[Rockhounds] Volcanos, earthquakes and things

Tue Jan 8 15:12:57 PST 2008

Hi Jim, Pete, Earl, & list

The problem seems to be that I'm not rich enough to buy all the article on
the subject.
Found one of 39$ and one that costs 45$ to read and so on.
The summaries don't reveal enough to warrant a buy but: it seems possible to
measure velocity of seismic waves in granodiorites through the EM-field that
is generated by piezoelectric quartz when these waves pass through the rock.

I cannot see how that can be achieved if the orientation of quartz crystals
really is random regarding either c-axis or a-axis. As you stated, random
orientation would cause the tiny EM-fields to cancel each other out.

This time I have a partial reference (which means that I think that the
article is relevant but I'm to avaricious to purchase it ;-)))
I'm confident that Springer Verlag is trustworthy in what they publish. I'm
less confident about my assumption that is entirely based on one
paragraph... But as Holmes always said: "pure deduction, dear Watson" (LOL)

http://www.springerlink.com/content/w322028071826247/

Vladislav Babuka1, Vladimír Schenk1 and J. Buben

(1)  Geophysical Institute, Czechosl. Acad. Sci., Prague 

Received: 22 November 1973  

Summary  The mean compressional wave velocities in unsaturated and water
saturated granodiorite specimens are higher by 18 and 33 per cent,
respectively, than the mean velocity determined by piezo-electric field
measurements in the uppermost zone of a granodiorite massif. After the
saturation the velocity of the ultrasonic waves in the granodiorite
specimens increased by 12 per cent and the velocity anisotropy decreased
from 8 to 5 per cent on the average

 Here's another one, same subject but even less text:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2478.1974.tb00112.x

There's more out there I think. I'll look if I have the time.

Axel

> -----Oorspronkelijk bericht-----
> Van: rockhounds-bounces at lists.drizzle.com 
> [mailto:rockhounds-bounces at lists.drizzle.com] Namens Jim Murowchick
> Verzonden: dinsdag 8 januari 2008 21:19
> Aan: Rockhounds at drizzle.com: A mailing list for rock and gem 
> collectors
> Onderwerp: Re: [Rockhounds] Volcanos, earthquakes and things
> 
> Hi Axel, Pete, and everyone--
>     I was just wondering--a prismatic piezoelectric crystal 
> will generate a positive charge at one end and a negative 
> charge at the other when stressed.
> Even if the crystals are aligned, wouldn't there be about 
> equal numbers of crystals in orientations 180 degrees from 
> each other (antiparallel)?  If so, then the charges on the 
> crystals should effectively cancel each other out in the rock.
>     Also, for quartz, I seem to remember that the 
> piezoelectric effect is strongest along the a axes.  If so, 
> then even with aligned prismatic crystals, there would be an 
> infinite number of possible orientations of the a axes 
> (rotated around the c-axis direction).  Again, any electric 
> fields produced by compaction would cancel out in the rock.  
> Does that make sense, or am I missing something?  Good mental 
> exercise.
> Jim Murowchick
> 
> 
> On 1/8/08 2:04 PM, "Axel Emmermann" <axel.emmermann at pandora.be> wrote:
> 
> > Hi Earl,
> > 
> > I particularly like the "straws in syrup" analogy. That crossed my 
> > mind too before I was thrown off by the gravity hoax.
> > I just got word that the gravity-link is not proven but rather 
> > expelled to the realm of the esoteric... Back to the cellar for a 
> > fresh box of stale ideas ;-))) Still, any process that causes 
> > polarization of quartz could result in possible EM fields upon 
> > compression of the rock.
> > 
> > Yeah, that help ;-)))
> > 
> > Thin sections and polarized light to determine if any prevalent 
> > orientation is present? Then squeeze along prevalent c-axis 
> and measure electric field?
> > 
> > 
> > Cheers
> > Axel
> > 
> > 
> > 
> > 
> >> The idea of quartz growing with c-axes aligned with the 
> gravitational 
> >> field is an interesting one, and also easily testable.  
> Has this ever 
> >> been demonstrated?  In plutonic rocks the dominant control is the 
> >> flow of viscous magma, which tends to rotate any elongate mineral 
> >> grain into parallelism with the flow layers, and also 
> tends to rotate 
> >> the long direction of those grains parallel to the flow 
> vectors.  You 
> >> thus see, in some plutonic rocks, a strong preferred 
> orientation of 
> >> elongate mineral grains, but the orientation is controlled 
> by magma 
> >> flow patterns, not gravity.
> >>  
> >> In metamorphic rocks the directions of quartz c-axis 
> orientations are 
> >> often strongly aligned, but here the control is tectonic plate 
> >> movements setting up strong deformation stresses in the 
> rocks.  There 
> >> is a vast literature on this subject (and on the plutonic 
> rocks too).
> >>  
> >> In sedimentary rocks the quartz grains, if they have any elongate 
> >> character to them, tend to lie with their long axes parallel to 
> >> bedding.
> >> The long axes of the grains would naturally tend to be parallel to 
> >> the c-axes of the original crystals.  You can also get lineation, 
> >> with all the c-axes pointing in the same direction as well 
> as lying 
> >> within the plane of bedding.  Here the dominant controls 
> are gravity 
> >> (which determines that bedding planes will be horizontal in most 
> >> cases) and fluid flow (which determines the direction the 
> c-axes will 
> >> line up).
> >>  
> >> I think the key point is that oriented quartz grains can 
> be expected 
> >> in many types of rock (indeed, have been proven by 
> measurement to be 
> >> present), so it might indeed be possible for those grains 
> to exhibit 
> >> some cumulative piezoelectric effect during earthquake deformation.
> >> That's a part of the literature I haven't followed.
> >>  
> >> That help?
> >>  
> >>          Cheers-    Earl
> >>  
> >> Dr. Earl R. Verbeek
> >> Resident Geologist
> >> Sterling Hill Mining Museum
> >> P:  973-209-7212
> >> F:  973-209-8505
> >> E:  shmm at ptd.net
> >>  
> >>  
> >> -----Original Message-----
> >> From: rockhounds-bounces at lists.drizzle.com
> >> [mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of Axel 
> >> Emmermann
> >> Sent: Tuesday, January 08, 2008 8:07 AM
> >> To: 'Rockhounds at drizzle.com: A mailing list for rock and gem 
> >> collectors'
> >> Subject: RE: [Rockhounds] Volcanos, earthquakes and things
> >>  
> >> Hi Kreigh & Kitty & all,
> >>  
> >> I'm gathering data for a speech on the subject for my club. A 
> >> somewhat frivolous speech since none of the below has been 
> confirmed 
> >> by solid research as far as I know. More like exploring an 
> idea than 
> >> a real speech
> >> ;-)))
> >>  
> >> It seems that compression of quartz bearing rock layers 
> generates the 
> >> cumulative effect of the piezo-electric field of billions of tiny 
> >> quartz crystals.
> >> The reason for this is that quartz crystals grow with their c-axis 
> >> aligned with the earth's gravitational field. So , any 
> plutonite with 
> >> micro-crystals of quartz would have those crystals aligned 
> following 
> >> it's orientation to the earth's axis at the time it solidified. 
> >> Pressure on the rock in the direction of the c-axis of the 
> crystals 
> >> would generate tiny electric fields round each crystal. The effect 
> >> (although I think that it still needs some
> >> proof) may be the cause of the so called quake-lights. It 
> may even be 
> >> strong enough to directly influence sensory perception and cause 
> >> hallucinations in persons that are susceptible to it: UFO 
> sightings, 
> >> alien abduction stories, ghost apparitions, feelings of anxiety, 
> >> elfs, cobolds... A lot of myth and perhaps even man's 
> inclination to 
> >> religion and mysticism may have begun here.
> >>  
> >> In this respect I would find it logical that if seismic 
> disturbance 
> >> creates strong electrical fields it also causes ELF/VLF emissions.
> >>  
> >> I'm still looking for a way to measure flutuations of the elctric 
> >> field of quartz bearing rock when compressed near breaking point. 
> >> ;-)))
> >>  
> >> I'd like the opinion of a geologist on this one very much.
> >>  
> >> Cheers
> >> Axel
> >>  
> >>  
> >> 
> >> 
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