共查询到20条相似文献,搜索用时 31 毫秒
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Andreeva O. A. Akhmetov Z. S. Malashchuk V. M. Zhigalkin R. K. 《Geomagnetism and Aeronomy》2018,58(7):916-924
Geomagnetism and Aeronomy - Analysis of images of the full solar disk obtained by ground-based (BST-2, CrAO RAS) and space-based (SDO/AIA, SDO/HMI) instruments and the potential approximation... 相似文献
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Zhou Bengang 《中国地震研究》2005,19(4):430-441
INTRODUCTIONThe method of probabilistic seismic risk analysis was proposed by Cornell in1968(Cornell,1968).After more than30years development,it has become the main method for seismic riskassessment of engineering sites and seismic zonation,and has been u… 相似文献
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Analysisofforeshocksequenceofthe1975HaichengearthquakeofMs7.3Zhao-RongZUO(左兆荣);Jian-PingWU(吴建平)andZhi-LingWU(巫志玲)(Instituteof... 相似文献
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Mathematicalmodellingofnonlinearbehaviourofseismicity杨立明,石特临,郭大庆Li-MingYANG;Te-LinSHIandDa-QingGUO(EarthquakeResearchInstitut... 相似文献
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In the past decade, the most authoritative catalogues of Chinese earthquakes and the most popular with seismologists in China are the following:(1) Gu Gongxu, 1983, Catalogue of Chinese Earthquakes;(2) Min Ziqun, 1988, Concise Catalogue of Chinese Earthquakes;(3) Xie Yusuou, 1989, Catalogue of Chinese Earthquakes (M≥ 4.7) from 1900-1980 with Uniform Magnitudes; and(4) Min Ziqun, 1995, Catalogue of Chinese Historical Strong Earthquakes. Earthquakes that occurred before 1900 are mainly documented in historical records.Since 1950s, more recent earthquakes were documented in two major compilations of historical records finished in 1956 and 1983-1987. Separately this effort resulted in two chronicles: two volumes for the first one and five volumes for the second one. The magnitudes are converted from the maximum intensity. These magnitudes, by convention, are connected with surface wave magnitudes. However, it is clear that they do not have any strict seismological definition.The period of 1900-1962 documen 相似文献
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A method of estimation of occurrence probability of earthquake intensity at a given site from the results of a ten-year scale of earthquake prediction described with a probability of occurrence in a given "prediction cell" is proposed in this paper. 2316 cities and towns in China were analyzed by using this method. The probability of intensity Ⅵ-Ⅸ were given for every city. These results can be used for the earthquake insurance, loss estimation, and planning of disaster protection. 相似文献
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(陈锦标,沈萍,郑治真)Applicationofdigitalimageprocessingtothedeterminationofspatialdistributionofearthquakes¥Jin-BiaoCHEN;PingSHENandZ... 相似文献
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The seismic hazard of research area is evaluated by probabilistic analysis method for three different seismic statistical zone scenarios.The influence of uncertainty in seismic statistical zone delimiting on the evaluation result is discussed too.It can be seen that for those local sites along zone‘s border or within areas with vast change of upper bound magnitude among different scenarios the influence on seismic hazard result should not be neglected. 相似文献
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Although it has been shown that the implementation of the HHT-α method can result in improved error propagation properties in pseudodynamic testing if the equation of motion is used instead of the difference equation to evaluate the next step acceleration, this paper proves that this method might lead to instability when used to solve a nonlinear system. Its unconditional stability is verified only for linear elastic systems, while for nonlinear systems, instability occurs as the step degree of convergence is less than 1. It is worth noting that the step degree of convergence can frequently be less than 1 in pseudodynamic testing, since a convergent solution is achieved only when the step degree of convergence is close to 1 regardless of whether its value is greater or less than 1. Therefore, the application of this scheme to pseudodynamic testing should be prohibited, since the possibility of instability might incorrectly destroy a specimen. Consequently, the implementation of the HHT-α method by using the difference equation to determine the next step acceleration is recommended for use in pseudodynamic testing. 相似文献
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《中国地震研究》1997,(2)
In an extensional basin,the process of hanging wall block rotation above a detachment fault zone is controlled by block geometry,the shape of the main normal faults,and the detachment depth.A formula for calculating the detachment depth of a tilted block is established in geometrical aspect from the tilting angle of the rotational block,dip angle of the main boundary fault,and the sedimentary thickness in the basin.The calculated result shows that the detachment depth of the tilted block,controlled by a rotational planar normal fault in the Linxian basin,on the eastern slope of Taihangshan Mountain,North China,is about 12.5 km,which is consistent with the analytic result of seismic data in the area.The value is similar to the estimated depth of the usual brittle ductile transition in a rift zone.The geometrical model presented in this paper,however,can provide a range of structural patterns of hanging wall and the detachment depth for reference in hydrocarbon exploration and earthquake processes. 相似文献
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ShahidA.Khan M.AliShah M.Qaisar 《地震学报(英文版)》2003,16(4):382-394
Estimation of seismic hazard for the fast developing coastal area of Pakistan is carried out using deterministic and probabilistic approaches. On the basis of seismotectonics and geology, eleven faults are recognized in five seismic provinces as potential hazard sources. Maximum magnitude potential for each of these sources is calculated. Peak ground acceleration (PGA) values at the seven coastal cities due to the maximum credible earthquake on the relevant source are also obtained. Cities of Gwadar and Ormara with acceleration values of 0.21g and 0.25g respec-tively fall in the high seismic risk area. Cities of Turbat and Karachi lie in low seismic risk area with acceleration values of less than 0.1g. The Probabilistic PGA maps with contour interval of 0.05g for 50 and 100 years return period with 90% probability of non-exceedance are also compiled. 相似文献
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段星北 《地震学报(英文版)》1997,10(6):731-741
GeographicaldistributionofhypocentraldepthsofChineseearthquakesXING-BEIDUAN(段星北)InstituteofGeophysical,StateSeismologicalBur... 相似文献
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Application of mechanical and statistical models to the study of seismicity of syn-thetic earthquake
《地震学报(英文版)》1998,(4)
Applicationofmechanicalandstatisticalmodelstothestudyofseismicityofsyn-theticearthquakesandthepredictionofnaturalonesYAO-LINS... 相似文献
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Coda of local earthquakes that occurred during 2006–2007 are used to study the attenuation characteristics of the Garhwal–Kumaun
Himalayas. The coda attenuation characteristics are represented in terms of coda Q or Q
c
. It is observed that Q
c
increases with frequency. Q
c
also varies with increase in lapse time of coda waves. Q
c
increases up to an 85-s average lapse time. This is similar to observations around the world reported by many workers who
have interpreted this as a manifestation of the fact that heterogeneity decreases with depth. However, around a 90-s average
lapse time Q
c
is lower than its values for lower and higher average lapse times. This is interpreted as an indication of possible presence
of a fluid-filled medium or a medium having partial melts at around a 160-km depth. Q
0, i.e., Q
c
at 1 Hz, increases, and frequency parameter n decreases with increasing lapse time, barring around a 90-s lapse time. This
again shows that in general, heterogeneity decreases with increasing depth. The Q
0 and n values for smaller lapse times are similar to those for tectonically active areas. By comparing Q
c
values obtained in this study with those obtained by us using the 1999 Chamoli earthquake aftershocks, it is concluded that
the crust is turbid and the mantle is more transparent. However, whether the variation in Q
c
values between 1999 and 2006–2007 is temporal or not cannot be definitely established from the available data set. 相似文献
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Based on data of earthquake disaster events during 1954~2005 in the Chinese mainland, the classification and gradation of earthquake disasters have been studied by multivariate statistical analysis. Three fundamental structures of earthquake disasters have been found and an FAPE (factor analysis-principal component-equamax rotation) classification model and an HCWS (hierarchical cluster-ward method-seuclid) gradation model have been constructed. Earthquake disasters are divided into eight classes and five grades respectively in the models, which give a reasonable explanation to the phenomenon of earthquake disasters. 相似文献
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Biao Wei Tianhan Yang Lizhong Jiang Xuhui He 《Bulletin of Earthquake Engineering》2018,16(9):3739-3769
The high-speed railway in China has to pass through the site surrounded by several known faults. Different earthquake mechanics of those faults and propagation paths cause different ground motions, including different peak ground accelerations (PGA), durations and characteristic periods, acting on the high-speed railway bridges. However, the previous seismic vulnerability analysis mainly aimed at the influence of PGA instead of characteristic periods on the seismic fragilities of bridge structure rather than track–bridge system. By taking a typical and common continuous bridge recommended in Chinese criterion as example, the effects of the uncertain characteristic periods of ground motions on the seismic responses and fragilities of track–bridge system were analyzed based on a numerical method. The results indicate that the probabilities exceeding any damage state of most components, including the bridge and track parts, increase with the characteristic period of ground motions. The uncertain characteristic periods of ground motions should be fully considered for the seismic design of track–bridge system, especially when the uncertain characteristic periods change around a small value. In the seismic vulnerability analysis, the uncertain of the designed characteristic period of ground motions should be developed by considering the different earthquake mechanics of several known faults surrounding the bridge site and the complex propagation paths of ground motion waves through different soils. Using a constant characteristic period of ground motions only considering the soil profile at the local site of bridge possibly leads to an unsafe result in the current criterion. 相似文献
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