Fig. 7

Rayleigh wave phase velocity from synthetic vertical motions in Fig. 3 in 5 m ranges of distance from the source (5–10 m, 8–13 m, 11–16 m, 14–19 m, 17–22 m and 20–25 m). Plotted points represent observed phase velocity in each distance range and the solid line represents the theoretical Rayleigh wave phase velocity. The two dotted lines indicate the maximum and minimum wavelengths resolved by the linear array. The frequency bands of capable wavelength are focused