I was flipping thru the channels on the TV tonight, and came across a parapsychologist, who was in the midst of describing the alleged association of unusual magnetic fields with poltergiest phenomena (my BS meter is already on strong twitch just due to the subject matter). He claims that magnetic fields of this type can be caused by underwater streams, iron ore deposits, or earthquake faults. I can easily see a magnetic signature with iron ore, but the other two make no sense to me. Can there be a magnetic effect caused be the existence of a fault or underground stream?
The presence of a fault does NOT generate a magnetic effect.
An underground stream is NOT detectable from above ground by any known means.
No one has ever demonstrated generation of a magnetic effect from flowing or static water.
It may be that bedrock deformations due to slow (or fast) movement on a fault may have electromagnetic effects, but if ESP can detect this, the practitioner can collect $10,000 or whatever it is from James Randi.
Consider piezoelectric effects caused by the deformation of crystals, and the crystalline nature of some rocks. And, springs and wells often rise or fall in association with earthquakes, ie before the actual quake. This may be a ‘squeezing’ or ‘fracturing’ effect underground, however, rather than a piezoelectric effect on ionized ground water.
PS, there aren’t a lot of underground streams, although there are water tables and directional seepage therein.
Drat, simul-post.
Are volcanoes detectable by the high-speed magma generating a field before it errupts? I can’t imagine, if so, that it would give much warning.
[QUOTE=spingears]
An underground stream is NOT detectable from above ground by any known means.
[QUOTE]
Except for Ground Penetrating Radar (GPR).
Example: http://www.quantumlynx.com/water/back/vol6no1/story4.html
Before the volcano erupts, the magma isn’t moving at high speed. Afterwards, the warning is moot.
Volcanic activity predictions are based on earth tremors (like earthquakes) and deformations (swelling of the solid crust).
[QUOTE=GeoDude]
[QUOTE=spingears]
An underground stream is NOT detectable from above ground by any known means.
What’s more, at the bottom of that article: “A study is being conducted by the University of Calgary to assess geophysical results obtained from PFRA projects using GPR, electromagnetic and seismic methods. In addition, several water sourcing projects applying geophysical techniques are in progress in Alberta.”
Seismic methods seem fairly explanatory – it’s the same technique to map faults for oil exploration. However, electromagnetic could very well use changes in the EM field. At the very least, Spingear’s assertion that there are no known methods of detecting underground water seems busted.
I am not a physicist, but in an effort to assist the OP it is my understanding that a magnetic field can only be generated in three ways:
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From an electrical current.
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From a permanent magnet.
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From a changing electric field.
If you do not have an electric current, and you do not have a permanent magnet, and you do not have a changing electric field, then it’s my understanding that you cannot generate a magnetic field.
There are powerful magnetic fields associated with nuclear reactions, and these can induce very large currents and give rise to powerful magnetic fields, however the source of them all is that nuclear reaction.
The Earth can be considered (for our purposes here) a permanent magnet. Changing water flow or earthquake fault movement could disturb the Earth’s field, generating the sub-Hz magetic field fluctuations mentioned in Squink’s post.
As MaryEFoo and Squink’s cite mention, there are piezoelectric crystals. According to the Wikipedia cite, a 1cm cube of quartz with 1/4 ton of pressure on it can generate 12,500 Volts of electricity. So pressure waves travelling through such a medium might generate a changing electric current, thereby producing a magnetic field.