On 19/03/2011 09:24, harry wrote:
On Mar 18, 9:14 am, "Nightjar\"cpb\"@""insertmysurnamehere wrote:
On 18/03/2011 07:33, harry wrote:
...

Supposing the 1:1000 is correct. Sounds to
me like a figure pulled from the air as there is not sufficient data
to establish this....

The head of seismic hazard at the British Geological Survey disagrees
with you:

http://dalje.com/en-world/japan-quak...r-event/346034

I know which of you two I would accept knoes what he is talking about.

Colin Bignell

If the figure was 1 in say 997, then yo would know it might be derived
from some statistics. But 1 in1000? Too round a number. Hence
invented. Pulledout of the air. Opinion.

Except that it is normal practice to rate the probability in decades for
under a century, centuries for under a millenium and millenia for longer
periods. Otherwise you get people who actually think it is possible to
be more accurate than that.

Colin Bignell