Fig. 3

a–f Deconvolution waveforms of the six stations. The black solid lines track the frequency-varying time lapse of the shear wave. The horizontal white dotted lines indicate the reference travel time from the geological profile. The letter after the station code indicates the site classification, and H is the borehole depth. g Three representative deconvolution waveforms from different filter windows, and the vertical black lines in a denote the position of the three slices. h The travel times of the six stations, and the black hollow points denote the frequency that the wavelength is equal to the borehole depth