Abstract: The mechanism of Indian Ocean tsunami of 26 December 2004 was newly revealed by American geophysicists. The tsunami could be partially caused by the lowest normal modes of the earth spheroidal oscillation excited by the earthquake. This mechanism is in principle similar to that of water spouting from a Fish Bowl, in which water is stimulated by self-excited standing waves of the round wall of the basin. This investigation would make early tsunami alert possible and more reliable.

Key words: fish basin, water spouting effect, tsunami physics, standing wave, self-excited oscillation