Seismoacoustic wavefield transformation through heterogeneity of lower atmosphere

Problem of seismoacoustic wave’s excitation in a layered system composed of homogeneous isotropic elastic half-space – homogeneous fluid layer – fluid half-space, by harmonic force acting on elastic medium is considered. This system simulates Earth, near-surface layer of air with sharp temperature contrast and atmosphere. Expressions for wavefields obtained in the form of Fourier – Bessel integrals. Focus is concentrated on study of acoustic waves in the fluid half-space. Approximate solution valid on large (in comparison with the wavelength) distances from the seismic source is derived. We examine the case where sound speed in the layer higher than in the fluid half-space (this holds antiwaveguide propagation of acoustic waves), and the case of low-velocity layer, when near-surface refraction waveguide occurs. Acoustic waves average by period radiation powers obtained in integral expressions for three different areas of fluid half-space. Numerical analysis of the radiation power is conducted in the case of high-velocity and low-velocity near-surface layers. Results of data processing from field experiments on acoustic and seismic signals detection during industrial explosions in quarry (northwest Russia) presented.