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Don't you understand how strain, or release of strain, in crystals causes electromotive force? (some people call it “electricity”)
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In piezoelectricity, the field, and the current, is entirely within the crystal. So there isn't going to be any net electricity due to strain in a slab of rock containing quartz crystals. And I don't think that there will be any noticeable ohmic heating just from one compression or decompression. So the idea under consideration is not that pressure causes electricity in earthquakes. Rather, it's that electricity causes pressure. Then the question is, "What causes the electricity?" I'm of the opinion that this comes from pressure, but not due to the piezoelectric effect (because that would be circular). Rather, tectonic pressure buckles the crust, which relieves the pressure on the underlying rock. If the rock had been forcibly ionized, due to electron degeneracy pressure, it can now undergo charge recombination. So when the pressure is relaxed, electrons can flow back in. Interestingly, this has two effects, both of which increase the lateral pressure, which is the prime mover here. First, ohmic heating from the electric current causes the rock to expand. Second, the electric field motivating the current causes piezoelectric deformation of quartz crystals, again causing the rock to expand. This lateral expansion forces the buckled crust to buckle even more. The increased buckle further reduces pressure on the underlying rock, enabling even more charge recombination. So it's a force feedback loop, which will continue to accentuate itself until the crust is under enough pressure to rupture the fault.Maol wrote:Don't you understand how strain, or release of strain, in crystals causes electromotive force? (some people call it “electricity”).
There is a lot more literature than this. Such reductions can be measured by satellites, or by gravimeters on the surface of the Earth, hundreds of kilometers away from an earthquake zone. I haven't really got my mind fully wrapped around this, but needless to say that crustal buckling shouldn't produce a reduction in gravity. If anything, bringing the crust a little bit closer to the satellite should increase the gravity field. So there has to be more to this than just gravity.The results of prediction of occurrence of mining tremors and bursts in the course of the exploitation of the remaining part of the hard coal in seam 510 of the mine “Pstrowski”, Upper Silesia, have been presented in the paper. The exploitation has taken place under extremely difficult conditions hazardous for the mining crew.
To predict the occurrence of mining tremors, bursts and direction of migration of increased elastic strain in the rock mass, the microgravity method has been applied.
The microgravity observations were carried out in the measurement points located at mutual distances equal 20 m in three profiles of the lengths 700 m, 760 m and 260 m respectively. The profiles were located in mining workings in the vicinity of the exploited part of the bed. In the course of exploitation, lasting 25 months, 29 series of measurements including 3600 individual microgravity observations were carried out. Microgravity observations were made with a Worden-Master gravimeter.
The observed time changes of gravity microanomalies were essential for prediction. Local negative changes of gravity microanomalies signalled the approaching mining tremor. The tremor would cover an area of the radius 60 m to 100 m. The regional time changes of the gravity microanomalies appearing as linear trends of these anomalies signalled the development of the fields of elastic strain in the whole investigated area and the approaching violent release of elastic strain energy from the rock mass.
The values of the amplitudes AMP of the above-mentioned trend were the measure of this hazard. In the course of the investigations each shock was preceded by considerably increased values of AMP.
Right -- so crustal deformation causes gravity anomalies. But how? Like I said in the previous post, warping the crust upward, toward the gravimeter, should increase the gravity field, not decrease it. And if the pressure is compacting the matter, again the gravity field should be increased. I just love how scientists pass off observations as explanations, and make it sound like confirmation of their model, when really, the data invalidate their model.Now, researchers at the California Institute of Technology have found that within subduction zones, the regions where one of the earth's plates slips below another, areas where the attraction due to gravity is relatively high are less likely to experience large earthquakes than areas where the gravitational force is relatively low.
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So why would gravity and topography be related to seismic activity?
One possible link is via the frictional behavior of the fault. When two plates rub up against each other, friction between the plates makes it harder for them to slide. If the friction is great enough, the plates will stick. Over long periods of time, as the stuck plates push against each other, they may deform, creating spatial variations in topography and gravity.
In addition to deforming the plates, friction causes stress to build up. When too much stress builds up, the plates will suddenly jump, releasing the strain in the sometimes violent shaking of an earthquake.
If there were no friction between the plates, they would just slide right by each other smoothly, without bending or building up the strain that eventually results in earthquakes.
So in subduction zones, areas under high stress are likely to have greater gravity and topography anomalies, and are also more likely to have earthquakes.
Well, that would have been about 6 years ago.Maol wrote:When was the last time any of you read the first post in this thread?
V.E.Khain, E.N.Khalilov. Cycles in geodinamic processes: their possible nature. Moscow, Scientific World, 2009,520 p.
V.E.Khain, E.N.Khalilov. Space-time regularities of seismic and volcanic activity. Bourgas, Bulgaria, SWB, 2008, 304 c.[19][20];
E.N.Khalilov. Global Network of Forecasting the Earthquakes: New technology and new philosophy. SWB, London, 2009, 65 p.[21]
E.N.Khalilov. Gravitational waves and geodynamics. (Edited by academician, Prof.Dr.V.E.Khain), Moscow-Baku, IAS/ICSD, 2004, 330 p. [22][23]
V.E.Khain, E.N.Khalilov. ABOUT POSSIBLE INFLUENCE OF SOLAR ACTIVITY UPON SEISMIC AND VOLCANIC ACTIVITIES: LONG-TERM FORECAST. SCIENCE WITHOUT BORDERS. Transactions of the International Academy of Science H & E. Vol.3. 2007/2008, SWB, Innsbruck, 2009 ISBN 978-9952-451-01-6 ISSN 2070-0334 [24][25];
V.E.Khain, E.N.Khalilov. GLOBAL CLIMATE FLUCTUATION AND CYCLICITY OF THE VOLCANIC ACTIVITY. Transactions of the International Academy of Science H & E. Vol.3. 2007/2008, SWB, Innsbruck, 2009 ISBN 978-9952-451-01-6 ISSN 2070-0334 [26][27];
E.N.Khalilov. ABOUT POSSIBILITY OF CREATION OF INTERNATIONAL GLOBAL SYSTEM OF FORECASTING THE EARTHQUAKES “ATROPATENA” (Baku-Yogyakarta-Islamabad).NATURAL CATACLYSMS AND GLOBAL PROBLEMS OF THE MODERN CIVILIZATION. Special edition of Transaction of the International Academy of Science.H&E.ICSD/IAS, Innsbruck, 2007, pp. 51–69. ISBN 978-9952-81-15-2-0 [28]
Walter Kofler,Elchin Khalilov. ON PERSPECTIVES OF APPLICATION OF NEW TECHNOLOGY OF SEISMIC RESISTANT CONSTRUCTION IN YOGYAKARTA SPECIAL TERRITORY (INDONESIA). SCIENCE WITHOUT BORDERS. Transactions of the International Academy of Science.H&E. Vol.2, Innsbruck, 2005/2006, pp. 340–360. ISBN – 978-9952-25-049-7.[29]
E.N.Khalilov. Global Network of Forecasting the Earthquakes. SWB, Bourgas, 2009, 55 c. ISBN 978-9952-451-02-3
E.N.Khalilov. ABOUT INFLUENCE OF GEODYNAMIC PROCESSES ON THE RESULTS OF MEASUREMENTS OF CAVENDICH BALANS.SCIENCE WITHOUT BORDERS. Transactions of the International Academy of Science H&E. Vol.3. 2007/2008, SWB, Innsbruck, 2009. ISBN 978-9952-451-01-6 ISSN 2070-0334
Cool! I'm still trying to find the seismic data for "slow quakes". I found a 2013 article by one of the principal investigators (Slip weakening as a mechanism for slow earthquakes) that talked about the structural properties of the fault, but then I hit the pay wall. The article you mentioned said "only the most sensitive seismic instruments picked up the tectonic action", but I can't find the data.Chromium6 wrote:Solving the Mystery of 'Slow Quakes'
The picture that is emerging here is of a large number of closely interconnected phenomena, including earthquakes, tidal forces, space weather, etc. So none of it is OT.ElecGeekMom wrote:I hope it's not too OT.
I "think" that it would be the latter -- smaller earthquakes occurring more frequently. This actually would seem to be a good thing, in that the pressure necessary for a catastrophic quake would never build up, since the pressure was being periodically relieved by small quakes. That, of course, assumes that the fracking was occurring all of the way down the fault line. If the pressure was only being relieved at one end, there would still be the potential for a catastrophic quake at the other end.Lloyd wrote:Would fracking increase earthquakes overall, or make them more numerous but smaller?
I couldn't hear the sounds, but my thesis on the Seneca Guns is that they occur where telluric currents encounter capacitance, and charge disparities can build up. Then, a sudden "fair weather lightning" occurs, discharging the potential. So conductivity due to fracking, and Seneca Guns due to capacitance, would be mutually exclusive.Lloyd wrote:I don't well remember your explanation of Seneca guns, but do you suppose the sounds mentioned...
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