Underground Imaging Using Shear Waves: Stacking Method of the Reflected Scattered Waves

Abstract

Electrical and electromagnetic methods are widely used to detect buried relics. However, in marshes or swamps where the moisture constant is high, these methods are difficult to use, because the electromagnetic wave is strongly attenuated by the presence of water. Although seismic prospecting utilizing elastic waves and the common depth point stacking method (CDP method), which assumes reflection at the stratum plane, are suitable for the investigation of stratigraphic structure ( e.g., at depths of 100 to 1000 m ), commercial equipment and the CDP method are not suitable for detecting relics which exist at shallow depths ( e.g., 0–10 m ). Therefore, we proposed an underground imaging method using shear waves and a method based on stacking of reflected scattered waves in which point reflection is assumed. The experimental results confirm the feasibility of our proposed method. However, the resolution of the underground image is insufficient to detect relics. Therefore, an improvement in the resolution is necessary.