Excitation of Rayleigh and Love waves in double-layered half-space

In this paper, we report on the seismogram synthesis of Rayleigh and Love waves in horizontally double-layered elastic half-space. For purpose of analytically extracting surface wave components from full-wavefield, we first derive a compact expression of Green's function in this medium, from which the excitation formulae of Rayleigh and Love waves are then obtained. Secondly, adopting a set of medium parameters close to those of the Earth, and with Rayleigh poles and Love poles solved in complex domain, we manage to compute synthetic seismograms of the two surface waves separately. Their phase-velocity dispersion and particle motion are also explored. For Rayleigh wave, the senior modes behave rather differently from the fundamental mode. While different Love modes share similar patterns, which are generally in conformity with the classic picture.