Chris Hogg wrote:
On Thu, 17 Mar 2011 10:56:11 +0000, The Natural Philosopher
wrote:

Chris Hogg wrote:
On Thu, 17 Mar 2011 05:56:01 +0000, Alan
wrote:

In message , "Nightjar
\"cpb\"@" wrote


Exactly. The sixth largest earthquake ever recorded in probably the
worst place it could happen.
So why didn't they design the facility for the worst ever earthquake
recorded (plus a large margin on top)?
If an earthquake of this magnitude had a one-in-a-thousand-years
probability (not sure if that's actually the case in this instance),
and the plant is 40 years old (1970's vintage IIRC), dose that bring
the probability of it being hit by a really bad earthquake down to 1
in 25? If so, they seem rather short odds, bearing in mind the
potential consequences.

No. Your maths is wrong. There would have to be a one in a thousand
yearchance of the earthquake being *exactly where it was*.

Maths wasn't far out, see AW's post. What you're questioning is my
assumption that this quake had a one-in-a-thousand-years probability
at that site. I thought this had been said somewhere. If not
one-in-a-thousand-years probability at that site, then what is it?
Really big quakes (eg Richter 8) anywhere seem more frequent than
that, see http://en.wikipedia.org/wiki/Richter_magnitude_scale.

Richter 9. The site could have stood an 8 pretty easily.