利用双差地震定位方法,针对京西北地区(39.5°—41.5°N,113.5°—116.5°E)2008—2016年记录的地震进行重新定位,最终得到1819次地震精定位结果.分析表明:地震密集区域多集中分布在NE和NW向断裂交汇区域,成条带的地震走向更加清晰,成簇性地震分布更加收敛,体现了断裂对震中分布具有较强的控制作用;震源深度优势分布主要集中在4—14 km范围,表明京西北地区地震主要发生在的中上地壳;震源深度剖面显示,在不同的地震密集区,孕震深度有一定差别,揭示了断裂的深部展布特征,反映了一些地区深部发震构造的复杂性.%Using double difference position method, the seismic records in northwest Beijing(39.5°—41.5°N, 113.5°—116.5°E)since 2008 to 2016 is relocated and the new hypocentral location of 1819 earthquakes are obtained. The results show that the concentrated areas of earthquakes focus mostly in the join regions of the faults in NE and NW strikes. The strike of cluster earthquakes becomes clearer, and more convergence, reflecting that the fracture having a strong role in the earthquake epicenter distribution. The dominant distribution of focal depth is in the range of 4—14 km, it indicated that the earthquakes occurred mainly in the middle upper crust. The focal depth profile, showing in the dense region of different earthquake, shows that the seismogenic depth has certain difference, and also reveals the deep fracture distribution characteristics, while also reflects the complexity of the seismogenic structure in deep part.
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