宁南汤家坪地壳形变异常的调查研究     

程式  钱洪  杨永林  朱文庆 《四川地震》2003,(1):12-16

根据宁南汤家坪流动水准、基线测量出现的重大异常，进行了野外实地考察。发现点位是稳定的；A点与B、C点之间是跨断层的；但原始选点报告所提供的断层产状与作者实测的断层产状有一定的偏差。通过对相关资料分析，认为该场地的地壳形变异常是可靠的。并对其形成机理作了初步探讨。  相似文献   

玛尼7.9级地震对昆仑山口西8.1级地震的触发作用及动力背景初探   总被引：6，自引：1，他引：6  

陈兵  江在森  车时  王庆良  朱桂枝  王继英 《中国地震》2003,19(1):1-7

根据库仑静应力变化的概念，对青藏块体中部地区1997年11月8日玛尼7．9级地震及2001年11月14日昆仑山口西8．1级地震的应力触发作用进行了初步研究。不同震源机制解计算结果表明，玛尼地震造成了昆仑地震断层面上10^-3MPa量级的库仑应力增量，该变化仅使得昆仑地震的发生提前了最长10年左右，表明当前地壳应变能水平可能并不很低。对照20世纪初以来全球7级以上强震频度和强度演化特征与地球自转变化的关系，认为地球自转幅度衰减、变化频率升高是近期强震活动的重要控制因素。昆仑山口西8．1级地震的发生，可能是地球自转持续加速阶段后期，青藏块体内部区域应力场逐渐强化，及玛尼地震应力触发的结果。  相似文献   

Introduction of structural aseismic research in China in recent four years     

罗奇峰  石春香  曹炳政  杨树龙  熊华  李仕栋 《地震学报(英文版)》2003,16(6):656-675

Introduction Greeting the coming of the 21st century, Professor HU Yu-xian and other Chinese scholars briefed the trend of earthquake engineering in China and aboard (HU, 1999; HU, ZHOU, 1999). The experiences and lessons learning from the destructive earthquakes in China and abroad in re-cent years, the damage action of the large velocity impulse in ground motion in near field in seis-mic design, numerous earthquake examples show that there are many weaknesses in aspects of earthquake p…  相似文献   

Seismicity anomalies before the great earthquake of M_S=8.1 in the Kunlun Pass and its significance to earthquake prediction     

刘蒲雄  郑大林  车时  潘怀文  刘桂萍  杨立明 《地震学报(英文版)》2003,16(2)

Introduction The MS=8.1 earthquake occurred in west of the Kunlun Pass on November 14, 2001. It is the greatest earthquake occurred in China since the last half of the century and is an important event in recent seismic history of China. Some specialists consider that the earthquake occurred in the area where the earthquake monitoring capability is lowest in Chinese mainland; no striking precursory seismicity was found. The study on the precursory seismicity before the earthquake has not b…  相似文献   

Lithospheric structure and continental geodynamics     

许忠淮  石耀霖 《地震学报(英文版)》2003,16(5):544-560

This paper briefly reviews main progress in the research on lithospheric structure and continental geodynamics made by Chinese geophysicists during last 4 years since 22nd IUGG general assembly in July 1999. The research mainly covers the following fields: investigations on regional lithospheric structure, DSS survey of crust and upper mantle velocity structure, study on present-day inner movement and deformation of Chinese mainland by analyz-ing GPS observations, geodynamics of Qingzang plateau, geophysical survey of the Dabie-Sulu ultra-high pressure metamorphic belt and probing into its formation mechanism, geophysical observations in sedimentary basins and study on their evolution process, and plate dynamics, etc.  相似文献   

Study of Triggering Action Between the Mani （Ms7.9） and the West Kunlun Mountains Pass （ Ms 8.1 ） Great Earthquakes and Their Dynamic Background     

Chen Bing  Jiang Zaisen  Che Shi  WANG Qingliang  Zhu Guizhi  Wang Jiying 《中国地震研究》2003,17(3):199-205

Based on Coulomb static stress variation, the stress trigging action of the Mani ( Ms7.9, Nov.1997) earthquake on the West Kuulun Mountains Pass (MsS.1, Nov. 2001 ) earthquake is researched. Results of different source mechanism resolutions show that a 10_3 MPa Coulomb stress due to the Mani earthquake was added to the fracture fault of the Kunlun earthquake, and this may shift the broken date to about 10 years earlier, and infer that the stress level in the crust is not low. Comparing the relationship between strong earthquake strength and frequency and earth rotation change, it is shown that the strength‘s decrease and the variation period‘ s shortening of earth rotation are important controlling factors on strong earthquake activity. This great event with Ms = 8.1 took place probably due to a gradual strengthening background of regional stress field within the Qinghai-Xizang block in the period of acceleration of change of day‘s length and stress triggering from the Mani earthquake.  相似文献   

Research on Earthquakes in Cities of China     

Shi Zhenliang  Cao Xuefeng  Yan Xiujie 《中国地震研究》2003,17(3):248-255

In this paper, we briefly describe the general destruction caused by historic earthquakes in major cities of China, preliminarily analyze the heaviness and widespread occurrence of earthquakes in cities of China, and suggest that research on scenario earthquakes in cities should be developed as a part urban disaster reduction research.  相似文献   

硒在干酪根中的两种不同赋存状态:TEM证据   总被引：9，自引：0，他引：9  

温汉捷  裘愉卓  刘世荣 《地球化学》2003,32(1):21-28

对拉尔玛Se—Au矿床和渔塘坝硒矿床中干酪根的高分辨透射电镜(TEM)研究表明，两个矿床的Se在干酪根中的赋存状态是截然不同的。前者Se在干酪根中的富集可能主要以有机结合态的形式存在，主要是取代干酪根中的硫；而后者Se在干酪根中的富集主要以超微包体Se的形式吸附在干酪根中。两种不同的赋存状态可能主要取决于干酪根中硫含量的多少以及成矿时氧化还原条件的变化。研究表明，TEM是研究元素在干酪根中赋存状态的有效手段。  相似文献   

GIS空间数据的采集误差及其分析   总被引：2，自引：0，他引：2  

李蕾蕾  岳东杰  石双忠 《现代测绘》2003,26(6):21-23

本文详细阐述了GIS数据采集过程中的误差来源，重点分析了通过地图、遥感和摄影测量等方式采集数据所产生的误差及其特性，分析了其对GIS数据的影响与消减方法。  相似文献   

Petrology, geochemistry and isotopic ages of eclogites from the Dulan UHPM Terrane, the North Qaidam, NW China   总被引：35，自引：0，他引：35  

Shuguang Song  Jingsui Yang  J.G Liou  Cailai Wu  Rendeng Shi  Zhiqin Xu 《Lithos》2003,70(3-4):195-211

The Dulan eclogite–gneiss region is located in the eastern part of the North Qaidam eclogite belt, NW China. Widespread evidence demonstrates that this region is a typical ultrahigh-pressure (UHP) metamorphic terrane. Eclogites occur as lenses or layers in both granitic and pelitic gneisses. Two distinguished sub-belts can be recognized and differ in mineralogy, petrology and geochemistry. The North Dulan Belt (NDB) has tholeiitic protoliths with high TiO₂ and lower Al₂O₃ and MgO contents. REE patterns and trace element contents resemble those of N-type and E-type MORB. In contrast, eclogites in the South Dulan Belt (SDB) are of island arc protoliths with low TiO₂, high Al₂O₃ and show LREE-enriched and HFSE-depleted patterns. Sm–Nd isotope analyses give isochron ages of 458–497 Ma for eclogite-facies metamorphism for the two sub-belts. The ages are similar to those of Yuka and Altun eclogites in the western extension of the North Qaidam-Altun eclogite belt. The Dulan UHP metamorphic terrane, together with several other recently recognized eclogite-bearing terrenes within the North Qaidam-Altun HP-UHP belt, constitute the key to the understanding of the tectonic evolution of the northern Tibetan Plateau. The entire UHP belt extends for more than 1000 km from the Dulan UHP terrane in the southeast to the Altun eclogite–gneiss terrane in the west. This super-belt marks an early Paleozoic continental collision zone between the Qaidam Massif and the Qilian Massif.  相似文献