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91.
台湾海峡及其西边地区正常地震动态及危险性特征   总被引:1,自引:2,他引:1  
柯龙生  林世敏 《台湾海峡》1994,13(2):190-197
本文从地震的时,空分布特征,区域应力场动态,能量释放方式,b值及震群特征6个方面研究了台湾海峡及其西边地区地震活动的正常动态及异常特征。结果表明,具有前兆意义的变化模式表现为区域地震活动在时间,空间及功能方面的有序性变化,即:(a)地震空间分布由分散转为集中,形成条带或空区;(b)断裂活动由多组转为单一,应力场趋向一致;(display status  相似文献   
92.
台湾海峡西部海域软质海底多毛类的生态   总被引:2,自引:0,他引:2  
吴启泉 《台湾海峡》1993,12(4):324-334
本文根据1984-1985年4航次底栖生物调查资料,首次全面地研究了台湾海峡西部海域多毛类的种类组成,数量分布及其与环境因子的关系。结果表明,该海域多毛类404种,习见种191种,区系属亚热带性质;平均生物量4.33g/m^2,平均栖息密度68个/m^2;有沿岸性和外洋性两种明显不同的生态类型,前者位于沿岸水系常年控制海域,种类多,数量较大,后者位于南部粗粒沉积物分布区,种类较少;多毛类高数量区与  相似文献   
93.
The role of the hydrological regime in the nutrients and zooplankton composition and dynamics has been analysed in five lagoons of La Pletera salt marshes (NE Iberian Peninsula) during a complete hydrological cycle (2002–2003). Two of the lagoons have their origin in the old river mouths while the other three were recently created in the framework of a Life Restoration project. This fact has also allowed us to study the effect of the lagoon age on nutrient and zooplankton composition and dynamics. The salt marsh hydrology is determined by a prolonged period of confinement without water inputs, irregularly interrupted by sudden water inputs due to flooding events (sea storms or intense rainfalls). While the dynamics of oxidized nitrogen compounds in the lagoons depends on the water inputs variability within each hydrological cycle, the internal load of phosphorus, total nitrogen and organic matter is related more to the cumulative mechanisms during the confinement periods. Accumulation processes may be easily related to lagoon age, since old lagoons have higher content of nutrients and organic matter, suggesting that these lagoons progressively accumulate nutrients during the successive confinement events. This is the usual case for most Mediterranean salt marshes without an artificially manipulated water regime. The zooplankton community in La Pletera integrates the effects of both the hydrological regime and the lagoon age since the former determines the temporal pattern of the main zooplankton species and the latter explains differences in composition and structure between old and new lagoons.  相似文献   
94.
95.
Abstract.  The major problem in coastal areas of developing countries is disturbance caused by anthropogenic influence. This disturbance can be quantified by analysing the distribution and composition of marine communities using uni- and multivariate techniques and the biotic index. A study of benthic macrofauna was carried out along the São Sebastião Channel, northern coast of São Paulo State, Brazil, in an area with a submarine outfall, a petroleum terminal and a commercial harbour. Sampling was undertaken seasonally, by means of a van Veen grab (0.1 m2) at 15 oceanographic stations, from November 1993 to August 1994. A total of 392 species were identified (129 Polychaeta, 127 Mollusca, 98 Crustacea, 28 Echinodermata and 10 other phyla). The sedimentary pattern recorded for the São Sebastião Channel is very heterogeneous, influenced mainly by strong wind-driven currents, and differs from nearby shelf areas. The study area could be divided into three regions based on sediment texture and fauna: one region dominated by medium and coarse sand with low values of organic carbon; a second area where pelitic fractions were dominant with high values of organic carbon and nitrogen; and a third region characterised by fine and very fine sand, presenting intermediate organic carbon values. No temporal significant variation in abundance and species composition was found, except in autumn. The use of the 'marine Biotic Coefficient' showed the same ecological trend as the faunal abundance and demonstrated that the central continental region of the channel is affected by human activities.  相似文献   
96.
台湾海峡毛颚动物分布的初步研究   总被引:9,自引:0,他引:9  
蒋玫  王云龙  徐兆礼 《台湾海峡》2003,22(2):150-154
本文分析了台湾海峡毛颚动物的种类组成、数量分布特征,并就其与环境因素的关系进行了初步探讨.结果显示与台湾海峡西部、东海等邻近海域相比,本区毛颚动物具种数少,数量小,季节变化幅度较小等特点.它的数量分布状况与闽斯沿岸流、南海西南季风漂流以及黑潮支流在本区运动消长有关。  相似文献   
97.
蔡爱智 《台湾海峡》2002,21(4):496-500,T005,T006
由纯火山岩组成的林进屿位于台湾海峡西部近岸海中,熔岩喷发年代为上新世。这个典型的火山岛自早全新世海进到达这里以后的6-7ka以来,长期处于大风浪冲击的环境而导致海岸纸后退,并在海蚀崖滩上塑造出各种奇形怪状的火山地貌,裸露出一系列小型的古火山喷口群和火山颈。研究林进屿火山岛的地貌成因不仅具有一定的科学意义,尤其将引起国内外地学界特别是海峡两岸学术界的兴趣。  相似文献   
98.
台湾岛及其邻域地层和构造特征   总被引:1,自引:0,他引:1  
台湾碰撞造山带作为世界上最年青的造山带之一,具有其独特的地质环境。它位于菲律宾海板块和亚欧板块的交汇处,东北面为东北-近东西走向的琉球沟-弧-盆系,东侧为西北向运动的菲律宾海板块,向南为近南北走向的吕宋岛弧,并与冲绳海槽和马尼拉海沟的形成演化密切相关,从而造就了众多形态复杂、成因各异的区域地层和构造现象。台湾岛自东向西可划分为海岸山脉带、台东纵谷、中央山脉、西部山麓带和沿海平原带五个构造-沉积单元。以台东纵谷为界,两侧在地形地貌、地层组成、岩石性质、重力、磁力等地质地球物理特征上均表现为明显不同,分别隶属于不同的板块构造单元,西侧属于欧亚板块的中国大陆边缘,东侧的海岸山脉带则是北吕宋火山岛弧的向北延伸。  相似文献   
99.
为了探讨西太平洋暧地区热带波动的天气效应,利用1980年2-9月140°E日本静止卫星纬度时间剖面卫星云图,分析了5d和14d左右周期热带波动云的演变特征,井综合分析了14d周期的云系演变型式与流场的关系,为预报热带中期天气变化规律提供了依据;热带波动中30-60d大气低频振荡的云量变化最显著,北半球夏半年热带波动的天气压主要在10°N-0°,各半年在10°N-10°S,超过这个区域热带云量的港分布型式就有明显的变化。  相似文献   
100.
The characteristics of the Kuroshio axis south of Kyushu, which meanders almost sinusoidally, are clarified in relation to the large meander of the Kuroshio by analyzing water temperature data during 1961–95 and sea level during 1984–95. The shape of the Kuroshio axis south of Kyushu is classified into three categories of small, medium, and large amplitude of meander. The small amplitude category occupies more than a half of the large-meander (LM) period, while the medium amplitude category takes up more than a half of the non-large-meander (NLM) period. Therefore, the amplitude and, in turn, the curvature of the Kuroshio axis is smaller on average during the LM period than the NLM period. The mean Kuroshio axis during the LM period is located farther north at every longitude south of Kyushu than during the NLM period, with a slight difference west of the Tokara Islands and a large difference to the east. A northward shift of the Kuroshio axis in particular east of the Tokara Islands induces small amplitude and curvature of the meandering shape during the LM period. During the NLM period, the meandering shape and position south of Kyushu change little with Kuroshio volume transport. In the LM formation stage, the variation of the Kuroshio axis is small west of the Tokara Islands but large to the east due to a small meander of the Kuroshio. In the LM decay stage, the Kuroshio meanders greatly south of Kyushu and is located stably near the coast southeast of Kyushu. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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