天津近海海域隐伏断裂地震危险性评价1     

刘红艳  陈宇坤  闫成国  杨菲 《中国地震研究》2013,27(4):542-552

Based on faults surveying and research data in the Tianjin offshore areas, through studying tectonic structure, Quaternary activity, deep structure, stress and strain fields and seismicity in the Tianjin offshore areas, the activity and tectonic features of the faults are determined synthetically. Using seismo-geological data, and the historical and modern seismicity data, the frequency-magnitude relationship model normalized by 500a is established and based on the relationship between the upper limit of maximum magnitude Mu and at/b, the maximum magnitudes of the sea section of the Haihe river fault and the Haiyi fault are calculated. Then Poisson probability model is adopted and the quantitative parameters, such as the maximum magnitude, occurrence probability, recurrence cycle of the faults in the south Tianjin offshore areas in the coming 50 - 200a, are calculated.  相似文献   

中国东部中强地震潜在震源区地震复发概率分布     

李姜一  周本刚 《震灾防御技术》2016,11(1):1-10

本文对中国大陆东部102个中强潜在震源区内1500a以来5—6级地震的复发间隔进行了统计分析,得到了中强地震复发间隔不仅受潜源内断层活动性影响,还与发震构造是否交汇及邻区构造活动等因素有一定关系。中强地震复发间隔大致满足指数分布,通过给出的概率模型可以计算出研究区内各潜在震源区未来一定时间内的发震概率,为地震危险性分析提供一些基础资料。  相似文献   

云南龙蟠—乔后断裂剑川段古地震初步研究     

汤勇  胡朝忠  田勤俭  王林  杨攀新  熊仁伟 《地震》2014,34(3):117-124

通过遥感影像解译和详细的野外考察,发现龙蟠乔后断裂带剑川段晚第四纪以来长期活动,横跨断裂的水系左旋断错量可分为40 m、140m、550 m、1040m四个等级。经详细考察.后选择后菁拉分盆地开挖探槽。探槽揭示了两次M>6.5古地震事件:一次发生在10010±40aB.P.之前;另一次发生在6130±40a B. P.和6320±40a B.P. 之间。结合前人研究,分析得出剑川盆地全新世以来发生了3次M>6.5的地震,发生时间分别为1751 年、6230士130a B. P.和10737±468aB.P.,其重复间隔约为5300a。由于1751年剑川6¾级地震相对于前两次地震释放的能量偏小,而且其离逝时间较前一次要明显长一些,故本段的地震危险性仍值得关注。  相似文献   

Recurrence time in the homoclinic tangle     

G. Contopoulos  C. Polymilis 《Celestial Mechanics and Dynamical Astronomy》1995,63(2):189-197

We find the minimum recurrence time for the lobes of an unstable periodic orbit (i.e. the number of iterations required in order that an image of a given lobe intersects itself). This time is much shorter than the usual recurrence time derived by applying Poincaré's theorem. As the energy of the system increases the minimum recurrence time decreases. The minimum recurrence time can be found also when the energy exceeds the escape energy, in which case the usual Poincaré recurrence time is not defined.  相似文献   

Earthquake—Affected Time—Space Domain,Recurrence Interval and Effective Preparation Time of Earthquakes     

WangShengzu  ZhangZongchun 《中国地震研究》2002,16(4):380-395

The study shows that earthquake-affected time-space domain(ETSD),i.e.a time-space range in which strong earthquakes are unable to occur owing to the influence of a prior earthquake occurring,shows a hyperbolic margin curve in the t(time)-r(distance)coordinate plane,which has a maximum affected radius r0 at t=0 and a maximum influence time t0(i.e.the insitu recurrence interval of earthquakes)at r=0.Based on the time-distance distributions of posterior earthquakes relative to pror ones in the regions of North China,Northwest China,Qinghai-Xizang(Tibet)plateau and Southwest China,the optimized and 90%-confidence margin curves are estimated using optimization and statistical analysis methods.This indicates that the concept and method of ETSD with 3-dimension(time-distance-magnitudes)instead of those of “recurrence interval “with 1-dimension(time)or 2-dimension(time-magnitude) provides a new approach to understanding the fluctuation of seismic activities,estimating the effective earthquake-preparation time of potential hypocenters,and therefore improving the mediumand long-term prediction of strong earthquakes.  相似文献   

澜沧、耿马地震前的复发周期时空扫描     

刘正荣 《地震研究》1991,(4)

继文献〔1〕和①,本文作者以1988年11月6日云南省澜沧、耿马地区发生的7.6、7.2级地震为例,采用复发周期时空扫描的方法、对地震预报中短期预报的方法进行了追踪研究。结果表明大震前的异常是清楚的。异常分为两个阶段:第一阶段是外围异常阶段,震前逐步形成外围异常、形如围空、然后是外围异常逐步消失;第二阶段为极震区附近异常的逐步增强、扩大与稳定直至发震。看来采用复发周期时空扫描的方法是可以预报某些强震的。  相似文献   

Recurrent events on a Quaternary fault recorded in the mineralogy and micromorphology of a weathering profile, Yangsan Fault System, Korea   总被引：1，自引：0，他引：1  

Gi Young Jeong  Chang-Sik Cheong 《Quaternary Research》2005,64(2):221-233

Recurrence characteristics of a Quaternary fault are generally investigated on the basis of field properties that are rapidly degraded by chemical weathering and erosion in warm humid climates. Here we show that in intense weathering environments, mineralogical and micromorphological investigations are valuable in paleoseismological reconstruction. A weathering profile developed in Late Quaternary marine terrace deposits along the southeastern coast of the Korean Peninsula was disturbed by tectonic movement that appears to be a simple one-time reverse faulting event based on field observations. A comparative analysis of the mineralogy, micromorphology, and chemistry of the weathering profile and fault gouge, however, reveals that both the microfissures in the deformed weathering profile and larger void spaces along the fault plane were filled with multi-stage accumulations of illuvial clay and silt minerals of detrital origin, suggesting a repetition of fissuring and subsequent sealing in the weathering profile as it underwent continuous mineralogical transformation and particle translocation. We reconstruct a sequence of multiple faulting events unrecognized in previous field surveys, which requires revision of the view that the Korean Peninsula was tectonically stable, during the Late Quaternary.  相似文献   

海原断裂高湾子地点三维探槽的开挖与古地震研究   总被引：22，自引：6，他引：22       下载免费PDF全文

冉勇康  焦德成 《地震地质》1997,19(2):2-107

对海原断裂高湾子地点进行大比例尺地质地貌填图和三维探槽开挖，揭示出７次古地震事件，除１９２０年地震外，它们的年龄分别为距今（１０００４±３１９６），（６６８９±１６９），（６１２０±５０５），（４２０８±５７７），（２７６３±３７２）和（１００５±４６５）ａ；重复间隔分别为（３３１５±３２００），（５６１±５３２），（１９２０±７６６），（１４２５±６８６），（１５７８±５９５）和（９８０±４６５）ａ。事件Ⅲ，Ⅳ，Ⅴ，Ⅵ，Ⅶ的水平位移量分别为（５．６±２．３），（１．５±１．１），（１．５±１．１），（２±１）和（７±０．５）ｍ。显示出重复间隔时间的分段性和特征行为的分级性。两次类似１９２０年强度的地震间隔期间，有３次位移量为１～２ｍ的地震发生  相似文献   

新西兰韦恩加瓦河砾石的沉积环境、阶地断错和8级地震重复率          下载免费PDF全文

程绍平 《地震地质》1988,10(1):39

新西兰北岛南部韦恩加瓦河地区在晚更新世冰缘气候控制下,由沉积和侵蚀的交替作用形成较高较老的阶地。较低较新的阶地是在全新世中期以来的现代正常气候条件下形成的。这些阶地分别被怀拉拉帕断层水平错动297米、100米,57米和28米。距今10000年以来,怀拉拉帕断层的平均水平滑动速度为10毫米/年。1855年8级地震的重复率为1500年  相似文献   

川西则木河断裂带强震复发周期的初步研究   总被引：2，自引：0，他引：2  

任金卫 《内陆地震》1990,4(2):107-115

本文从地震活动性和断层活动性两方面初步研究了川西则木河断裂带上地震的复发周期。通过古地震地貌现象的研究,发现则木河断裂北段西昌一带自晚更新世以来多次发生强震,其中全新世时期至少有4次。并得出晚更新世时期,强震在原地重复的周期为2000年,全新世时期为1800年,则木河断裂带滑动速率的研究表明,晚更新世时期断层滑动速率为4.5mm/a,全新世时期为4.9mm/a,以此估计则木河断裂带上晚更新世时期,强震重复的平均周期为965—1380年,全新世时期为885—1275年。  相似文献