Detect tunnels..

[HiiiQ]

I think that we should take advantage of the fact that 99thpercentile is visiting this forum. He's probably the only one who can answer my question.
Would it be possible to detect tunnels/voids by utilising a laptop with a oscilloscope program and a buried piezoelectric speaker(geophone) hooked up to the sound card. By hitting the ground with a large hammer the reflected waveform might give enough clues of a nearby tunnel?

 

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[Mr. Mojo]

I used to design ultrasound detection probes for industrial uses. You would likely need to produce multiple waveforms for any analysis of the signal upon return. That being, building a transmitter/reciever with the all the variables such as frequency, physics of waves, material impedance *which would be so varied that an accurate model would be an exaustive feat in itself. I believe that you could do better utilizing your efforts on dowsing. I have utilized this to find underground sewers, water lines, and gas lines. Experienc is the only way to learn. I have never tried to dowse a filled, compacted trench or a tunnel the may be at any depth. I am not sure of this possibility. I am sure that if a piezioelectric device could detect the tunnel, an experienced dowser would have just as good of chance.

 

[gldhntr]

ground resistivity unit......

 

[99thpercentile]

If anyone can come up with a method for finding tunnels reliably and in a reasonable amount of time then they would be financially rewarded. What you are describing is close to a description of a shallow seismic refraction survey. A shallow seismic refraction survey can be performed with an array of geophones, typically 24 spaced between 1 ft and 10 ft, and a source which can be a sledge hammer hitting a small steel disk. The geophones measure the ground motion at the point where they are located and may be piezoelectric transducers. The geophones may be p-wave, which measure the vertical displacement; s-wave, which measure the motion in the XY plane; or a combination of p-wave and s-wave which are called three component geophones. With a single receiver at best you could monitor active tunneling or a person walking by, but would have no method of locating the source.

I'm not going to comment on dowsing. One of the other suggestions of resistivity imaging is a better solution than a seismic method, but it is still not a silver bullet.

 

[HiiiQ]

With dowsing I can only detect (and recover) cristals. I'm looking for a way to discriminate them away and locate only metals but it's not going to be easy. BTW Close to my house (exit 14 on the I-81 WVa.) There is a large indian burial mound and (with L-rods)i detect a tunnel leading away from it...
Anyway ultrasound would probably not travel very far trough the ground. Infrasound might be better.

 

[aarthrj3811]

Hey HiiiQ...I took a set of L-rods to a mine shaft that was in a little stream canyon. I went above it and took GPS readings as I folowed it. After a 1/2 mile I plotted the readings onto a map.The line crossed 2 roads up the mountain...I found the tunnel where it crossed both roads. The top of the mountain was close so I followed the tunnel up hill. I found the entrance to the mine. I think I can locate tunnels but have not found any unknown tunnels yet....Art

 

[HiiiQ]

99thpercentile, even if a number of piezoelectric geophones are used, would the suggested setup (laptop & oscilloscope program) work?
Can you post the waveforms (if you have any recorded)of two different locations (with a nearby tunnel & without one) for comparison?

 

[Mike(Mont)]

You heard about the guy put on his job application "Graduated in the top 92% of my class"! As for dowsing for crystals, you might want to read the book "Supersensonics" by Christopher Hills. It has to do with how the light waves are polarized. Different crystal types have a different phase angle (fundamental angle) and wave length.

 

[HiiiQ]

One of the methods that I've used to discriminate between cristals was placing flat on the ground (under direct sunlight) a lens from Polaroid sunglasses. I would go around it as I would around a MFD. Each time I would turn the lens clockwise a bit & walk around to check for signal lines. If you want to try this you might want to use a compass to take note of the polarization angle that sends a signal line to you're desired target. You can also get the same effect by using a keychain laser (it is 100% polarized)pointed at the ground. All you need is something to hold it in vertical position.
Thank you for the suggestion but I won't read that book. Somehow I doubt that a "really" successfull dowser would share anything of value.
Same goes for me. If I had found gold using the above method,I wouldn't be sharing it. Altough it might work for somebody else. At least with this method there's no signal drift or ghost signals. Whatever is causing the signal line is always there at the end of the line. Waiting to be dug out...

 

[Mike(Mont)]

Well, the idea that only greedy people write dowsing books or share their info for free is not accurate. Of course you are entitled to your opinion, and I also realize many people cannot learn from a book. Dr. Hills retired a millionaire at age thirty. Think most of his dowsing business sales were donated to other humanitarian efforts he worked on the rest of his life. Like he says, don't take his word for anything. You've got to prove it to yourself.

I know he talks about tunnels being a concentrator of waves, but I can't find it right now. But when I do I'll post it here.