The wave field inside the thin (ideal) liquid layer placed on elastic half-space (the simplest model of the shelf)

In the example of a wave propagating in a liquid layer, which is placed on an elastic halfspace, the head interference wave (being connected with $P$-wave in the elastic halfspace) is considered. The attenuation of this wave with regard to the horizontal distance between source and receiver is smaller than expected in the classical theory. The wave field, which is connected with the $P$-wave, is considered in the time and frequency domain. The stationary field has periodically placed resonance peaks. The peaks are caused by specific behavior of the complex roots with changing frequency, such as the roots crossing a branch line. Bibl. 3 titles, ill. 6.