岷县漳县MS6.6地震近场地震波谱质心分布与发震构造

采用近场15个地震台记录的2013-07-22岷县漳县MS6.6地震主震波形，计算平均谱质心频率并给出地理分布。结果表明，高频分布椭圆分布在临潭-宕昌断裂主支的西南侧。由此认为，这次地震的逆冲块体应是处于临潭-宕昌断裂西南侧的另一平行次级断层之间的块体，发震构造并非临潭-宕昌断裂；谱质心最高频率的分布范围揭示了地震波能量辐射最强的区域，与现场考察的宏观极震区相吻合。

The Seismogenic Fault and Near Field Distribution of Spectrum Centroid for Minxian-Zhangxian MS6.6 Earthquake

In this paper, the vertical component seismic record data of 15 near-field stations of the Minxian-Zhangxian MS6.6 earthquake are used to analyze the main shock. The average centroid frequency is calculated, and its geographical distribution is given. The results show that the high frequency distribution is in southwestern sides of the Lintan-Tanchang fault, not along the Lintan-Tanchang fault; the elliptical long axis parallels to the fault strike. That is to say, the thrust block of this earthquake is between the southwest side of Lintan-Tanchang fault and the other fault. The geographical distribution of the highest frequency of the spectrum is in agreement with the macroscopic epicenter. It can be considered that the highest frequency region of the spectral centroid is the most serious area of earthquake disaster.