SEGJ Technical Conference

Surface-wave phase velocity tomography for near-surface characterization using active source seismic data

Abstract We present a workflow to estimate phase velocity dispersion curves between two stations for surface-wave tomography using active source seismic data. To improve the stability of phase velocity estimation, we stacked cross-coherences between two stations from different shot gathers. We further applied a time variant window to give weight around surface wave travel time in phase velocity estimation using continuous wavelet transform (CWT). Our numerical and field examples demonstrated that the proposed CWT-based approach could effectively estimate phase velocity dispersion curves between two stations, reducing the influence of noise such as body waves, higher modes of surface waves, and scattered waves. By applying tomography for estimated dispersion curves, we could retrieve sharp lateral variation of seismic velocity structure, compared with the conventional multichannel approach. Thus, our approach with CWT could be applied for exploration seismic data to improve lateral resolution of near-surface characterization.