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Yabuki & Matsu'ura反演方法是利用ABIC最佳模型参数选取方法和平滑的滑动分布作为约束条件,由形变观测数据计算发震断层滑动分布.本文基于日本列岛同震GPS观测数据和发震断层曲面构造模型,利用Yabuki&Matsu'ura反演方法计算2011年日本东北地区太平洋海域Mw9.0级地震的发震断层同震滑动分布.反演结果表明,断层面上的最大滑动量为35 m,较大滑动分布在浅于30 km的震源中心上部,最大破裂集中在20 km深度的地方,其地震矩约为3.63×1022N·m,对应的矩震级为Mw9.0.模拟结果显示Yabuki&Matsu'ura反演方法更适用于倾角低于40°的断层模型反演.最后,本文基于上述方法获得的发震断层滑动模型,利用地球体位错理论正演计算该地震在中国及其邻区产生的远场形变,正演计算结果基本可以解释由中国GPS陆态网络观测到的同震形变. 相似文献
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Yabuki & Matsu'ura反演方法是利用ABIC最佳模型参数选取方法和平滑的滑动分布作为约束条件,由形变观测数据计算发震断层滑动分布.本文基于日本列岛同震GPS观测数据和发震断层曲面构造模型,利用Yabuki & Matsu'ura反演方法计算2011年日本东北地区太平洋海域Mw9.0级地震的发震断层同震滑动分布.反演结果表明,断层面上的最大滑动量为35 m,较大滑动分布在浅于30 km的震源中心上部,最大破裂集中在20 km深度的地方.其地震矩约为3.63×1022N·m,对应的矩震级为Mw9.0.模拟结果显示Yabuki & Matsu'ura反演方法更适用于倾角低于40°的断层模型反演.最后,本文基于上述方法获得的发震断层滑动模型,利用地球体位错理论正演计算该地震在中国及其邻区产生的远场形变,正演计算结果基本可以解释由中国GPS陆态网络观测到的同震形变. 相似文献
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中国地震局第二地形变监测中心已监测到与1990年4月26日青海共和7.0级地震有关的大幅度隆起垂直形变资料．基于这些形变资料,本研究首先利用全局搜索性能优良的遗传算法和弹性半空间单一矩形均匀滑动模型,对该地震的震源位错参数进行了初步反演;然后以遗传算法的反演结果为初始值,利用拟牛顿阻尼最小二乘方法对该地震的震源位错参数进行了更精细的反演．结果表明,共和7.0级地震的发震断层为一走向NW60左右、倾向SW、倾角37左右的右旋走滑逆冲断层,同震断层破裂长度约37 km,宽度约6 km,错动幅度约2.7 m．反演结果还同时表明,遗传算法与最小二乘方法相结合是一种行之有效的联合反演方法,它既可以保证实现全局最优解,防止最小二乘方法的局部极值解问题,又可以有效地解决遗传算法达到全局最优解区域后收敛速度过慢的问题． 相似文献
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2003年9月25日(世界时)十胜近海地震(Mw～8．0)随后的GPS时间序列揭示出了显著形变。我们采用“网络反演滤波”技术，对震后30天内后续断层滑动的时空演变进行了反演。后续断层滑动集中在同震破裂带附近，即在2003年地震断裂带、1968年十胜近海地震和1973年根室近海地震震源区之间的位置。反演表明，2003年地震断裂带中断层滑动速率衰减迅速，而周围地区衰减速度较慢。后续断层滑动地区的应力一速度路径大致遵循dτ／d In(v)～0．6MPa，这暗示着稳态速度强化摩擦。尽管不能排除其他的解释，但在沿走向的方向上，同震破裂和后续断层滑动互补的空间模型还是可能表明了摩擦特征的空间变化。 相似文献
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在分析了地震地质、物探、卫片等新的资料的基础上，认为在菏泽地震区地下隐伏着一条北东向深大断裂带。地震区内的解元集－小留集断裂与北西向的成武－定陶断裂构成共轭破裂导致藻泽５．９级地震发生，北东向断裂是其主要的发震构造。由菏泽５．９级地震前沿发震断层的ＭＬ≥３．０级地震震中迁移、震源深度的变化及跨断层形变测量资料表明，发震断层在区域构造应力场的作用下逐步克服障碍，使断层贯通，与此同时在发震构造断层面上 相似文献
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2018年12月24日在西藏日喀则市谢通门县发生MW5.6地震。利用Sentinel-1A卫星数据和D-InSAR技术,获得该地震LOS方向的同震形变场图像,并以此为约束反演地震断层的几何参数和同震滑动分布特征。反演结果表明,谢通门MW5.6地震发震断层近南北走向,断面倾向西,倾角约35°,破裂长度约12 km,同震滑动主要集中在4~11 km深度范围内,以正断倾滑为主,最大滑动量0.18 m,矩震级MW5.6。2018年谢通门地震发震构造是谢通门—申扎伸展断裂系中的一条新生盲断层。 相似文献
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《地震地质》2017,(1)
根据喜马拉雅断裂系的构造形态,采用缓倾角反铲型断层模型模拟MHT上地震破裂部分的坡坪式发震构造。利用Alos-2及Sentinel-1获取的InSAR数据,反演获得了2015年尼泊尔Gorkha地震及其最大余震Kodari地震的同震滑动分布模型。与单独利用Alos-2或Sentinel-1 InSAR数据的反演结果相比,利用Alos-2和Sentinel-1 InSAR数据联合反演能够提供Gorkha地震破裂的更多细节信息,尤其对深部信息的约束更加明显。联合反演得到的破裂深度最大可达24km,穿过了该区域的闭锁线,到达了闭锁和蠕滑的转换区域。反演的断层模型倾角在3°~10°之间,最大滑动量出现在地下17km处,约4.5m。Gorkha地震和Kodari地震发震性质相似,都是发生在MHT断层上的低角度逆冲型地震,其中Gorkha地震略带右旋分量。反演结果还显示,Gorkha地震与Kodari地震的破裂滑动在空间上存在互补性,Kodari地震就发生在Gorkha地震的破裂空区内。通过计算Gorkha地震对Kodari地震发震断层的库仑破裂应力加载,发现Kodari地震震中恰位于库伦破裂应力正负交界区域,库仑破裂应力加载达0.4MPa,表明Kodari地震可能受到了Gorkha地震的触发。 相似文献
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本文采用一个非均匀破裂圆盘位错模式,考虑到介质-仪器系统的影响,计算了它在不同幅射方向的P波初动位移与半周期,以及几组用于测定震源参数的理论曲线。在采用1/4周期测定介质的Q值和球面拟合震源机制解的基础上,给出了一个小震震源参数与震源机制的联合测定方法。该方法的实质是,将震源断层面作为被测参数的一部分,并同时考虑它对其它被测参数的影响,从而获得单个小震震源参数与震源机制的相应解。最后,根据新丰江水库区四个台的小震资料作了实测与分析,所得结果为:介质的平均Q值约450,地震矩1019——1020达因厘米,平均应力降约35巴;其震源机制解亦反映了本区构造应力场的主要特征。 相似文献
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安徽地区震源参数特征研究 总被引：1，自引：0，他引：1
根据安徽数字测震台网记录的23个地震波形事件,首先采用Atkinson方法得到安徽地区的非弹性衰减特征,再用Moya方法得到24个台站的场地响应。在此基础上,扣除传播路径、场地响应和仪器响应的影响,利用遗传算法得到2009年以来安徽测震台网记录的42个ML≥2.0地震的震源参数,并对这些震源参数特征进行了系统的分析与研究。研究结果表明,安徽地区地震的地震矩与近震震级之间存在较好的线性关系,近震震级与矩震级存在一定的偏差,应力降与近震震级存在明显的正相关,震级越大,拐角频率越小,震源破裂半径越大。 相似文献
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We derive the relative moment rate function for the shocks with Mw > 5 in the 1997-98 central Italy seismic sequence, started with the Mw = 5.7, 09/26/97 00:33 event, by applying an empirical Green functionmethod. By using three conveniently placed broadband MedNet stations we obtain apparent source time functions indicating clear directivity effects for all of the analysed earthquakes, with rupture propagation generally directed outward from the epicentral area of the09/03/97 foreshock sequence. Taking a simple source model, forward modeling is utilized for determining fault parameters such as length, rupture propagation velocity and direction and, for the three major events,slip distribution. The effects of the break propagation directions onthe sequence evolution is discussed. A possible inconsistencyresults for the shallow 04/03/98 shock, which could be avoided if alink with the deep 03/26/98 event is assumed.Our analysis evidences the importance of a quick determination for the fault parameters in order to image the possible induction of fracturing on nearby structures. 相似文献
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The seismicity and tectonic stress field characteristics of the Longmenshan fault zone before the Wenchuan MS8.0 earthquake 
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下载免费PDF全文 The seismicity of Longmenshan fault zone and its vicinities before the 12 May 2008 Wenchuan MS8.0 earthquake is studied. Based on the digital seismic waveform data observed from regional seismic networks and mobile stations, the focal mechanism solutions are determined. Our analysis results show that the seismicities of Longmenshan fault zone before the 12 May 2008 Wenchuan earthquake were in stable state. No obvious phenomena of seismic activity intensifying appeared. According to focal mechanism solutions of some small earthquakes before the 12 May 2008 Wenchuan earthquake, the direction of principal compressive stress P-axis is WNW-ESE. The two hypocenter fault planes are NE-striking and NW-striking. The plane of NE direction is among N50°?70°E, the dip angles of fault planes are 60°?70° and it is very steep. The faultings of most earthquakes are dominantly characterized by dip-slip reverse and small part of faultings present strike-slip. The azimuths of principal compressive stress, the strikes of source fault planes and the dislocation types calculated from some small earthquakes before the 12 May 2008 Wenchuan earthquake are in accordance with that of the main shock. The average stress field of micro-rupture along the Longmenshan fault zone before the great earthquake is also consistent with that calculated from main shock. Zipingpu dam is located in the east side 20 km from the initial rupture area of the 12 May 2008 Wenchuan earthquake. The activity increment of small earthquakes in the Zipingpu dam is in the period of water discharging. The source parameter results of the small earthquakes which occurred near the initial rupture area of the 12 May 2008 Wenchuan earthquake indicate that the focal depths are 5 to 14 km and the source parameters are identical with that of earthquake. 相似文献
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The integral characteristics of source geometry, source duration, and rupture propagation for the Sumatra-Andaman earthquake of December 26, 2004 and for the March 28, 2005 earthquake near northern Sumatra have been determined. The source parameters were found by analyzing records of the higher orbits of long-period surface waves. The results are compared with the large-scale average characteristics of tomographic models for the source process based on different data sets that diverge in some details, as well as with the aftershock distribution for the considered earthquakes. 相似文献
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The parameters of split S waves from local weak earthquakes along eastern Hokkaido Island are studied over the period of 2003, including the strong Tokachi-oki September 26, 2003 earthquake (M = 8.0). Earthquake records of five stations belonging to the ISV seismological network were used. The studies of the split S wave parameters showed that they vary in space and time along Hokkaido Island. The zones of the Hidaka Mountains (ERM, MYR), Tokachi Plain (IWN, URH), and Kushiro Plain (AKK) are distinguished along Hokkaido. The anisotropy coefficients beneath the ERM, MYR, IWN, URH, and AKK stations attain 10.5, 10, 5, 3.5, and 6.5%, respectively. Beneath ERM, azimuths of the fast S wave (?) are predominantly in the N-S direction until July and in the E-W direction from July (parallel and normal to the Japan trench strike). By the time of the Tokachi-oki earthquake, the ? directions were oriented SE in agreement with the direction of the Pacific plate motion. The ? directions on the northern side of the Hidaka Range (MYR) are predominantly orthogonal to those beneath ERM, which can be evidence for differences in the direction of deformations on opposite sides of the range. Higher seismicity, the variation of S wave parameters, and a high anisotropy of the medium point to an intense development of deformation (dilatancy) processes in the area of the Hidaka Mountains. The fast wave azimuths beneath AKK are predominantly 50°–70°, and this orientation is consistent with the direction of migration of the Kurile arc front along the trench. Beneath IWN, the azimuths ? are oriented along the N-NE directions, and beneath URH, along the direction of the Pacific plate motion (100°–150°). Strengthening of mechanical properties of the medium and development and accumulation of shear deformations in a subhorizontal plane are supposed to take place in the Tokachi Plain area. 相似文献
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溧阳——介休——五原北西向地震条带,是唐山地震后华北地区地震活动最为活跃的地带。通过研究发生在这条带上强震的震源机制,破裂过程,震源参数及迁移特点,发现这条带上的较强地震具有以下特点: 1.ML5.0级地震的破裂面走向均为北西向,与条带的总体走向基本一致。反映这些地震具有沿破裂面方向迁移的特点。 2.强震是从中间向北西及南东两个条带的延伸方向交替扩展迁移的,并且强度有逐个增大的趋势。而1980年3月9日在条带上平遥地区发生ML=5.7级地震后,再不具备上述迁移,震级增大的特点。 3.截止现在,均以中强震释放能量。其中多数的主压应力P轴与华北地区统一的主压应力方位基本一致,但仍有几个强震与华北地区总体走向明显不同,说明局部条件的影响在这个带上有时可以起主导作用。 相似文献