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1.
地电阻率变化与孕震过程研究   总被引:1,自引:0,他引:1  
王志贤  彭远黔 《地震》1996,16(4):396-402
在分析唐山7.8级地震前后地电阻率异常变化特征的基础上,研究地电阻率异常量△ρ/ρ0与应变的关系,给出了地电阻率异常量△ρs/ρ0对应变ε的转换关系式;分析和研究地电阻率异常发展,演变特征与地震孕震,发生过程的联系及其前兆异常标志。  相似文献   

2.
分析了阳原台地电阻率ρ_s年变化的特征及其原因,研究了该台1989年后ρ_s年变幅增大的诸种可能因素,认为大同6.1级地震前后地震活动增强是引起ρ_s年变幅增大的主要原因。  相似文献   

3.
王志贤  彭远黔 《中国地震》1997,13(2):189-196
通过研究唐山7.8级地震ρs震时突变现象。发现ρs震时突变具有变化幅度显著,空间分布普遍以及与震前ρs异常变化性质的相反的似弹性回跳现象等。研究了与ρs震时突变有关的震前ρs的前兆标志及其特征,用从复杂的ρs异常变化中识别和判定与地震有直接关系的地震前兆,对提高地电方法地震水平具有重要的实际意义和应用前景。  相似文献   

4.
地电阻率异常变化与地震成组活动关系的研究   总被引:3,自引:0,他引:3  
本文给出了部分地电台ρs异常变化与研究区内地震组活动的实例,研究了ρs异常变化总体特征和发展演化过程特征与地震发生的关系,以及单次地震可能预报的前兆标志。对地电预报地震特别是首发地震后的震情判断和预报具有实用意义。  相似文献   

5.
大柏舍地电台映震能力初析   总被引:2,自引:0,他引:2  
分析了大柏舍地电台18年的有效观测资料,研究了ρs异常变化与周围一定范围内发生的Ms≥4.0级地震的对应关系,评价了该台的映震能力,结果表明,在所发生的13次Ms≥4.0级地震中,有10次地震前观测到了明显的ρs异常变化,其中Ms≥4.3级地震,都有ρs前兆反应,5次5级以上地震尤为显著,表明该台具有较强的映震能力。  相似文献   

6.
本文研究了武威地电台周围150km范围内发生的景泰6.2、门源6.4、天祝西4.7、旦马5.6、雅布赖4.7级地震和共和7.0级地震(△=270km)该台地电阻率(ρs)变化,结果显示:对于前4次地震,该台EW道测值出现10^-1-10^-2量级的ρs短临异常,共和和雅布赖地震前后观测到10^-1量级的ρs短期下降异常。作者研究认为,ρs异常可以是该台EW道探测范围内介质不完整,孕震后期震源力学过  相似文献   

7.
安维光  郭宝娥 《山西地震》1994,(2):17-20,26
对阳原台1979年4月至1992年6月的ρ_s月均值,用差值法消除年变以后,突出了正常背景和异常特征。得出消除年变后的ρ_s月差值,反映台站220km内5级以上地震的效果是好的结论。  相似文献   

8.
本文介绍了相干加强的原理及其在地电阻率分析预报地震中的应用研究,计算了大柏舍台和宝坻台ρ_s连续几年的资料,结果发现地震前ρ_s有较为突出的短临异常.  相似文献   

9.
金安忠 《内陆地震》1993,7(2):197-208
讨论了自1976年唐山地震后,在华东地区地电阻观测台网范围内发生6级强震前ρ_s异常的时空分布特征。对观测值ρ_s的异常变化与地震活动性、岩石体积应变以及应力降等的关系作了对比。指出它们之间在空间上存在有一致性,且在时间上有同步性。研究结果表明:中强地震前,ρ_s的异常变化与地震活动性有关。这说明在某种程度上,ρ_s异常可视为异常信息。ρ_s异常持续时间较短,幅度较小,异常数目也相对较少,空间分布呈散射状,且异常形态的叠加小于唐山大震前的ρ_s异常叠加值。表明使用ρ_s观测方法预测中强地震比预测强震要困难得多,因此目前最根本的是要提高观测台网的监测能力,增大台网的密度,并通过深入研究震源区周围异常特征、改善观测台站条件来完善地震预报研究。  相似文献   

10.
一、引言视电阻率(ρ_s)曲线变化常常是多种多样的,引起异常的原因也是极其复杂的,因而对视电阻率异常很难作出肯定判断。82年4月中旬以来,渡口视电阻率产生了十分有趣的异常变化,引起了省内外地震工作者的密切注意。笔者会同渡口中心站的同志赴现场考查后,提出可能是灌水影响的一种解释。  相似文献   

11.
12.
The determination of the coefficient of viscosity of eruptive products gives useful elements to the knowledge of possible variations of composition and physical conditions of the magmas.  相似文献   

13.
14.
Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long (>1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary.  相似文献   

15.
Geomagnetism and Aeronomy - The magnetic evolution of the active region of the Sun at the level of the photosphere has been studied. Magnetic synoptic maps of the 2007 Kitt Peak Observatory were...  相似文献   

16.
Резюме Дается вывод формул для вычислений длины хорды, длины и азимутов нормаляных сечений и длины геодезической линии эллипсоида. Применяются тригонометрические функции данных величин и постоянные принятого ргфгргнц-эллипсоида, что является целесообразным при использовании вычислителQjных машин, особенно автоматов. Рабочие формулы рекомендуются в форме (8–11).

Dedicated to Professor František Fiala on His 85th Birthday

Address: Veveři 95, Brno.  相似文献   

17.
Summary The author mentions the aims of the World-wide gravity project he established in the Ohio State University in Columbus, in 1950. He outlines the practical procedure of the gravimetric computations of the undulationsN and the vertical deflection components and and emphasizes that only by the global international cooperation and additional gravity observations at sea carried out during the last decade it has been possible to gather to Columbus the needed gravity material. Since there exist still large gravimetrically unsurveyed areas it is of vital significance to study what gravity anomalies are best to be used for these regions. The given figures concerning the accuracy of theN, and , estimated theoretically and obtained in practice, indicate that in the gravimetrically well surveyed parts of the world like in Europe and the United States we can get gravimetrically on basis of existing gravity material theN-values with accuracy of about 5–10 meters, and and with the accuracy of about 1. The geoid undulationsN are already computed in Columbus for more than 6000 points of the northern hemisphere. The sample maps show the interesting geoid of Europe and vicinity between the latitudes 60° and 30° and longitude 5° W and 30° E, drafted on basis of more than 1000N-values computed at the corners of 1°×1° squares. It is interesting to realize that the geoid undulations in all this area are positive, the extreme values being between 40 and 50 meters. The geophysical significance of the geoid maps of this kind is pointed out.  相似文献   

18.
Summary A simple model is proposed suitable for studying the effect of the ground layer of the atmosphere, polluted by aerosol, on the albedo. This model is founded on solving the equation of transfer of radiative energy. The numerical results are discussed, particular attention being paid to the analysis of errors due to neglecting the multiple reflection of solar radiation on the aerosol particles. A method which would also include the multiple reflection is proposed, and the conditions under which the presence of the aerosol is responsible for an increase or decrease of the solar radiation balance on the Earth's surface, are analysed.  相似文献   

19.
Summary The results of two different methods of the determination of the non-linearity of the gravimeter scale are compared; the economy is discussed as well.  相似文献   

20.
Summary The maintenance of the axisymmetric component of the flow in the atmosphere is investigated by means of a steady-state, quasi-geostrophic formulation of the meteorological equations. It is shown that the meridional variations in the time-averaged axisymmetric variables can be expressed as the sum of three contributions, one being due to the eddy heat transport, another to the eddy momentum transport, and a third to the convective-radiative equilibrium temperature which enters the problem through the specification of a Newtonian form of diabatic heating. The contributions by the large scale eddies are evaluated through the use of observed values for the eddy heat and momentum transports.The contributions from each of the three forcing mechanisms to the temperature and zonal wind fields are invstigated individually and found to be of about equal importance. The sum of the three contributions are also presented for the temperature, the zonal wind, the stream function associated with the mean meridional circulation and the corresponding vertical motion. Although the results fail to reproduce the main observed features of the lower stratosphere, they are found to be in good agreement with observations in the middle latitude troposphere. At any pressure level, for example, the computed mean zonal wind has a jet-like profile and the axis of the jet is found to slope to the south with height, as observed in the atmosphere.Based in part on a thesis submitted by the first author as partial fulfillment of the requirements for the Ph.D. degree at the University of Michigan. — Publication No. 194 from the Department of Meteorology and Oceanography, The University of Michigan.  相似文献   

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