Asian Tsunami computer animation gif

Discussion in 'Current Affairs, News and Analysis' started by WEATHERMAN1956, Dec 30, 2004.

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  1. I have to admit I am struggling to see how the Western parts of some countries have been affected, not to say the evidence isn't visible but perhaps someone with a much higher forehead might explain the physics to me ? 8O
  2. Water travels very much like radio waves. When they encounter an obstacle, the wave will "bend" or diffract around the obstacle. The amount of diffraction is related to the frequency. In the case of these waves, there was sufficient space behind the wave to allow the wave to fan out past the obstacle. If there had been many waves behind, the next wave would have "killed" the diffracted part of the wave by swamping it.

    Point: The strength of wave seen on the West coast would have been significantly less than the main wave, hence much less devestation.

    Hope this helps..

  3. 8O

    Good effort Ghost! An actual easy way to understand what my physics teacher failed get into my thick skull for 4 years and then gave up trying!

    Who says you cannot learn anything from Arrse...

  4. Thanks ghost......
  5. Very interesting. Do we know what the different colours denote? Different waves or is it depression/elevation relative to normal sea surface.

    Interesting that the wave slows markedly as it approaches the Bangladeshi coast. Bangladesh normally takes it in the neck with the sea.
  6. Bangladesh has a huge lowlands and delta area at the coast, and suffers flooding all the time.

    If the gif is anything to go by, the main force of the wave seems to head over directly west and east. By the time it gets to Bangladesh, the sting seems to have gone from its tail, fortunately for them.

  7. Was about to mention Bangladesh...................very quiet it still there 8O
  8. Cutaway

    Cutaway LE Reviewer

    Very true, the majority of wave behaviour can be understood from basic radio propogation.
    I think you meant wave refraction as opposed to diffraction, something with which the HF bods will be very familiar.

    The relatively small wave becomes a large breaker when the wave is channeled into a strait or a shallower part of the ocean. (The inability of water to be compressed, etc)
    This can be seen around our shores, albeit in a more benign way, in both the Irish and North Seas, where the North Atlantic swells are stuffed into these relative puddles.
  9. You are correct in stating that radio waves refract in the atmosphere. However, the term diffraction relates to waves in one medium. (i.e not passing through atmosphere/vacuum/glass/water etc)

    The above link explains diffraction very well with pictures. Refraction is explained here,

    and the significant difference is that refraction is the bending of waves (esp radio waves) as they pass from one medium to another.

    Hope this clears it up.

  10. Cutaway

    Cutaway LE Reviewer

    Cheers for that Ghost, I was probably taking the word diffract too literally.

    That or it was yet another day I decided that school wasn't on my agenda !