[Lowfer] LF interference - slightly off topic...

[mikea]

On Tue, Mar 03, 2009 at 10:46:22AM +0000, Dave Pick wrote:
> Laurence
> 
> What are they cabled to? Control box, mains...?
> 
> Dave 'YXM
> 
> 2009/3/2 Howell, Laurence (Shanghai/Singapore) <L.Howell at conocophillips.com>:
> >
> > I was out tracking/tracing a new LF interference source and came upon
> > http://www.kl1x.com.morningprobe2.jpg
> >
> > Any idea what these are for as they are littered all over the city -
> > sidewalks, gardens etc? I was thinking heating or ground conductivity
> > testing but the wiring is just too extensive - we must hundreds of miles
> > of this stuff....we arent far from DRNK...
> >
> > Laurence

I think those are geophones. I'm used to seeing them out in the wild, used
by oil surveyors to detect echoes from rock layers and structures after a
blast or a thump from a thumper truck. They're a rather common sight in 
Texas and Oklahoma, but I've never seen them pounded into a sidewalk 
before. 

Interesting ... .

-- 
Mike A