OT Mile high tower planned for Japan.

[harry]

[Andrew Mawson]

... er ... well that's ok, no fault lines or earthquake zones for at least a mile or two then ......

Andrew

[newshound]

Recent programme on Radio 4 (I think) saying that taller structures are more immune to earthquakes because their natural frequency is lower than those characteristic of severe earthquakes. It's resonance in blocks ~

10 stories high which brings them down.

ISTR that some skyscrapers in earthquake zones have dynamic protection (big weight in upper stories with actuators and/or dampers).

[Tim Streater]

During the '89 San Francisco earthquake, I was in my office which was only about 20 miles from the epicentre. The building itself, a computer centre, had been built to withstand bomb attacks and so was quite strong, but I remember looking out of the window at pine trees which had large oscillations of some amplitude rippling up their trunks.

[Brian Gaff]

Why would you want a mile high tower in the first place though? Brian

[charles]

because it can be done.

[Jethro_uk]

Because ground real estate is rare ?

I'm sure there was a sci-fi write (Arthur C Clarke) who suggested massive high-rise cities with floors devoted to agriculture - self supporting communities.

And there's always the holy grail of a space elevator. Which AFAICS is the only way we will ever make space travel commonplace.

I wonder how easy it would be to drop some sort of chain/cable from a spacecraft to earth, and then take it back up in a massive loop like a conveyor ? Like most parts of the "space race" it would seem to be a materials and engineering problem, rather than a scientific one.

[pamela]

Wow! That must have been quite an experience.

[ARW]

It would be a quick trip to the lav.

[Andrew Gabriel]

A colleague was in San Francisco during the quake. He was buying a dressed crab at Fishermans Wharf when it hit. He heard a pile a plates go crashing over and the guy serving him yelled something about it's a quake and dropped the crab. Friend thought he was pulling his leg for a moment, until it got worse. Took him and his wife a day to get back to whereever they were staying (outside the city), as all the Bay area bridges were immediately closed, and not much transport was working.

Some years earlier, he had been in Kuwait when it was invaded. This prompted many jokes from colleagues about "make sure you don't travel with Jim".

I was at Menlo Park (working for Sun) late one evening when a

5.something hit. That was quite interesting. The office was mostly empty by then, and the initial creaking sound was ignored by me thinking it was something like the aircon switching on/off. However, when the vertical blinds starting swinging enough that they were all crashing into the windows, it was more obvious what was happening.

Fortunately, I had read the warnings in the building saying you must stay in the building during a quake. This was because it's built on reclaimed bay, and whilst the building is built on piles down to the underlaying bedrock, the surrounding land and car park is much more liable to slump into the bay during a bad quake leaving the building surrounded by lake. This wasn't a bad quake though.