用频谱研究小金地震震源参数  

A STUDY OF THE SOURCE PARAMETERS OFTHE XIAOJIN EARTHQUAKE BY SPECTRUM ANALYSIS

作　　者：赵英萍[1] 韦士忠 陈绍明[1] 

机构地区：[1]河北省地震局黄壁庄地震台,国家地震局地球物理研究所,河北省地震局

出　　处：《华北地震科学》1994年第4期68-75,共8页North China Earthquake Sciences

摘　　要：本文用ＣＤＳＮ宽频带数字记录，计算了不对称双侧破裂模式的Ｐ波远场位移谱，用频谱方法研究中强地震的震源参数，并将它应用于１９８９年９月２２日四川小金ＭＳ＝６．６级地震的震源参数研究中。研究结果表明，断层长度为８．４ｋｍ；宽度为２．９ｋｍ；动力学参数：地震矩为４．７×１０１７Ｎ·ｍ；平均位错６４．６ｃｍ；应力降１８．９×１０５Ｐａ．并用余震震源深度分布的空间图象证明了：地震断层为走向ＮＷ３３°的走滑断层，断层面倾向为北东，倾角约为２０°。In this paper, using the CDSN broad - band digital recordings, we calculated the spectrum of thedisplacements of P waves in the far-field radiated from a fault whose mode of rupture is bilateral andasymmetrical. The source parameters of moderately strong eaarthquakes are studied by the spectralmethod, and are applied to the Xiaojin earthquake with M= 6. 6 in Sichuan Province which occurred onSeptember 22, 1989. The results show that the fault is 8. 4km long; 2. 9km wide. The dynamic parameters are estemated as fallows: the seismic moment, 4. 7 × 1017N. m F the average dislocation, 64. 6cm,stress drop, 18.9 × 105Pa. We also used the three-dimensional image of the focal depth distribution ofthe after shocks to prove that the earthquake malt is a strike-slip one, striking NW33°, dipping NEwith dip angle being 20°

关 键 词：震源参数 数字记录 频谱 小金地震 地震 

分 类 号：P315.63[天文地球—地震学]