青海称多M_(S)5.3、甘德M_(S)3.8震群谱振幅相关系数变化特征

Characteristics of correlation coefficient of the spectral amplitude of Chengduo M_(S)5.3 earthquake swarm and Gande M_(S)3.8 earthquake swarm in Qinghai Province

利用青海省数字台网记录的地震波形资料,计算了2018年青海称多M_(S)5.3震群和2021年青海甘德M_(S)3.8震群的谱振幅相关系数,结果显示:称多震群谱振幅相关系数分布在0.74—0.91,前震序列谱振幅相关系数相对偏高;甘德震群谱振幅相关系数分布在0.41—0.52,最大地震M_(S)3.8发生前2天谱振幅相关系数略有升高,2次地震余震谱振幅相关系数均逐渐减小。对比2次序列发现视应力均存在高值的变化过程,但异常不显著。

Using the seismic waveform data recorded by Qinghai Digital Network,the correlation coefficients of spectral amplitude of Qinghai Chengduo M_(S)5.3 earthquake swarm in 2018 and Qinghai Gande M_(S)3.8 earthquake swarm in 2021 are calculated.The results show that the correlation coefficients ofthe spectral amplitude of Chengduo earthquake swarm are in the range of 0.74-0.91,and the correlation coefficients ofits foreshock sequence are relatively high.The correlation coefficients of the spectral amplitude of Gande earthquake swarm arein the range of 0.41-0.52,and the correlation coefficient of spectral amplitude increases slightly two days before the main earthquake.The correlation coefficients of the spectral amplitude of the two earthquakes’aftershocks decrease gradually.Comparing the two sequences,it is found that the apparent stress has a high-value change process,but the significance of the anomaliesis not obvious.