Temporal Variation Of Vp/Vs Ratio Before And After Jinggu Earthquake

In order to study on October 7,2014,6.6 earthquake ching(N23.4 E100.5)the wave velocity variation characteristics of the process,this paper use many sets and da,single ChanZhen places valley earthquake gestation of earthquake wave velocity change time change process was studied.First of all,using more than one and the method to calculate the pregnancy the quake-hit areas and the surrounding area(N22?24,E100?102)in October 2008 to September 2016,the average wave velocity ratio,and further narrowing the scope of research(N23?24,E100?101)than the same period the average wave velocity,and the seismic ray coverage before and after the analysis,eliminate the influence caused by uneven distribution of rays.Results show that the average wave velocity was one year before the earthquake ching is reduced,before an imminent recovery,and in the December 6,2014,5.8,5.9 magnitude aftershock after a brief recovery,and on November 14,2015,a 4.6 magnitude aftershock after recovery.Secondly,using the single ChanZhen method based on repeated earthquake research idea,to the shock of the earthquake zone of seismic ray through the pregnancy plexus-wave velocity change stations to study found that:for the earthquake plexus to ray through the pregnant earthquake zone in the station or belong to ching breaking wave velocity ratio and apparent velocity in the year before start to appear different low amplitude of area of recovery before the earthquake.At the same time,because the surrounding plexus in the king valley after the earthquake and the number of ching aftershock sequence in this paper,through research into the surrounding five stations to study wave velocity change scene valley after the earthquake the wave velocity variation of the focal region and its adjacent areas.Results show that the earthquake wave velocity ratio after the initial larger change after a short time(about half a month)to restore again low,on December 6,2014 strong aftershocks,wave velocity ratio rose,until November 14,2915,ching strong magnitude 4.6 aftershock after fully recovered.Calculated at the same time of each bundle-stations of apparent velocity,found that obvious changes in the apparent velocity wave velocity than change.In this paper,we study the two main results:ching before the earthquake wave velocity variation characteristics as follows:the decline in the imminent rise-before earthquake recovery,ching focal region and its adjacent area before the earthquake magnitude 6.6 earthquake appeared obviously last 1 year or so of wave velocity ratio low process change(about 1.2%);Ching after the main shock,before the next strong aftershocks,wave velocity than before the decline-low-the imminent recovery-the process of the earthquake,the earthquake aftershock earthquake situation judgment has the certain reference function.