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潜在震源区内部非均匀特征研究 总被引：4，自引：5，他引：4
潜在震源区是未来可能的震中集合体。我国目前采用的地震危险性分析方法中，一般采用面源模型，潜在震源区面积平均约占３×１０３—４×１０３ｋｍ２。假定地震危险性在潜在震源区内的分布是均匀的。已有的研究结果表明，较大面积的地震均匀分布模型对地震危险性的估计过低。本文利用全国地震烈度区划采用的潜在震源区划分模型和地震数据，统计了历史地震震中在潜在震源区内的空间相对分布情况，给出了潜在震源区内强震非均匀分布的定量描述方法和初步研究结果。应用本文研究结果，可以给出更科学、合理的地震危险性分析和地震区划结果。 相似文献
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Based on the models of non-uniform earthquake distribution in the potential source,the seismic zonation of Western Panzhihua and Central and Southern Shanxi Province is studied.The results show that the usual uniform distribution model may underestimate the seismic risk and result in a reduction of the areas of high intensity.The influence of each non-uniform probabilistic distribution method on the result of seismic zoning is discussed. 相似文献
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According to the joint probabilistic distribution model of magnitude and space,the author discusses the relationship between the probabilistic distribution of magnitude in a seismic province and that in an area with potential seismic sources.The results show that if the magnitude probabilistic distribution follows the truncated exponential form in a seismic province,there must be some potential source in which the magnitude probabilistic distribution does not conform to that form.The result is consistent with the concept of "characteristic earthquake" derived from the study of actual records of seismicity and the study of geology.The author suggests that the relationship between the probabilistic distribution of magnitude in a seismic province and that in a seismic potential area must be considered in the study of the analysis of seismicity,seismic zonation and engineering seismology,for the purpose of the evaluation of the probabilistic distribution of magnitude correctly in every area with potential s 相似文献
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Introduction In the probability analysis method of seismic risk considering time-space inhomogeneity of seismic activity and adopted commonly in China (State Seismological Bureau, 1996) (called in-homogeneous distribution model for short), the division of seismic statistical regions, delimitation of potential seismic sources and estimation of seismicity parameters are the main links that affect significantly the estimation of ground motion parameters of a site. HUANG and WU (2005) studied … 相似文献
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针对上海及邻近区域划分的46 个潜在震源区,采用概率地震危险性分析方法计算上海中心地区基岩地震动参数,分析对反应谱不同周期起主要影响的潜在震源区,并研究主要潜在震源区对不同周期反应谱的概率贡献。研究结果表明:对于长周期反应谱,远距离高震级潜在震源区概率贡献随着周期的增加而增大,甚至超过场地所在潜在震源区的概率贡献;在上海地区进行长周期项目地震安全性评价中,应充分考虑150 km以外的高震级潜在震源区的影响;对于上海地区的超高层建筑等长周期建筑物而言,长江口、南黄海等地区的地震影响风险较大,郯城地区的地震影响也不容忽视,应引起重视。 相似文献
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新编制的地震动参数区划图采用了潜在震源区三级划分方案,以体现背景地震活动空间分布的不均匀性,并在地震构造区内归纳出统一的地震构造模型.本文根据西南地区潜在震源区三级划分的成果,分析了龙门山地震统计区内的龙门山和成都地震构造区的基本特征,历史地震活动强度及频度,主要活动构造的构造变形样式,建立了地震构造区的发震构造模型,确定了构造区的本底地震及划分构造源的地震构造标志.同时,提出了确定背景源空间分布函数的简单方法. 相似文献
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It is proposed that some possible macroseismic epicenters can be determined quickly from the relationship that the microseismic epicenters located by instruments bear with faults.Based on these so-called macroseismic epicenters,we can make fast seismic hazard estimation after a shock by use of the empirical distribution model of seismic intensity.In comparison with the method that uses the microseismic epicenters directly,this approach can increase the preccision of fast seismic hazard estimation.Statistical analysis of 133 main earthquakes in China was made.The result shows that the deviation distance between the microseismic epicenter and macroseismic epicenter falls within the range of 35km for 88% earthquakes of the total and within the range of 35to 75km for the remaining ones.Then,we can take the area that has the microseismic epicenter as its center and is 35km in radius as the area for emphatic analysis,and take the area within 75km around the microseismic epicenter as the area for general analysis.The relation between the 66 earthquake cases on the N-S Seismic Belt in China and the spatial distribution characteristics of faults and the results of focal mechanism solution were analyzed in detail.We know from the analysis that the error of instrumental epicenter determination is not the only factor that gives effects to the deviation of the macroseismic epicenter.In addiditon to it,the fault size,fault distribution,fault activity,fault intersection types,earthquake magnitude,etc,are also main affecting factors.By sorting out ,processing and analyzing these affecting factors,the principle and procedures for quickly determining the possible position of the macroseismic epicenter were set up.Taking these as a basis and establishing a nationwide database of faults that contains relevant factors,it is possible to apply this method in practical fast estimation of seismic hazard. 相似文献
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巴塘3次续发性中强地震震源的研究 总被引：1，自引：0，他引：1
本文使用ＣＤＳＮ宽频带数字地震波形记录，通过波谱分析研究了巴塘３次续发性中强地震震源的几何参数和动力参数，并同余震震源空间立体分布图像研究结果进行对比分析。 相似文献
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The first step in any seismic hazard study is the definition of seismogenic sources and the estimation of magnitude-frequency relationships for each source. There is as yet no standard methodology for source modeling and many researchers have worked on this topic. This study is an effort to define linear and area seismic sources for Northern Iran. The linear or fault sources are developed based on tectonic features and characteristic earthquakes while the area sources are developed based on spatial distribution of small to moderate earthquakes. Time-dependent recurrence relationships are developed for fault sources using renewal approach while time-independent frequency-magnitude relationships are proposed for area sources based on Poisson process. GIS functionalities are used in this study to introduce and incorporate spatial-temporal and geostatistical indices in delineating area seismic sources. The proposed methodology is used to model seismic sources for an area of about 500 by 400 square kilometers around Tehran. Previous researches and reports are studied to compile an earthquake/fault catalog that is as complete as possible. All events are transformed to uniform magnitude scale; duplicate events and dependent shocks are removed. Completeness and time distribution of the compiled catalog is taken into account. The proposed area and linear seismic sources in conjunction with defined recurrence relationships can be used to develop time-dependent probabilistic seismic hazard analysis of Northern Iran. 相似文献
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利用概率地震危险性分析(CPSHA)方法,对山东某场地进行地震危险性分析,通过对该场地划分潜在震源区,确定地震活动性参数及地震动衰减关系,计算分析地震危险性概率,基本确定对该场地地震动峰值加速度起主要贡献的几个潜在震源区及贡献值,并确定该场地50年超越概率10%的水平向基岩地震动加速度峰值。结果发现,CPSHA方法以具体的构造尺度和更加细致的构造标志来划分潜在震源区,使潜在震源区规模缩减,从而更能反映地震活动在空间分布上的不均匀性。 相似文献
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潜在震源区内部空间非均匀分布地震区划方法在攀西地区和晋中南地区的应用 总被引：2，自引：1，他引：2
本文依据潜在震源区内部地震非均匀分布模型研究了攀西地区和晋中南地区地震区划问题。研究结果表明，一般使用的均匀分布模型会低估地震危险性结果，导致高烈度分区的面积缩小。本文讨论了不同的确定非均匀分布概率的方法对地震区划结果的影响。 相似文献
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In the paper, we have discovered the abnormal area distribution features of maximum variation values of ground motion parameter uncertainty with different probabilities of exceedance in 50 years within the range of 100°～120°E,29°～42°N for the purpose to solve the problem that abnormal areas of maximum variation values of ground motion parameter uncertainties emerge in a certain cities and towns caused by seismicity parameter uncertainty in a seismic statistical region in an inhomogeneous distribution model that considers tempo-spatial nonuniformity of seismic activity. And we have also approached the interrelation between the risk estimation uncertainty of a site caused by seismicity parameter uncertainty in a seismic statistical region and the delimitation of potential sources, as well as the reasons for forming abnormal areas. The results from the research indicate that the seismicity parameter uncertainty has unequal influence on the uncertainty of risk estimation at each site in a statistical region in the inhomogeneous distribution model, which relates to the scheme for delimiting potential sources. Abnormal areas of maximum variation values of ground motion parameter uncertainty often emerge in the potential sources of Mu≥8 (Mu is upper limit of a potential source) and their vicinity. However, this kind of influence is equal in the homogeneous distribution model. The uncertainty of risk estimation of each site depends on its seat. Generally speaking, the sites located in the middle part of a statistical region are only related to the seismicity parameter uncertainty of the region, while the sites situated in or near the juncture of two or three statistical regions might be subject to the synthetic influences of seismicity parameter uncertainties of several statistical regions. 相似文献
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新地震区划图潜在震源区划分的主要技术特色 总被引：13，自引：7，他引：6
简要介绍了新地震区划图潜在震源区划分方案的形成过程,重点分析了潜在震源区三级划分、东西部地区潜在震源区划分技术途径的差异、不同级别活动块体边界带对高震级潜在震源区划分的控制作用、发震构造模型及其在潜在震源区划分中的应用等主要技术特色.共划分出29个地震带、77个地震构造区和1199个潜在震源区.与中国地震动参数区划图(2001)中综合方案相比,东西部地区潜在震源区的个数都有较大的增加,其中东部地区体现在震级上限6.0、6.5和7.0级的中强潜在震源区个数的明显增加,与划分工作中加强了该地区中强地震发震构造的判识研究相关;而西部地区体现在震级上限7.5和8.0级的高震级潜在震源区个数的大幅度增加,与划分工作中注重了活动块体边界带高震级潜在震源区划分,以及强调应用发震构造模型指导潜在震源区划分的技术特色相协调. 相似文献
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7级以上的强震并不是在一片空白上突然发生的,而是在一种间歇性的地震活动背景下发生的,研究这种背景地震活动的规律,为判定一个活动期的强震的潜在震源区提供信息。本文通过对华北历史上记录到的18次7级以上强震的震前史和震后史的研究,提出了华北地区强震背景地震活动的四条规律:①强震前多有6级以上的背景地震发生;②并且多有信息地震发生;③短时间近距离的两个强震之间可能出现缓震现象;④强震具有一定的减震作用。文中根据这四条规律,对华北地区1501——1730年的强震潜在震源区做了判别分析。 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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The Shanxi reservoir earthquakes are significant seismic events in southern Zhejiang Province in recent years, an area with fewer and weaker earthquakes. The seismicity showed an intermittent characteristic and group distribution. The epicenters located by the seismic network did not show a predominant direction and the seismogenic structure is not clear. In the study, the nonlinear imaginary wave travel time equation was linearized and solved, and the source position, initial imaginary velocity and travel ... 相似文献
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文中根据对我国华北、西北和西南地区45个城镇的地震危险性分析结果,对中国烈度区划图上预报的基本烈度进行了初步的概率标定。结果发现区划图上所提供的基本烈度大致相应于50年内超越概率为0.14的烈度水平。 文中的计算是按照地震危险性分析的一般步骤进行的。以下是在实际应用中考虑的几个主要问题:1)根据地震地质条件和历史地震震中分布合理地划分潜在震源的位置和大小;2)确定与当前地震活动相一致的震级—频度关系;3)选用能够反映不同区域地质构造的烈度衰减规律。 本文结合图表对地震危险性分析的结果进行了分析和讨论。 相似文献
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本文将潜在震源的不确定性分为震源类型与震源几何尺度的不确定性两类,用逻辑树方法概括了潜在震源区划分的各种可能方案,并据此给出了考虑潜在震源区划分不确定性的地震危险性分析的计算步骤。用本文的方法对上海市地震危险性进行了分析。 相似文献