Empirical Approach in Developing Vs/Vp Ratio for Predicting S-Wave Velocity, Study Case; Sungai Batu, Kedah

In recognition of the difficulties in acquiring seismic refraction shear wave data and the ambiguities involved in its processing, Vs/Vp ratio for sedimentary areas of Sungai Batu have been developed and assessed in this study. Two seismic refraction survey line L1 and L2 were conducted using P- and S-wave were acquired and processed along the same line regarding study area. The resulting velocities were extracted from seismic tomography profile to compute specific ratios after linearity and correlation checks. It is found that Vs is linearly related to Vp, with coefficients of determination (R²) of about 0.74 and 0.52 for L1 and L2 respectively. The specific ratios were computed as 0.3 and 0.4 for L1 and L2 respectively Another data sets acquired along different lines were used to validate the ratios. The mean absolute percentage errors were calculated for both modelling and validation data sets and found that the different percentage between Vs measured and Vs calculated is 20.7% and 22% respectively. (paper)