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1.
唐山-河间-磁县新生地震构造带   总被引:11,自引:8,他引:11       下载免费PDF全文
徐杰  牛娈芳 《地震地质》1996,18(3):193-198
地震构造研究往往注重那些形成历史长且规模较大的活动断裂带。实际上还存在一种与现代地质环境和区域应力状态基本保持一致的最近构造阶段新发育的断裂带,即新生断裂带。地震活动与这两种构造带关系密切。根据地震和地质构造等资料分析认为,唐山-河间-磁县地震带是一条晚第三纪开始发育的新生地震构造带  相似文献   

2.
唐山-河间-磁县新生地震构造带   总被引:30,自引:5,他引:30       下载免费PDF全文
地震构造研究往往注重那些形成历史长且规模较大的活动断裂带。实际上还存在一种与现代地质环境和区域应力状态基本保持一致的最近构造阶段新发育的断裂带,即新生断裂带。地震活动与这两种构造带关系密切。根据地震和地质构造等资料分析认为,唐山-河间-磁县地震带是一条晚第三纪开始发育的新生地震构造带。  相似文献   

3.
张家口-蓬莱断裂带地震构造特征的初步探讨   总被引:93,自引:15,他引:78       下载免费PDF全文
徐杰  宋长青 《地震地质》1998,20(2):51-154
北西向张家口-蓬莱断裂带由近20条北西至北西西向断裂组成,是一条对新生代区域地质构造发育起到重要控制作用的地壳构造带。断裂带新生代活动由中部向西北和东南部发展,总体表现左旋走滑性质。断裂带有山西断陷盆地带等几条北东向活动构造带与之交汇,形成北西和北东向两组断裂相互交切的构造组合,出现5个复杂的构造交接段。6级以上强震和大多数中小地震群集于这些地段,其中北西和北东向断裂都可能发生地震,显示共轭破裂错动特征,但北东向断裂发生的地震强度较大。张北-尚义6.2级地震发生于断裂带与山西断陷盆地带交接段的西缘,是断裂带向西北扩展的结果  相似文献   

4.
华北东南部介休-新乡-溧阳北西向新生地震构造带   总被引:6,自引:2,他引:6       下载免费PDF全文
徐杰  王若柏 《地震地质》1997,19(2):30-134
根据华北地区东南部的地震活动、地质构造和地球物理等资料,对介休-新乡-溧阳北西向地震带的地震地质条件作了分析。此地震带具有统一的现代区域构造应力背景,是华北东南部的一条现代地壳剪切破裂带;沿此带发育由一系列晚第三纪以来继承性活动的和新产生的北西向断裂组成的活动断裂带,它斜穿不同的构造单元是一条新生地震构造带  相似文献   

5.
1976年盐源—宁蒗地震序列的破裂特征   总被引:1,自引:0,他引:1  
张四昌  王绍晋 《地震》1995,(3):275-279
使用地震活动图象和震源机制资料的构造分析方法,研究盐源-宁蒗地震序列的破裂特征。结果认为:6.7级地震破裂面是北北东向左旋走滑断层,5.6级6.4级地震破裂面是两条北西西向右旋走滑断层,构成以北北东向断为主干的共轭破裂组合,该序列受弥渡-木里地壳深部活动断裂带控制。  相似文献   

6.
田勤俭  张军龙 《地震地质》2008,30(1):324-332
阿尔泰构造带的活动断裂主要为NW—NNW向。按构造位置可分为阿尔泰西缘活动断裂带、阿尔泰中央活动断裂带和阿尔泰东缘活动断裂带。阿尔泰东缘活动构造带由科布多(Hovd)活动断裂带、哈尔乌苏湖(Har Us)活动断裂带2条大型右旋走滑活动断裂和中间的挤压盆地带构成。在2条走滑断裂带上,前人发现多处地震地表破裂带。通过对阿尔泰东缘构造带中南段地区的野外调查,在哈尔乌苏湖断裂带中段的Jargalant断裂、科布多断裂带南段的Tugen gol断裂上新发现地震地表破裂带。其中,沿Jargalant断裂地震地表破裂带长约50km,右旋位错量约4~5m,是一次规模大、活动较新的破裂事件。可见,在阿尔泰东缘活动断裂带的不同断裂段上均有保存较好的地震地表破裂,显示阿尔泰东缘是活动强烈的地震构造带  相似文献   

7.
北天山地区活动逆断裂-褶皱带构造与潜在震源区估计   总被引:27,自引:7,他引:20       下载免费PDF全文
北天山山前逆断裂-褶皱带是典型的大陆内部活动挤压构造,该地区的地表活动构造、隐伏活动构造及活动背斜都受地下深处近水平滑脱断层控制。对1906年玛纳斯地震(M7.7)的发震构造、地表变形与破裂特征和山前活动逆断裂带上古地震的研究表明,北天山山前隐伏活动深断坡具备大地震发生的构造条件,大致以金钩河为界分为东西两段,相应地构成两个大地震潜在震源(M8)。山前第2条玛纳斯逆断裂-褶皱带和第3条独山子逆断裂-褶皱带中的各个活动背斜,以及西湖隆起等可能是8个中强地震的潜在震源(M6)。  相似文献   

8.
雅鲁藏布大峡谷地区构造和地震活动特征   总被引:2,自引:0,他引:2  
雅鲁藏布大峡谷地区位于喜马拉雅东构造结前锋地带,新构造运动和地震活动都十分强烈,两者关系密切。区内发育有北北东-北东向和北西西-北西向两组断裂构造,调查研究表明,它们的规模、性质、活动时代、活动强度等特征具有明显的差异:北西西-北西向断裂规模较大,多为逆冲、逆走滑断层,形成较早;北北东-北东向断裂单条规模相对不大,常集中分布,构成北北东向的剪切拉张断裂构造带,形成较晚,第四纪晚期活动明显。强震主要发生在喜马拉雅山差异运动强烈地带或地段,如块体周边的深大断裂带及其附近。7级以L地震主要与断裂构造带中规模较大、全新世强烈活动段、断裂几何构造复杂部位或多组方向断裂交汇密切相关。其中,7.5级以上地震发生在断裂构造带中走滑分量较大的北西向和北东向断裂带上。  相似文献   

9.
渤海位于渤海湾盆地的东部,是我国华北地区新构造活动最强烈的地区之一,盆地内的沉积盖层(N-Q)中断裂极为发育。许多研究者从不同角度对渤海新构造进行过研究,但认识不一。笔者基于以往的工作,对该区新构造作了较深入的分析,确定渤海新构造运动起始于中新世晚期(12~10Ma BP)。从三维空间分析盖层断裂,并按其与盆地基底断裂的成因关系,将新构造活动的断裂分为继续活动断裂和新生断裂,并划分出3条主要的新构造活动断裂带:北东(偏北)向营口-潍坊断裂带北段是继续活动构造带,右旋逆平移活动,活动性弱;北西西向北京-蓬莱断裂带亦为继续活动构造带,左旋正平移活动,活动性较强;北东向庙西北-黄河口断裂带为新生构造带,右旋平移活动,活动性强。后两者组成一对以庙西北-黄河口断裂带为主的偏共轭活动构造带,该区域地震活动与之关系密切。最后探讨了渤海地区新构造期北东东-南西西至近东西向水平挤压的构造应力场及其与新构造活动断裂带发育的关系。提出新构造应力场与古近纪盆地裂陷阶段的应力场截然不同,新构造为地壳共轭剪切破裂系统,古近纪盆地构造是发育于地壳上部的伸展构造系统,这是两期不同体制的构造系统。  相似文献   

10.
华东地区中强地震构造背景和地质标志研究   总被引:3,自引:0,他引:3  
华东地区,特别是下扬子-南黄海地区,是我国一个重要的中强地震活跃区,在地震区(带)划分上,华东地区北半部属华北地震区,南半部属华南地震区。根据我们的研究,其边界大致从大别山北麓到杭州湾南岸一带,这条边界也是一条重要的鹇构造运动边界,其北部为华北新生代断陷区,南部为华南新生代隆起区,下扬子-南黄海地区的地震活动性,虽比华北其他地区低,但比华南大部地区,尤其比浙南和闽北地区高得多。华东地区中强地震在空间分布是不均匀的,它们只发生在某些地区和某些特定构造部位,其地质标志主要可归结为以下5点:1.新构造差异带;2.活动断裂带;3.断陷陡深带;4.构造分水岭;5.地貌断阶带。  相似文献   

11.
In previous seismotectonic studies,the emphasis was placed on the inherited active fault zones.In the recent tectonic stage that essentially keeps in step with the current regional geologic environment and the stress field,however,there are also some newly generated fault zones.By studying the seismicity in North and Southwest China,it has been known that the NE-trending Tangshan-Hejian-Cixian and NW-trending Tengchong-Gengma-Lancang seismic zones are just two newly generated fault zones.As distinguished from the inherited fault zones,they are called the newly generated seismotectonic zones.This paper deals with the existence of these two seismogenic zones from their seismicity and geological structures,gives a preliminary analysis of their characteristics,and shows their significance.  相似文献   

12.
We developed a seismic hazard model for Taiwan that integrates all available tectonic, seismicity, and seismic hazard information in the region to provide risk managers and engineers with a model they can use to estimate earthquake losses and manage seismic risk in Taiwan. The seismic hazard model is composed of two major components: a seismotectonic model and a ground-shaking model. The seismotectonic model incorporates earthquakes that are expected to occur on the Ryukyu and Manila subduction zones, on the intermediate-depth Wadati-Benioff seismicity zones, on the active crustal faults, and within seismotectonic provinces. The active crustal faults include the Chelungpu fault zone, the source of the damaging MW 7.6 Chi-Chi earthquake, and the Huangchi-Hsiaoyukeng fault zone that forms the western boundary of the Taipei Basin. The ground-shaking model uses both US, worldwide, and Taiwanese attenuation relations to provide robust estimates of peak ground acceleration and response spectral acceleration on a reference site condition for shallow crustal and subduction zone earthquakes. The ground shaking for other site conditions is obtained by applying a nonlinear soil-amplification factor defined in terms of the average shear-wave velocity in the top 30 m of the soil profile, consistent with the methodology used in the current US and proposed Taiwan building codes.  相似文献   

13.
本文分析了华北平原第四纪主要构造格局和强震活动特点,划分了主要强震构造带,并对其发震能力作了评价。认为坝县-束鹿-邯郸断裂带、唐山-河间-磁县断裂带和黄骅-德州-东明断裂带3条北东向右旋走滑断裂带为华北平原裂谷系从早第三纪伸展拉张作用进入晚第三纪-第四纪走滑剪切拉张作用的产物,这3条断裂带分别位于3个北东向坳陷带中部,并构成了第四纪沉降中心,与营口-潍坊断裂带一起构成华北平原内的主要强震构造。本文最后提出了华北平原区划分潜在震源区应注意的几点问题,进而针对第四代区划图中华北平原区潜在震源区划分综合方案提出了补充修改意见。  相似文献   

14.
Based on the studies of earthquake activity, tectonic movement, crustal shortening rate, fault activity, local stress field and historical characteristics of strong earthquake activities in Xinjiang, we divide the south part of Xinjiang into 4 seismotectonic zones, namely, the eastern segment of south Tianshan seismic belt, the Kalpin block, the Kashi-Wuqia junction zone, and the west Kunlun Mountains seismic belt. Using earthquake catalogues from Xinjiang since 1900, and on the basis of integrity analysis of earthquake records in different magnitude ranges, the seismicity state of different seismotectonic zones is analyzed quantificationally by calculating the mean value of annual strain energy release, annual rate of earthquakes with different lower limits of magnitude, b-value, and the parameter m of accelerating strain release model. The characteristic indexes of seismicity state for each of the seismic tectonic zones are then determined, which provide a quantitative basis for earthquake tendency analysis and judgment.  相似文献   

15.
新发现的冀东南堡油田位于地震和断裂活动较强的渤海湾地区,抗震设防问题不容忽视。本文分析了油田所在地区的地震活动和地震构造环境,并在此基础上划分出了潜在震源区,确定了地震动衰减关系,进行了地震危险性分析。然后根据油田周边相关工程的工程地质条件特征,建立了场地土动力模型,进行了土层地震反应计算,确定了场地设计地震动参数。结果表明,局部场地条件对地震动峰值和反应谱的影响较大,需对场地工程地质条件进行详细研究。  相似文献   

16.
We associate waveform-relocated background seismicity and aftershocks with the 3-D shapes of late Quaternary fault zones in southern California. Major earthquakes that can slip more than several meters, aftershocks, and near-fault background seismicity mostly rupture different surfaces within these fault zones. Major earthquakes rupture along the mapped traces of the late Quaternary faults, called the principal slip zones (PSZs). Aftershocks occur either on or in the immediate vicinity of the PSZs, typically within zones that are ??2-km wide. In contrast, the near-fault background seismicity is mostly accommodated on a secondary heterogeneous network of small slip surfaces, and forms spatially decaying distributions extending out to distances of ??10?km from the PSZs. We call the regions where the enhanced rate of background seismicity occurs, the seismic damage zones. One possible explanation for the presence of the seismic damage zones and associated seismicity is that the damage develops as faults accommodate bends and geometrical irregularities in the PSZs. The seismic damage zones mature and reach their finite width early in the history of a fault, during the first few kilometers of cumulative offset. Alternatively, the similarity in width of seismic damage zones suggests that most fault zones are of almost equal strength, although the amount of cumulative offset varies widely. It may also depend on the strength of the fault zone, the time since the last major earthquake as well as other parameters. In addition, the seismic productivity appears to be influenced by the crustal structure and heat flow, with more extensive fault networks in regions of thin crust and high heat flow.  相似文献   

17.
大凉山断裂带与安宁河-则木河断裂带的地震活动性分析   总被引:3,自引:0,他引:3  
韩渭宾  蒋国芳 《地震研究》2005,28(3):207-212
通过对比分析,研究了大凉山断裂带和安宁河-则木河断裂带的地震活动性。认为在历史上安宁河-则木河断裂带的地震活动无论是频次还是强度都高于大凉山断裂带,这与活断层及古地震研究的结论是一致的。而且,地震活动性分段比较的结果显示,普格附近的空段2和冕宁附近的空段1发生强震的可能性最大,其次为西昌钝角交汇区.另外,需要注意强震前先发生中强震的可能性。  相似文献   

18.
The study is focusing on the stress and strain inversions from focal mechanisms in a revised seismotectonic zonation of northeastern Italy and western Slovenia. The recent increase of monitoring capability of the local seismic network, the updated geological-structural model of the area, and the novelties emerged from studies on the spatial organization of the seismicity allowed a redefinition of the seismotectonic zones. The stress and strain tensors inversion is inferred from 203 focal mechanisms, corresponding to earthquakes occurred between 1984 and 2016 with coda-duration magnitude range from 2.0 to 5.6. The inverted stress domains reveal an articulated picture of the interaction of the Adria microplate with the Eurasian plate. A dominant strike-slip stress field characterizes the eastern part of the area, while the seismotectonic zones of the central part are undergoing to thrusting regime. The stress pattern inferred in the western part of the study area outlines a complex picture with prevailing strike-slip regime and dominant compression only in a seismotectonic zone. The comparison of stress and strain tensor orientations evidences a relative uniformity of the crustal strength in the eastern and northwestern zones of the study area. The central and western zones appear to be characterized by planes of mechanical weakness not favorably oriented for failure with respect to the stress tensor.  相似文献   

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