Fig. 15From: Cause of destructive strong ground motion within 1–2 s in Mukawa town during the 2018 Mw 6.6 Hokkaido eastern Iburi earthquakeSpectral ratios for the Mw 3.9 earthquake (Event 2: 09 December 2018). The spectral ratios are derived from the S-wave part Fourier spectra of each station divided by the MKW01 spectraBack to article page