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1.
Studyonthefeatureselectionandclassifica┐tionefectofprecursorydataofgroundtiltZHENG-YUANLI(李正媛),DE-FUCHEN(陈德福),YI-LINWU(吴奕麟)a...  相似文献   

2.
Calculationoftheparametersofgeoresistivi┐tyanisotropyandcasehistoryofearthquakeprecursorsFU-YEQIAN1)(钱复业),YU-LINZHAO1)(赵玉林)a...  相似文献   

3.
(毛桐恩,姚家榴)Therelationshipbetweencrust-mantlestructuralratioandseismicactivity¥Tong-EnMAOandJia-LiuYAO(InstituteofGeophysics,St...  相似文献   

4.
NumericalsimulationofthedetachmentdynamicsinNorthChinaBasinDong-Ning;ZHANG(张东宁)andRong-ShengZENG(曾融生)(InstituteofGeophysics,S...  相似文献   

5.
Microearthquakeanalysisforhydraulicfrac┐turingprocesYING-PINGLI(李应平)DepartmentofEarth,AtmosphericandPlanetarySciences,Masach...  相似文献   

6.
StudyofCurieisothermalsurfaceinSichuanBasinandtheseismicareaonitswesternmar┐ginXIANZHANG(张先),XI-FENGHU(虎喜凤),JING-XIUSHEN(沈京秀...  相似文献   

7.
GlobalshearstrespaterninmainseismicactivebeltsLEIXIAO(肖磊)PEI-SHANCHEN(陈培善)InstituteofGeophysics,StateSeismologicalBureau,Bei...  相似文献   

8.
Experimental study of ultralong wave band for electro-magnetic signals and acoustic emission during rock fracture(曹惠馨)(钱书清)(吕...  相似文献   

9.
Akinematics-upliftmodelfortheHimalayanTibetanregionXian-JieSHEN(沈显杰)andLadislausRYBACH(InstituteofGeology,AcademiaSinica,Beij...  相似文献   

10.
Featuresofisostaticgravityanomalyandseis┐micactivityintheCentralAsianregionSHENG-MINGFANG1)(方盛明)RUIFENG2)(冯锐)CHANG-ZHENGTIAN...  相似文献   

11.
Based on the time series of observational variations of the length of day (LOD) and seismic data in the world, the relations of the decadal fluctuation and seasonal variation in the Earth’s rotation with global seismic activity are studied in this paper. The results suggest that there are overall correlations on temporal scale and regional discrepancy on spatial scale between global seismic activity and the Earth’s variable rotation, especially the seismic activity in the Eurasian seismic zone (not including southeast Asia) and the Lower California-Eastern Alaska seismic zone correlating well with the Earth’s variable rotation. According to the relations mentioned above, the observational data of the Earth’s rotation might provide a referential basis for monitoring global seismic activity.  相似文献   

12.
    
Based on the time series of observational variations of the length of day (LOD) and seismic data in the world, the relations of the decadal fluctuation and seasonal variation in the Earth’s rotation with global seismic activity are studied in this paper. The results suggest that there are overall correlations on temporal scale and regional discrepancy on spatial scale between global seismic activity and the Earth’s variable rotation, especially the seismic activity in the Eurasian seismic zone (not including southeast Asia) and the Lower California-Eastern Alaska seismic zone correlating well with the Earth’s variable rotation. According to the relations mentioned above, the observational data of the Earth’s rotation might provide a referential basis for monitoring global seismic activity. This project is sponsored by the National Key Basic Research Project and the National Natural Science Foundation of China. The English version is improved by Prof. Xin-Ling QIN, Institute of Geophysics, SSB, China.  相似文献   

13.
The effects on the = 2 geoid component and Earth's rotation due to internal mass anomalies are analyzed for a stratified viscoelastic mantle described by a Maxwell rheology. Our approach is appropriate for a simplified modeling of subduction. Sea-level fluctuations induced by long-term rotational instabilities are also considered. The displacement of the Earth's axis of rotation, called true polar wander (TPW) and the induced eustatic sea-level fluctuations, are extremely sensitive to viscosity and density stratification at the 670 km seismic discontinuity. Phase-change models for the transition zone generally allow for huge amount of TPW, except for large viscosity increases; the dominant contribution in Liouville equations comes from a secular term that reflects the viscous behaviour of the mantle. In chemically stratified models, TPW is drastically reduced due to dynamic compensation of the mass anomalies at the upper-lower mantle interface. When the source is embedded in the upper mantle close to the chemical density jump, transient rotational modes are the leading terms in the linear Liouville equations. Long-term rotation instabilities are valuable contributors to the third order cycles in the eustatic sea-level curves. Rates of sea-level fluctuations of the order of 0.05–0.1 mm/yr are induced by displacements of the Earth's axis of rotation compatible with paleomagnetic data.  相似文献   

14.
强震发生前震源系统可能处于不稳定状态,在这种情况下,震中附近地区的地震活动或许会对微小的应力变化敏感.地球自转会在震源断层面上引起应力,地球自转速率变化也会在震源断层面上引起应力变化.由于地球自转速率变化非常微小,在震源断层面上引起应力变化也非常微弱,如果震源区处于极不稳定状态,这种微弱的应力变化或许会激发一些地震活动.这些被激发的地震活动将会表现出与地球自转速率变化的显著相关性.为了考察2011年3月11日日本本州9.1地震发生前震中附近地区是否存在与地球自转速率变化显著相关的地震活动,选取2000年1月-2011年2月M≥5.0地震集中活动区域为研究区域,根据USGS发布的1991年1月-2011年2月的地震目录,利用舒斯特(Schuster)统计检验方法,研究了地球自转与本州M_W9.1地震前发生的地震活动之间的相关性.检验结果用P值来评估,P值越低表示相关性越显著.结果如下:在研究区内5.4≤M≤6.9地震的P值的时间变化显示本州M_W9.1地震前从2009年6月-2010年1月存在低于0.5%的P值.当P值达最低值时,约82%的5.4≤M≤6.9地震发生在地球自转速率季节性变化的加速期,显示出了地震活动与地球自转速率加速之间的显著相关性.取3°×3°的空间窗,以0.1°的步长沿经度和纬度滑动对P值进行空间扫描,可以得到P值的空间分布.扫描区域远大于研究区,经纬度范围为(33°N-43°N,138°E-147°E).在P值的空间分布图上,可发现在P值处于最低值期间,低于0.5%的P值集中分布在研究区的北部,本州M_W9.1地震震中位于这个低P值区的边缘.因此,本州M_W9.1地震前在其破裂区内存在显著的与地球自转相关的地震活动现象,说明破裂区内存在非常不稳定的地区.  相似文献   

15.
地球自转与气候动力学──振荡理论   总被引:5,自引:2,他引:3       下载免费PDF全文
考虑地球自转速率随时间的变化,并应用描写低纬地球流体(大气和海洋)的水平运动方程,分析了地球自转速率变化对低纬大气和海洋振荡的影响.研究指出:地球自转速率的变化不但会直接影响低纬大气和海洋的振荡周期和振幅,而且会影响纬向风和洋流的变化,从而导致海温和海平面的变化.所以,地球自转速率的变化是影响全球气候变化的重要因素之一.关键词##4地球自转速率;;气候变化;;大气和海洋的振荡  相似文献   

16.
制约和影响中国大陆地震活动大形势的动力因素研究   总被引:5,自引:0,他引:5  
从地球动力学角度,研究制约和影响我国大陆地震活动的兴衰起伏的内在原因,揭示我国大陆地震活动期(300年)、幕(20年左右)、段(几年)实际是由于太阳黑子活动、地球自转速率变化、全球强震活动水平在不同阶段迭加和组合的结果。  相似文献   

17.
把磁场观测数据向导电区域延拓,是地球电磁学的经典问题之一.从准静态近似和非零矢势规范的电磁场方程出发,依据矢量的球面分解唯一性定理,本文建立支配三维非均匀电寻率分布全球地慢中的环型场、极型场和电位势场的耦合方程组烤虑地球深部研究对认识全球地幔非均匀性横向变化尺度的限制,提出横向缓变意义下三维非均匀地幔中电场和磁场的摄动理论,其零级近似不要求电导率分布一维球对称.作为零级近似可解的例证,研究了地幔深源极型场的反扩散问题,在利用地面磁场观测反演到核幔边界时,可以考虑地幄横向非均匀性影响.  相似文献   

18.
It is one of the classical problems in Earth′s electromagnetism that continuation of the observatory data of magnetic field into the conducting region. This paper built the coupling vector equations governing the poloidal, toroidal and potential fields in 3-D inhomogeneous conducting mantle. Considering the limitation on variable scale of inhomogeneities in global mantle from study of the Earth′s deep interior, a perturbation theory of gradually lateral variation was presented. It is unnecessary that the 1-D spherical symmetric distribution of electric conductivity as zero-degree approximation. Serving as a example of solvability of the zero-degree approximation, it was demonstrated how the gradually lateral variation of electric conductivity effect on anti-diffusive problem of poloidal field in Earth′s mantel.  相似文献   

19.
天山地震带及乌恰交汇区强震活动特征   总被引:2,自引:0,他引:2  
高国英  王秀达 《内陆地震》1993,7(3):271-278
根据1880~1990年天山和乌恰地区M_s≥5.5级地震资料,分析讨论了研究区内各带强震活动的韵律特征和相关性、强震活动的整体迁移规律及环境因子与强震之间可能存在的某些内在联系。用信息熵和马尔柯夫方法对各地震带资料进行了统计计算。认为:在大区域构造应力场作用下,由于力源和构造环境的差异,造成区内应力场分布不均匀,应力在一定范围内变化、调整和传递,形成了各带地震活动在时间和空间分布上的差异。据此对整个天山地震带和乌恰区近期强震活动趋势作了判断。  相似文献   

20.
在构建现代地球模型时,地球内部分层结构主要是根据地震波资料确定的;而地球内部密度及弹性参数,特别是地幔以下大尺度结构的密度分布,则主要是根据地球自由振荡的弹性简正模观测资料确定的.本文概述了地球自由振荡简正模本征值的求解理论和方法,介绍了球型和环型模态位移场表达式,讨论了地球自由振荡模态的衰减、分裂与耦合效应;总结了多线态分裂谱线探测和分裂参数估计的方法,综述了利用弹性简正模开展地震矩张量、地球三维非均匀性结构和内核超速旋转约束与反演研究的主要进展和存在的问题.最后作为展望,本文还讨论了地球自由振荡简正模的未来研究趋势.  相似文献   

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