Interactions between submarine channel systems and deformation in deepwater fold belts: Examples from the Levant Basin, Eastern Mediterranean sea   总被引：1，自引：0，他引：1  

Ian R. Clark  Joseph A. Cartwright 《Marine and Petroleum Geology》2009,26(8):1465-1482

Submarine channel levee systems form important hydrocarbon reservoirs in many deep marine settings and are often deposited within a structurally active setting. This study focuses on recent submarine channels that developed within a deepwater fold and thrust belt setting from the Levant Basin, eastern Mediterranean Sea. Compressional deformation within the study area is driven by the up-dip collapse of the Nile cone above the ductile Messinian Evaporites. Structures such as folds and strike slip faults exert a strong control on channel location and development over time. From this study four end-member submarine channel–structure interactions can be defined: Confinement, diversion, deflection and blocking. Each of these channel–structure interactions results in a distinct submarine channel morphology and pattern of development compared to unconfined channel levee systems. Each interaction can also be used to assess timing relationships between submarine channel development and deformation.  相似文献   

Welcome mats? The role of seagrass meadow structure in controlling post-settlement survival in a keystone sea-urchin species     

Patricia Prado  Javier Romero  Teresa Alcoverro 《Estuarine, Coastal and Shelf Science》2009

Processes acting on the early-life histories of marine organisms can have important consequences for the structuring of benthic communities. In particular, the degree of coupling between larval supply and adult abundances can wield considerable influence on the strength of trophic interactions in the ecosystem. These processes have been relatively well described in rocky systems and soft-sediment communities, and it is clear that they are governed by very different bottlenecks. Seagrass meadows make interesting study systems because they bear structural affinities to both soft sediments as well as rocky substrates. We examined the early-life history of Paracentrotus lividus, one of the dominant herbivores in Mediterranean seagrass meadows, to identify the drivers of population dynamics in this species. We measured spatial and temporal variability in sea urchin post-settlement in 10 Posidonia oceanica meadows in the North-Western Mediterranean over a period of two years, and compared the numbers with the one-year old cohort a year later (i.e. the new population recruitment) as well as between successive size–age groups. Urchin post-settlers differed substantially between meadows but were present in both years in all meadows surveyed, suggesting that larval supply was not limiting for any of the studied sites. However, in six of the studied meadows, the one-year cohort of urchins was absent in both years, indicating that post-settlement processes strongly affected urchins in these meadows. In contrast, in four of the studied meadows, there was a strong coupling between post-settlers and one-year cohort individuals. These meadows were structurally different from the others in that they were characterised by an exposed matrix of rhizomes forming a dense seagrass mat. This mat apparently strongly mediates post-settlement mortality, and its presence or absence dictates the successful establishment of urchin populations in seagrass meadows. As the population aged, the relationship between size–age groups decreased evidencing the action of other processes. Yet, these results indicate that differences in physical structure are a vital bottleneck for sea urchin populations in seagrass meadows. Exploring the interaction between ecosystem structure and early-life history may provide a broader and more unified framework to understand the dynamics of a range of benthic habitats, including rocky substrates, soft sediments and seagrass meadows.  相似文献   

Tapered Suction Caissons： A Numerical Investigation into Their Pull-out Performance   总被引：1，自引：0，他引：1  

M. Zeinoddini  J. Keyvani  M. Nabipour 《中国海洋工程》2009,23(4):695-707

  相似文献   

Model Test Study on Ice-Induced Vibrations of Compliant Multi-Cone Structures     

黄焱  史庆增  宋安 《中国海洋工程》2009,23(2):317-328

For the study on the ice-induced vibration of a compliant mono-cone structure,a series of model tests were performed from 2004 to 2006.In these tests,the ice sheet before the compliant conical structure was found to be failed in two-time breaking.Based on this important finding,model tests study of the ice force on a compliant multi-cone structure were performed from 2006 to 2007.in these tests,the ice sheet broke before each single cone non-simultaneously.The exciting energy of the total ice force was found to be in a wide range of frequencies,and the structure can be easily excited with nonlinear resonance.  相似文献   

Distribution and spatial variation of hydrothermal faunal assemblages at Lucky Strike (Mid-Atlantic Ridge) revealed by high-resolution video image analysis     

Daphne Cuvelier  Joze Sarrazin  Ana Colao  Jon Copley  Daniel Desbruyres  Adrian G. Glover  Paul Tyler  Ricardo Serro Santos 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(11):2026-2040

Whilst the fauna inhabiting hydrothermal vent structures in the Atlantic Ocean is reasonably well known, less is understood about the spatial distributions of the fauna in relation to abiotic and biotic factors. In this study, a major active hydrothermal edifice (Eiffel Tower, at 1690 m depth) on the Lucky Strike vent field (Mid-Atlantic Ridge (MAR)) was investigated. Video transects were carried out by ROV Victor 6000 and complete image coverage was acquired. Four distinct assemblages, ranging from dense larger-sized Bathymodiolus mussel beds to smaller-sized mussel clumps and alvinocaridid shrimps, and two types of substrata were defined based on high definition photographs and video imagery. To evaluate spatial variation, faunal distribution was mapped in three dimensions. A high degree of patchiness characterizes this 11 m high sulfide structure. The differences observed in assemblage and substratum distribution were related to habitat characteristics (fluid exits, depth and structure orientation). Gradients in community structure were observed, which coincided with an increasing distance from the fluid exits. A biological zonation model for the Eiffel Tower edifice was created in which faunal composition and distribution can be visually explained by the presence/absence of fluid exits.  相似文献   

海洋红藻多管藻内生真菌EN-22 的化学成分研究   总被引：4，自引：0，他引：4  

赵婷婷  李晓明  李景梅  李可  崔传明  李春顺  王斌贵 《海洋科学》2009,33(7):81-86

对采自广西涠州岛近海多管藻(Poiysiphonia urceolata)分离到的一株内生真菌EN-22的次生代谢产物的化学成分进行了研究.利用正相硅胶柱层析、葡聚糖凝胶Sephadex LH-20柱层析、制备薄层层析(PTLC)以及重结晶等分离手段从该菌发酵液中分离得到15个化合物,通过一维、二维核磁共振技术、质谱技术等鉴定了所有化合物的结构,分别为:4-(4-喹啉)-4-羟基-2-丁酮(1),3-羟基-3-(2-氧丙基)吲哚-2-酮(2),3-吲哚乙醇(3),3-吲哚甲酸(4),2-羟基-3-吲哚丙酸(5),2-酮-3-吲哚乙醇(6),3,3-二吲哚-2-羟基-丙醇(7),β-咔啉(8),尿嘧啶(9),环-(S-脯氨酸-S-异亮氨酸)(10),(22E,24R)-3β,5α,9α-三羟基麦角甾-7,22-二烯-6-酮(11),(22E,24R)-5α,6α-环氧麦角甾-8,22-二烯-3β,7α-二醇(12),5α,6α-环氧-24(R)-甲基胆甾-7,22-二烯-3β-醇(13),胡萝卜苷(14),过氧化麦角甾醇(15);其中化合物1和2为新天然产物,并首次报道化合物1的碳谱数据.  相似文献   

渤海鱼类复殖吸虫群落结构     

李庆奎  邱兆祉 《海洋通报》2009,28(1)

根据 1983-1986 年渤海鱼类复殖吸虫调查的结果,对其群落结构进行研究.共发现复殖吸虫 14 科 48 属 84 种.多元分析结果表明:渤海复殖吸虫可以分为内海和外海两个群落:内海的黄姑鱼多睾吸虫(Pleorchis nibeae)-天津褶膜吸虫(Ectenurus tiagjinensis)-多变颈源吸虫(Derogenes varicus)群落(简称PED);外海的球形孔肠吸虫(Opecoelus sphaericus)-褐菖鲉孔肠吸虫(Opecoelus sebastisci)-马面魨拟孟氏吸虫(Paramanteriella cantherini)群落(简称OOP).PED 的种类组成、数量和多样性均高于 OOP,但优势种类和优势度却相对较低.群落结构差异与渤海地理环境、宿主组成、水环境等多因子相关.  相似文献   

桩板组合结构的技术特点及应用     

鞠美丽  廖绍华  傅相明 《海岸工程》2009,28(1):51-55

介绍了桩板组合结构的组成和特点,及其在实际工程中的应用。该结构可作为滩海地区进海路路堤、人工岛护壁、保滩促淤丁坝和离岸堤主体结构。  相似文献   

一种地震数据多串口采集方法   总被引：1，自引：0，他引：1  

丁炜  廖成旺  邓涛  王浩 《大地测量与地球动力学》2009,29(Z1):110-113

地震监测系统常常使用串口异步通讯监测数据、传输命令,但由于核心器件所带的串口数量不足,通常需要扩展串口。提出以TL16C754B为核心器件的多串口数据采集方法,包括具体的系统电路的设计方法和部分驱动的编程源代码。由于该设计具有成本低、稳定性高、低耗、抗干扰能力强、电路简单等优点,已被成功地运用于微动台阵观测仪器中。  相似文献   

吉南老岭地区控矿构造特征分析   总被引：1，自引：0，他引：1  

于城  松权衡  李卫东  黄斌 《吉林地质》2007,26(3):1-5

吉南老岭地区矿产资源丰富,大中型矿床众多,是吉林省的主要成矿区带。本文主要研究大地构造背景和地壳的演化规律及本地区韧性断裂、脆性断裂、韧脆性断裂及变质变形作用等构造类型的特征,进而阐明这些构造对矿产的控制作用。  相似文献