中国东南沿海潮灾与防潮对策研究   总被引：2，自引：0，他引：2  

吴培木 《台湾海峡》1994,13(3):308-315

中国东南沿海是中风暴潮灾害的最严得岸段，本文针对闽，粤，海南三省台风暴潮灾害概况，防潮现状及其存在问题，提出防潮减灾的对策和见解，以祈提醒人们居安思危，防患未然。  相似文献   

Formation of ‘Beach Rock’ at Siesta Key, Florida and its influence on barrier island development     

Darren Spurgeon  Richard A. Davis  Jr.  Eugene A. Shinnu 《Marine Geology》2003,200(1-4):19-29

Seaward-dipping strata of carbonate-cemented shell debris located along the coast of Siesta Key on the Gulf Coast of the Florida peninsula have long been interpreted to be beachrock equivalent in age to the Pleistocene Anastasia Formation (Stage 5e) of the east coast of Florida. Detailed examination of thin sections along with radiometric dating and isotopic analyses demonstrates clearly that this is a Holocene deposit that is not beachrock but was lithified in a meteoric environment. Whole rock dates, dates from shells only, and from cement only demonstrate that these beach deposits were in place by at least 1800 yr BP and might have been there as long ago as 4300 yr BP. This means that some type of barrier island was in place at that time. Previous investigations have depicted Siesta Key as having a maximum age of 3000 yr with these deposits being located about 2 km landward of the beach deposits. This suggests that the beach deposits might have been the site of the original position of Siesta Key. These data also indicate that sea level must have been near its present position at the time that these foreshore beach deposits were deposited; sometime between 1800 and 4300 yr ago. This scenario indicates that sea level along this coastal reach probably reached its present level at least about 2000 yr ago.  相似文献   

Three‐dimensional simulation of tsunami run‐up around conical island     

Byung Ho Choi  Dong Chule Kim  Efim Pelinovsky  Seung Buhm Woo 《Coastal Engineering》2007

At the circular Babi Island in the Flores tsunami (1992) and pear shaped island in the Okushiri event (1993), unexpectedly large tsunami run‐up heights in the lee of conic islands were observed. The flume and basin physical model studies were conducted in the Coastal Hydraulic Laboratory, Engineering Research and Development Center, U.S. Army Corps of Engineers to provide a better understanding of the physical phenomena and verify numerical models used in predicting tsunami wave run‐up on beaches, islands, and vertical walls. Reasonably accurate comparison of run‐up height of solitary waves on a circular island has been obtained between laboratory experimental results and two‐dimensional computation model results. In this study we apply three‐dimensional RANS model to simulate wave run‐up on conical island. In the run‐up computation we obtain that 3D calculations are in very good comparison with laboratory and 2D numerical results. A close examination of the three‐dimensional velocity distribution around conical island to compare with depth‐integrated model is performed. It is shown that the velocity distribution along the vertical coordinate is not uniform: and velocity field is weaker in the bottom layer and higher on the sea surface. The maximum difference (about 40%) appears at the time when solitary wave reached the circular island.  相似文献   

台湾海峡西岸林进屿古火山喷口群的地貌成因     

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   

南极乔治岛某些火山岩的岩石学和地球化学特征     

韩宗珠 《海洋科学》1990,1(4):29-33

  相似文献   

东亚岛弧地形横剖面与板块运动   总被引：2，自引：2，他引：2  

史学建 《海洋地质与第四纪地质》1997,17(4):91-99

通过对东亚岛弧横剖面形态的系统分析，并结合弧前的构造应力的分析，作者认为，东亚岛弧形成于板块东移的构造环境中，横剖面形态存在两种基本类型即内缓外陡型和内陡外缓型，这两种不同的横剖面具有不同的弧前应力，前者表现弧前挤压，后者表现弧前引张，这反映地貌形态与构造应力之间的密切关系。  相似文献   

东海海底地形分区特征和成因研究   总被引：20，自引：0，他引：20  

刘忠臣  陈义兰  丁继胜  张卫红  吴永亭  郭发滨 《海洋科学进展》2003,21(2):160-173

东海一直以其特殊的大地构造地位受到国内外地学界的关注,但作为主要受构造控制的东海海底地形的研究,以往简单趋势性描述居多,专门深入系统的研究尚不多见。不久前完成的高精度、全覆盖多波束海底地形勘测覆盖了东海部分外陆架、大陆坡全部、冲绳海槽和东部岛坡的一部分,取得了海量的测深数据。据此编绘的勘测多波束水深图和结合测区外的传统资料编绘的海底地形图使我们有机会可以重新审视和系统研究东海的海底地形特征。在定量确定了陆架坡折线、陆坡坡脚线和东部槽坡坡脚线的基础上划分出了大陆架、大陆坡、冲绳海槽平原和东部岛坡4大地形区,继之对各区的海底地形特征进行了研究和描述,并在区内选取了有代表性的5条剖面进行了剖析。另外,从地球内营力和外营力两方面分析了影响东海海底地形发育的因素。调查分析表明:整个东海地形分带明显,地形类型多样:大陆架十分宽阔,总体北宽南窄,从大陆向海平缓倾斜,发育了广泛的NW-SE向沙脊群,自大陆向东南呈扇形发散;大陆坡呈NE-SW向条带展布,海底地形陡峻,呈阶梯状下掉,总体北缓南陡,其上峡谷密布,上穿切外陆架,下直达海槽,同时坡麓上海台沟谷伴生发育;冲绳海槽北浅南深,其内在平坦的背景上发育了众多的海山和海丘,其中心又有槽中槽地形;东槽坡地形复杂,发育了  相似文献   

利用双向缓冲区算法综合海图岛屿     

GAO Wang-jun    PENG Ren-can  GUO Li-xin  LIU Guo-hui  CHEN Yi  ZHANG Ming 《测绘学院学报》2008,(5)

阐述了岛屿综合的内容和原则。介绍了双向缓冲区算法的概念并给出了双向缓冲区算法的定义,研究并证明了双向缓冲区算法的特性。分析了利用双向缓冲区算法综合海图岛屿的原理,并通过实验验证利用双向缓冲区算法综合海图岛屿具有较好的效果。  相似文献   

海南岭壳铜(银-金)矿床地质特征及找矿方向   总被引：1，自引：0，他引：1       下载免费PDF全文

周迎春 《地质找矿论丛》2008,23(3):209-212,244

岭壳铜(银-金)矿床赋存于白垩纪岭壳村组流纹质角砾凝灰熔岩和早白垩世花岗闪长岩中.目前已发现11条铜(银-金)矿(化)体,矿体的产出严格受断裂破碎带控制,与成矿关系密切的围岩蚀变呈现出自东(20线)向西的钾化→绢云母化→强高岭石化、绿泥石化蚀变分带,矿化相应呈现从铜(金)向铜(银)的过渡.根据其对称性的蚀变分带,应加强20线以东的地质找矿;根据成矿元素分形和统计研究发现,Au,Ag矿化具有专属性,即在流纹质凝灰熔岩中寻找Cu,Ag矿,而在花岗闪长岩中以寻找Cu,Au矿为主.  相似文献   

西藏冈底斯带石炭纪—二叠纪岛弧造山作用：火山岩及地球化学证据     

王立全  潘桂棠  朱弟成  周长勇  袁四化  张万平 《地质通报》2008,27(9):1509-1534

系统研究了西藏冈底斯带石炭纪—二叠纪火山岩的时空分布、岩相学、元素及Sr、Nd、Pb 同位素地球化学和构造环境、源区性质,并与喜马拉雅带二叠纪火山岩进行了对比研究。冈底斯带石炭纪—二叠纪火山岩近东西向集中分布在冈底斯构造带中北部地带,空间上从东至西火山活动的强度和规模渐次减小,时间上从早至晚火山活动的强度和规模总体由弱到强。冈底斯带石炭纪—二叠纪火山岩形成于活动大陆边缘的岛弧构造环境,从早到晚岛弧造山作用经历了初始岛弧→早期岛弧→成熟岛弧的发展演变过程,火山岩浆来源于富集型地幔部分熔融作用,原始岩浆在形成和演化的过程中有俯冲洋壳及随带的深海沉积物和再循环进人地慢的地壳物质组分的强烈混染,明显不同于受地壳物质组分强烈混染的喜马拉雅带二叠纪陆缘裂陷型火山岩。综合研究冈底斯带及其邻区近年来的最新调查与研究成果,从北向南拟建了石炭纪—二叠纪冈底斯岛弧→雅鲁藏布江弧后裂谷盆地→喜马拉雅陆缘裂陷盆地的弧盆系时空结构演化模式,探讨了冈瓦纳大陆北缘石炭纪—二叠纪活动大陆边缘的岛弧造山作用与青藏高原古特提斯演化的耦合关系及其动力学机制,讨论了冈底斯带松多乡榴辉岩的形成过程。  相似文献