Though it's true that tsunamis are ocean waves, calling them by the same name as the ordinary wind-driven variety is a bit like referring to firecrackers and atomic warheads both as "explosives." Triggered by volcanic eruptions, landslides, earthquakes, and even impacts by asteroids or comets, a tsunami represents a vast volume of seawater in motion -- the source of its destructive power.

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Natural hazards such as earthquakes, tsunamis, and volcanoes affect both coastal and inland areas. Long-term data from these events, including photographs, can be used to establish the past record of natural hazard event occurrences. These data are also important for planning, response, and mitigation of future events.

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Thousands of people have died after a violent earthquake under the sea near nothern Indonesia sent huge waves crashing into coastal areas across south and east Asia.

The recent tragic events following the December 2004 magnitude 9.0 earthquake in the Indian Ocean have reminded us of the need for scientific understanding and modeling of complicated physical phenomena in order to prevent unnecessary loss of life from natural disasters (cf. Post and Vatta 2005). While the full-scale physics and modeling of tsunamis are difficult problems requiring the use of supercomputers and complicated custom software, a number of approximations can be made that render the problem of tsunami propagation tractable for a computer of modest power running off-the-shelf software such as Wolfram Research's Mathematica.

Information about what to do during and before a Tsunami

What causes a Tsunami? Geology.com explaines

The "Before/After" button below (the one that is currently labelled Before. Click To See After.) toggles the image between the "Before" and "After" satellite photos. You can also toggle the image by clicking on the image itself. The "PREV" and "NEXT" links will take you to the previous or next image set ... there are 20 sets in this series.

Developing methods and tools to reduce Tsunami hazard and protect life