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