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1.
1303年在山西洪洞附近发生的8级巨大地震, 是中国根据现存较为详细的文献记载史料所确定的最早的一次8级地震。 这次地震距今已有700多年的历史, 而地震所在区域至今仍有持续不断的小地震活动。 本文根据地震破裂区1981年至2013年的中小地震精定位地震目录, 采用震源断层面拟合方法, 反演得到了1303年山西洪洞地震的震源断层面参数: 走向19.3°、 倾角88.5°、 滑动角-170.0°。 断层面长75.5 km, 宽26.2 km, 深度为地下11.12 ～37.35 km。 将地震破裂区的地震精确定位资料以近东西向的洪洞断裂为界划分为地震北段和地震南段, 分段进行地震震源断层拟合, 反演得到洪洞地震北段震源断层面参数: 走向13.7°、 倾角76.6°、 滑动角-157.6°。 断层面长32.7 km, 宽21.7 km, 深度为地下11.97～32.86 km; 南段震源断层面参数: 走向20.3°、 倾角87.1°、 滑动角-154.6°。 断层面长45.9 km, 宽16.6 km, 深度为地下9.32 km～25.50 km。 无论是分段还是不分段, 反演得到的洪洞地震震源断层均是右倾的近直立断层, 属于右旋走向滑动性质。 分段计算得到的地震北段震源断层深度比南段更深, 将反演得到的震源断层与临汾盆地深部构造最新研究成果进行了分析对比, 北段震源断层深度及倾角大小与深地震剖面推测得到的深大断裂几乎相同。 震源断层在地表的投影与洪洞地震的高烈度区能够较好地对应。 相似文献
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Fault plane parameters of Sanhe-Pinggu M8 earthquake in 1679 determined using present-day small earthquakes 
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下载免费PDF全文 Xiaoshan Wang Xiangdong Feng Xiwei Xu Guiling Diao Yongge Wan Libin Wang Guangqing Ma 《地震科学（英文版）》2014,27(6):607-614
The great Sanhe-Pinggu M8 earthquake occurred in 1679 was the largest surface rupture event recorded in history in the northern part of North China plain. This study determines the fault geometry of this earthquake by inverting seismological data of present-day moderate-small earthquakes in the focal area. We relocated those earthquakes with the double-difference method. Based on the assumption that clustered small earthquakes often occur in the vicinity of fault plane of large earthquake, and referring to the morphology of the long axis of the isoseismal line obtained by the predecessors, we selected a strip-shaped zone from the relocated earthquake catalog in the period from 1980 to 2009 to invert fault plane parameters of this earthquake. The inversion results are as follows: the strike is 38.23°, the dip angle is 82.54°, the slip angle is -156.08°, the fault length is about 80 km, the lower-boundary depth is about 23 km and the buried depth of upper boundary is about 3 km. This shows that the seismogenic fault is a NNE-trending normal dip-slip fault, southeast wall downward and northwest wall uplift, with the right-lateral strike-slip component. Moreover, the surface rupture zone, intensity distribution of the earthquake and seismic-wave velocity profile in the focal area all verified our study result. 相似文献
3.
利用于田震中300 km范围内的1个GPS连续站和12个GPS流动站数据,解算得到了2014年新疆于田MS7.3地震地表同震位移,并反演了发震断层滑动分布,探讨此次地震对周边断裂的影响.地表同震位移结果显示,GPS观测到的同震位移范围在平行发震断裂带的北东-南西向约210 km,垂直发震断裂带的北西-南东方向约为120 km,同震位移量大于10 mm的测站位于震中距约120 km以内;同震位移特征整体表现为北东-南西方向的左旋走滑和北西-南东方向的拉张特征,其中在北东-南西方向,I069测站位移最大,约为32.1 mm,在北西-南东方向,XJYT测站位移最大,约为28.1 mm;位错反演结果表明,最大滑动位于北纬36.05°,东经82.60°,位于深部约16.6 km,最大错动量为2.75 m,反演震级为MW7.0,同震错动呈椭圆形分布,以左旋走滑为主并具有正倾滑分量,两者最大比值约为2.5：1,同震错动延伸至地表,并向北东方向延伸,总破裂长度约50 km,地表最大错动约1.0 m;同震水平位移场模拟结果显示贡嘎错断裂、康西瓦断裂和普鲁断裂等不同位置主应变特征具有差异性,这种差异特征是否影响断裂带以及周围区域的应力构造特征,值得关注. 相似文献
4.
运用Sentinel-1A卫星数据和D-InSAR技术,获取2021-05-21云南漾濞M_S6.4地震的同震形变场。结果显示,漾濞地震同震形变场长轴近NW展布升降轨形变场符号相反,视线向最大沉降量和抬升量为0.1 m。InSAR同震形变场反演的滑动分布主要集中在沿走向2～12 km,倾向1～9 km的范围内,最大滑动量0.35 m,发震断层长9.8 km、宽4 km,滑动量主要集中在地下3～6 km范围内,滑动角-146.7°。同震位移场及滑动分布模型反映本次地震为发震断层的右旋走滑事件,地震破裂未达到地表。断层模型反演结果显示,矩震级为M_W6.1,发震断层以北西走向右旋走滑运动为主,初步认为本次M_W6.1地震发震断裂可能是一条NW向的维西—乔后断裂西侧的隐伏次生断裂。 相似文献
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对历史记载的公元1738年玉树西北地震的震级及其发震构造目前仍存有争议。卫星影像解译和野外调查发现沿甘孜-玉树断裂当江段分布一条长约75km的左旋走滑地震地表破裂带,其最大同震水平位移约2.1m。综合分析该地表破裂带特征、探槽揭露信息、测年结果以及历史文献记载等资料,认为当江段应为1738年玉树西北地震的发震断层,基于震例类比和经验公式估算该次地震的震级为71/2级。沿甘孜-玉树断裂的历史地震破裂分布显示,玉树段在隆宝镇以西存在近50km长的破裂空段;当江段距1738年地震的离逝时间也可能已经接近其地震复发周期,上述两个段落未来均存在大震危险。 相似文献
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2017年11月13日伊拉克北部地区苏莱曼尼亚省发生了MW7.3地震, 造成了重大的人员和经济损失。 本文利用升降轨的Sentinel-1和降轨的ALOS-2卫星的SAR数据, 通过差分干涉测量技术获取了该地震的同震形变场, 联合DInSAR和MAI技术, 采用抗差最小二乘法求解该地震的同震三维形变场。 基于改进的考虑地形起伏的均匀位错模型反演确定了发震断层的断层参数, 最后基于非均匀位错模型得到了发震断层的分布式滑动分布模型。 结果显示: ALOS-2卫星降轨轨道观测到的伊拉克地震引起的LOS向地表形变最大为55.8 cm抬升和47.9 cm下沉; Sentinel-1卫星观测到的伊拉克地震引起的LOS向地表形变为: 升轨轨道最大为87.9 cm抬升和17.1 cm下沉; 降轨轨道最大为55.6 cm抬升和38 cm下沉; 相对于前人的研究成果, 本文利用改进的考虑地形起伏的反演方法得到的发震断层几何参数表明发震断层为NNW走向, 倾向角为352°, 同震破裂以逆冲为主, 同时兼有一定的左旋走滑分量。 基于均匀位错模型反演得到的断层滑动分布结果表明, 同震破裂未延伸至地表, 主要滑动量集中在12~18 km, 最大滑动量位于15 km深度, 达到4.3m, 反演得到的矩震级为MW7.35, 与UGSG、 GCMT等机构给出的结果一致。 相似文献
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北京时间2021年5月22日,青海省果洛州玛多县发生MS7.4地震,震中位于巴颜喀拉地块内部,根据震源机制解和野外地表破裂调查确定发震构造为以左旋走滑运动为主的江错断裂。本研究利用大疆Phantom 4 RTK无人机在震后采集大量地表破裂照片,采用集成SfM（Structure from Motion）算法的PhotoScan软件处理获得高分辨率DEM和正射影像,同时结合野外实地考察对研究区地表破裂的分布特征及断错地貌类型进行详细解译。利用基于MATLAB语言开发的位移测量软件LaDiCaoz,限定玛多地震在研究区产生的左旋走滑位移约为0.4 m。地表破裂精细化解译显示,在左旋右阶阶区发育小规模的挤压鼓包和里德尔共轭剪切破裂,在左旋左阶阶区发育走向为N40°～50°E,宽度达数十厘米的张裂缝带,指示发震构造的左旋走滑性质。本研究为震后基于无人机摄影测量技术快速提取地表破裂的定量参数和进行地表破裂精细化研究提供了可行、高效和科学的技术方法。 相似文献
8.
云南活动性断裂带的结构变异与孕震体构造的空间关系 总被引：2，自引：1，他引：1
中国的强震主要发生在一些板内大型走滑断裂带上,地震的破裂基本上是以走滑型破裂为特征。在这些活动性的走滑断裂带上形成的孕震体构造与该走滑断裂结构在空间的变化有关,并且表现出几种主要的变异形式。结合西南地区地震构造的实例,本文剖析了这几种结构变异形式,阐明了孕震体构造存在的空间机制。本文从地震与构造丛集相关及其所具有的分维特征入手,展开了对孕震区断裂结构变异特征的识别和孕震体空间机制的探讨,表述了一条活动性大断裂必须由若干次级断裂和无数中小断裂的空间组合,才能形成孕震体的必要条件。 相似文献
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本文根据建立在平均二维破裂模式基础上的地震定标律,导出了地震矩 M0与各常用震级之间（1gM0-MS,ML,mb）,各种震级之间（Ms-ML,Ms-mb,ML-mb）,各震源参数之间（断层长度IgL,断层面积 lgS,平均错距 lgD-Ms,拐角频率 1gfc-ML）的各种常用的关系式.利用这些关系式,由一个震级值就可以估算出一系列震源参数.本文还求出了平均破裂速度 Vr=2.65km/s,总破裂时间 T（s）=0.5L（km）,平均位错速度 D（t）=11.4m/s.用矩震级 Mw 度量地震的大小,有四个优点:（1）地震矩反映了形变规模的大小,因此是度量地震大小的最佳物理量.（2）它是一个绝对力学标度,对任何大小地震都有意义,可测量,且不产生饱和问题.（3）它和我们已熟悉的震级标度可衔接.（4）它是一个均匀的震级标度,适用于宽尺度的地震统计.因此,Mw 是一种值得推广的震级标度. 相似文献
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The 10 January 2018 MW7.5 Swan island, Honduras earthquake occurred on the Swan island fault, which is a transform plate boundary between the North American and Caribbean plates. Here we back-project the rupture process of the earthquake using dense seismic stations in Alaska, and find that the earthquake ruptured at least three faults (three stages) for a duration of ~40 s. The rupture speed for the longest fault (stage 3) is as fast as 5 km/s, which is much faster than the local shear wave velocity of ~4 km/s. Supershear rupture was incidentally observed on long and straight strike-slip faults. This study shows a supershear rupture that occured on a strike-slip fault with moderate length, implying that supershear rupture might commonly occur on large strike-slip earthquakes. The common occurrence of supershear rupture on strike-slip earthquakes will challenge present understanding of crack physics, as well as strong ground motion evaluation in earthquake engineering. 相似文献
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基于InSAR技术,利用欧空局升降轨Sentinel-1A/IW宽幅数据,获取了2017年8月8日四川九寨沟7.0级地震InSAR同震形变场,并以升降轨InSAR观测结果为约束,反演了断层滑动分布,基于三种不同接收断层计算了同震库仑应力变化.结果表明,同震形变场发生在塔藏断裂、岷江断裂和虎牙断裂交汇的三角地带,升降轨干涉位移均显示本次地震的形变场影响范围约为50 km×50 km,形变场长轴方向为NW向,升降轨观测的形变量相反,反映断层运动性质以走滑运动为主,升降轨数据观测得到的最大LOS （Line of Sight,视线向）形变量分别为~22 cm和~14 cm.非对称形变场反映出断层两侧的运动差异.反演结果显示,最大滑动量约为1 m,平均滑动角为-9°,矩震级为MW6.5,地震破裂主要集中在地下1~15 km深度范围内,但整体而言本次地震破裂较为充分,基本将该区域1973年及1976年4次 > MW6.0地震的破裂空区完全破裂.考虑到塔藏断裂和虎牙断裂的运动性质,可初步判定发震断层为虎牙断裂北侧延伸分支.基于三种不同接收断层模型的同震库仑应力变化计算结果反映出该区域以应力释放为主,进一步触发较大走滑型余震的可能性不大. 相似文献
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RELOCATIONS AND FOCAL MECHANISM SOLOTIONS OF MS5.5 QIANGUO EARTHQUAKE SWARM IN JILIN PROVINCE IN 2013 下载免费PDF全文
下载免费PDF全文 We relocated a seismic swarm, which started in a mass from 31 October, 2013 in Qianguo County of Jilin Province, by using double difference location method, based on the phase data of regional digital seismic network and the crustal velocity model of Sunliao Basin. The characteristics of seismogenic fault have been investigated based on the spatial distribution image of the seismic swarm and the geophysical data near the epicenter area. The relocated epicenters of the swarm earthquakes have a precision of 0.9km in E-W, 0.7km in N-S and 1.2km in U-D direction, and show an apparent concentrated seismic belt trending N-W, with a length and width of 12km and 6km, respectively. The source depths of all events are shallow, with 80%in a range of 6~8km, and the events are apparently crowded together on the depth cross section. According to the relocated spatial distribution characteristics of the seismic swarm, the features that the medium size events happened successively, and the focal mechanism of the large size events in the swarm, we infer that the seismogenic tectonics of Qianguo seismic swarm is the thrust nappe structure inside the Keshan-Da'an fault zone. The fault plane inclines to the East direction, and is steep when close to the ground surface, which shows the typical characteristics of a listric thrust fault. The longitudinal length of the rupture plane is greater than the transverse length. According to the features of seismogenic tectonics, we infer that the three MS ≥ 5.0 earthquakes occurred at the lower layer of the thrust rupture surface of the fault, while the aftershocks were triggered by the three events and occurred mainly at the upper layer of the rupture surface. 相似文献
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本文以完整的形式给出拉梅常数不相等情形的半无限弹性介质中任意倾角的矩形滑动断层引起的地震位移场解析表示式。以一些数值结果说明介质的泊松比、断层面的倾角、上界和下界对地面的地震位移场的影响。在比较1966年邢台地震的地形变资料和计算得到的各种走向、倾向、倾角、断层面长度、宽度、震源深度和错距的单个的矩形滑动断层引起的地面位移之后指出,简单的滑动断层错动模式不能同时很好地解释观测到的邢台地震的水平和垂直形变。为了解释观测结果,提出了一个复合的断层模式。这个复合断层模式由六个简单的矩形滑动断层构成。运用网格尝试法,得到了基本上符合观测到的水平和垂直位移场的震源参数。 相似文献
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The seismogenic fault and the dynamic mechanism of the Ning’er, Yunnan Province MS6.4 earthquake of June 3, 2007 are studied on the basis of the observation data of the surface fissures, sand blow and water eruption, land-slide and collapse associated with the earthquake, incorporating with the data of geologic structures, focal mecha-nism solutions and aftershock distribution for the earthquake area. The observation of the surface fissures reveals that the Banhai segment of the NW-trending Ning’er fault is dominated by right-lateral strike-slip, while the NNE-trending fault is dominated by left-lateral strike-slip. The seismo-geologic hazards are concentrated mainly within a 330°-extending zone of 13.5 km in length and 4 km in width. The major axis of the isoseismal is also oriented in 330° direction, and the major axis of the seismic intensity VIII area is 13.5 km long. The focal mechanism solutions indicate that the NW-trending nodal plane of the Ning’er MS6.4 earthquake is dominated by right-lateral slip, while the NE-trending nodal plane is dominated by left-lateral slip. The preferred distribution orientation of the aftershocks of MS≥2 is 330°, and the focal depths are within the range of 3~12 km, predominantly within 3~10 km. The distribution of the aftershocks is consistent with the distribution zone of the seismo-geologic hazards. All the above-mentioned data indicate that the Banhai segment of the Ning’er fault is the seismogenic fault of this earthquake. Moreover, the driving force of the Ning’er earthquake is discussed in the light of the active block theory. It is believed that the northward pushing of the Indian plate has caused the eastward slipping of the Qinghai-Tibetan Plateau, which has been transformed into the southeastern-southernward squeezing of the southwest Yunnan region. As a result, the NW-trending faults in the vicinity of the Ning’er area are dominated by right-lateral strike-slip, while the NE-trending faults are dominated by left-lateral strike-slip. This tectonic 相似文献
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通过卫星影像解译和野外实地调查,获得滇西南地区孟连断裂的几何特征和活动性参数。孟连断裂总体走向NE-NEE向,不具有明显的分段性,连续性较好。断裂从单侧控制着沿线的勐滨、孟连和勐马三个新生代盆地的发育。断裂沿线地貌以线性较好的断层谷、断层崖和断层陡坎为主,并发育多级左旋位错的河流、冲沟和阶（台）地等,观测到的最小左旋位错约为7 m。采用高精度Li-DAR测量方法,对4处典型水平位错地貌进行精细测量,根据获得的相应地貌面年代,得到孟连断裂晚第四纪以来平均左旋走滑速率为2.2±0.4 mm/a。其结果与滇西南地区其他NE向左旋走滑断裂滑动速率相当,反映了区域构造活动的整体协调性。根据跨断层地质体最大左旋位错量9.5±1.8 km,估算断裂开始左旋走滑的时代为距今4.7±1.6 Ma左右,即中新世中晚期。 相似文献
16.
根据近场小孔径观测台网记录的余震序列资料，研究了2000年1月15日云南姚安MS6.4地震序列的地震物理过程. 用地震标定律关系估算主震的地震矩M0=1.58×1018N·m，矩震级MW=6.0，平均位错=0.63m，断层长度L=16.6km，断层宽度W=5.6km. 余震序列的高精度定位结果和能量分布走向，很好地证实了主震的断层破裂走向为N50°W，震区马尾菁断裂为主震发震构造，断层错动性质以右旋走滑为主. 用横波记录资料及波谱分析方法估算出余震的震源参数: 地震矩范围为1010～1016N·m，震源破裂半径a为80～500m，地震应力降范围为0.01～9.5MPa. 较大应力降(Δσ>1.0MPa)沿主断层线性排列，大应力降(Δσ>2.0MPa)与ML≥3.0级地震相关. 余震能量释放和高应力降的地震多发生在6.0～11km的深度范围，说明在这一深度范围内最大程度地集中了地壳中的应力. 相似文献
17.
Historically, large and potentially hazardous earthquakes have occurred within the interior of Alaska. However, most have not been adequately studied using modern methods of waveform modeling. The 22 July 1937, 16 October 1947, and 7 April 1958 earthquakes are three of the largest events known to have occurred within central Alaska (M
s
=7.3,M
s
=7.2 andM
s
=7.3, respectively). We analyzed teleseismic body waves to gain information about the focal parameters of these events. In order to deconvolve the source time functions from teleseismic records, we first attempted to improve upon the published focal mechanisms for each event. Synthetic seismograms were computed for different source parameters, using the reflectivity method. A search was completed which compared the hand-digitized data with a suite of synthetic traces covering the complete parameter space of strike, dip, and slip direction. In this way, the focal mechanism showing the maximum correlation between the observed and calculated traces was found. Source time functions, i.e., the moment release as a function of time, were then deconvolved from teleseismic records for the three historical earthquakes, using the focal mechanisms which best fit the data. From these deconvolutions, we also recovered the depth of the events and their seismic moments. The earthquakes were all found to have a shallow foci, with depths of less than 10 km.The 1937 earthquake occurred within a northeast-southwest band of seismicity termed the Salcha seismic zone (SSZ). We confirm the previously published focal mechanism, indicating strike-slip faulting, with one focal plane parallel to the SSZ which was interpreted as the fault plane. Assuming a unilateral fault model and a reasonable rupture velocity of between 2 and 3 km/s, the 21 second rupture duration for this event indicates that all of the 65 km long SSZ may have ruptured during this event. The 1947 event, located to the south of the northwest-southeast trending Fairbanks seismic zone, was found to have a duration of about 11 seconds, thus indicating a rupture length of up to 30 km. The rupture duration of the 1958 earthquake, which occurred near the town of Huslia, approximately 400 km ENE of Fairbanks, was found to be about 9 seconds. This gives a rupture length consistent with the observed damage, an area of 16 km by 64 km. 相似文献
18.
利用IRIS全球地震台网30°—90°的长周期P波记录, 反演了2008年3月21日新疆于田MS7.3地震的破裂过程, 得到了此次地震的破裂时空图像, 并初步分析了余震分布与主震断层滑动量分布的关系. 结果表明, 此次地震是一个破裂尺度长100 km、 宽20 km的破裂过程; 破裂持续时间约为40 s, 在第13 s时地震矩释放速率达到峰值, 断层面上一次大的破裂行为几乎构成了整个地震的破裂过程. 地震所释放的标量地震矩为4.23×1019 N·m, 其矩震级为MW7.02. 由主震断层静态滑动量分布图可以看出, 整个破裂区以正断左旋走滑为主, 显示出双侧破裂特征, 最大滑动量为151 cm, 位于初始破裂点沿断层出露地表处. 精定位后的余震在断层面上的投影结果显示, 80%以上ML4.0—4.9余震和全部ML≥5.0余震均发生在初始破裂点附近区域及其南西方向, 位于主震破裂滑动位移量迅速减小的区域, 反映了震源区介质强度的不均匀性. 相似文献
19.
The seismogenic fault and the dynamic mechanism of the Ning’er, Yunnan Province MS6.4 earthquake of June 3, 2007 are studied on the basis of the observation data of the surface fissures, sand blow and water eruption, landslide and collapse associated with the earthquake, incorporating with the data of geologic structures, focal mechanism solutions and aftershock distribution for the earthquake area. The observation of the surface fissures reveals that the Banhai segment of the NW-trending Ning’er fault is dominated by right-lateral strike-slip, while the NNE-trending fault is dominated by left-lateral strike-slip. The seismo-geologic hazards are concentrated mainly within a 330°-extending zone of 13.5 km in length and 4 km in width. The major axis of the isoseismal is also oriented in 330° direction, and the major axis of the seismic intensity VIII area is 13.5 km long. The focal mechanism solutions indicate that the NW-trending nodal plane of the Ning’er MS6.4 earthquake is dominated by right-lateral slip, while the NE-trending nodal plane is dominated by left-lateral slip. The preferred distribution orientation of the aftershocks of MS≥2 is 330°, and the focal depths are within the range of 3～12 km, predominantly within 3～10 km. The distribution of the aftershocks is consistent with the distribution zone of the seismo-geologic hazards. All the above-mentioned data indicate that the Banhai segment of the Ning’er fault is the seismogenic fault of this earthquake. Moreover, the driving force of the Ning’er earthquake is discussed in the light of the active block theory. It is believed that the northward pushing of the Indian plate has caused the eastward slipping of the Qinghai-Tibetan Plateau, which has been transformed into the southeastern-southernward squeezing of the southwest Yunnan region. As a result, the NW-trending faults in the vicinity of the Ning’er area are dominated by right-lateral strike-slip, while the NE-trending faults are dominated by left-lateral strike-slip. This tectonic framework might be the main cause of the frequent occurrence of MS6.0～6.9 earthquakes in the area. 相似文献
20.
1999年山西大同Ms 5.6地震的震源断层 总被引：9，自引：0，他引：9
大同震区先后在 1989、1991和 1999年发生MS >5地震 ,利用大同遥测地震台网的记录资料进行比较精确的地震序列震源定位 ,结合宏观烈度分布和震源机制解资料 ,详细地分析对比了 3次子序列的异同。结果显示 ,1999年MS5 .6地震的震源断层是走向NWW、长 16km、宽12km、埋深 5km以下、倾角近直立的左旋走滑断层。而前 2个子序列是NNE为主的右旋走滑断层活动所致 ,表明地震破裂方向发生了变化。这种 2个以上方向先后出现、并且强弱有别的地震破裂是普遍存在的 ,表明震源环境的复杂程度与地震序列的类型有关。虽然震区存在NE向的大王村断裂和NW向的团堡断裂 ,但目前没有证据说明震源断层和 2条构造断层连通。 3次子序列的震源断层都是走滑断层 ,也和 2条构造正断层有别。 1999年的子序列可能属于新破裂。 相似文献