糊北荆门处于长江三峡东部,南漳——荆门断裂南端附近。近十多年来经常发生一些小震(图1)。这些地震中有些地震定位困难,精度较低,利用和达法确定震源位置时,震源深度多为30多公里,甚至达40—50公里,令人费解。有人认为该区地壳结构特殊,存在一个较深的震源区,也有人认为可能是震相识别和定位中存在错误,两种看法均无充分证据。多年来成为长江三峡及邻区地震活动分析中的疑难问题。为此,我们详细复核了三峡地震台网和钟祥地震台的地震记录图,考察了记录图形,同时调查了荆门附近的放炮情况,确认1976年以来公布的地震目录中有42次1.7(?)M_L(?)2.6级地震均为人工爆破(见表1),炸药量在几吨至十几吨(T.N.T)之间。本文总结了这些爆破的记录图形特征,并根据这些定点爆破资料初步估算该区直达波速度和明显的速度介面深度。 Poke north Jingmen in the eastern Three Gorges of the Yangtze River, near the southern tip of Nanzhang - Jingmen fault. Some minor earthquakes often occur in the past ten years (Figure 1). Some of these earthquakes are difficult to locate and have low accuracy. When determining the location of the hypocenter by the sum-up method, the focal depth is more than 30 km or even 40-50 km, which is puzzling. Some people think that the crustal structure is special in this area, and there is a deep source region. Some people think that there may be mistakes in identifying and locating seismic phases, and neither of them has sufficient evidence. Over the years as the Three Gorges and adjacent areas of seismic activity in the analysis of difficult problems. To this end, we reviewed in detail the seismograms of the Three Gorges Seismic Network and the Zhongxiang Seismic Station, examined the recording patterns and investigated the blasting near Jingmen. It was confirmed that there were 42 1.7 (?) Earthquakes in the catalog of earthquakes released since 1976, M_L (?) 2.6 earthquakes are manual blasting (see Table 1), the amount of explosives in a few tons to ten tons (TNT) between. This paper summarizes the recorded graphic features of these shots, and based on the data of these shots, estimates the direct wave velocity and the apparent velocity interface depth in this area.