2006年文安地震孕育、发生的应力场动态图像  

Dynamic Images of Stress Field during Genesis and Occurrence of the 2006 Wen'an Earthquake

作　　者：王晓山[1] 刁桂苓[1] 冯向东[1] 赵英萍[1] 

机构地区：[1]河北省地震局,河北石家庄050021

出　　处：《地震研究》2011年第3期266-270,404,共5页Journal of Seismological Research

基　　金：中国地震局地震行业科研专项(200808053);山东省自然科学基金项目(Y2005E02);河北省科技支撑计划(09276904D)共同资助

摘　　要：利用数字地震记录反演了河北地区ML≥2.0地震的震源机制解,通过对震源机制解各参数的统计分析,发现应力轴的优势取向和华北构造应力场完全吻合,反映它们受到大区域动力因素的制约。进行震源机制解一致性参数计算,并对一致性参数进行空间平面插值,得到了2006年文安地震前震源机制解一致性参数空间动态的变化特征。文安地震前在震源区附近出现了大范围的一致性参数低值区域,并且低值区域面积随时间增长逐渐扩大,这可能是中强震前的一种具有动力学意义的前兆现象。Through digital seismic waveform data, the focal-mechanism solutions of the ML ≥2.0 earthquakes in l-iet）el region are inversed. The analysis of the solutions shows that the dominant orientation of stress axial is completely consistent with that of the tectonic stress field of North China. This phenomenon indicates that the focal-mecha- nism solutions are restricted by the dynamic factors in a large-scale area. The consistent parameters of the focal mechanism solutions are calculated and spatially interpolated and their characteristics of spatial dynamic variation before the 2006, Ms5.1, Wen＇an Earthquake are got. The result showed that a larger area with the low value of the consistent-parameters appeared around the focal region before the Wen＇an Earthquake, and it expanded grad- ually along with time. This phenomenon might be a dynamic precursor of the medium-strong earthquake.

关 键 词：震源机制解 一致性参数 空间插值 文安地震 

分 类 号：P315.7[天文地球—地震学]