【摘要】 本文试用数字地震记录求取尾波Q值及其与频率的关系.在微机上处理触发数字地震仪记录的资料,原始记录经数字滤波器作窄带通滤波得到一组分频记录,经过时间序列分析的方法,可得到能量密度随时间衰减的曲线,该曲线比从可见记录求得的较为可靠.以散射模型的理论表达式进行曲线拟合,求得Q值及其与频率的关系.值得注意的是,这个结果对某一台站并非常数,尾波Q值是时间窗(即研究所用尾波的整个延续时间)的函数,其原因可能是由于不同到时的尾波采样区域和深度不同,以及多次散射的影响等.因此,当把Q值作为地震预报的一个参数时,延续时间是一个重要的可选择的因子.更多还原

【Abstract】 This study is an experiment of using digital seismic records to find the coda Q and its dependence on freqency. Data are recorded by triggered digital seismometers,and then are put into a microcomputer. After narrow band-pass filtering of the digital records,the digital seismograms become a set of pseudo-single frequency records. With the approach of time series analysis,decay curves of energy density against time are plotted. These curves are more reliable than those from visual seismograms. Fitting these decay curves to theoretical expression of a scattering model,the coda Q and its dependence on freqency are obtained. It can be noticed that these results are not constant for a certain station. The coda Q obtained is a function of time window which is the whole duration time of the coda used for study. The reason of this relation may be due to the difference in sampling area and depth for different arrival time of codas and the effect of multiple scattering. Therefore,when considering the coda Q as an earthquake prediction parameter,the duration time is an important factor to make choice.更多还原