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Originally Posted by FrankM
No, I haven't read about moonquakes. The article cited the duration of the vibrations generated by a moonquake as compared to earthquakes. It does not appear the moon has a central magna core, which in the earth acts a bit like silly putty. I suggest one take a golf ball and replace the core with silly putty and then see how far you can wack it.
As mentioned in the prior posts, piezoelectric action is not the primary mechanism for generating electrical charge generation in rock under extreme pressure. Since this action was not understood more than 5 years ago, NASA hadn't developed instrumentation to detect surface charge changes caused by moonquakes or even for earthquakes. The NASA researcher, Friedemann Freund, has suggested a network of surface charge detectors be deployed to identify charges being generated in an earthquake prone area, California.
Traditional seismologists are still depending upon mechanical sensors to detect earthquake action even though they have never been able to determine an impending earthquake with any degree of certainty. As with any new concept, the old school will be reluctant to change, as many are ill prepared cope with radical (to them) electromagnetic technology used in detecting earthquake pre-cursors.
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That golf ball idea might make a big seller at the prank shop Frank!
So I went back and re-read this link you gave:
http://www.scec.org/instanet/01news/...nov_freund.pdf
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Because the positive holes turn any rock momentarily into a pure p-type semiconductor [King and Freund, 1984],
the charge carriers will propagate outward from their source volume. When they intersect the surface of the Earth, the
ground potential is expected to become highly positive [Freund and Liu, 2000].
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In a sense the thread title is outdated then, correct? Because piezo-electric effect is peculiar to only certain minerals whereas the electric effect you describe may occur in
any rock type?
What instrument is suitable to measure the currents near & in caves? I have lava tube caves in my area.
Thanks for keeping in touch Frank.
