地壳的Q结构与观测结果的解释

本文分析了地壳Q结构对于实测Q值结果的影响。对已发表的大部分实测数据进行分析,结果表明地震波射线路径与Q值显著相关。因此,在对实测的Q值空间分布状况进行解释的时候,不仅要考虑地震波频率的影响,还应对射线路径—距离效应进行分析和校正。本文还按照现有中国大陆地壳速度模型计算了地震射线在水平层状介质中的传播路径及震中距与射线最低点深度的函数关系,给出了华北及西南部分地区地壳Q结构。

THE STRUCTURE OF CRUSTAL QUATITY FACTOR AND THE EXPLANATION OF OBSERVED RESULTS

This paper deals with the effect of the structure of crustal quality factor Q on the measurement of Q value.Most of reported results show that there is some positive correlation between Q value and ray path of seismic waves.Therefore,for explaining the spatial distribution of observed Q values,not only the effect of seismic frequencies,but also analysing and correcting the effect of ray path on epicentral distance must be considered.Finally,according to current crustal velocity model of Chinese Continent,by calculating the seismic ray path in horizontal layered medium,the authors obtained the functional relation between the epicentral distance and the maximum depth of ray path,and give the structures of crustal Q in North China and partial areas of Southwest China.