|Waves are caused by the movement of wind on the surface of water. When wind blows on water, its energy is transferred to water due to the friction between the water and air molecules. Strong winds cause larger waves. Waves do not move horizontally, they move up and down.
Tsunami: Theses are different from the surface waves and are caused by underwater earthquakes, landslides and volcanic eruptions. The word tsunami comes from the Japanese word meaning "harbor wave".Tsunamis are caused by an underwater earthquake, a volcanic eruption, an sub-marine rockslide, or, more rarely, by an asteroid or meteoroid crashing into in the water from space. Most tsunamis are caused by underwater earthquakes, but not all underwater earthquakes cause tsunamis - an earthquake has to be over about magnitude 6.75 on the Richter scale for it to cause a tsunami. About 90 percent of all tsunamis occur in the Pacific Ocean.