A STUDY OF THE CODA Q-VALUE AND ITS RELATIONSHIP WITH FREQUENCY OF THE LUANXIAN DISTRICT

Through processing the data of digital seismic records with high precision collected in the Luanxian Region,the Qc values of the medium corresponding to seven different frequencies (f=1.5,3.0,6.0,10.0,15.0,20.0,25.0 Hz) have been obtained by using the coda wave analysis method. It is found that the Qc value versus frequency can be approximated by the relation Qc=afb. We have obtained a= 46,b=0.85 for shorter lapse time and a= 72,b=0.90 for longer. The large values of b show the strong dependence of Qc on frequency. The value of a (for Qc at 1 Hz) is quite small. These results indicate that Luanxian is a region with strong' tectonic motion.