考虑到长江三峡地震台网的实际观测条件,利用地震图上比较准确量得的(?)-(?)时间差,导出计算机定位直接搜索法中的准则函数,对三峡地区1959年以来仪器记录的地震进行重新定位,共得到216次弱震的震源位置,其震中平均误差约7km,震源深度平均误差的5km。另外还求得各次地震的虚波速度值。其空间分布特征的初步分析表明,随震源所在区域和深度的不同,虚波速度值存在较大的差异,它反映了该区地震波速分区和深度结构的特征。 Considering the actual observation conditions of the Three Gorges seismic network in the Three Gorges area, the criterion function in the direct search method of computer positioning is derived from the relatively accurate time (?) - (?) Obtained from the seismogram. The repositioning of the earthquakes resulted in a total of 216 hypocenter hypocenters with an average epicentral error of about 7 km and an average depth of focus of 5 km. In addition, the virtual wave velocity of each earthquake is calculated. The preliminary analysis of its spatial distribution shows that there is a big difference in the value of the virtual wave velocity with the location and depth of the focal source, which reflects the characteristics of the seismic velocity zoning and depth structure in this area.