S-wave velocity (Vs) model uncertainty derived from multiple equations of Vs and number of blows (N) at Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia

To reduce hazard risk in earthquake-prone areas, it is crucial to conduct ground motion prediction for a future earthquake. It is well understood that a shear wave velocity (Vs) profile of soil at site interest is significant for ground motion estimation. In this study, we examine uncertainty in a Vs derived from the from Standard Penetration Test (SPT)-N value at a borehole site of Institut Teknologi Sepuluh Nopember (ITS), Surabaya, Indonesia. Here, we used various empirical Vs and N equations from different authors to determine variations in the Vs profile. We found that the estimated S-wave velocity profile errors are about 20% at depths of 0 - 30 m. These uncertainties are helpful for the determination of variability of ground motion prediction at ITS.