Reply #6: Yeah, it's a series of waves...

[Violet_Crumble]

The second one that hit Thailand sounds like it was bigger than the first...

I found this. It's not specifically about this tsunami, but about tsunamis in general and how they act...

How many waves are there in a tsunami?

A tsunami generally consists of a series of waves, often referred to as the tsunami wave train. The amount of time between successive waves, known as the wave period, is only a few minutes, in some instances, waves are over an hour apart. Many people have lost their lives after returning home in between the waves of a tsunami, thinking that the waves had stopped coming.

http://www.tsunami.org/faq.htm#How%20many

Violet...