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利用华北遥测台网和首都圈数字地震台网112个台站记录到的1993—2004年发生在首都圈地区3983次地震的P波绝对到时资料和相对到时资料,采用双差地震层析成像方法联合反演首都圈地区的地震震源参数,给出了2809次地震的重新定位结果.经地震重新定位后,P波绝对走时均方根残差由初始的1.2s降为0.3s,定位精度有了非常显著的提高.重新定位后的地震震中更集中分布在断层带地区,条带状更为清晰.在唐山地区的唐山—大城断裂带,地震主要集中在断裂带内,两侧的地震比较稀少.从重新定位后的震中分布可以看出,研究区域内的地震活动带呈现更明显的北北东向和北西西向的条带状分布,说明这两组方向的断裂最为活跃.用双差地震层析成像方法得到的唐山地区的地震震源位置,沿北东方向剖面在深度上呈现明显的3个小震群的特点,震源最大深度为25km.唐山地区地震重新定位结果的对比性研究表明,双差层析成像方法得到的震源参数的精度高于常规地震层析成像方法和双差法.
Using P-wave absolute arrival time and relative arrival time data of 3983 earthquakes in the capital circle area from 1993 to 2004 recorded by telemetry stations in North China and 112 stations in the metropolitan circle digital seismograph, double-difference seismic tomography The inversion results of 2 8009 earthquakes are obtained by using the imaging method to retrieve the seismic source parameters of the metropolitan area.After the earthquake repositioning, the root mean square residual error of P-wave absolute travel time is reduced from 0.3s to 0.3s The accuracy has been significantly improved.Researched earthquakes are more concentrated in the fault zone, the strip shape more clearly.In Tangshan - Tangshan fault zone, the earthquake is mainly concentrated in the fault zone, the two sides Seismic shocks are rather sparse. According to the post-relocation epicenter distribution, the seismic activity zones in the study area show a more pronounced north-north-east and north-west-west stripe distribution, indicating that the two groups have the most active faults. The locations of the epicenter of the earthquake in Tangshan area obtained by the double-difference seism tomography method show the obvious features of three small swarms in the depth along the northeast direction with the maximum depth of 25km. Comparative study results show that the positioning accuracy of source parameters double difference tomography obtained than conventional seismic tomography method and a double difference method.