The Asian Tsunami was the result of a large subsea earthquake that occured at 0059 GMT 0659 Local Time on Boxing Day 2004. It was the largest Natural Disaster in modern times causing in excess of 200,000 deaths.

The Best Resource come from the New York Times which has an excellent Interactive Map but you’ll need to scroll down half way and find the Multimedia Section.

The BBC has an extensive set of reports including a good animation to show the causes of the Tsunami. There is also a timeline of events as the giant wave crossed the Indian Ocean. The Guardian also has a special Web Report. The CBC has some good multimedia links as well. Tsunami Videos has some amazing footage.

The Early Warning System which may have saved many is costly but being used in Japan

The impacts on the main countries, including excellent satellite images of the can be seen at:

The free Encyclopaedia Wikipedia has a good list of entries which include descriptions of what a Tsunami is.