Mini Tsunami's AKA Freak / Rogue waves .

[colintrav]

Whats your thoughts on this Act of Nature that unleashes such a power that it can cause Ships to sink!, Would it not be better to term them as  " Mini Tsunami " With waves reaching 29m plus  makes sense really!  QE2 ,Bremen and the Caledonia Star have all encounterd such waves and survived .

And with what i've read that the ESA [ European Space agency ] stating that more than 200 super tankers and Container ship's exceeding 200m  , in length over the last 20 years have been sunk due to severe weather .


Whats your thoughts ..

[bobrayner]

Would it not be better to term them as  " Mini Tsunami "

No. A tsunami is a very different kind of wave. Tsunamis have very long wavelengths; in deep water, their velocity is very high and amplitude very low. For instance, the 2004 Indian Ocean tsunami passed many ships in the open ocean without them noticing (40-50cm according to satellite measurements).

A freak wave is "just" a big sea wave; it's driven by the same forces that drive normal sea waves, and has a similar wavelength. The obvious difference is a bigger amplitude.

Like other sea waves, it's a "surface wave"; if you are deep enough in the water (more than half the wavelength) the wave does not move you. A tsunami is different - the whole water column moves.

If you're interested in freak waves from a shipping point of view, there might be some interesting links here:
http://scholar.google.com/scholar?q=maxwave

Or a good summary here:
http://en.wikipedia.org/wiki/Freak_wave