[TowerTalk] seismoelectrics, EM, dipoles

[knormoyle at surfnetusa.com]

I was doing some googling. This post does involve EM waves and dipoles, so is on-topic :). However there's 
numbers and antennas, so it may be OT.

There's an interesting thing that people are researching/using for  doing well surveys: the seismoelectric 
effect. Apparently seismic waves can create EM waves in differential layers of a porous or water-bearing 
medium. The effect was discovered/predicted long ago (30's-'40s?) but there seems to be more recent work. 
Probably because they're getting better gear now.

They have some gear they use for water well surveys.apparently the issues are signal to noise, power line 
interference.

But the idea that an EM wave is created in response to a seismic wave is real. (they use hammer blows or a 
charge)

Now before anyone claims that rods in hands can respond to this level of EM...no way.

There are a number of overviews of seismoelectrics on the 'net 
here's one from this year (was published in a reputable journal)
http://www2.ggl.ulaval.ca/personnel/paglover/Mypdfs/2010_Glover_Jack
son_Borehole_Electrokinetics.pdf


The mechanism by which the EM waves are induced is interesting. There are little companies in CA with the gear 
that claim good results. (google "EKS water well")

kevin
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