Abstract: Most of the contents in the paper are excerpts from the chapter on Tsunamis in the Ph.D Thesis of the author [5] and the same suitably modified to fit into as a research paper so as to get free and direct access to readers. The paper begins with a historical account on tsunamis. A brief account of some ten most colossal tsunamis of recent times is given. An elementary treatment of wave motion makes the paper suitable for both the common man and scientist. The situations when the tsunami strikes the land with the crest and with the trough are separately dealt with. Protection and warnings from tsunamis are briefly dealt with. Some of the diagrams are drawn by the author himself and the paper ends with a conclusion.

Keywords: Amplitude, Crest, Draw-down, Run-up, Trough, Tsunami, Wavelength.