agreed Hyper Al. post 377.
yesterdays BBC special bulletin had a detailed info on how tsunamis where triggered. If the earthquake had happened way below at a greater ocean depth, the sea water itself would have dampened much of it, even before it reached the shores. But if it occurs in shallower water regions, the waves wont shock absorb it much. In this case, you are taking abt 4 to 6 hours for the waves ot hit the shores from the epi-centre
Now, whats good is that Japan has volunteered to help the UN set the EWS system up and running by next year end. So we will now have world class systems monitoring both the Pacific and the Indian oceans.