SELF-MODULATION OF SEISMIC WAVES IN THE SUBSURFACE SOIL

Abstract

Nonlinear effects of modulation instability of seismic waves during their propagation in subsurface soils are studied in numerical experiments. The results show that self-modulation and generation of subharmonics take place at high amplitudes of seismic waves in cases of their resonance intensification in soil layers and precede the chaotic stage in the case of further increase in amplitudes. Generation of these effects is related to dispersion of seismic wave propagation velocities in subsurface soils due to their nonlinear response.