The name tsunami is original form Japan.it means harbor wave. They were called tidal waves but they have nothing to do with tides. A tsunami is a long high sea wave caused by an earthquake.
Even though tsunamis slow down as they approach the shoreline they can still be traveling at highway speeds of over 50 miles per hour. A huge wall of water traveling at this speed can cause a lot of damage.
The tsunami had hit Thilande,Japan,Indonesia Siri,Malasia,the Maldives,Madagascar,Sommilia,Benglest,South Africa,Kenya,Tanzania,Seychelles and the deadliest of all India.