What is Tsunami?

• A Japanese word meaning "harbor wave"

 
• A water wave or series of wave generated by an impulsive vertical displacement of the sea surface of seafloor

 
• A tsunami can have a wavelength of 100km or more and a period in the order of one  hour

 
• Calling tsunami a tidal wave or a seismic sea wave is a misnomer, because tsunami is not caused by earth- moon gravitational system and there are tsunamis caused by non-seismic incidents