ИСТИНА

Tsunami generation by bottom earthquake is accompanied by the formation of residual hydrodynamic fields – traces of tsunamigenic earthquake. We consider the cases of homogeneous and stratified (two-layered) ocean of constant depth on a rotating Earth. Equations for description of potential and vortex residual fields originated from co-seismic bottom deformation are derived within the framework of linear shallow-water theory. Fully analytical solutions to the respective axisymmetric problems are obtained. On the base of the analytical solutions, under typical conditions for a tsunami source, the spatial structure of the residual fields is analyzed, the role of stratification is discussed, and the amplitude of residual horizontal displacements of water particles as well as the maximum velocity and the energy of the residual geostrophic vortex are estimated.