兰州盆地活断层的高分辨率浅层地震勘探技术

High-resolution Shallow Seismic Prospecting Techniques for Active Fault Investigation in Lanzhou Basin

针对城市活断层浅层地震探测的一些技术问题,在兰州盆地的金城关断层和刘家堡断层沿线开展活断层浅层(50 m以内)地震勘探技术研究。主要采用纵波和横波多次覆盖共CMP点地震反射方法,获得了目标场地地震图像资料,尤其横波地震剖面更加清晰地反映出超浅层构造空间特征。以红艺村测线(HYC)和师范学校西测线(SFXX)为例,分析总结了数据采集、资料处理、剖面解释三方面浅层活断层地震探测的技术要点。结果可以为兰州市及类似复杂构造地区活断层地震调查提供技术参考。

Focused on some technique problems in the shallow seismic prospecting for active faults in urban area, research work on the high-resolution shallow seismic prospecting technique is taken across the Jinchengguan fault and the Liujiapu fault in Lanzhou basin. Both P- and SH- wave CMP reflection methods are used to find out the characteristics of active fault in the very shallow strata（ ≤50 m）. Those seismic profiles of the target area reveal the characteristics of tectonic deformation evidently, especially the SH-reflection profiles. In the paper, the key technical points such as data acquisition, data processing and profile interpretation are summarized by using HYC and SFXX survey lines as the examples. The result will be beneficial to further geophysical investigation for active faults in Lanzhou and other area.