共查询到19条相似文献，搜索用时 500 毫秒
1.
2.
3.
2010年1月24日,山西省运城市河津-万荣交界地区发生Ms4.8地震.由于本次地震强度较低,并未形成地表破裂带,分析其发震构造具有一定的困难.地震现场工作队只能根据浅层人工地震剖面、附近钻孔资料、烈度等震线长轴和震中区附近活动断裂等来推定,认为西辛封隐伏断裂为可能的发震断裂.为此,下面我们将在分析本次地震的震源机制解、序列三维空间分布特征的基础上,结合本次地震的宏观考察结果,确定其发震构造并探讨发震机理. 相似文献
4.
5.
根据邢台7-2 级和6-8 级地震震中区的浅层和超浅层地震勘探结果,查明了震中区浅部铲形断裂的性质及活动年代,认为新河断裂(F1) 自晚更新世以来已不再活动,它不是发震断裂。另外,结合该区深地震反射剖面和深地震测深剖面结果,讨论了震中区的深浅部构造形态及它们的相互关系,从而确定了发震断裂应为震源之下的高倾角超壳断裂①。邢台地震的发生是由于地幔岩浆的上侵作用产生附加应力场,并与区域构造应力场共同作用使该断裂重新活动,引发了邢台地震,并引起浅部断层及地表物质的运动 相似文献
6.
1936年灵山63／4级地震极震区烈度分布及发震构造 总被引：3，自引：0，他引：3
根据现场调查材料,对1936年4月1日广西灵山6 3/4级地震震中区烈度进行评定并绘制了等震线图。图中烈度Ⅸ、Ⅷ度区呈“T”形,两长轴方向与区内NEE及NNW方向断裂吻合。据此认为该震的发震构造为NEE和NNW两组断裂,6 3/4级地震系两组断裂共轭破裂的结果。又据低烈值沿NEE方向衰减较慢,认为NEE组断裂同时起控震构造作用。 相似文献
7.
8.
核电厂地震安全性评价中的地震构造法,要求鉴定发震构造和划分地震构造区,在以往实践中,发震构造鉴定往往基于地表活动断裂构造,且表征为线状震源.当存在较强非随机分布的地震活动且难以找到清晰的地表活动断裂构造形迹时,地震构造法就难以合理地表现这些地震的危险性.本文以云南滇中大姚—姚安发震构造鉴定为例,探讨了在地表活动构造形迹不清,中强地震活动性较强的滇中大姚—姚安地区,采用面状发震构造来表征地震危险性的方法,讨论了在地震构造法中采用面状发震构造的必要性、鉴定思路和方法,并建议在今后的核工程地震危险性评价地震构造法中应充分考虑面状发震构造的应用. 相似文献
9.
利用2013~2017年3期GPS观测资料,通过结合区域构造背景分析呼图壁MS6.2地震震中及附近区域水平运动速率、主应变率、面膨胀率及最大剪应变率动态变化特征。结果表明,呼图壁地震前发震构造南部区域地壳速率高于北部区域运动速率,造成发震构造两盘运动速率不同,地壳能量积蓄。呼图壁地震释放了区域积蓄的应变能量,由于区域构造因素,影响范围较小。震前震中附近区域处于压缩环境,易于聚集应变能量;震时震中区出现面膨胀等值线密集高梯度带,是地壳应变能量交换和释放剧烈区域。震中区最大剪应变变化不大,反映呼图壁地震逆冲性质,最大剪应变高值区对地震危险性有预示作用。 相似文献
10.
唐山震害与发震构造的关系关于唐山地震的地质背景以及发震构造，地震学者们从不同的角度做了不同的论述，已经揭示了唐山地震发震构造的总体面貌。本文只是根据唐山震害与发震构造的关系，谈一谈个人认识。１９９０－１９９２年，我们对唐山地震震害进行了较为全面的调查... 相似文献
11.
利用差分干涉雷达测量技术获取的宏观震中区的同震形变场，结合对地震活动性、震源机制、野外考察等资料分析，对昆仑山口西8.1级地震同震形变场特征进行了研究. 结果表明:宏观震中位于库赛湖东北侧，宏观震中区发震断层可分为两个形变中心区域，其中西段长约42 km，东段长约48 km，整个发震断层主破裂段长90 km；由干涉形变条纹分布格局可清楚地判断出发震断层的左旋走滑特征；断层两盘变形特征不同，南盘变形程度明显大于北盘；宏观震中附近最大斜距向位移量为288.4 cm，最小斜距向位移量为224.0 cm，宏观震中发震断层最大左旋水平位错为738.1 cm，最小地面左旋水平位错为551.8 cm. 相似文献
12.
IntroductionOnNovember14,2001,aMS=8.1earthquakeoccurredonthewestofKunlunshanPassintheborderareaofQinghaiandXinjiang,whichwasthestrongestearthquakeinChinesemainlandsincetheMS=8.0earthquakeoccurredinDangxiongdistrictofXizangAutonomousRegiononNovember18,1951.TheearthquakeoccurredontheEasternKunlunTectonicZone,whichwasapalaeoplatejunctionzoneinsideTibetanPlateau.ItdividedTibetanPlateauintothesouthandnorthparts.ThezoneplayedaveryimportantroleinTibetanPlateausdeformationprocessanddynamicev… 相似文献
13.
Based on the analysis of coseismic deformation in the macroscopic epicentral region extracted by Differential Interferometric Synthetic Aperture Radar (D-InSAR), and combined with the seismic activity, focal mechanism solutions of the earthquake and field investigation, the characteristic of coseismic deformation of M S=8.1 western Kunlunshan Pass earthquake in 2001 was researched. The study shows that its epicenter lies in the northeast side of Hoh Sai Hu; and the seismogenic fault in the macroscopic epicentral region can be divided into two central deformation fields: the west and east segments with the lengths of 42 km and 48 km, respectively. The whole fault extends about 90 km. From the distribution of interferometry fringes, the characteristic of sinistral strike slip of seismogenic fault can be identified clearly. The deformations on both sides of the fault are different with an obviously higher value on the south side. In the vicinity of macroscopic epicenter, the maximum displacement in look direction is about 288.4 cm and the minimum is 224.0 cm; the maximum sinistral horizontal dislocation of seismogenic fault near the macroscopic epicenter is 738.1 cm and the minimum is 551.8 cm. 相似文献
14.
V. G. Krishna 《Journal of Seismology》2018,22(6):1395-1408
We present an approach based on controlled source seismology (CSS) methods, especially developed for processing and modeling of the local earthquake seismograms. Record sections of the local earthquake seismograms generated for multiple source depths illuminate the upper crustal velocity structure in the region. Extensive travel times and synthetic seismograms modeling of the observed record sections reveal the P and S velocity structure in the region. The strength of this approach essentially lies with the possibility of validating the upper crustal velocity models inferred in various subregions of the seismogenic region. A redundant and significantly large number of virtual source local earthquake seismogram sections, gathered for multiple source depths and varying source mechanisms in each of the subregions, validate the same set of P and S velocity models in that region. Further, those models are found to generate the synthetic seismograms consistent with the observed sections. The proposed approach effectively utilizes a reliable dataset from a great volume of well-located local earthquake recordings of a state-of-the-art digital seismograph network. Such a dataset of local earthquake seismograms in the Koyna-Warna active earthquake zone is used here to demonstrate this approach and obtained subregion-specific models of upper crustal P and S velocity structure in the epicentral region. The results indicate that the technique presented here is efficient for processing and modeling the local earthquake seismograms and deriving upper crustal velocity models in the seismogenic regions. 相似文献
15.
16.
Based on the analysis of coseismic deformation in the macroscopic epicentral region extracted by Differential Interferometric
Synthetic Aperture Radar (D-InSAR), and combined with the seismic activity, focal mechanism solutions of the earthquake and
field investigation, the characteristic of coseismic deformation of M
S=8.1 western Kunlunshan Pass earthquake in 2001 was researched. The study shows that its epicenter lies in the northeast side
of Hoh Sai Hu; and the seismogenic fault in the macroscopic epicentral region can be divided into two central deformation
fields: the west and east segments with the lengths of 42 km and 48 km, respectively. The whole fault extends about 90 km.
From the distribution of interferometry fringes, the characteristic of sinistral strike slip of seismogenic fault can be identified
clearly. The deformations on both sides of the fault are different with an obviously higher value on the south side. In the
vicinity of macroscopic epicenter, the maximum displacement in look direction is about 288.4 cm and the minimum is 224.0 cm;
the maximum sinistral horizontal dislocation of seismogenic fault near the macroscopic epicenter is 738.1 cm and the minimum
is 551.8 cm.
Foundation item: National Natural Science Foundation of China (40374013) and “Researching on the Disaster Earthquake” (2003) of Public Welfare
Research Item, Ministry of Science and Technology of China. 相似文献
17.
通过对荣县MS4.9地震震中及附近地区地震监测、地震地质、地震活动背景和区域地震活动性的分析表明,荣县MS4.9地震震前经历了区域地震平静至活跃、再发震的过程,该序列为正常的震群型,震中区及其附近的华蓥山断裂地震带和马边地震带的震后地震学参数均正常。荣县MS4.9地震发震断裂为荣县-威远基底断裂,华蓥山断裂带及其附近地区2018年开始的5—6级地震活跃与川西地区东昆仑断裂带2017年8月九寨沟MS7.0强震的发生存在呼应关系。 相似文献
18.
为研究川滇地区地壳密度的时空演化特征与强震孕育的关系,本文基于2011—2014年川滇地区的重力复测资料,利用阻尼最小二乘反演算法,获得了川滇地区0—50 km深度范围内分辨率为55 km×55 km×10 km （长×宽×高）的三维动态密度变化模型。以所获取的动态密度变化为依据,分析了川滇地区三维密度变化特征与2013年四川芦山MS7.0、2014年云南鲁甸MS6.5和四川康定MS6.3地震的关系,并由此对强震重点构造部位的深部地壳结构特征、孕震背景及区域动力学过程进行了深入分析。结果显示:川滇地区出现多个与主要活动断裂带展布方向基本一致的密度变化高梯度带,在三次地震的震中区及其附近观测到明显的区域性密度变化异常。15—35 km深度范围内的密度变化水平剖面显示:强震容易发生在上地壳密度变化正、负异常过渡的高梯度带和密度变化四象限分布的中心;中地壳深度密度变化低异常是强震孕育的主要介质条件;下地壳深度密度变化低异常或密度变化高梯度带均有可能是孕育地震的主要介质结构。0—50 km深度的垂直剖面上的密度变化结果显示,地震震中区及附近浅部、深部地壳呈现解耦变化。壳内垂向正负密度变化过渡带可能是强震孕育的又一个主要特征构造。 相似文献
19.
A magnitude 7(3/4) earthquake happened in Linfen, Shanxi, on May 18, 1965(the 34th year of Qing Emperor Kangxi). In the Catalogue of Chinese Historical Strong Earthquakes, the epicenter of this earthquake is located at the northwest of Zhangli Village of Xiangfen County and Dongkang Village of Yaodu District, Linfen City(36.0°N, 111.5°E), and the epicentral intensity is Ⅹ. It was inferred by previous studies that Guojiazhuang Fault is the seismogenic structure of the earthquake. In this paper, in cooperation with the Archives of Linfen City and Earthquake Administration of Linfen, the author looked up in details the first-hand materials of the earthquake damage to the ancient town of Linfen and its surrounding areas, and based on this, drew the isoseismals of the earthquake. Through discussions with relevant experts, we consider that it would be more appropriate that the location of the macroscopic epicenter of this earthquake is in Donguan area of the ancient town of Linfen, the epicentral intensity is Ⅺ, and the major axis of the isoseismals is in NWW. Later, in the implementation of "Linfen city active fault detection and seismic risk evaluation", we found two earthquake fault outcrops near the macroscopic epicentral area of the 1695 Linfen earthquake. Shallow seismic exploration lines and drill rows perpendicular to the strike of the fault outcrops were arranged to implement the exploration. The results demonstrate that the right-lateral stepover composed of Guojiazhuang Fault and Liucun Fault, together with the Luoyunshan Fault(Longci segment), were involved in the 1695 Linfen earthquake, the intersection of the faults is the microscopic epicenter of the earthquake, and the above-mentioned three faults are the seismogenic structure of the earthquake. In addition, the seismic geological remains in this region(landslides, earthquake ground cracks, sand emitting channels, etc.) are mainly distributed on the hanging wall of the Guojiazhuang Fault, this proves from another perspective that the earthquake remains is the product of activity of Guojiazhuang Fault in 1695. 相似文献