アナログモデル実験で再現された付加体構造に対する反射法地震探査記録の合成

抄録

The aim of this study is to construct database of interpretation templates by synthesizing the seismic responses on the complex geologic structures reproduced by scaled analogue modeling. We combine such “analogue geological modeling” and “seismic modeling” to obtain clear seismic responses of complex geological structures.
The procedure starts with an “analogue geological modeling” that uses granular materials to reproduce a three-dimensional geological model of thrust-and-fold belt type of deformation. Then the detailed digital structural geometry is reconstructed by digitizing the stratigraphic boundaries of the model sections. The 3D geometry is then used to execute “seismic modeling”, and the synthetic seismic record is obtained. The complex wave field recognized in the synthetic seismic sections shows the influence of the three-dimensional structure. Seismic data generated by the modeling are processed with 2D migration technique to make depth images. These sections can be adopted for investigation of the interpretation pitfall by comparing inline and cross line data sets.
The features of the synthetic seismic sections are commonly observed on the actual seismic profiles at the Nankai Trough area. This fact suggests that the analogue model experiments are valid and our approach is effective. We are going to apply this approach to other geological structures, and construct data base of templates that can be used for the interpretation work in the future. Such database will help improving efficiency of petroleum explorations, which will be carried out in more and more complex geology.