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利用祁连山中东段活动断裂的定量参数和“时间相依”的概率模型,对该地区断裂在未来一定时段内的发震概率进行了分析,认为该地区老虎山－毛毛山断裂的毛毛山段和金强河段的发震概率较高,其他断裂的发震概率很低;未来10年和20年,毛毛山段的发震概率分别为157．6％和29．03％,金强河段的发震概率分别为15．33％和28．41％,2段联合发生7．5级地震的概率分别为28．67％和49．19％,未来50年2段联合发生7．5级地震的概率为81．79％,通过对兰州地区1125年7．0级地震破烈带遗迹的考察,得出马衔山断裂未来50年发生Ms≥7.0地震的概率为19．87％。 相似文献
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海原断裂带分段地震潜势分析 总被引：2，自引：0，他引：2
利用近年来在海原断裂带各断裂段取得的最新古地震资料,通过实时概率模型,对海原断裂带东段、中段、西段进行了地震潜势的定量评估。得出海原断裂带东段、中段、西段未来100年内发生7级以上地震的概率分别为3．15％、11．35％、5．15％,未来200年内发生7级以上地震的概率分别为6．05％、22．8％、9．75％。 相似文献
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龙门山断裂带上的汶川地震摧毁了四川的几座城市,夺去了69000多人的生命。计算结果显示,该地震可能使部分鲜水河断裂、东昆仑断裂大部以及部分岷江断裂应力增加了0．2～0．5bar,更加接近破裂状态。这3条位于青藏高原东部的活动断裂带均在离汶川发震带150-400km的库仑静应力影响范围内。由于部分受力断层上的应变累积至少已有一个世纪之久,最近的汶川地震有可能触发或加速这些断层带上新的7级以上强震的发生,从而可能造成从四川省康定至道孚、青海省玛沁至甘肃省洛大以及邻近区域的强烈震动。本文利用由计算得到的汶川地震引起的应力变化以及过去10年观测到的背景地震发生率,对该地区在未来10年内发生破坏性地震的概率以及可能的空间分布进行了预测。结果表明,研究区内在未来10年内发生M≥6级地震的概率为57％～71％,发生M≥7级地震的概率为8％～12％,是汶川地震前发震概率的2倍。 相似文献
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华东地区未来中强震的概率预测 总被引：1，自引：1，他引：0
利用概率统计方法 ,对华东地区 1 999～ 2 0 0 5年发生不同震级的地震概率进行预测 ,结果表明 ,该地区仍处于地震活跃时段 ,发生 5级地震的概率不断增加 ,到 2 0 0 0年发生 5级以上地震的平均概率为 0 .5左右 ,但近 1～ 2年内发生 6级以上地震的可能性不大 ,发震概率仅为0 .1 5。 相似文献
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交城断裂带北段最大潜在地震发震概率评估1 总被引：1，自引：1，他引：0
基于太原市目标区交城断裂带的定量研究,特别是对活动断裂上的古地震资料进行的系统、详细的分析与总结,建立了反映该断裂地震地质特点和运动学属性的复发模式和概率模型.引入震级-地表破裂长度、震级-震源破裂长度、震级-断层破裂面积以及震级-地震矩的经验关系进行震级估计,最后进行综合评估以确定交城断裂带北段潜在地震的最大震级.复发模式的建立兼顾了泊松和准周期两种模式,利用专家意见法组合相应的Poisson模型和BPT模型,计算活动断裂最大潜在地震的复发概率.结果表明,交城断裂带北段潜在地震最大震级为Ms7.2级,而未来50a、100a、200a发生Ms7.2级地震的概率分别为2.1％、4.0％和7.9％. 相似文献
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安宁河、 则木河构造区近期强震危险性的概率估计 总被引：5，自引：0，他引：5
2008年5月12日汶川8.0级地震发生后, 作为历史强震多发地段南北地震带中南段的安宁河、 则木河构造区强地震危险性受到广泛关注。 本文在分析安宁河、 则木河构造区强震活动特点的基础上, 利用地震危险性韦布尔概率估计方法, 对该区未来10年内发生6.5级以上强震的累计概率和条件概率进行了计算, 并结合前人针对汶川地震破裂对周边断层产生的库仑应力变化及潜在震源区判定等研究结果, 对该区强地震危险性进行了综合判断。 结果表明, 汶川8.0级地震发生后, 安宁河、 则木河构造区5级以上中强地震似有逐步活跃的趋势; 根据韦布尔概率模型计算得出的该区2021年前发生6.5级以上强地震的概率高达0.93, 条件概率为0.32。 因此, 该构造区, 尤其是区内的冕宁—西昌一带未来10年发生强地震的可能性相对较高。 相似文献
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山西地震带历史地震序列的统计分析 总被引：2，自引：0，他引：2
在工程地震工作中需要知道某地震带或某地区未来100年内的地震活动水平,以便适当选择历史地震的统计时段,从而得到和地震活动水平相适应的不同潜在震源区的各级地震的年平均发生率。 本文利用极值理论、最大熵原理、马尔可夫模型的方法、莫尔纳方法和伯努里模型方法计算了山西地震带未来100年内中强震的年平均发生率、平均重现期大于等于某级地震的个数和发震概率,计算结果表明,山西地震带未来百年内将发生≥6.0级地震3次,发震概率为0.94左右;将发生≥6.5级地震1—2次,发震概率为0.84左右;有可能发生≥7.0级地震,发震概率为0.53左右;发生≥7.5级地震的可能性不大,发震概率为0.32左右;发生≥8.0级地震的可能性很小,发震概率为0.15左右。 相似文献
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Zhao Chengbin 《中国地震研究》2007,21(3):245-254
Study on fault activity is a fundamental part of earthquake prediction and earthquake relief in big cities.In the active fault exploration in Zhengzhou,the spatial distribution,geological features and activity of the Huayuankou fault,the Shangjie fault and the Xushui fault were determined using the seismic prospecting method.New understanding about the characteristics of the faults was gained.This provides reliable basic data for future earthquake forecast and earthquake relief work in Zhengzhou.In addition,we proposed some ways to identify fault activity through analyzing the characteristics of the activity of a fault and raised an effective method for exploring active faults in big cities and exploring concealed faults in regions covered with thick overburdens. 相似文献
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THE ACTIVITY FEATURES OF XIADIAN FAULT ZONE REVEALED BY RONGJIABAO TRENCH AND ITS PROBABILISTIC SEISMIC HAZARD EVALUATION 
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下载免费PDF全文 The time-dependent probabilistic seismic hazard assessment of the active faults based on the quantitative study of seismo-geology has the vital practical significance for the earthquake prevention and disaster management because it describes the seismic risk of active faults by the probability of an earthquake that increases with time and the predicted magnitude. The Poisson model used in the traditional probabilistic method contradicts with the activity characteristics of the fault, so it cannot be used directly to the potential earthquake risk evaluation of the active fault where the time elapsing from the last great earthquake is relatively short. That is to say, the present Poisson model might overestimate the potential earthquake risk of the Xiadian active fault zone in North China because the elapsed time after the historical M8 earthquake that occurred in 1679 is only 341a. Thus, based on paleoearthquake study and geomorphology survey in the field, as well as integrating the data provided by the previous scientists, this paper reveals two paleo-events occurring on the Xiadian active fault zone. The first event E1 occurred in 1679 with magnitude M8 and ruptured the surface from Sanhe City of Hebei Province to Pinggu District of Beijing at about 341a BP, and the other happened in (4.89±0.68)ka BP(E2). Our research also found that the average co-seismic displacement is ~(1.4±0.1)m, and the predicted maximum magnitude of the potential earthquake is 8.0. In addition, the probabilistic seismic hazard analysis of great earthquakes for Xiadian active fault zone in the forthcoming 30a is performed based on Poisson model, Brownian time passage model(BPT), stochastic characteristic-slip model(SCS)and NB model to describe time-dependent features of the fault rupture source and its characteristic behavior. The research shows that the probability of strong earthquake in the forthcoming 30a along the Xiadian active fault zone is lower than previously thought, and the seismic hazard level estimated by Poisson model might be overestimated. This result is also helpful for the scientific earthquake potential estimation and earthquake disaster protection of the Xiadian active fault zone, and for the discussion on how to better apply the time-dependent probabilistic methods to the earthquake potential evaluation of active faults in eastern China. 相似文献
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1654年礼县8级地震的发震区地处新构造活动强烈的青藏高原东北缘,位于南北地震带中北段,发育多条活动断裂。礼县8级地震发生在黄土覆盖区,距今约370年,受自然侵蚀与人类活动的影响,其地表破裂带和次生灾害现在已经难以分辨。为此,文章收集整理了1970年以来的地震台网和流动台网观测资料,基于地震层析成像方法,经过联合反演计算,研究1654年礼县8级地震的发震构造。研究根据岷县—礼县—两当一线的小震活动分布,推测存在"岷县—礼县—两当断裂",可能是1654年礼县8级地震的发震断裂,但仍需野外地质工作的进一步研究。 相似文献
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In order to provide a basis for the earthquake resistance protection zoning of Anshan City, westudied the activity of faults. In the study, the synthetic geophysical prospecting techniqueswere used. These techniques include the shallow artificial earthquake method, electric method,geologic radar method, etc., with shallow artificial earthquake sounding as the main means.In the meantime, the data of geophysical prospecting and borehole record of this city werecollected and the methods of field investigation and sample age dating were also used incombination. The results show that there are 5 hidden or semi-hidden faults in Anshon City.Among these faults, Dashitou-Songsantai fault, Ningyuantun fault and Dayangqi fault trendNW, the middle Pleistotene Tanggangzi fault trends NE, while the early Pleistocene or Pre-Quaternary Ertaizi fault trend NW. According to the definition of active faults, none of thesefaults is active. This paper also discussed the cause for the formation of seriously damagedareas in Ans 相似文献
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哈尔滨市目标区内主要断裂断错地表的最新活动时代为第四纪早期,晚更新世以来无断错地表的活动迹象。通过对城市活动断层地震危险性评价的技术思路、哈尔滨市工作区的地震地质环境与潜在震源区划分、目标区主要断裂活动特征的综合分析,确定了目标区内3条主要断裂未来可能发生地震的最大震级,并以兴安-东蒙活动地块与工作区作为分析的两种范围尺度,在适当调整工程地震学地震危险性概率分析方法的基础上,综合估算了目标区和目标区内单条断裂未来100年的发震概率。结果表明:哈尔滨市目标区主要断裂未来发生4.0级上破坏性地震的可能性极小,可能地震的最大震级为MS5.5 相似文献
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本文根据卫星影象判读,论述临汾地区主要活动断裂及沿北西向左幕-县底断裂密集分布的地震形变遗迹,结合地震史料,讨论1695年临汾8级地震的地质构造背景 相似文献
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应用浅层地震勘探法对宁夏吴忠地区北部的浅部地壳结构和隐伏活动断裂进行研究。结果表明,该区存在2条隐伏断裂,分别为银川主断层南段和新华桥断层。推测银川主断层南段为近SN走向的W倾正断层,断层下盘地层界面一般呈近水平状展布,而在断层上盘,T_Q及其以下的地层界面向断面方向倾伏并显示出逆牵引现象,断层向上错断了第四系内部。钻孔联合地质剖面及浅层地震探测结果共同揭示新华桥断层为一条走向NE,倾向SW的正断层,深、浅地震测线控制的新华桥断层延伸长度9 km左右,向上错断了第四系内部的T_(02)界面。 相似文献
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THE DISCUSSION FOR THE NEW ACTIVITY OF THE TIANQUAN SEGMENT OF LONGMENSHAN FAULT ZONE AND ITS RELATIONSHIP TO THE 1327 TIANQUAN EARTHQUAKE,SICHUAN 下载免费PDF全文
下载免费PDF全文 The 2008 Wenchuan earthquake occurred along the Longmen Shan fault zone, only five years later, another M7 Lushan earthquake struck the southern segment where its seismic risk has been highly focused by multiple geoscientists since this event. Through geological investigations and paleoseismic trenching, we suggest that the segment along the Shuangshi-Dachuan Fault at south of the seismogenic structure of the Lushan earthquake is active during Holocene. Along the fault, some discontinuous fault trough valleys developed and the fault dislocated the late Quaternary strata as the trench exposed. Based on analysis of historical records of earthquakes, we suggest that the epicenter of the 1327 Tianquan earthquake should be located near Tianquan and associated with the Shuangshi-Dachuan Fault. Furthermore, we compared the ranges of felt earthquakes(the 2013 M7 Lushan earthquake and the 1970 MS6.2 Dayi earthquake)and suggest that the magnitude of the 1327 Tianquan earthquake is more possible between 6½ and 7. The southern segment of the Longmen Shan fault zone behaves as a thrust fault system consisting of several sub-paralleled faults and its deep structure shows multiple layers of decollement, which might disperse strain accumulation effectively and make the thrust system propagate forward into the foreland basin, creating a new decollement on a gypsum-salt bed. The soft bed is thick and does not facilitate to constrain fault deformation and accumulate strain, which produces a weak surface tectonic expression and seismic activity along the southern segment, this is quite different from that of the middle and northern segments of the Longmen Shan fault zone. 相似文献