The paper deals with the modeling of the resonant vibrational source of the acoustic waves of infrasonic frequency range for the Earth's global tomography problems. The model of the hydroacoustic vibrational source includes a gasfilled resonance radiator operated under the free surface of the liquid. It is shown that for the effective radiation of the acoustic waves in the infrasonic frequency range two conditions must be carried out. First of them defines the depth of immersing of the radiator taking into account the influence of reflected wave from free surface on the full wave field. The second condition is connected with the dependence of the resonant frequency of the gasfilled radiator from its size and gas pressure from the depth of immersing. The combination of these conditions allowed us to define the main parameters of a radiators for the superpower vibrators and to show the opportunity of creation of resonant vibrational sources with power 100-500 kWt in the frequency range 1-5 Hz.