http://simulations.narod.ru/ Global tsunami can be started with asteroid impact or earthquake or thermonuclear bomb. It simulated with 2d wave equation. It is wave equation on sphere surface. Land influence neglected. triangular mesh used. The method is some kind of finite difference method. See fromulas in laplacian.jpg Matlab simulations.
run colormap_gui.m to run GUI with colormap visualization.
run land_gui.m to run GUI with land shape changing visualization.