云南鲁甸6.5级地震序列的谱振幅相关系数变化特征

Variation Characteristics of the Correlation Coefficient of Spectral Amplitude of Yunnan Ludian M_S6. 5 Earthquake Sequence in 2014

使用云南数字地震台网记录的波形资料,计算了云南鲁甸MS6.5地震序列的谱振幅相关系数。8月3日19时至8月4日5时,谱振幅相关系数由序列的最小值持续升高至最大值,期间发生了4次4级余震,表明震源机制逐渐趋于一致,4级地震发生在谱振幅相关系数波动相对较大的阶段。其后谱振幅相关系数一直维持在0.82的高值状态,8月17日距离鲁甸地震震中110 km的同一构造区永善发生MS5.0地震,表明谱振幅相关系数高区域应力水平较高。

Using seismic wave recorded by Yunnan Digital Seismic Network, we calculated the correlation coefficient of spectral amplitude of Ludian Ms6. 5 earthquake sequences in Yunnan in 2014. From 19：00 on Aug. 3 to 05 ： 00 on Aug. 4, four times of ML≥4. 0 aftershocks occurred in the period of the correlation coefficient of spectral amplitude raised from minimum to maximum of the earthquake sequence, and the focal mechanism became to be more consistent gradually in this period. Then, the correlation coefficient of spectral amplitude kept at a high state of 0. 82. A Ms5.0 earthquake occurred at Yongshan area on Aug. 17, which belongs to the same geological structure with Ludian earthquake and the two epicenters are only 110 km apart All these indicate that the higher correlation coefficient of spectral amplitude is corresponding to the high level of the stress filed.