Potential Seismic Risk in Taiwan Strait Region

GPS observation indicates that the Fujian coastal region of China mainland, the region of Taiwan Strait and northern Taiwan island all show a generally homogenous horizontal motion with weak deformation. Historical earthquake record over more than 800 years and modern instrumental data reveal that there is potential seismic risk in and around Taiwan Strait region. After the National Seismic Zoning Map of China (2001) the expected seismic risk in northern part of the Taiwan Strait is lower than that in middle and southern part. The suggested northern route of the Taiwan Strait passage project seems to be relatively save seismically.     

台湾海峡及其两岸地震和地热特征

本文主要论述了台湾海峡及其两岸地震和地热的各自特征以及它们之间的关系。该地区的4个北东向地震带刻划了各个块体的相互关系。台东地震带的震源机制解表明台湾纵谷具有复杂的过渡性构造。台湾西部和台湾海峡的地震活动也受到菲律宾海板块的控制。福建沿海的地震活动与巴士断层活动有关。在自东向西各地震带的活动能量急剧下降的同时,相应的地热流异常值有一个上升趋势,海峡西岸的地热异常高值多分布在NE与NW向断裂的交汇点上。     

Phytoneuston in the southern Taiwan Strait

In June and November 1988 samples were collected by the improved Manta neuston net at 18 stations in the southern Taiwan Strait.One hundred and two species and variations of phytoneuston are identified.Total individuals of phytoneuston in June are more than those in November.The horiwntal distribution of phytoneuston is that the dense area occurs in the southern Taiwan Bank in June, while it appears in the western Taiwan Bank in November.The diet variations of phytoneuston are very obvious.The.abundance of phytoneuston occurs in the afternoon (16:00),and the minimum at midnight which is opposite to zooneuston.The relationships between phytoneuston and environment, and between phytoneuston and zooneuston are also discussed.     

Preliminary Analysis of Seismic Risk in Taiwan Strait and Study on Feasibility of Construction of Tunnel Across the Strait

The collision between Eurasian and Pacific plates along the eastern margin of the Asian continent resulted in formation of a series of island-arcs, one of which is the Taiwan Island-arc, and the Taiwan Straits is a foreland basin in the continent-arc collision zone. The Quaternary fine-grained sediments occur evenly in the upper part of the basin, and the Pliocene deposits in the lower part. The stepped faults run in the deposits, indicating that the tectonic movement tended to weaken after the Pliocene. Strong seismic zones of Taiwan Island released large amount of plate overthrust-collision compressive stress and have their screen and prevention roles for the straits. Only the intersections between offshore NW-trending transform-like faults and seashore NE-trending faults on the southern and northern terminations of the Island are prone to strong earthquakes. The possibility of occurrence of M?≥?6 earthquake should be very low in the area for the planned future tunnel. Moreover, the seismic intensity is rapidly attenuated from the surface downward. Thus, the seismic intensity for the tunnel under the seabed will be much lower. In seismotectonic view, the construction of tunnel is feasible.     

Preliminary Analysis of Seismic Risk in Taiwan Strait and Study on Feasibility of Construction of Tunnel Across the Strait

The collision between Eurasian and Pacific plates along the eastern margin of the Asian continent resulted in formation of a series of island-arcs, one of which is the Taiwan Island-arc, and the Taiwan Straits is a foreland basin in the continent-arc collision zone. The Quaternary fine-grained sediments occur evenly in the upper part of the basin, and the Pliocene deposits in the lower part. The stepped faults run in the deposits, indicating that the tectonic movement tended to weaken after the Pliocene. Strong seismic zones of Taiwan Island released large amount of plate overthrust-collision compressive stress and have their screen and prevention roles for the straits. Only the intersections between offshore NW-trending transform-like faults and seashore NE-trending faults on the southern and northern terminations of the Island are prone to strong earthquakes. The possibility of occurrence of M ≥ 6 earthquake should be very low in the area for the planned future tunnel. Moreover, the seismic intensity is rapidly attenuated from the surface downward. Thus, the seismic intensity for the tunnel under the seabed will be much lower. In seismotectonic view, the construction of tunnel is feasible.     

台湾海峡强震活动及其动力环境

本文根据１９９４年９月１６日台湾海峡７．３级强震序列的空间活动图象变化特征，结合历史地震资料，比较分析了台湾海峡区域史今地震活动的总体演变过程，表明该区强震发生与周边地区的台湾，日本及菲律宾大地地震，在时间进程，强度变化和地域分布关系上存在关地球物理场变化的影响。     

台湾海峡南部漂浮植物

1988年6和11月,在台湾海峡南部用改进的Manta型漂浮生物网采集漂浮植物,共鉴定漂浮植物102种及变种.漂浮植物具有明显的季节变化,6月总数量高于11月.在平面分布上,6月漂浮植物密集区出现在台湾浅滩南部.11月密集区出现在台湾浅滩西部.漂浮植物数量具有一定的昼夜变化,最高值出现午后4时,最低值在午夜前后,与漂浮动物相反.讨论了漂浮植物与环境的关系,以及漂浮植物与漂浮动物的关系.     

台湾海峡中,北部的蟹类

本文根据我所1983年5月至1984年5月台湾海峡中、北部海洋综合调查资料进行研究,结果表明,本区蟹类已鉴定到种的有112种,其中以梭子蟹科(30种)、玉蟹科(25种)和长脚蟹科(23种)占优势,优势程度较高的种类依次为红色相机蟹、双斑(虫寻)、模糊新短眼蟹和刺足掘沙蟹。全区蟹类平均生物量和栖息密度分别为1.55g/m~2和13个/m~2,其分布以近岸水域高于调查区东侧水域;在季节变化上以秋季最高,冬季最低;细颗粒沉积区蟹类生物量高,粗颗粒沉积区种数较丰富。     

台湾海峡的温度逆跃层

本文利用1940～1986年国内外海洋观测资料约3600站次,分析了116°～121°E,21°30′～26°N区域内海水的温度逆跃层,结果表明本海域秋、冬、春季西岸海区出现温度逆跃层,同渤海相比,本区温度逆跃层的上界深度较深,厚度较大强度也较大,文中对该类温度逆跃层的成因作了初步探讨。     

台湾海峡西岸近40年的气候变化

本文以平潭，东山两海岛气象站的资料为主要依据，用统计学的方法研究了近４０ａ台湾海峡西岸的气候变化（气象要素和灾害天气的变化），并对沿海种植防护林所产生的局部气候效应了分析，与同期福建省的气候变化相比，既有相同的趋势，也有海峡自身的特点。     

台湾海峡地震与地质构造,地壳运动的关系

在我国辽阔的渤海、黄海、东海和南海，只有渤海发生过Ｍｓ≥７级地震。而面积狭小的台湾海峡却发生３次７－８级地震、３４次５－６．９级地震，是我国大陆邻近海域地震活动强度最大、频度最高的地方。     

台湾海峡地质构造特征

台湾海峡及其邻区构造可分为３个一级构造单元，即闵浙中生代隆起区、台湾峡新生代坳陷区和台湾新生代岛弧褶断区。其中台湾海峡新生代坳陷区由海峡的主体和台湾西部兵陵平原区组成，它的东、西边界分别是台湾屈尺－老浓断裂带和粤滨外深断裂带。本文在以往海峡西岸东南海海长东－南澳断裂带研究基础上，对近年来台湾海峡、特别是海峡新生代坳陷区各次一级构造单元的深部地质结构，海底地形地貌、沉积特征、断裂构造、火成岩分布和地     

台湾海峡晚更新世以来的高分辨率地震地层学研究

基于4 530 km高分辨率单道地震数据和钻孔资料,采用高分辨率地震地层学的方法,对台湾海峡晚更新世以来的地层进行了划分,自上而下共识别出R₀、R₁、R₂、R₃、R₄等5个主要反射界面,分别对应海底、3 ka BP前后高海平面、最大海泛面、海侵面和 Ⅰ 型层序界面,并以此划分出4个地层单元:晚全新世浅海-滨海沉积A,中全新世浅海沉积B,早全新世海侵沉积C,晚更新世陆相河流沉积D。在海平面变化的作用下,海峡地区先后发育低水位沉积D（低位体系域）,海侵沉积C （海侵体系域）、高水位沉积B和A（高位体系域）。研究了台湾海峡的典型地震相,提出了关于台中浅滩（云彰隆起）处的楔状沉积体的新观点,认为该楔状体为全新世中期以来形成的三角洲沉积受波浪和潮流作用改造而形成的潮流沙脊,其物质主要来源于台湾。识别出了晚更新世和早全新世古河道沉积,海平面变化和地势高低是其形成时间差异的主要因素。     

Transient,seasonal and interannual variability of the Taiwan Strait current

We have constructed a fine-resolution model with realistic bathymetry to study the spatial and temporal variations of circulation in the Taiwan Strait (TS). The TS model with a resolution of 3～10 km derives its open boundary conditions from a larger-scale model. The QSCAT/NCEP winds and AVHRR SST provide forcing at the sea surface. Because of the high resolution in model grids and forcing, the model achieves a previously unavailable level of agreement with most observations. On biweekly time scales surface-trapped current reversals often lead to Strait transport reversals if the northeasterly wind bursts in winter are sufficiently strong. On seasonal time scales the northward current is the strongest in summer since both summer monsoon and pressure gradient force are northward. The summer northward current appears to be relatively unimpeded by the Changyun Rise (CYR) and bifurcates slightly near the surface. With the arrival of the northeast monsoon in fall, downwind movement of China Coastal Water (CCW) is blocked by the northward current near 25.5°N and 120°E. In winter, the northward current weakens even more as the northeasterly monsoon strengthens. The CCW moves downwind along the western boundary; the CYR blocks part of the CCW and forces a U-shaped flow pattern in the northern Strait. Past studies have failed to reveal an anticyclonic eddy that develops on the northern flank of CYR in winter. On interannual time scales a weakened northeast monsoon during El Niño reduces advection of the cold CCW from the north and enhances intrusion of warm water from the south, resulting in warming in the TS.     

台湾海峡海雾的气候分析

台湾海峡的雾主要集中于冬、春季、夏季较少,日变化表现为下半夜至上午前明显,中午至我前后出雾的机会较少,雾的持续时间以１－２ｄ为主,语文中还分析了产生雾过程的天气型,得出地面低压槽、温带气旋或静止锋等系统是造成台湾海峡雾的主要大气系统。     

台湾海峡西岸大风的统计分析

本文通过气候特征分析,得出台湾海峡西岸大风的出现主要集中在10月至翌年3月,研究了盛季大风的分布、变化规律及造成大风的环流特征,并通过回归分析,得出在中纬度纬向环流指数偏小,低纬度副高偏弱时大风天数偏多等结论。     

台湾海峡小型底栖生物数量的量分布

海洋小型底栖生物是海洋生态环境中一重要生物类群,在海洋环境中表现出种类繁多、数量大、生命周期短、生产量高等特点,是底栖生物食物链中不可忽视的一环,在生态系统的能量转换中具有重要作用,已在生态研究中把它作为重要的研究对象。     

Preliminary study on nanodiatom in the Taiwan Strait

INTRODUCTIONNanophytoplanktonhasbecomeanewresearchfieldsincethe1980s.Amongthis,nanodiatom(<20pm)isthemajorflora.ItisthefoodforaqUaticanimalsandtheimPOrtantlinkoffoodchain.NanodiatomisanimPOrtantoceanicprimaryproducer(WeberandEI-Sayed,1987;Gao,1990;ChenandQian,1992;Chengetal.,1993).Manyscholarshavedonealotoftaxonomicandecologicalworkonnanodiatom.InChina,monographswerepublishedbyProfessorT.G.Chin(JinDe-clang)(1965,1982and1992),butthoseworksfocusedonmorphologicalandecologicalcharact…     

台湾海峡灯光围网渔船的技术经济分析

本文系根据1980～1989年福建省在台湾海峡生产的48组具有代表性的标本船之技术经济资料,以柯布·道格拉斯生产函数和经济指标评析其生产状况及技术经济效果。结果表明,近年来,福建省灯光围网渔船的宏观技术水平已明显提高;然而因其捕捞努力量大幅度增加,单位捕捞努力量渔获量曲线呈抛物线状,其长期趋势为CPUE=-0.311+0.9032f-0.06397f~2;预测投资在功率范围为147～294kW的灯光圈网渔船在台湾海峡生产可望受益。     

东北季风期台湾海峡的逆温现象

利用2006-2008年3个航次水文资料,结合日本海洋数据中心(JODC)的历史温度数据分析了东北季风期台湾海峡的逆温现象。结果显示,除台湾浅滩及海峡西岸浅水区外,几乎整个台湾海峡皆有逆温现象。逆温幅度和发生频率在海峡西部较高,海峡东部及粤东近海较低。逆温层上界深度春季较秋、冬季深,逆温频发区(发生频率大于60%)随着季节南北向移动,秋季频发区的最南端位于厦门近海,冬季扩展至台湾浅滩北部,春季回退至平潭近海。分析表明,浙闽沿岸水随季节南北向伸缩导致了逆温频发区的同步移动。除了季节变化外,逆温现象在2006年和2007年冬季有显著差异,2006年逆温仅出现在海峡西部近岸海域,2007年扩展至海峡东部且向南伸至粤东近岸,浙闽沿岸水的横向伸缩是造成此差异的主因。