When a tsunami stroke some shore line of the countries of Indonesia, Malaysia, India and other neighboring countries this year, many facts about the tsunami also came up to enlighten the mind of the people about it. Including the fact that tsunami is not synonymous to tidal wave. Many facts are informative while scare some for those who realize, after the tragedy, that they could be a possible victim of the killer waves.

But there is a big misconception about a tsunami that spread during that time that was highlighted by the media, which bother me whether this is a fact or a false idea.

According to them, the big wave that travels across the ocean from its source to the shore line never losses its height and energy. Thus, no matter how far are we from the source of the tsunami, like earthquake, the wave that was created will surely hit the countries surrounding it with a wave that is as big as it was created.

But this idea is absolutely false. Yes, using the law of conservation of energy, the energy exerted by the earth movement to created the wave will not loss as the wave reaches the shore line. But it was forgotten that the wave travels radially outward from the source. That is, assuming no energy loss as the wave travels, the energy from movement of the earth that created the tsunami will be equally distributed along the circumference of the wave. But as the wave travels radially outward, the circumference increases proportionally with the distance from the source thus decreasing the energy distribution for a fix length of wave. For example, a 100 meter length of wave in the shoreline very far from the source of wave has a lower energy than a 100 meter length of wave located near to the source of wave.

This fact assures us that if a tsunami is created in the middle of the Pacific Ocean, if the wave reaches the shoreline of the countries surrounding it, it is smaller compare to its original size.