瀑布沟水库库区介质衰减、台站响应和震源参数研究

Study of Attenuation Characteristics, Site Response and Seismic Source Parameters of the Pubugou Reservoir Region

摘要:

利用数字地震台网2007年1月到2011年12月记录到的瀑布沟水库及邻区地震波形资料，采用Atkinson方法计算了库区介质品质因子；并利用Moya方法计算了台站场地响应；在获得介质品质因子和台站场地响应的基础上联合反演计算了瀑布沟库区67次构造地震和208次爆破地震的震源波谱参数，同时讨论了它们的时空特征。结果表明：瀑布沟库区Q值与频率的关系为Q（f）=47.1*f0.92；各台站的场地响应随频率变化不大，场地响应均在1附近。

Abstract:

On the basis of digital seismograms recorded by the Pubugou reservoir digital seismic network, we obtained the nonelastic coefficient of Pubugou reservoir area by using the method proposed by Atkinson. The site response of each station was obtained by using the Moya method. The frequency-dependent Q（f） at the reservoir area is estimated as Q（f）=47.1*f0.92； the site response of each station is approximately 1.0, showing little amplification. On the basis of the Q（f） and the site responses, we detected approximately 67 tectonic earthquakes and 208 source parameters of blasting shocks by using the Atkinson inversion method. The results show obvious differences in the source parameters of the tectonic earthquakes and blast shocks. The parameters near the reservoir dam area and Hanyuan County were lower because of the blasting vibration.