SEGJ Technical Conference

Estimation of the high velocity layer in surface with surface wave method -Multi mode inversion of the Rayleigh wave using with group velocity-

Abstract The surface wave methods are widely used to determine the surface S-wave velocity structure because of its mobility and economic efficiency. However, the method has a difficulty to identify the mode order of the phase velocity. We cannot separate the fundamental mode and higher modes from the phase velocity from observed data directly. We try to grasp the group velocity directly from observed data and check the mode order of phase velocity using with the group velocity. The examination of group velocity has ability to obtain a high reliability section of fundamental mode of phase velocity and give a useful information to detect the S-wave velocity structure from phase velocity.