Geoff,

Your torsion seismo is just the sort of thing that is getting quite a bit 
of interest in the seimo community right now--lots of papers, etc. on 
rotational seismology.  I don't much understand most of them, but at the 
moment there seem to be a number of folks studying it.  Only problem I can 
think of is that the rotational motions may be much smaller than the usual 
Up-Down, N-S & E-W linear motions except maybe for local quakes, but it 
sounds like it might be an interesting thing to look at.

Best regards,
Brett

At 09:22 AM 11/10/2009 -0700, you wrote:
>Your Setup is the very kind I like to see.
>
>I once made a torsion seismometer using
>a spring made out of an aluminum antenna
>rod split down the middle and fastened
>at both ends in clamps like the scientists use.
>Then it had a long lever arm of wood with a
>magnet on the end. It was a hopeful dream
>that never realized itself due to annoying
>torments in my life. The period must have
>been longer than a second. I have faith (chuckle)
>in torsional kind of seismic devices.
>If you made two and put them back to back
>you may possibly cancel out tilt and only
>look at vertical motions. But not exactly sure.
>Thanks for the input Mr. Sparks,



Best Regards,
geoff

Watch our wiggles
http://bnordgren.org/seismo/gif_images.htm

or watch some very very good wiggles
http://aslwww.cr.usgs.gov/Seismic_Data/telemetry_data/ANMO_24hr.html


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