Using Apparent Stress for Post-seismic Tendency Determination:Taking Qianguo Earthquake Sequence as An Example

We calculated the apparent stress of the 11 M_S ≥ 4.0 earthquakes in the Qianguo earthquake sequence occurred from October 31, 2013 to April 30, 2014 using their seismic waveform data. The results indicate that the apparent stress and corner frequency of approximate magnitude earthquake in the source region increased before the occurrence of the 3 M_S ≥ 5.0 earthquakes. It means that the stress increased in the source region. Then the apparent stress and corner frequency of earthquake in the source region decreased. We do the post seismic trend judgment upon the results.