川滇地区强余震的震级分布和距离分布特征          下载免费PDF全文

吕晓健  高孟潭  高战武  米素婷 《地震学报》2008,30(4):397-404

研究了川滇地区1966年以来12次主震震级MSge;6.5的地震序列中,主震与强余震（本文定义为所有MSge;5的余震）震级差分布特征和强余震与主震距离的分布特征. 结果表明,强余震与主震震级差服从截断的指数分布,据此推导出了强余震与主震震级差的概率密度函数; 强余震距离分布的优势范围是距主震10——39 km,且强余震与主震震中的距离服从正态分布.   相似文献   

5月12日汶川8.0级地震强余震观测的电磁同震效应   总被引：8，自引：2，他引：6  

汤吉  詹艳  王立凤  徐建郎  赵国泽  陈小斌  董泽义  肖骑彬  王继军  蔡军涛  徐光晶 《地震地质》2008,30(3):739-745

2008年5月12日汶川8.0级大地震发生后,在武都汉王地震台及其附近地区进行了为期22d的余震序列电磁异常连续监测,观测到多次余震事件的电磁同震现象。通过与汉王强震台的地震记录数据比较发现,同震信号存在于所有的电场和磁场记录分量中,它们与地震波的到达同步,而不是在地震发生的时刻出现。地震发生时的电磁辐射信号似乎在记录数据中有所显示,但是与地震波到达观测点时的电磁信号相比幅度要小得多  相似文献   

汶川8.0级地震序列及相关问题讨论   总被引：13，自引：0，他引：13  

蒋海昆  黎明晓  吴琼  宋金 《地震地质》2008,30(3):746-758

汶川8.0级地震序列具有明显的分段特性,较强余震分布于茂县、绵竹以南及平武以北。主破裂过程在中南段以逆冲为主,序列逐渐衰减,呈主余型的序列衰减特征;北段是汶川地震破裂过程的终止区域,主破裂过程在该区域以走滑为主,形成多震型的序列特征,也成为汶川序列较大余震的主体活动区域。序列较强余震活动明显受引潮力调制,大多数较强余震发生在固体潮大、小潮时段,并且16时前后是较强余震的优势发震时段。序列衰减系数p值随时间增加而逐渐增大,最终基本稳定在1附近变化。结合以往的研究,对序列类型及最大强余震震级、强余震活动持续时间等进行了初步讨论。初步的统计结果还显示,8级左右强震序列中主震与最大余震之间的震级差正比于主震破裂尺度,这意味着当震级大体接近时,较大的破裂尺度与较为充分的能量释放相对应  相似文献   

Seismic Damage Characteristics of the Wenchuan Great Earthquake on May 12,2008 and Suggestions for Disaster Prevention     

Gao Mengtan  Zhou Bengang  Pan Hua 《中国地震研究》2009,23(4):480-487

The paper introduces the tectonic background,focal mechanism and distribution of aftershock of the Wenchuan earthquake on May 12,2008. The earthquake is considered to be the result of long-term interaction between the eastward movement of the Bayan Har Block and the Sichuan Basin. Most of the earthquake energy was released in an area (the seismic source body) 330km long,52km wide and 20km deep over 100s. Energy release in the source body was extremely uneven,and strong ground motion in the epicenter area shows obvious asymmetrical character in the time and space scale. The high-intensity area is distributed along the source body,and the intensity distribution bears an obvious anomalous characteristic. The investigation results indicate that more than 90 percent of casualties caused by this earthquake were in the areas of intensity IX or above. Houses,schools and hospitals etc. suffered serious damage. Lifelines such as transportation,water conservation etc. also suffered significant damage. Besides,earthquake-triggered avalanches,landslides,mud-rock flows and so on were extremely serious. The tremendous earthquake disaster highlighted the deficiencies in disaster prevention and mitigation management,scientific earthquake research,technology and application of earthquake disaster prevention,and publicity of earthquake preparedness and disaster reduction.  相似文献   

Tectonic Features of the M_S8.0 Wenchuan Earthquake and Its Aftershocks     

Tian Qinjian    Diao Guiling  Hao Ping  Feng Xiangdong  Sun Qing 《中国地震研究》2009,23(4):383-391

The M8.0 Wenchuan earthquake occurred on the Longmenshan fault zone. Based on field investigation of the surface rupture and focal mechanism study of the aftershocks, we discuss the geological relationship of the main, secondary and triggered ruptures. The main rupture is about 200km long and can be divided into the south part and the north part. The south part consists of two parallel fault zones characterized by reverse faulting, with several parallel secondary ruptures on the hanging wall of the main fault, and the north part is a single main fault zone characterized by lateral strike-slip and reverse faulting. Compared to a 300km long aftershock distribution, the surface rupture only occupies 200km, and the remaining 100km on the northeast of the main rupture was triggered by aftershocks. Study on the ruptures of this earthquake will be useful for studying the earthquake risk evolution on the Longmenshan fault system.  相似文献   

Spatio-temporal point pattern analysis on Wenchuan strong earthquake     

Peijian Shi Jie Liu    Zhen Yang Agricultural College  Jiangxi Agricultural University  Nanchang  China China Earthquake Networks Center  Beijing  China 《地震学报(英文版)》2009,(3):231-237

For exploring the aftershock occurrence process of the 2008 Wenchuan strong earthquake, the spatio-temporal point pattern analysis method is employed to study the sequences of aftershocks with magnitude M≥4.0, M≥4.5, and M≥5.0. It is found that these data exhibit the spatio-temporal clustering on a certain distance scale and on a certain time scale. In particular, the space-time interaction obviously strengthens when the distance is less than 60 km and the time is less than 260 h for the first two aftershoc...  相似文献   

Characteristics of coseismic water level changes at Tangshan well for the Wenchuan MS_8.0 earthquake and its larger aftershocks     

Baojun Yin      Li Ma Huizhong Chen Jianping Huang  Chaojun Zhang  Wuxing Wang 《地震学报(英文版)》2009,(2):149-157

Coseismic water level changes which may have been induced by the Wenchuan MS8.0 earthquake and its 15 larger aftershocks(MS≥5.4) have been observed at Tangshan well.We analyze the correlation between coseismic parameters(maximum amplitude, duration, coseismic step and the time when the coseismic reach its maximum amplitude) and earth-quake parameters(magnitude, well-epicenter distance and depth), and then compare the time when the coseismic oscillation reaches its maximum amplitude with the seismogram from ...  相似文献   

关于用科氏力预测最大余震问题的讨论   总被引：1，自引：0，他引：1  

郭增建  郭安宁 《中国地震》2009,25(4)

对用科里奥利力效应预测余震最大强度的某些问题进行了讨论.并介绍了用该效应对2008年汶川8级地震的最大余震所作的正确预测.  相似文献   

科里奥利力对断层作用的统计研究   总被引：2，自引：1，他引：1  

盛书中  万永革  田力 《中国地震》2009,25(3)

首先给出了分解到已知断层面法向和切向上的断层错动科里奥利应力(简称为科里奥利法向应力和切向应力)表达式,然后从哈佛大学矩心矩张量目录中选取主余震资料进行分析,按断层分类研究了科里奥利法向应力和主震震级与其最大余震震级差及主震地震矩与余震地震矩总和之差的折合矩震级间的关系.研究结果显示:地震断层错动过程中虽然产生了使断层两盘相互拉离(或挤压)的科里奥利法向应力,它降低(或增加)了断层错动时断层面上的摩擦阻力,但是应力量值太小(科里奥利法向应力估计最大不到0.1MPa,即不到一个大气压),不足以对断层错动及主震能量释放产生影响,从而影响余震的最大震级和总体水平.  相似文献   

序列衰减与余震激发研究进展及应用成果   总被引：3，自引：0，他引：3       下载免费PDF全文

宋金  蒋海昆 《地震地质》2009,31(3):559

着重于序列衰减与余震激发,系统介绍了修改的大森公式、ETAS模型及BASS模型的最新理论研究进展及应用成果。修改的大森公式是迄今为止对序列衰减的最好描述,据此可对序列衰减特征进行定量表述。大森公式本质上是一种典型的现象统计模型,但由于其参数少、计算简单,并且确实能够反映序列衰减的总体特征,因而在实际中应用广泛。ETAS模型考虑了具有统计自相似特征的次级余震激发问题,次级余震激发强度与父地震强度有关,这在物理过程方面对大森公式进行了大大的拓展。由于考虑了次级余震的激发问题,ETAS模型不但在余震序列研究方面比修改的大森公式有了明显的进展,而且在诸如平静检测、余震群集剔除、背景地震活动评估、外因触发地震活动检测等方面也有诸多应用。BASS模型遵循修改的Bath定律,而ETAS模型遵循的是与父地震震级有关的相似率,这是BASS模型与ETAS模型的最大区别,因而相对ETAS模型而言,BASS模型是一种完全自相似的理想化模型,但目前基于BASS模型的应用研究尚不多见  相似文献