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Geophysicists Discover How Rocks Produce Magnetic Pulses
KentuckyFC (1144503) writes "Since the 1960s, geophysicists have known that some earthquakes are preceded by ultra-low frequency magnetic pulses that increase in number until the quake takes place. But this process has always puzzled them: how can rocks produce magnetic pulses? Now a group of researchers has worked out what's going on. They say that rocks under pressure can become semiconductors that produce magnetic pulses under certain circumstances.
When igneous rocks form in the presence of water, they contain peroxy bonds with OH groups. Under great temperature and pressure, these bonds break down creating electron-holes pairs. The electrons become trapped at the site of the broken bonds but the holes are free to move through the crystal structure. The natural diffusion of these holes through the rock creates p and n regions just like those in doped semiconductors. And the boundary between these regions behaves like the p-n junction in a diode, allowing current to flow in one direction but not the other. At least not until the potential difference reaches a certain value when the boundary breaks down allowing a sudden increase in current. It is this sudden increase that generates a magnetic field. And the sheer scale of this process over a volume of hundreds of cubic meters ensures that these magnetic pulses have an extremely low frequency that can be detected on the surface. The new theory points to the possibility of predicting imminent earthquakes by triangulating the position of rocks under pressure by searching for the magnetic pulses they produce (although significantly more work needs to be done to characterize the process before then)."
When igneous rocks form in the presence of water, they contain peroxy bonds with OH groups. Under great temperature and pressure, these bonds break down creating electron-holes pairs. The electrons become trapped at the site of the broken bonds but the holes are free to move through the crystal structure. The natural diffusion of these holes through the rock creates p and n regions just like those in doped semiconductors. And the boundary between these regions behaves like the p-n junction in a diode, allowing current to flow in one direction but not the other. At least not until the potential difference reaches a certain value when the boundary breaks down allowing a sudden increase in current. It is this sudden increase that generates a magnetic field. And the sheer scale of this process over a volume of hundreds of cubic meters ensures that these magnetic pulses have an extremely low frequency that can be detected on the surface. The new theory points to the possibility of predicting imminent earthquakes by triangulating the position of rocks under pressure by searching for the magnetic pulses they produce (although significantly more work needs to be done to characterize the process before then)."
see Triboluminescence!
Science, bitches.
piezo effect? With magnetism, electricity can't be far behind. I wonder if that can't start underground coal fires.
“He’s not deformed, he’s just drunk!”
Surely it's the heat causing this? Not the pressure?
Don't nobody tell ICP.
those pulses are clearly a MUTO mating call.
The Kruger Dunning explains most post on
Given that lots of animals are sensitive to magnetic fields, this would also seem to explain them reacting prior to earthquakes.
I am Slashdot. Are you Slashdot as well?
The other option is of course the tin-foil hat version. The magnetic pulses are causing the earthquakes and are actually of human origin.
Why is it that the holes can move but the electrons can't? I thought holes were just places where electrons could be but aren't, so moving holes implies movement of electrons.
http://www.masturbateforpeace.com/
Jim Berkland used to monitor the classified ads in the newspaper for trends in missing pets. Back when there were newspapers, and they had classified ads.
And TT Brown had done some interesting research into geologic piezoelectricy, although Wikipedia only talks about his anti gravity research.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
The new theory points to the possibility of predicting imminent earthquakes by triangulating the position of rocks under pressure by searching for the magnetic pulses they produce (although significantly more work needs to be done to characterize the process before then)."
But that will only find certain types of igneous rocks formed underwater peroxy bonds under pressure. Not all rocks under pressure. Still if this type of rock is prevalent enough in a region, it could be useful.
Also geologists have been calculating rocks under stress using so many methods and observation. The problem is the slippage and failure occur unpredictably. The stress can be estimated. The strain may be observed. At least the surface strain. But the ultimate (or failing) strength of the rock layers is largely unknown.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
When I see the word "semiconductor" I think "transistor". I wonder if this discover can lead to a new type of commercially practical semiconductor. Obviously not on the size scale of seismic plates, but perhaps this effect can be created in other materials,now that we know it exists.
Up until haarp cut the magnetic graph feed you could often see anomolies preceed earthquakes there.
Its www.electricquakes.org and they still have other feeds pertaining to earthquake electrical activity as well as discussion about the likely piezoelectric foundation for them.
Its only been the earthquake overlords at usgs that have denied this for so long.
Friedemann Freund is a man with a lot of ideas.. At Yuri's night at the NASA Ames campus, he demonstrated this magnetic pulse-from-rock by using a dense column of rock and a hydrolic press. He had a saucer sized capactive sensor that was tied to a small microcontroller for remote-sensing/field usage that could detect the change in the electric feild near the rock column as it was compressed. He mentioned that he'd instrumented a fault line. He mentioned that the current released was strong enough to ionize the air around the faultline if a lot of rock was compressed at once. Compression can happen before an earthquarke, which is why it may serve as an early warning detector. He also thinks that some animals go nuts before an earthquake because they can smell traces of the the ionized air.
Here is his profile: http://www.seti.org/users/frie...
He also has some interesting ideas about the origins of life on earth, specifically the chemistry of mud on the ocean floor, about how long polymer chains can form; the working material for the first cells, and alternative theories of oxygen formation in our atmosphere..
Except all studies seem to indicate that animals do NOT act any differently before an earthquake. It's all seems to be post hoc, ergo propter hoc reasoning.
The Kruger Dunning explains most post on
detect sarcasm?
Clever work. I'd go so far as to call it... igneous.
Tip your wait staff.
Animals freaking out beforehand everywhere is unlikely , however standing right above a fault-line where a sudden discharge of energy may be a different story.
Since the 1960s, geophysicists have known that some earthquakes are preceded by ultra-low frequency magnetic pulses that increase in number until the quake takes place.
The pluses would have been more impressive if they decreased in number at some point with anti-pulses. I'm guessing they meant frequency instead of number.
The idea of geological circuits reminds me of "Earth" by David Brin.
This summary made me think of LEDs and earthquake lights. Even if there is light generation, though, I can't imagine that it would be very intense. And then there's the whole "buried under meters of rock" issue.
IAAP (I am a physicist), and my work field concerns also geophysics. TFA is very suspicious for several reasons. I just list the simplest points to understand
First, there are way too much self references: take for example the first sentence "Rocks, especially igneous rocks, behave as semiconduc- tors under certain conditions". They connect this sentence to four papers previously published by one of the authors (Freund). Nobody else in the scientific world ever verified that rocks are semiconductors ?!? This does not make a good start for the topic they are going to discuss.
The authors claim that it is more than 50 years that the boundary between earthquakes and VLF emission has been established. Unfortunately this is not true: if it were, seismic network would be composed of radio receivers, they are way cheaper than seismometers. The existence of a connection between VLF emission and earthquakes is still an open question, and there are no conclusive proofs supporting it.
What we know is that earthquakes are usually not associated to a simultaneous VLF emission, so a theory explaining how earthquake precursors can trigger a VLF emissions should also justify why earthquakes have no VLF emission as well.
Figure 1 of TFA is a masterpiece of deception: please look at the value range in the graphs showing the computed and measured events: do you still think that the numerical predictions estimated by the authors and the field measurements can be defined "similar" ?!? They only share the same shape, when drawn on very different time and amplitude ranges!
Summing up, I am afraid that this paper isn't going to be of any help with earthquake prediction...the next, please!
The next step will be to see if there is enough evidence to support a theoretical assertion. Then, testing and experimentation can be devised to either support or disprove that theory.
They're suggesting that the Earth's mantle (silicon with an extremely high percentage of impurities present) may act like a semiconductor (silicon with tiny percentages of specific impurities present), creating a natural Zener diode, a huge but inefficient one. I'm with you - skeptical. Still, it should be possible without too great an investment in manpower or materials to support or disprove their hypothesis. Should it survive that step to become a theory, supporting or disproving it shouldn't take too much more work.
Let's say it's a huge earthquake, something along the line of the 8.something earthquake that shook Fukushima, causing tsunami and untimately got that nuke plant to melt ...
In a big quake like that, how _far_ can the magnetic pulse propagate ?
10 miles ? 100 ? 1000 ?
Has anyone got any info ?
Muchas Gracias, Señor Edward Snowden !
Rocks - silicates - are full of oxygen. They are silicon dioxide. The electrical currents in question result from changes in the oxidation state of the oxygen atoms, an electron-hole semiconductor effect. This is distinct from piezoelectricity, which is a very short-lived phenomenon.
The authors claim that it is more than 50 years that the boundary between earthquakes and VLF emission has been established. Unfortunately this is not true: if it were, seismic network would be composed of radio receivers, they are way cheaper than seismometers. The existence of a connection between VLF emission and earthquakes is still an open question, and there are no conclusive proofs supporting it. What we know is that earthquakes are usually not associated to a simultaneous VLF emission, so a theory explaining how earthquake precursors can trigger a VLF emissions should also justify why earthquakes have no VLF emission as well.
This has nothing to do with VLF. It concerns ULF/ELF emissions at ~1Hz. The VLF band is 3000Hz-30000Hz. You should read more carefully before going trolling.
It is interesting that the pulses were measured in Lima, Peru, where 'earthquake lights' were caught by surveillance cameras as they illuminated the night sky during an earthquake a few years ago:
https://www.youtube.com/watch?v=f14pQakxXjc
The camera in that video is pointed toward the ocean...there is an undeveloped rocky island off the coast, but it has no manmade electrification. Pilots on inbound airplanes reported lights emerging from that spot. Also, thanks to the timestamp, the flashes are known to correspond to arrival of the S-waves...so perhaps the stress from the seismic waves produced an electrical discharge similar to the mechanism proposed for the magnetic pulses.
I am the one (FF) whose work has been quoted repeatedly in this paper - a fact which triggered the comment that "Nobody else in the scientific world ever verified that rocks are semiconductors" - followed a question mark, an exclamation mark and another question mark.
Well, as someone who might have made a significant discovery, may option is to publish in scientific papers, describe exactly how I had done the crucial experiments, and invite the "scientific world" to duplicate my experiments. Sorry, I can't force anybody to actually do it. There is the old jaded story that Galileo invited the cardinals who were about to judge him for heresy to come out into the plaza at night to look through his telescope. He promised them that they would see for themselves the four moons circling Jupiter. The story goes on to report that most of the cardinals chose not to peek through Galileo's telescope - because they "knew" that Galileo's new view of the planetary world could only be wrong.
There are still lots of "cardinals" out there not wanting to see for themselves... ...and there are others, including a (geo)physicist, who claim to have duplicated the FF experiments. However, sneakingly (or out of sheer stupidity) he changed the experimental procedure in such a way that the outcome would be different. This led to the loud proclamation that the FF experiments are irreproducible and, hence, must be wrong.
By the way, the arXiv paper describes an electromagnetic phenomenon in the ULF frequency range, around 0.1 to 5 Hertz. The proclaimed physicist who finds serious faults in that paper spends an entire paragraph talking about VLF which, by definition, refers to the frequency range of 3 - 30 kiloHertz (3,000 to 30,000 Hertz). I believe that there are 3-4 orders of magnitude differences between ULF and VLF. I wonder how this might have escaped his attention?
Summing up, I am afraid that this critique isn't going to cut it...the next, please!
This is one of the authors (FF) of the paper under discussion.
(1) All magmas contain contain dissolved gases, the same gases that come out of the mouth of volcanoes, water being one of the major components. All minerals that crystallize out of those magmas contain dissolved gases, water being one of them, forming hydroxyls such as Si-OH. Many, if not most of those Si-OH occur as pairs, Si-OH HO-Si. Work done already in the 1980s strongly indicates that, during cooling, in the temperature window around 500ÃC, the two OH facing each other in the hydroxyl pair defects rearrange their electrons in such a way that the two hydroxyl protons become reduced to H2, while the two hydroxyl oxygens become oxidized from the 2- to the 1- state, forming peroxy Si-OO-Si. This is nothing else by a redox reaction known to chemists around the world, applied here to a system in the solid state that takes place deep in the Earth's crust. The up-shot of this brief discussion is that EVERY rock deep in the Earth's crust that goes through this cycle as part of its geological history will contain peroxy defects.
(2) Geologists can calculate rocks under stress as much as they want, so long as they do not know (and acknowledge) that those rocks ubiquitously contain peroxy defects and how those peroxy defects behave, their results have little or no bearing on the question at hand: How can electronic charges, positive and negative, be generated by stressing rocks?
Staring at the conditions under which rocks rupture catastrophically, is also quite unproductive. The reason is that, when stresses are applied, most of the process leading to the activation of mobile electronic charges, positive and negative, has already occurred. Looking at the build-up of stress long before rupture provides much more insight.
Of course, "nobody should trust this..." but it would be nice, if everybody would invest a little more brain power and pay a little bit more attention to what the story is all about.
It's not about the Earth's mantle. The Earth's mantle is so hot that equilibrium thermodynamics rules supreme. It's about the rocks in the Earth's crust, in the "seismogenic zone" between about 7-35 km, where some 85% of all earthquakes occur. In this part of the Earth's crust the rocks are at temperatures, typically below 500ÃC, where thermodynamic equilibrium cannot be maintained and where reactions are possible (and do occur) to which the scientific community has not paid enough attention or no attention at all: redox conversion of solute hydroxyl pairs, Si-OH HO-Si to peroxy plus hydrogen, Si-OO-Si + H2.
Many in the mainstream geoscience community call this reaction "hypothetical" even though there is perfectly good information that this reaction does ubiquitously occur in the depth of the Earth crust - under conditions outside thermodynamic equilibrium. The fact that the mainstream geoscience community has not (yet) grasped it doesn't mean that this redox conversion is hypothetical. Every step of this redox conversion has been described in the geoscience literature since the early 1980s - except that most geoscientists chose to ignore it because understanding it requires a bit more knowledge than what is usually taught in geoscience departments. FF.