New tsunami advisory warning - Japan

Michael Thomas mike at
Mon Mar 28 09:04:48 CDT 2011

Gavin Pearce wrote:
>> *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.

Quite right. The other part is that the water becomes a very fast moving
river, especially in places where it's not normally one. Watching the
footage from the Santa Cruz harbor it wasn't the height that was a particular
problem, but the fact that all of a sudden you had a 5-10 knot current.
And this happened at low tide, so it would have been far worse if it happened
at high tide. There was a pretty spectacular photo of the tsunami that
appeared to be around the Emeryville flats. Only about 6 or so inches high,
but massive. Had it been at high tide, it could have probably done some
nasty things... like, oh for example, the sewage treatment plant next
to the Bay Bridge comes to mind.


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