东南沿海地震带（含台湾海峡地区）地震活动期的讨论   总被引：2，自引：1，他引：2  

严尊国  李普丽 《华南地震》1996,16(2):10-15

东南沿海地震带（含台湾海峡地区）地震活动存在一个３４０年左右的主要分期，目前处在１４００年以来的第二活动期。本文充分注意到７０余年的次级分期影响，分析表明，第二活动期可以简单划分为平静和释放两个阶段，释放阶段存在两个应变释放高潮时段自１９８６年进行第二高潮时段，１９９４年９月台湾海峡７．３级地震其主要标志之一，预计这一高潮时段将持续至２０４０年左右，其间可能会有效次Ｍ≥６级地震发生，并且不能排除继  相似文献   

Analytical expressions for Fresnel volumes and interface fresnel zones of seismic body waves. Part 2: Transmitted and converted waves. Head waves     

Michal Kvasnička  Vlastislav Červený 《Studia Geophysica et Geodaetica》1996,40(4):381-397

Summary Fresnel volumes and interface Fresnel zones of transmitted and head waves are studied. The relation derived for transmitted waves may also be used for converted reflected waves. Considerable attention is devoted to the penetration of Fresnel volumes across structural interfaces, particularly for head waves.  相似文献   

中国东南沿海中生代酸性火山岩的锶和钕同位素特征与岩浆成因   总被引：26，自引：1，他引：26  

薛怀民  陶奎元 《地质学报》1996,70(1):35-47

中国东南沿海中生代火山岩叠置在几个不同的基底构造单元之上，不同单元内的火山岩在锶、钕同位素组成上存在着很大的差异。其中隶属于下扬子亚板块的浙西－赣东北区火山岩的＾８７Ｓｒ／＾８６Ｓｒ初始值普遍较低，而＾１４３Ｎｄ／＾１４４Ｎｄ初始值则较高。  相似文献   

ECONOMIC GLOBALIZATION AND ITS IMPACTS ON URBAN SYSTEM IN CHINA     

Xu Xueqiang  Zhang Rong 《地理学报(英文版)》1996,(1)

Tl1eincreaseindomeSticmarkotalonecouldnotachieveeconon1icgrowthti1atChinaexpenencedinthel98os.Chinahasanaverageannualgrowthrateofl4.3perwtinthepenodofl978-l99o,whichisoneofthehighestinAsiaandtheworId.Sucl1highecononticgrowthhasbamachievedthrougheconon1icrefon11sandglobalizationofitseconomy.TheglobaliZationofitseconon1yisanintentionaleffortoftheopa1policyadoPtedinl978.BecauseofthelrlOCationaladvantage,itisnotsuI`Prisingtofindthateconomicgrowthofthecoastalprovincesisfasterthanililandprovince…  相似文献   

IMPACTS OF SEA LEVEL RISE ON MAJOR PROJECTS AND URBANDEVELOPMENT IN CHINA''S COASTAL PLAINS     

yang Guishan  Shi Yafeng 《地理学报(英文版)》1996,(4)

LIntroductionSeaIevelnse(SLR)isacertainresu1tcausedbyclimaticwampandunreasonableanthropogedcaCtivities,itwillbringaboutaseriesofnegaivethesonenvironmentalevoltalonandsocio-econonucdevelopmentincoastalarea.Cboaisavastcowtrywithl8,OOOkmand14,OOOkmofcontinentalandislandcoastlinesrespeCtively.Over3Ohaddleandbigcitiesandneariy2Oimportantharbours,includingTianJin,ShanghaiandGuanghouarelocatedinthecoastalareawhere4lpercentofthenation'spopulahonandoveY5operedofGNP(GrossNationalProduCt)iscon…  相似文献   

Central Chile: An example of quasi-static crustal behavior     

Sergio E.  Barrientos 《Island Arc》1997,6(3):281-287

Abstract Indications of transient crustal displacement associated with the 3 March 1985, M, = 7.8, Central Chile earthquake are evidenced by various observational devices. Almost half a meter of coastal uplift at localities close to the epicentral region was detected by repeated leveling lines. A tide gauge at Valparaiso revealed minor coseismic coastal subsidence (∼ 10 cm) continuously developing after the earthquake. Two limnigraphs, 27 km apart, that were situated at the extremes of Rapel Lake to the south of the leveling line, have recorded continuously the equipotential lake level for more than 10 years, providing a permanent very-long-base tiltmeter. The water level difference at the two limnigraphs as a function of time resembles a ramp function, beginning approximately at the time of the earthquake occurrence and gradually developing over a period of 10 months with a maximum amplitude of 120 mm or 4.4 p radians in tilt. The shape of the time-dependent tilt is mimicked by the sea level signal recorded at Valparaiso, ∼ 100 km away from Rapel Lake, showing a maximum coastal subsidence of 0.6 m. Comparisons of sea level changes produced by the 1971, M, = 7.5, earthquake indicates that they represent rupture in different portions along the seismogenetic region as well as a different rupture mode. Gravity surveys carried out in three different pre- and post-seismic epochs, along the segment of the leveling line which shows major coseismic uplift, indicate that the whole region has subsided, post-seismically, 10 em in 5 years. These observations are interpreted in terms of a variable slip dislocation model. Inversions show that it is the more than 2 m of fault displacement in 10 months of post-seismic movement along the contact between the Nazca and South America plates, which is interpreted to be responsible for the time-dependent elevation changes.  相似文献   

福建滨海牛山岛-兄弟屿断裂活动性与地震   总被引：3，自引：0，他引：3       下载免费PDF全文

陈园田  谢志平 《地震工程学报》1997,19(2):34-40

闽南粤东沿海的泉州—汕头地震带是我国东南沿海地震活动水平最高的地方．该地区经济发达，人口密集，是我国最著名的侨乡．因此，进一步深入研究牛山岛—兄弟屿断裂带及其活动性对该区的地震监测预报、防震减灾和重大工程的地震安全性评价都具有重要意义．研究结果表明，牛山岛—兄弟屿断裂带今后仍有可能发生ＭＳ≥７地震  相似文献   

The water is not empty: cross‐cultural issues in conceptualising sea space     

S.E. Jackson 《The Australian geographer》1995,26(1):87-96

This paper provides an analysis of the neglect and marginalisation of indigenous peoples’ sea rights. It aims to explain how a complex and ecologically appropriate alternative law of the sea has largely escaped research interests and, until recently, has not been recognised by western systems of law and resource and environmental management. It is argued that the dominance of western views and concepts of nature and landscape predicated on western knowledge and values marginalises indigenous concepts of nature and undermines effective indigenous control of social space. Cultural differences between Aboriginal and non‐Aboriginal ways of constructing meaning in the sea provide the vantage point from which to explore the relations between differences in cultural values, property rights, and political and economic control over marine and coastal environments.  相似文献   

SEISMIC ANISOTROPY IN THE LOWER CRUST INDUCED BY THE LATTICE PREFERRED ORIENTATIONS OF MINERALS   总被引：2，自引：0，他引：2       下载免费PDF全文

David Mainpric 《地震地质》1989,11(4):24

To identify the physical properties responsible for the seismic reflections from the deep ductile shear zones, we have undertaken a study on the effect of lattice preferred orientation (LPO) on the seismic velocity anisotropy. LPO has been quantitatively determined by U-stage measurement for plagioclase (An 49), diopside and hornblende from an extensively deformed basic mylonite from Jotun Nappe, Norway. The typical plagioclase fabrics are produced by plastic flow on (010) [001], and  相似文献   

Fabric development in brittle-to-ductile shear zones   总被引：3，自引：0，他引：3  

Carol Simpson 《Pure and Applied Geophysics》1986,124(1-2):269-288

Brittle-to-ductile shear zones from two separate geological settings are shown to have nucleated on zones of predominantly brittle deformation. The shear zones are not simply foliated cataclasites, since they contain abundant evidence of dynamic recrystallization of constituent minerals. A small quartz diorite lens in the Borrego Springs shear zone, southern California, contains centimeter-scale cataclasite zones that exhibit a gradual transition into foliated rock. Alteration of magnesiohornblende to actinolite, feldspar to white mica plus quartz, and biotite to chlorite, produced elongate minerals that define the foliation. During the later stages of deformation, intracrystalline slip and dynamic recrystallization of quartz and feldspar were important deformation mechanisms.The widespread occurrence of mineralized dilatant cracks predated the development of meter-to-decimeter-scale ductile shear zones in the Striped Rock granite, southern Virginia. Again, important deformation mechanisms in the final stages of deformation were intracrystalline slip and dynamic recrystallization of quartz.In both field areas the role of fluids has been important from the onset of brittle deformation. Fluids may have enhanced early fracturing in addition to causing the alteration and hydrolytic weakening of host rock minerals and the introduction of new mineral species. Each of these processes is thought to have contributed to the later localization of crystal plastic deformation in the rocks.  相似文献