You don't want to go there---it's like saying that Titanic was 
"unsinkable". Structures are designed to safely survive a certain design 
lateral and vertical acceleration. Up until the Northridge quake, most 
equipment rooms for TV were designed for 1.0 G lateral and 0.5 G 
vertical. Some seismic records in the 1994 Northridge quake pointed to 
vertical accelerations approaching 1.0 G. I don't know what current 
design accelerations are. I have heard that the Chile quake of a year or 
so ago has caused some rethinking of code requirements, and I don;t know 
what the accelerations were for the 1964 Alaska quake, but the tsunami 
that caused was a different challenge in coastal areas as was the Indian 
Ocean tsunami. Nothing is "proof"!

On 2011-02-23 11:05 PM, Steven C. Barr wrote:
> are quake-proof

-- 
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada           (905) 713 6733     1-877-TAPE-FIX
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.