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Tsunami Infographics

I'm no tsunami expert, but I think that some infographics designed to help readers understand how the Asia tsunami was formed are giving the wrong picture. Take this one from India Today magazine. It shows a nuclear-size mushroom wave at the source (notice the ship on the wave). Experts, however, say that the height of the wave at the source is almost imperceptible. Guess that's why we need special equipment to pick up the initial waves at the source (these detect changes in sea pressure and not vertical lift). Ironically, the magazine shows the height of the wave near the source as being around 1 m. Compare this with Time Magazine's infographic, which shows it a bit better (no mushroom wave at least), although I'm still not at ease with the disproportionately large vertical height at the source.

The problem here I think is that there are three important causal factors at play: earthquake at sea --> huge displacement of water at source --> height and speed of waves at shore. But these graphics are following the development of the one factor that they think their readers are interested in: height of waves at shore. But then instead of explaining how the waves gain height when the approach shore, they take the easy way out and show it using folk-physics - massive explosion gives rise to giant waves and these then move to shore.

The missing link here is the depiction of the huge displacement of water due to the violent rupture which was 1,000 km long and 10 m in height. Both the above infographics don't show the extent of this displacement.

The best infographic thus far, in my opinion, is from the BBC. They quite simply separate the depiction of the earthquake and the formation of the waves: they use multiple graphics to show how the waves were created. The NY Times goes even further and focuses on just the height of the waves in different parts of SE Asia.

Have you come across other visual explanations of how the Asian tsunami's were created? Use this space to voice your opinions.

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