断层结构非均匀性对地震活动性影响的细胞自动机模拟          下载免费PDF全文

李锰  杨峰 《地震学报》2011,33(5):672-682

基于断层强度分布的非均匀性,构建了由81×81个细胞单元组成的4种不同匀质度及其各自6种不同随机构型共计24个非均匀二维单断层模型样本,并通过设计的细胞自动机模拟程序,在保持其它模拟参数不变的条件下对它们进行了模拟试验.研究结果表明,随着断层结构非匀质度的增加,其宏观变形破坏行为由相对脆性向塑性变化;地震序列类型依次表...  相似文献   

“交通灯”系统及其在诱发地震监测中的应用     

邱宇  房立华  王蕊嘉  范莉苹  蒋长胜 《中国地震》2021,37(2):349-367

随着页岩气开采、地热能源开采、CO2封存和水库蓄水等工业活动的开展,由此产生的诱发地震危害问题日益严重。为了对诱发地震进行有效监测和管控,地震学家设计了"交通灯"系统,当地震活动达到一定阈值时,相关人员可根据系统警报及时采取应对措施,减轻地震灾害。本文调研了近年来多个国家的"交通灯"系统研究和应用进展,介绍了其发展历史、设置原理及应用案例。"交通灯"系统的发展和完善应综合考虑震级、震动强度、b值和断层分布,以及建筑结构、城镇距离、人口密度、公众反应等社会因素。同时,在诱发地震频发区域,应建设密集的专用监测台网,提高微震检测和定位能力,并引入模板匹配和人工智能等新的自动处理方法,及时产出高完备性、高精度的微震目录,对微震的时空演化进行有效监测,形成时效性较强的"交通灯"系统。  相似文献   

福建省现代地壳垂直运动与断裂活动     

刘与锟  郭逢英  陈兆煌  黄立人  马青 《大地测量与地球动力学》1998,(4)

根据福建省境内１９７２年以来两次精密水准复测资料,利用速率面拟合法研究福建省现今地壳垂直运动的特征,并结合本区地质构造和地震活动性探讨这种运动的地球物理意义。资料分析表明,本区内新华夏系构造带是强震活动的主要场所,强震活动地点则又受到与这些新华夏系构造交汇的次一级的东西向构造、北西向构造和环状构造活动的制约;在主要构造断块的交接带上则表现为较显著的地壳垂直运动的差异性,差异活动较强烈的地区与本区地震活动的分布特征有着良好的一致性,且地震均落在地壳垂直运动速率变化较大的地区或其邻近海域  相似文献   

Origins and environments of pediments     

C. R. Twidale 《Australian Journal of Earth Sciences》2013,60(3-4):423-434

Three types of pediment have been recognised. The first are cut bedrock surfaces, veneered (and hence smoothed and protected) by coarse alluvial debris. Characteristically developed in the Brachina area of South Australia, they form in the piedmont zone in areas of mixed sedimentary outcrop and in areas where there are large variations in river and stream discharge, including occasional high floods. They are not restricted to any conventionally defined climatic region or regions, though their development is favoured by stream regimes characteristic of arid and semiarid lands.

The second and third types are typical of granite regions. The debris veneer of the second form, well developed around Ucontitchie Hill, mainly consists of weathered rock in situ, though in places there is also a thin discontinuous veneer of transported material. The mantis consists of grus and is readily eroded, exposing the weathering front as a rock platform or pediment, such as that found adjacent to Corrobinnie Hill. The mantled and rock forms are well developed in arid and semiarid tropical and subtropical lands, though it is suggested that they have their congeners in cooler mid latitude areas.

Brachina type pediments characteristically occur in flights, and they persist in the landscape, as also do rock pediments. But the Ucontitchie type is readily eroded and is a single cycle form. Brachina and Ucontitchie type pediments are the most common members of an isomorphous series. Similarly, the Ucontitchie and Corrobinnie types of granitic areas are end members of a continuum.

None of three pediment forms indentified is necessarily associated with scarp retreat.  相似文献   

Landforms and Neotectonics in the Equatorial Passive Margin of Brazil     

《Geodinamica Acta》2013,26(1):51-71

Neotectonic movements have been proposed in the literature in order to explain some landforms of the equatorial passive margin of northeastern Brazil. Its seismo-tectonic activity is concentrated in a few sectors located on or near the coast. Active or recently active structures are mainly identified in Neogene deposits. Identifying a contribution of neotectonics to the morphogeny is difficult in a context where most major morphostructural patterns are explained by Cretaceous tectonics related to oceanic opening and by differential erosion induced by Tertiary epeirogenic uplift. We aim to assess the nature of features considered as possibly neotectonic in origin. Seismogenic faults are not related to significant topographic breaks, except on the coast, where they usually reach only a few meters in height. A study of landforms located near zones of seismo-tectonic activity indicates a possible, probably weak, contribution of neotectonics to the formation of a few high scarps. These scarps occur along or near fault zones reactivated in Cretaceous times. We conclude that neotectonic movements are the result of ongoing deformation along predominantly strike-slip fault zones, with long term deformation rates similar to those recorded by dated landmarks (0.01 mm.yr ^-1). Despite reported deformation rates that can amount in places to 0.4 mm.yr ^-1, neotectonic rates are lower than erosion rates. The consequence is that major structural landforms in the region mainly originated in Cretaceous to early Tertiary events.  相似文献   

Understanding the active tectonics in Australia: constraints from isotope dating and tracing     

I.Tongu? UYSAL  ZHAO Jianxin  Uwe RING 《《地质学报》英文版》2013,87(Z1):389-389

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库仑应力变化及其在地震学中的应用研究进展          下载免费PDF全文

刘方斌  王爱国  冀战波 《地震工程学报》2013,35(3):647-655

首先介绍了库仑应力的定义及其物理含义。阐述了库仑应力在强震对余震的触发作用、强震对后续地震序列的触发、应力影区对地震的抑制作用、地震活动性分析以及相关软件的应用等五个方面的应用研究进展。最后探讨了库仑应力在地震学应用中存在的不足与前景。  相似文献   

西秦岭北缘断裂带断层气浓度空间分布特征与强震危险性分析          下载免费PDF全文

苏鹤军  张慧  李晨桦  伍剑波  周慧玲 《地震工程学报》2013,35(3):671-676

以西秦岭北缘断裂带不同段断层气Hg、Rn浓度空间分布特征分析为基础、通过对历史大震背景、现今地震活动影像以及b值空间分布特征的对比分析,从地球化学的角度,对西秦岭北缘断裂带不同段落的活动习性进行深入探讨,并识别出该断裂带潜在大震危险区段。可为未来地震趋势判定及震情跟踪提供重要的基础资料。  相似文献   

全球及各地震区带强震活动周期特征   总被引：2，自引：0，他引：2       下载免费PDF全文

宋治平  尹继尧  薛艳  张国民  刘杰  朱元清  张永仙 《地球物理学报》2013,56(6):1868-1876

基于地震活动周期谱的Morlet小波分析,确定了全球和13个地震区带的强震活动周期及其置信度.结果显示全球地震活动存在着多个显著稳定的活动周期,而各地震区带除了存在着与全球整体地震活动基本一致的周期外,还存在着特有的活动周期成分.本文研究为探讨全球及区域强震活动趋势及其动力源提供了基础数据.  相似文献   

2012年宁蒗5．7级地震的震兆和前兆异常特征     

杨芬 《四川地震》2013,(4):37-40,45

2012年6月24日宁蒗5．7级地震发生前,地震活动性存在中期异常,地下流体存在中短临异常。地震活动性方面存在滇西地区5级以上地震东西迁移规律性活动、滇西地区4级以上地震成条带分布和程海断裂发生4级窗口地震等中期震兆异常。水氡、固体二氧化碳、水温和流量存在中短临前兆异常。地下流体前兆中期、短期和短临阶段都出现同步性异常。  相似文献