Thomson-Sintra ASM, 525, Route des Dolines, B.P. 38, 06561 Valbonne Cedex, France
CNRS URA 190, Universite de Nice-Sophia Antipolis, 06108 Nice Cedex 2, France
A physical mechanism for the amplitude of the pressure peak created by the impact of a missile at a gas--liquid interface is proposed. The different factors affecting this acoustic pressure peak are discussed. They include the inclination of the missile trajectory, the existence of wavelets roughening the surface of the gas--liquid interface, and the finite compliance of the missile. The difference between the impact and a true shock is stressed: the missile impact indeed creates a true acoustic shock that however plays no role in the generation of the high-pressure peak.