Tsunamis used to be the stuff of movies and until it's devastation in Asia, most people didn’t think it was possible for tsunamis to occur in that magnitude. With that realization, people have become aware of the risk and possible consequences of this natural calamity.
What is a tsunami?
Tsunamis are not caused by strong winds but by tectonic displacements (earthquakes, volcano eruptions, landslides) that occur on the seafloor. Earthquakes that produce tsunamis are those that reach 6.5 or more on the Richter scale. The average speed of the waves is 300 mph and can last from 5 minutes to an hour.
In open sea, tsunamis usually go unnoticed, having amplitudes of just 1 meter or even less. However, in some situations, waves that enter shallow water can swell to several feet and in some rare cases, rise high enough to strike coastal areas with terrible force.
