We have developed a molecular dynamic approach for studying tsunami generation. In a two-dimensional model developed a force, which models the generation of disturbance, was incorporated into the water after reaching thermodynamic equilibrium. The temporal evolution of an arising wave shows that at first the disturbance creates the wave of large amplitude which propagates with a significant velocity and a cavity at the site of disturbance. When the wave reaches shallow water, the amplitude and velocity decreases, and the wave changes its shape that is consistent with observations for areas with a large angle of bank. As the bank is approached, the wave density decreases, and foam formation takes place. From the very beginning the surface layer has a lesser density, as if one has "rarefied" water. During the wave propagation the rarefied water penetrates deeper.