Fig. 5

Rayleigh wave phase velocities from vertical motions in Fig. 4. Phase velocity analysis of synthetic waveforms in 20 or 10 m ranges from the source: a 5–25 m, b 5–10 m, c 10–20 m; and d 15–25 m. Gray shading represents normalized power of synthetic velocity at each frequency. Open red dots represent observed phase velocity. Solid lines are the theoretical dispersion curves of the Rayleigh wave fundamental mode for model A. The two dotted lines indicate the maximum and minimum wavelengths resolved by the linear array. The frequency bands of capable wavelength are focused