摘要
使用山东遥测台网 1 994～ 2 0 0 0年 (ML2 .8～ 4.2级 )间 75次地震的 30 0多条模拟地震资料和部分数字化资料 ,1 )测定了尾波振幅比和能量比 ,并估算了山东地区的尾波值和平均自由程 ,进而试求了吸收品质因子 Qi 和散射品质因子 QS,得出山东地区地震尾波的衰减主要是由散射所造成 ;2 )检验了用来定量描述尾波振幅随时间衰减状态的参数——尾波时间熵ST,得出山东地区中强震前尾波时间熵下降是明显的 。
Based on the simulated and digital earthquake records of 75 earthquakes recorded by telemetered seismic network of Shandong province from 1994 to 2000,the Coda amplitude ratio and energy ratio is determined, and the Coda Q-value as well as mean freedom distance in Shandong area is assessed.The absorption quality factor Qi and scattering quality factor Qs are also calculated.From those values we concluded that the attenuation of Coda wave in Shandong area was caused largely by scattering.Through examination to the parameter used to describe the attenuation of Coda amplitude with time(Coda time-entropy ST),we found that the attenuation of Coda time-entropy before medium and strong earthquakes is very clear,which may be useful in the prediction of medium and strong earthquakes..
出处
《华北地震科学》
2002年第1期25-31,共7页
North China Earthquake Sciences
