Abstract Using digital waveform data recorded by region seismic networks along with relevant seismic phase data collected by the China seismograph network, we calculate the attenuation characteristics and site response for the Panzhihua-Xichang area. The frequency dependent Q(f) is obtained by the iterative grid-search technique described by Atkinson and Mereu, based on a trilinear geometrical spreading model. The source spectra is determined by the model of Brune and the site responses of seismic stations derived by Moya’s method, which uses genetic algorithms. Our results demonstrate that the associated model for the regional quality factor for frequencies can be expressed as Q(f)=944f0.665 9 (from May, 2008 to December, 2013）and Q(f)=83.9f0.719 6 (from January, 2014 to June, 2015）for the Panzhihua-Xichang area. Site response results indicate that different stations show different amplifications. Site amplifications in the Panzhihua-Xichang area are between 1.13 and 6.93 times. For tectonically stable cratonic regions, the Q0 is usually high; in contrast, for tectonically active regions, such as the Panzhihua-Xichang area, the Q0 is generally low. Broken media caused by strong tectonic activity or upper-mantle heterogeneity and velocity structure may be the main reasons of low Q0 values in this area.
