的年极值波高和设计波高均为最大，而向莱州湾及渤海湾沿岸海区逐渐减小；在沿岸海区，由龙口至黄河口一带的极值波高较大。  相似文献   

Study on short-range numerical forecasting of ocean current in the East China Sea——Ⅰ Basic problems of ocean current forecasting and structure of the models     

Zhao Jinping  Chen Zhongyong  Shi Maochong 《海洋学报(英文版)》1993,12(3):335-345

Ocean current forecasting is still in explorative stage of study. In the study, we face some problems that have not been met before. The solving of these problems has become fundamental premise for realizing the ocean current forecasting. In the present paper are discussed in depth the physical essence for such basic problems as the predictability of ocean current, the predictable currents, the dynamical basis for studying respectively the tidal current and circulation, the necessity of boundary model, the models on regions with different scales and their link. The foundations and plans to solve the problems are demonstrated. Finally a set of operational numerical forecasting system for ocean current is proposed.  相似文献   

0421号热带风暴"海马"登陆前后环境场对其移向和强度影响的分析     

赵凯  濮梅娟 《台湾海峡》2005,24(3):370-376

0421号热带风暴“海马(Haima)”于2004年9月13日12:00在浙江省温州市沿海登陆,登陆后迅速减弱为热带低压,20:00在浙江境内消失.本研究采用物理量诊断分析法,探讨该热带风暴登陆前后涡度场、湿焓场变化对其移向和强度的影响.结果表明,该热带风暴登陆后,涡度(ξ)明显减弱.涡度局地变化(ξ/t)值分布显示,风暴移动方向的后方,涡度减弱的趋势比前方涡度增大的趋势更剧烈;风暴有向其外围(ξ/t)正值中心(即涡度增幅最大)移动的趋势.该热带风暴登陆前、后,湿焓都增大,但登陆后湿焓增大趋势已大大减弱;风暴有向湿焓局地变化(E/t)正值中心移动的趋势,即向能量增强最大的方向移动.  相似文献   

Simulations of Annual Cycle of Phytoplankton Production and the Utilization of Nitrogen in the Yellow Sea     

Tian?TianEmail author  Hao?Wei  Jian?Su  Changsoo?Chung 《Journal of Oceanography》2005,61(2):343-357

A nutrient dynamic model coupled with a 3D physical model has been developed to study the annual cycle of phytoplankton production in the Yellow Sea. The biological model involves interactions between inorganic nitrogen (nitrate and ammonium), phosphate and phytoplankton biomass. The model successfully reproduces the main features of phytoplankton-nutrient variation and dynamics of production. 1. The well-mixed coastal water is characterized by high primary production, as well as high new production. 2. In summer, the convergence of tidal front is an important hydrodynamic process, which contributes to high biomass at frontal areas. 3. The evolution of phytoplankton blooms and thermocline in the central region demonstrate that mixing is a dominant factor to the production in the Yellow Sea. In this simulation, nitrate- and ammonium-based productions are estimated regionally and temporally. The northern Yellow Sea is one of the highly ranked regions in the Yellow Sea for the capability of fixing carbon and nitrogen. The annual averaged f-ratio of 0.37 indicates that regenerated production prevails over the Yellow Sea. The result also shows that phosphate is the major nutrient, limiting phytoplankton growth throughout the year and it can be an indicator to predict the bloom magnitude. Finally, the relative roles of external nutrient sources have been evaluated, and benthic fluxes might play a significant role in compensating 54.6% of new nitrogen for new production consumption.  相似文献   

Reanalysis of the Atmospheric Flux of Nutrient Elements to the Southern Yellow Sea and the East China Sea     

万小芳吴增茂  常志清 《海洋通报(英文版)》2003,5(1):45-51

Based on the recent research results on dry and wet deposition of nutrient elements and sulphate,we estimate the atmospheric flux of nutrient elements and sulphate to the southern Yellow Sea and the East China Sea in each season.The results suggest that the concentrations of nutrient elements and sulphate in aerosol and precipitation show an apparent seasonal cycle with the maximum values in winter and the minimum values in summer.Depositions of nitrate and sulphate are dominated by wet deposition,while the deposition for phosphate is mainly dry deposition.Moreover,compared with the riverine inputs,the atmospheric deposition may be the main source of dissolved inorganic nutrients in the southern Yellow Sea and the East China Sea.  相似文献   

Degradation in Cemented Marine Clay Subjected to Cyclic Compressive Loading   总被引：1，自引：0，他引：1  

G. Gerald Moses  S. Narasimha Rao 《Marine Georesources & Geotechnology》2003,21(1):37-62

The influence of cyclic loading on the strength and deformation behavior of cemented marine clay has been studied. This marine clay is of recent Pleistocene origin and deposited in a shallow water marine environment. Open pits were dug in sheeted enclosures and from these pits, undisturbed samples were taken for strength testing. A series of standard triaxial shear tests and stress controlled one-way cyclic load tests were conducted at consolidation stress ranges below and above the preconsolidation pressure. For the stress levels below the preconsolidation pressure, the cyclic loading has brought about the collapse of the cementation bond through an increase in strains, and at higher pressure ranges, the soil behaves like typical soft clay. This experiment studied the rate of development of strain and pore water pressure and shows that rate is a function of number of cycles, applied stress, and stress history. In addition, soil degradation during cyclic loading is studied in terms of Degradation Index. Attempt has been made to predict stain, pore water pressure, and degradation index through an empirical model.  相似文献   

Variation of reactivity of particulate and sedimentary organic matter along the Zhujiang River Estuary   总被引：3，自引：0，他引：3  

Chen Jianfang  Jin Haiyan  Yin Kedong  Li Yan 《海洋学报(英文版)》2003,22(4):557-568

To investigate organic matter source and reactivity in the Zhujiang River (Pearl River)Estuary and its adjacent areas, particulate organic carbon (POC), particulate hydrolysable amino acids (PHAA), and Chl a during two cruises in July 1999 and July 2000 were measured. The highest POC and PHAA concentration was observed in the waters with maximum Chl a. The spectra distribution,relative content (dry weight in milligram per gram), PHAA-C% POC and other indicators such as the ratios of amino acids vs. amino sugars (AA/AS) and glucosamine vs. galactosamine (Glum/Gal) suggested that particulate amino acids in the water column and sediments in the Zhujiang River Estuary were mainly derived from biogenic processes rather than transported from terrestrial erosion. In inner estuary where high turbidity was often observable, organic matter was mainly contributed by re-suspension of bottom sediments with revealed zooplankton, microbial reworked characteristics, which suggest that these organic matters were relatively “old“. In the estuarine brackish region, organic matter in water column is mainly contributed by relatively fresh, easily degradable phytoplankton derived organic matter.During physical - biological processes within the eastuary, organic matter derived from phytoplankton was subjected to alteration by zooplankton grazing and bacterial reworking.  相似文献   

Simulation of green water flow on deck using non-linear dam breaking theory     

O. Yilmaz  A. Incecik  J. C. Han 《Ocean Engineering》2003,30(5):601-610

Experiments carried out with models of floating production, storage and offloading platforms (FPSOs) showed that the flow of water over the deck edge, onto the deck resembled a suddenly released wall of water rather than a breaking wave. Therefore green water flow onto the deck was simulated using dam breaking theory, but the theory’s shallow-water assumptions may be limiting. In this paper a non-linear dam breaking problem is formulated. Equations of motion in the Lagrangian form are used and the solution is sought as an infinite series in time. Comparisons with the shallow water approximation are carried out.  相似文献