Earth
Signals
By: Dave JohnsonI have often wondered if any
interesting electrical signals could be observed with copper probes driven into the
ground. As illustrated below. Three copper rods would be driven into the
ground. The separation might be about 10 feet between rods. The center rod is
used as the reference for the other two. |
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| The three rods would be connected
to an instrumentation Amplifier. Instrumentation Amps provide very high common
mode rejection. Only signals which produce a differential voltage would be
Amplified. I would expect to see a lot of 60Hz or 50Hz signals picked up
by the rods, caused by nearby power leakage. To remove those signals, a
notch filter could be added before additional signal Amplification. |
| What kind of signals could be
picked up? I’m not sure. I do know that some voltages have been
produced by quartz rocks, deep in the ground. When subjected to pressure
and small earth quakes, the piezoelectric nature of quartz can produce sizeable
voltages. Perhaps the act of walking between the electrodes would produce
a detectable voltage. Could small insects and larger burrowing animals also
produce voltages? |
| I would love to see someone build
such a circuit and give it a try. |
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