Fig. 6

F-K spectra from synthetic velocities recorded at frequencies of (a) 15.9, (b) 26.8, (c) 36.6 and (d) 47.6 Hz in array (2) and at frequencies of (e) 15.9, (f) 26.8, (g) 36.6 and (h) 47.6 Hz in array (3). Horizontal and vertical axes are wavenumbers in the perpendicular and longitudinal axes of the embankment. Gray shading represents the normalized power of the synthetic waveform at each wavenumber. The white dotted line in h) represents the wavenumber of the fundamental mode Rayleigh wave