New tsunami advisory warning - Japan

Gavin Pearce Gavin.Pearce at
Mon Mar 28 05:43:00 CDT 2011

> *yawn*.  A foot and a half isn't going to be all *that* bad

Sorry to continue off topic:

Try to imagine ... a temporary very high tide, rather than a cresting
wave. In addition to the "height", it's the wave-length you have to take
into account. Tsunami's rarely become towering breaking waves.

[That said, tsunamis can form into a bore - a step-like wave with a
steep breaking front. Likely if the tsunami moves from deep water into a
shallow river / bay]

1 1/2 foot on top of an existing high tide, could easily cause further
flooding in the wrong locations (although as mentioned, not to the
levels already experienced).

> travels in general at approx 970 kph (600 mph)

True in the deepest parts of open ocean - upon reaching the shore-line
it'll be travelling a lot slower.


// Gav


More information about the NANOG mailing list