What is tsunami?

Tsunami, a large, powerful, scary waves caused by sudden displacement of large quantities of water in the sea or ocean. The common causes for the displacement of large quantities of water are earth quakes, volcanic activity and landslides.  Tsunami waves do not resemble normal sea waves, because their wavelength is far longer.  The earth people are facing tsunami almost every year since 2004, it took away people's life and caused people homeless. The huge waves of tsunami moves into shallower water and getting higher, so they can be very aneretic when they hit coastal areas.