Subsurface imaging by seismic interferometry

摘要

The pseudo-reflection shot records can be generated by the cross-correlation of the transmission responses observed at the sensors located on the ground-surface, which is called "seismic interferometry" or "daylight seismic imaging." In this paper, we apply this technique to the field data observed by using several different types of micro-seismicity as seismic sources in order to appraise the practical applications of the seismic interferometry technology. Since this method requires a long record length, we newly developed a PC-based long-time seismic recording system with 96 channels. The experimental survey was carried out in a mountain area where two tunnels exists. Several micro-seismicity sources, for example running vehicles in the tunnel were adopted to make underground noise for the seismic interferometry. We acquired transmitted wave field generated by such sources moving in the tunnels. Obtained data were properly processed and it shows subsurface image clear enough to estimate underground structures and proved the seismic interferometry technology.