应用于城市活断层调查的地震方法技术

Application of the Seismic Method to Detecting Active Faults

用地震方法探测城市直下型活动断裂是一种不可替代的勘探技术。地震方法能够准确确定断层的位置 ,但对于断层的地质年代问题 ,地震方法本身难以解决 ,然而结合钻孔资料和测区标准地质剖面 ,根据地震深度剖面 ,可以定性地 (或半定量地 )确定反射波组的地质年代。确定城市直下型活动断裂的上断点需要采用高分辨率的地震反射技术 ,为有效地确定深部断裂的几何特征 ,特别是确定深浅断裂构造之间的关系 ,反射地震方法优于折射地震方法。

The seismic method is a necessary exploration method for detecting active faults buried directly beneath major cities. The position of the faults can be determined accurately using the seismic reflection method, but geological ages of faults can not be determined by the method itself. According to seismic depth sections, the geological ages of reflection events can be ascertained qualitatively (or half quantitatively) combined with borehole data and standard geological profiles of the measuring areas. Detecting upper terminal point of active faults buried directly beneath major cities has need of using the high-resolution seismic techniques. The reflection method is better to the refraction method for determining effectively geometric features of deep faults, determining particularly relation between deep and shallow faults.