Reply to comment on “Effect of surface wave inversion non-uniqueness on 1D seismic ground response analysis”

Abstract

Pettiti et al. (2014) commented on our study on the effect of surface wave inversion non-uniqueness on 1D seismic ground response analysis. They showed in their analyses that non-uniqueness has negligible effect on Fourier amplification and response spectra, which is in disagreement to our earlier observations (Roy et al. in Nat Hazards 68:1141–1153, 2013). The apparent discrepancies are due to the differences in the definition of problem used in the ground response analyses. Pettiti et al. (2014) extended our original profiles to a depth of 60 m and then assumed the presence of high-impedance layer of velocity 1,240 m/s, irrespective of the half-space velocity obtained from the surface wave inversion. This resulted in similar kind of responses of all the profiles in spite of the differences in their shear wave velocity and thickness variations. Otherwise, the observations made by Roy et al. (Nat Hazards 68:1141–1153, 2013) confirm findings of previous studies on the same topic (e.g., Boaga et al. in J Geophys Eng 8:162–174, 2011).