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March 22, 2011


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Great post!

Thanks, Evelyn. I think your series of conversations with your nuclear expert Dad have been a brilliant idea. For readers who haven't done so, it's well-worth following these at http://georneys.blogspot.com/.

This is a great example of what the blogosphere can - essentially uniquely - do.


I suppose it's belaboring the obvious, but any tsunami evacuation plan should include some form of public education that tells people yes, we have tsunami defenses, but we don't know if they're big enough to stop this tsunami, because we don't know how big this tsunami is.

I wish people understood enough about engineering to realize that what engineers design to specifications, and if the specifications aren't good enough, what they design may fail.

I'd also be curious if anyone will model the behavior of this tsunami hitting those walls, and whether the walls improved things, didn't help, or made them worse. ISTM that they could have acted as baffles, taking some of the steam out of the waves when they hit.

You've hit the nail on the head - there will always be some combinations of circumstances that exceed the design specifications of any engineered structure - they may be relatively unlikely, but never impossible. But there is a problem with a government, or any organisation that builds "defenses," acknowledging that they are not fail-safe. However, the possibility of being criticised for constructing something that is less than perfect should not be an excuse for failing to set out the facts and, as you say, ensuring that the facts are recognised in response and evacuation planning.

I would sincerely hope that behaviours of these defenses will be the subject of careful scrutiny, but, at the same time, I would doubt that there really is a solution. The fact is that a tsunami "wave" is fundamentally different from a normal one. A normal wave is simply a surface phenomenon, the water beneath unaffected. In a tsunami the entire water column - essentially the whole mass of the ocean - is on the move as a result of displacement of the ocean floor; it's like tilting the bathtub as opposed to splashing the surface. Hence the incredible surge (perhaps a better term than "wave"), and the momentum, to keep moving for long distances inland. Whether there is any way of defending against this is debatable.

Excellent article!

Perhaps when dealing with a leashed monster like nuclear energy- the expense to guard against a worst-case scenario isn't as prohibitive as the ensuing cleanup- lawsuits- etc..

Time will tell- thanks again Mr. Welland...


Finally getting back to reading blogs after a half-year hiatus. I knew you would have something worthwhile to say about this event, and I was not disappointed. Your links are especially useful. Thank you.

I saw the effects of the tsunami first-hand in the Santa Cruz Harbor, where two friends of mine have boats that they live on. This video is one of the better ones of the larger surges that came through. You can see the destroyed part of U-dock and some half-sunken boats and 0:05. http://www.youtube.com/watch?v=7B-ACV3pPqc&feature=related

It was a pretty intense day.

Hi Blaize, welcome back, and thanks much for the comment. The video is remarkable - and "surge" is exactly the right word, since it clearly is not a conventional wave but rather an unstoppable body of moving water; this was, of course, illustrated so dramatically and terrifyingly by the videos of the events in Japan where the body of moving water was essentially the ocean.

harmful natural disasters

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