'' tsunami '' ( from ; English pronunciation : or ) or tidal wave , is a series of waves in a water body caused by the displacement of a large volume of water , generally in an ocean or a large lake . Earthquakes , volcanic eruptions and other underwater explosions ( including detonations , landslides , glacier calvings , meteorite impacts and other disturbances ) above or below water all have the potential to generate a tsunami . Unlike normal ocean waves , which are generated by wind , or tides , which are generated by the gravitational pull of the Moon and the Sun , a tsunami is generated by the displacement of water . Tsunami waves do not resemble normal undersea currents or sea waves because their wavelength is far longer . Rather than appearing as a breaking wave , a tsunami may instead initially resemble a rapidly rising tide . For this reason , it is often referred to as a " tidal wave " , although this usage is not favoured by the scientific community because it might give the false impression of a causal relationship between tides and tsunamis . Tsunamis generally consist of a series of waves , with periods ranging from minutes to hours , arriving in a so-called " internal wave train " . Wave heights of tens of metres can be generated by large events . Although the impact of tsunamis is limited to coastal areas , their destructive power can be enormous , and they can affect entire ocean basins . The 2004 Indian Ocean tsunami was among the deadliest natural disasters in human history , with at least 230,000 people killed or missing in 14 countries bordering the Indian Ocean
2004 Indian Ocean tsunami
2004 Indian Ocean earthquake and tsunami
Tsunami