1000 resultados para Laizhou Bay


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The stratigraphic architecture, structure and Cenozoic tectonic evolution of the Tan-Lu fault zone in Laizhou Bay, eastern China, are analyzed based on interpretations of 31 new 2D seismic lines across Laizhou Bay. Cenozoic strata in the study area are divided into two layers separated by a prominent and widespread unconformity. The upper sedimentary layer is made up of Neogene and Quaternary fluvial and marine sediments, while the lower layer consists of Paleogene lacustrine and fluvial facies. In terms of tectonics, the sediments beneath the unconformity can be divided into four main structural units: the west depression, central uplift, east depression and Ludong uplift. The two branches of the middle Tan-Lu fault zone differ in their geometry and offset: the east branch fault is a steeply dipping S-shaped strike-slip fault that cuts acoustic basement at depths greater than 8 km, whereas the west branch fault is a relatively shallow normal fault. The Tan-Lu fault zone is the key fault in the study area, having controlled its Cenozoic evolution. Based on balanced cross-sections constructed along transverse seismic line 99.8 and longitudinal seismic line 699.0, the Cenozoic evolution of the middle Tan-Lu fault zone is divided into three stages: Paleocene-Eocene transtension, Oligocene-Early Miocene transpression and Middle Miocene to present-day stable subsidence. The reasons for the contrasting tectonic features of the two branch faults and the timing of the change from transtension to transpression are discussed. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The abundance and biomass of ciliated protozoa and copepod nauplii were investigated at 21 grid stations and two anchored stations in the Laizhou Bay, Bohai Sea, China in June 1998. Dilution incubations were carried out to investigate micro-zooplankton grazing pressure at the anchored stations during spring tide and neap tide. The dominant species were Tintinnopsis amoyensis, T. chinglanensis, T. pallida and aloricate ciliates. A total of 13 species of tintinnids were found. The total abundance of ciliates and nauplii ranged from 30 to 2390 ind l(-1) at grid stations. Tintinnopsis amoyensis was the only ciliate found at the anchored stations and in concentrations which varied from 0 to 6700 ind l(-1). The spatial distribution of ciliates was patchy. Tintinnopsis amoyensis and T. pallida were distributed in the Weihe River mouth and Xiaoqinghe River mouth respectively. The aloricate ciliates, T. chinglanensis and Codonellopsis ostenfeldi dominated offshore in sequence. The water mixing process may affect the spatial pattern of the dominant ciliate species. The abundance and biomass of copepod nauplii were in the range of 0-140 ind l(-1) and 0-7 mu g C l(-1) respectively, with the peak appearing at grid station 15. The total biomass of ciliates and copepod nauplii was in the range of 1(.)5-25 mu g C l(-1). Water column biomass of ciliates and nauplii varied from 2(.)37 to 52(.)3 mg C m(-2). At the anchored stations, the phytoplankton growth rates ranged from undetectable to 0 21 d(-1) and micro-zooplankton grazing rates from 0 13 to 0(.)57 d(-1). The grazing pressure of micro-zooplankton were 12 to 43% of the chlorophyll standing stock and 84 to 267% of the chlorophyll (C) 2000 Academic Press.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

河口和潮汐海湾是受陆海相互作用共同影响的一个复杂动力系统,是陆海相 互作用研究的理想区域。特别是大河影响下的邻近海域,其海岸带发育、动力地 貌、生态环境必将表现出复杂的特征,开展该区域的陆海相互作用研究是非常必 要的。本文采用遥感定量反演手段和泥沙模拟估算方法,结合多年潮汐数据、河 口段水文水质观测数据、近岸区遥感和历史图件等从研究莱州湾西南近岸物质组 成与输运特征,河口沙坝地貌演化及动力机制,河口拦门沙发育演变,水质状况 监测分析等方面探讨黄河影响下的风暴潮、水质污染灾害严重的莱州湾西南近岸 区域的陆海相互作用特征。 结果表明,近岸为典型粉砂淤泥质的莱州湾西南海岸,其泥沙主要来源于近 岸与外海再悬浮供沙、黄河来沙。海区内泥沙运移格局主要为外海泥沙有由河口 口门外向河道运移的趋势、莱州湾西部近岸海区存在一股黄河南向的沿岸泥沙 流,其主要在淄脉沟口以北区域沉积。在正常天气条件下,河口及附近海区泥沙 含量较低,风暴潮期间本海区的悬浮泥沙含量将增加4-5 倍,最高可达10 倍, 其泥沙运移范围主要在河口与近岸海域。 小清河河口属陆海双相缓混合型,其河口堆积地貌主要包括河口沙嘴、沙坝 和河道拦门沙体。径、潮流携带泥沙分别在河口区和口门以内落淤形成拦门沙体 和堆积沙坎。在NE 向波浪和NE-E 向的涨、落潮流作用下,局地再悬浮的泥沙 和沿岸流携带的部分输沙堆积在河口北侧,形成沿落潮流方向延伸的河口沙嘴; 河口段河道南移过程中存在沙嘴、沙坝相互转化的自调整过程,并认为1979-1982 年和1997-2000 年两个时间段为自调整过程的中期。 根据小清河河口沙坝的发育过程及其发育特征,本文提出了该沙坝地貌发育 演变的概念模式。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

本研究建立了沉积物中氯化石蜡(CPs)的分析方法,对莱州湾和该区域主要河流的表层沉积物中多氯萘(PCNs),多溴联苯醚(PBDEs)和CPs进行了分析,获得了他们在研究区域的含量水平、空间分布和单体分布模式,并初步探讨了它们在环境中的来源和迁移规律,估算了这三类污染物在莱州湾表层沉积物中的储量,初步评估了莱州湾沿岸的工业排放与人类活动对海洋生态环境的影响。 莱州湾海洋和河流沉积物PCNs的含量分别为65-470 pg/g dw,52-5100 pg/g dw,平均值分别为260 pg/g dw,1100 pg/g dw。莱州湾沉积物中PCNs的含量较低,与发达国家的背景值相当,主要河流沉积物与其他地区的近海、海湾、湖泊沉积物的含量相当。该区域的PCNs主要以5-Cl和6-Cl为主,为工业来源,主要受化工行业的影响。石化工厂热过程产生的低氯组分可能也是该区域PCNs的一个重要来源。莱州湾的PCNs主要来自水体颗粒的输入,而大气沉降来源的贡献不明显。 河流沉积物ΣPBDEs(不包括BDE-209)的含量分别为0.01- 53 ng/g dw,BDE-209的含量为0.74- 280 ng/g dw,平均值分别为4.4 ng/g dw,51 ng/g dw。在组成上,BDE-209占绝对优势,比低溴代BDEs高1-2个数量级,这是由于我国市场上十溴联苯醚是最主要的溴代阻燃剂。ΣPBDEs与亚洲一些地区含量相当,比北美和欧洲一些地区要低;BDE-209含量含量高出北美和欧洲一些地区,处于较高的水平。河流沉积物中BDE-47与-99,BDE-183与-153、-154具有很好的相关性,而且这几种单体质量分数相当,说明莱州湾区域存在五溴和八溴两种工业BDE阻燃剂来源。海洋沉积物中ΣPBDEs的含量为nd- 0.66 ng/g dw,平均值为0.32 ng/g dw,处于较低水平,BDE-209的含量为0.66- 12 ng/g dw,平均值为5.1 ng/g dw,与欧美一些地区相当,主要来自水体颗粒的输入。 本研究用电子捕获低分辨质谱(ECNI-LRMS)建立了沉积物中CPs的分析方法。该方法基于ECNI质谱对SCCP的响应与其氯含量在一定范围内呈线性关系的特性,建立SCCP的总响应因子与氯含量的工作曲线,从而建立定量方法。重点改进了传统方法中由于SCCP标准品和样品中氯含量不同所造成的响应因子的差别,不再要求标准品的含氯量与样品一致,从而提高了SCCP的分析效率与方法准确性。实验发现,当SCCP的实际氯含量在51%-63%之间时,二者线性关系良好(r2>0.96)。用不同氯含量的标准参考品测试,误差为8%-43%。仪器检测限和方法检测限分别为25-400 μg/L,20 ng/g。类似地,建立了中链氯化石蜡(MCCP)的分析方法,工作曲线的实际氯含量范围为44-57%,仪器检测限40-600 μg/L,方法检测限为6 ng/g。通过对比样品与标准品的峰形特征,严格控制保留时间来辨别SCCP与MCCP,实验证明由于二者叠加导致的误差:SCCP为8%,MCCP为14%,总体来说,用该方法得到的CPs数据是可靠的。本文所使用的净化方法能实现CPs与大部分有机氯化合物的分离。 用该方法对莱州湾的沉积物的CPs进行定量,除了两个河流样品MCCP的计算含氯量低于工作曲线以外,其他样品的SCCP和MCCP的计算氯含量都在工作曲线的范围之内。河流沉积物中SCCP和MCCP的含量分别为1-1200 ng/g dw,1-3300 ng/g dw,MCCP/SCCP均值为1.2;含量分布变化较大,一些河段受到工业排放的影响,CPs浓度高出均值1-2个数量级,MCCP/SCCP值也显著高出平均值。莱州湾区域大部分河流的CPs含量与欧洲、北美和日本一些地区相当,而一些受到点源污染的河段则处于较高的水平。河流中SCCP的质量分布在不同的站位不一样,在受到点源影响的样品中,C13的质量分数明显增大,占优势地位,可能是由MCCP携带的SCCP组分所致。MCCP的质量分布在河流和海洋中没有区别,都是C14占绝对优势。从氯取代的组分来讲,所有样品都是以6-8氯取代为主。海洋沉积物中SCCP和MCCP的含量分别为3-18 ng/g dw,1-13 ng/g dw, MCCP/SCCP均值为0.68,显著低于河流沉积物;SCCP的质量分布较为一致,都是以C10和C11为主。研究发现莱州湾区域SCCP与MCCP来源相似,但迁移规律有的不同。海洋环境中的MCCP可能主要来自水体颗粒的输入,而溶解态输入也是海洋环境中SCCP的重要来源。 对这三类污染物在莱州湾表层沉积物中的储量估算得到PCNs、ΣPBDEs、BDE-209、SCCP和MCCP在莱州湾表层0-10 cm沉积物中的储量分别为0.20t,0.25t,3.95t,6.52t,4.30t。拥有10%的渤海海域面积的莱州湾ΣPBDEs和BDE-209的储量分别占渤海海区总量的18-23%,18-32%,远远超过渤海的平均值。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This paper describes mainly the results of total nitrogen determination (T.N.)in the sediments from Sanggou Bay,Rushan Bay,Taozi Bay and Laizhou Bay,analysed by the author in 1982—1984,and the factors influencing the T.N. and its distributions in the above mentioned four bays.The distribution characteristics of the T.N.in these sediments are also discussed.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Five diagnostic experiments with a 3D baroclinic hydrodynamic and sediment transport model ECOMSED in couple with the third generation wave model SWAN and the Grant-Madsen bottom boundary layer model driven by the monthly sediment load of the Yellow River, were conducted to separately diagnose effects of different hydrodynamic factors on transport of suspended sediment discharged from the Yellow River in the Bohai Sea. Both transport and spatio-temporal distribution of suspended sediment concentration in the Bohai Sea were numerially simulated. It could be concluded that suspended sediment discharged from the Yellow River cannot be delivered in long distance under the condition of tidal current. Almost all of sediments from the Yellow River are deposited outside the delta under the condition of wind-driven current, and only very small of them are transported faraway. On the basis of wind forcing, sediments from the Yellow River are mainly transported north-northwestward, and others which are first delivered to the Laizhou Bay are continuously moved northward. An obvious 3D structure characteristic of sediment transport is produced in the wind-driven and tide-induced residual circulation condition. Transport patterns at all layers are generally consistent with circulation structure, but there is apparent deviation between the depth-averaged sediment flux and the circulation structure. The phase of temporal variation of sediment concentration is consistent with that of the bottom shear stress, both of which are proved to have a ten-day cycle in wave and current condition.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

研究区位于郯庐断裂中段与济阳坳陷的构造结合部,区内走滑构造广泛发育,主要的走滑断裂有7条,分别是郯庐断裂带的东西两支、垦东断层、孤东断层、长堤断层、埕东断层和发育于垦东凸起中部的浅层走滑构造带。走滑构造带与油气富集带有着明显的对应关系。 通过对研究区内二维、三维地震测线和平面构造图的精细解释和分析,分别揭示了各走滑断裂在平面、剖面和三维空间上的构造形态。根据走滑断裂及其伴生构造的平面和剖面上的几何学特征,将研究区内的走滑断裂划分为三种类型:成熟型走滑断裂、隐伏型走滑断裂、不连续型的走滑断裂。 从理论模式研究入手,推导了拉分盆地中盆地的走滑速率与沉降速率之间的关系,证实了走滑速率同盆地的几何形状参数、最大沉降深度和盆地的沉降速率存在着稳定的数值关系。通过对莱州湾地区潍北凹陷基底沉降历史的分析,建立了潍北凹陷沉降速率与郯庐断裂中段走滑速率之间的经验关系式,进而求出郯庐断裂中段新生代右行走滑位移量的大小为40km。 运用2DMove软件,对研究区内四条典型剖面进行构造复原,计算出了各条剖面每个时期的伸展参数,对研究区构造活动强度进行了定量分析,揭示了研究区的构造演化规律。通过运用Ansys软件进行有限元模拟,恢复了晚白垩世晚期-古近纪早期研究区内的构造应力场和应变场,揭示了扭张作用是研究区内走滑断层开始走滑的主要原因。 通过上述分析,结合对究区内近几年勘探开发成功和失败的实例分析,全面探讨了走滑活动对于油气成藏“生”、“储”、“盖”、“圈”、“运”、“保”各因素的影响。

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A three-dimensional (3-D) coupled physical and biological model was used to investigate the physical processes and their influence on the ecosystem dynamics of the Bohai Sea of China. The physical processes include M-2 tide, time - varying wind forcing and river discharge. Wind records from I to 31 May in 1993 were selected to force the model. The biological model is based on a simple, nitrate and phosphate limited, lower trophic food web system. The simulated results showed that variation of residual currents forced by M, tide, river discharge and time-varying wind had great impact on the distribution of phytoplankton biomass in the Laizhou Bay. High phytoplankton biomass appeared in the upwelling region. Numerical experiments based on the barotropic model and baroclinic model with no wind and water discharge were also conducted. Differences in the results by the baroclinic model and the barotropic model were significant: more patches appeared in the baroclinic model comparing with the barotropic model. And in the baroclinic model, the subsurface maximum phytoplankton biomass patches formed in the stratified water.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bayesian Belief Networks (BBNs) are emerging as valuable tools for investigating complex ecological problems. In a BBN, the important variables in a problem are identified and causal relationships are represented graphically. Underpinning this is the probabilistic framework in which variables can take on a finite range of mutually exclusive states. Associated with each variable is a conditional probability table (CPT), showing the probability of a variable attaining each of its possible states conditioned on all possible combinations of it parents. Whilst the variables (nodes) are connected, the CPT attached to each node can be quantified independently. This allows each variable to be populated with the best data available, including expert opinion, simulation results or observed data. It also allows the information to be easily updated as better data become available ----- ----- This paper reports on the process of developing a BBN to better understand the initial rapid growth phase (initiation) of a marine cyanobacterium, Lyngbya majuscula, in Moreton Bay, Queensland. Anecdotal evidence suggests that Lyngbya blooms in this region have increased in severity and extent over the past decade. Lyngbya has been associated with acute dermatitis and a range of other health problems in humans. Blooms have been linked to ecosystem degradation and have also damaged commercial and recreational fisheries. However, the causes of blooms are as yet poorly understood.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Research Background - Young people with negative experiences of mainstream education often display low levels of traditional academic achievement. These young people tend to display considerable cultural and social resources developed through their repeated experiences of adversity. Education research has a duty to provide these young people with opportunities to showcase, assess and translate their social and cultural resources into symbolic forms of capital. This creative work addresses the following research question. How can educators develop disengaged teenager's social and cultural capital through live music performances? Research Contribution - These live music performances afford the young participants opportunities to display their artistic, technical, social and cultural resources through a popular cultural format. In doing so they require education institutions to provide venues that demonstrate the skills these young people acquire through flexible learning environments. The new knowledge derived from this research focuses on the academic and self confidence benefits for disengaged young people using festival performances as authentic learning activities. Research Significance - This research is significant because it aims to maximise the number of tangible outcomes related to a school-based arts project. The young participants gained technical, artistic, social and commercial skills during this project. This performance led to more recording and opportunities to perform at other youth festivals in SE QLD. Individual performances were distributed and downloaded via creative commons licences at the Australian Creative Resource Archive. It also contributed to their certified qualifications and acted as pilot research data for two competitively funded ARC grants (DP0209421 & LP0883643)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Jack's Bay (the architecturalisation of memory) is a key work of the author's exhibition Lightsite, which toured Western Australian galleries from February 2006 to November 2007. It is a five-minute-long exposure photographic image captured inside a purpose-built, room-sized pinhole camera which is demountable and does not have a floor. The work depicts octogenarian Jack Morris, who for forty years held the professional salmon fishing license in the hamlet of Bremer Bay, on the SE coast of Western Australia. The pinhole camera-room is sited within sand dunes new Jack's now demolished beachside camp. Three generations of Jack's descendents stand outside the room - from his daughter to his great grand children. The light from this exterior landscape is 'projected' inside the camera-room and illuminates the interior scene which includes that part of the sand dune upon which the floorless room is erected, along with Jack who is sitting inside. The image evokes the temporality of light. Here, light itself is portrayed as the primary medium through which we both perceive and describe landscape. In this way it is through the agency of light that we construct our connectivity to landscape.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Jack's Bay expands understandings of the role of photographic media in the representation of landscapes. It does so by combining architectural construction with B&W photographic processing techniques. A purpose-built room-sized camera obscura is first constructed over a portion of the landscape to be recorded. Photosensitive paper is applied to the interior wall surfaces and is exposed to the inverted light entering a small aperture. These photographs are subsequently developed within the camera itself and consequently 'suffer' embellishments and aberrations from the makeshift darkroom conditions. In this way the specificity of both the landscape and the event of its recording are registered in the final image. Many images were destroyed in the process. The idea of the work is to help the viewer reflect on the role media plays in our understanding of landscape and to thus question the means by which they themselves record and interpret landscape representations.