Seismic waves generated before and after earthquakes produce vertical and horizontal motion of the Earth’s surface. The perturbations can propagate upwards and produce variations and oscillations of atmospheric characteristics at different altitudes. One of the mechanisms of such ionospheric perturbations is propagation of acoustic-gravity waves (AGWs) in the atmosphere caused by seismic excitations at the ground surface. The main difficulties in such explanation are high phase speeds of surface seismic waves, much exceeding the sound speed in the atmosphere near the ground. The strongest ground seismic waves are the surface Rayleigh waves, having phase speeds 3 - 4 km/s (sometimes up to 10 km/s). Traditional theory of atmospheric AGWs predicts that such supersonic excitation should produce not propagating, but trapped (or evanescent) gravity wave modes with amplitudes exponentially decaying with altitude. This can raise questions about the importance of seismic-excited supersonic waves in the formation of io