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How a 'Seismic Cloak' Could Slow Down an Earthquake
Daniel_Stuckey writes "The United States is currently gripped in a bout of earthquake mania, following a series of significant tremors in the West. And any time Yellowstone, LA, or San Francisco shakes, people start to wonder if it's a sign of The Big One to come. Yet even after decades of research, earthquake prediction remains notoriously hard, and not every building in quake-prone areas has an earthquake-resistant design. What if, instead of quaking in our boots, we could stop quakes in their tracks? Theoretically, it's not a crazy idea. Earthquakes propagate in waves, and if noise-canceling headphones have taught us anything, it's that waves can be absorbed, reflected, or canceled out. Today, a paper published in Physical Review Letters suggests how that might be done. It's the result of French research into the use of metamaterials—broadly, materials with properties not found in nature—to modify seismic waves, like a seismic cloaking device."
For some reason, this article made me think of that story about Tesla and his "oscillator" experiment:
http://www.angelfire.com/scifi...
I wonder if, rather than relying on these "metametals" in special soil, one could station units similar to these at strategic locations along fault lines, designed to pick up an earthquake's resonant frequency and generate a corresponding one tuned to cancel it out?
Being able to cancel out seismic earthquake waves would imply the ability to generate out of phase waves of similar amplitude. If we have that capability, we absolutely should use it to attack North Korea.
Is the seismic cloak made of sheep's bladders?
I wonder if one could station units similar to these at strategic locations along fault lines, designed to pick up an earthquake's resonant frequency and generate a corresponding one tuned to cancel it out?
What are the power requirements? How many stations do you need to do the job?
I remember reading about this!
http://www.gutenberg.org/ebook...
"I'm too busy to research this and form an educated opinion, but I do have time to tell everyone my uninformed opinion."
Let's see, first let's try and stop Plate Tectonics. First let's shut down that big old nuclear furnace at the center of the Earth... Nothing to big to do there...
After which the electromagnetic field shielding the earth stops
and we all get hella bombarded by solar winds..
This is a bad sci fi movie plot, April Fools
Harrison's Postulate - "For every action there is an equal and opposite criticism"
I'd like to order ten thousand amplifiers and about 20,000 kick-ass bass cabinets... oh, and one microphone and phase inverter...
if this is supposed to be a new economy, how come they still want my old fashioned money?
But where would we get a set of headphones that big??
Coder's Stone: The programming language quick ref for iPad
Everyone knows earthquakes are particles not waves!
Never answer an anonymous letter. - Yogi Berra
It doesn't mean what you think- oo practical building can resist all earthquakes. The building standards are more about if a large earthquake occurs the building damage should be it limited to a small area. And it isn't about having a usable building after a quake - it is about not killing the people inside or around it.
Speaking from experience, just because a building stands up during a quake it doesn't mean that the building won't be structurally broken and require significant repairs or replacement before it can be used. The energy has to go somewhere!
we could stop the earthquake wave propagation at the split point.
What could go wrong?
"Significant tremors in the west"? The recent earthquakes used to be business as usual back in the 80's-90's. We'd have them at least once or twice a year, if not more, and it never really raised an alarm. We've just had such a dry spell since 1999 (or '94, if you want to keep it in the LA basin), that these light/moderate earthquakes seem like big news. The bigger story should have been "Where the hell are all the earthquakes??" for the past 20 years.
What if you could attach a line of giant shock absorbers across fault lines? The plates wouldn't be able to move fast enough to cause an earthquake right?
Totally impractical, especially considering the amount of anchoring that would be needed to get a meaningful structural attachment to a tectonic plate, but I wonder if it would work in theory.
"When information is power, privacy is freedom" - Jah-Wren Ryel
Could this same noise-cancellation methodology be used to silence the reverb-ish spoken summaries that freak out my cat every time I load an article?
Full disclosure: I don't really have a cat.
The primary problem with this concept is that you have to know very precisely the composition of the ground where you install this barrier. Another problem is that environmental changes - soil moisture, temperature, are going to affect the material properties somewhat (but maybe not enough to matter).
Essentially, extremely low frequency waves that trash buildings don't perceive the ground as atomic, the waves act over their wavelength, which is very long, and so if you put things into the ground, it changes the material properties. Carefully drilled holes apparently can change the properties in dramatic ways. The word "cloak" is sexy, but the more interesting bit mentioned at the end of the paper was the prospect of building a bandstop damper with the low corner at 0 Hz.
It doesn't do you much good if your earthquake prevention device reflects the energy somewhere else dependent on the epicenter, and it also doesn't do you much good if it doesn't block enough frequencies to stop it from trashing your buildings. A bandstop filter would operate over a broad enough band to attenuate all the frequencies, and it wouldn't reflect energy to other buildings (which could have obvious liability concerns.) Imagine a plaintiff's attorney showing a standing wave pattern of destruction emanating from a field of holes drilled by the defendant's firm.
The other satisfying nature of this tech is that it's proactive. Instead of building structures that will probably collapse if a magnitude 8 happens anyway, you go out there and build armor that will stop the earthquake entirely. Also, a field of holes and concrete and various pertubations, all buried, is a lot less ugly than the structural changes needed to reinforce a building against a major earthquake.
It would be expensive to do the detailed surveys and compute the solution, but it would create more high education jobs, and it's probably worth doing.
Everyone knows earthquakes and magnetism have nothing to do with the Earth. They never met each other. Go ahead without fear. Nothing could ever possibly go wrong. No sudden liquefying, no mineral phase changes, no redirections or sudden subsidences and subductions tens, hundreds or thousands of miles away. Never! Please, try it in the US, first. Preferably near Wall Street on a big business day. During a mega-Fracking IPO event. Please.
You could dig up miles of ground to build seismic cloaks, or you could build your buildings on springs.
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are earthquakes not releases of build-up forces between two or more parts of the earth crust.
Why would you try to contain those forces and if so are you not making the next quake a stronger quake since forces will be still there
and if so does stopping earthquakes completely require a infinite amount of energy since force build-up gets higher each time
But not for technical reasons. While the engineering would be difficult to do, it's possible.
The problem is legal. It stems back to a question a friend of mine asked when noise-cancelling headphones first appeared. "If a sound wave has energy, and an equivalent wave 180 degrees out of phase also has energy, and when you combine the two you get no sound, where does the energy go?" Obviously the energy for both waves goes to regions where the two waves don't cancel.
So if you protected an area with this device, after an earthquake you'd be sued into oblivion by neighbors claiming your device increased damage to their property.
There is a HUGE amount of energy in an earthquake (enough to destroy cities). In order to cancel out those waves, we are going to need equally strong waves with the opposing waveform.
How will we find this huge quantity of power? The current grid struggles with normal demands. If you have to double (or more) the country's energy infrastructure, then this tech will never see any application.
(long since forgotten my /. password - so AC it is)
what are the consequences of sending those "anti-waves" on other parts of the world, there is a reason those 'waves' are going on.. those 'waves' are also a way of releasing kinetic energy that has been building up, but what will happen if you just send the released energy back, it might just pop out at the other side..
That immense energy has to go somewhere. I just don't see how it's possible to avoid simply moving the trail of destruction somewhere else. Maybe find a way to send it DOWNWARD?
If you start putting stupid autoplay on stories, they cannot be read at work. And Slashdot will die.
What the heck is wrong with you guys?
"Cats like plain crisps"
nyah nyah nyah, everyone with a R next to their name is an idjut! I am *so* progressive!
If it can produce waves powerful enough to dampen an earthquake, then it can produce an earthquake.
I am very small, utmostly microscopic.
Seriously, somebody needs to find a way to eliminate the wave propagation of heavy traffic. IMHO, those entrance ramp meters are a dumb idea. It just backs up traffic onto the local roads. Foot on the gas, people!
There's an idea!
I seriously doubt they could actually prevent the damage that something as tremendously powerful as an earthquake can do, but maybe they could prevent the media from going on and on and on about it ad nauseam after it happens. California and the SW US will become less and less important/useful as their drought continues to get worse, and most people will be leaving that area if they can, leaving it for those who can't afford to move. Maybe they'll invade Mexico.
When they have "The Big One", I suspect they'll be waiting a looong time for help. Kinda like Katrina, writ large. I don't think this spiffy new tech's gonna be good for much, if anything.
I call BS on this. There is a basic "fault" to this argument.
Ground can be solid rock or sedimentary deposits and the two react to quakes differently.
The 1926 Yokohama earthquake had vertical displacement of up around 9 feet as I recall from the books I have on it. A cloak would be worthless.
A slip fault at the San Andreas in Parkfield, CA might have part of your property moving North by some feet compared to the other side. You are not going to be able to stop those amounts of movement.
The crust shifts...
Cancel a shift in one zone can only increase stressors in surrounding zones.
Also as an expansion thought, if one were able to cancel the shift in the crust, would this not allow the crust to cool properly via now a broken earth convection current, create massive mountainous bulges in crumple zones elsewhere, create catastrophic instabilities world wide?
An earthquake is caused by Mother Earth.
She's sad.
Sad that there are too many taxes.
Sad that everyone complains about global warming, but no one does anything to stop it except jack up taxes.
Sad that everyone loves the hydrocarbons.
I wish we could lower taxes and stop the Global Hydrocarbon Extraction (tm).
Please, Al Gore, please lower taxes and solve global warming.
"Earthquakes propagate in waves, and if noise-canceling headphones have taught us anything, it's that waves can be absorbed, reflected, or canceled out."
Not waves that big, pal.
you got me. I fell for it.
Happy April 1.
I understand we can build cancellation structures for waves that do horizontal propagation, but what about vertical propagation?
I'm pretty sure this is an April Fools joke. While it would be *theoretically* possible to cancel out an earthquake by producing waves of the exact same amplitude but opposite phase, people are forgetting the "same amplitude" part. Earthquakes generate a HUGE (absolutely HUGE) amount of energy, and you have to throw the exact same amount of energy (with inverted phase) back at it. How are they going to generate this huge amount of energy? Certainly not with a few speakers. Even small earthquakes generate as much or more energy than a nuclear weapon.
Prior art: http://brutallegend.wikia.com/...
People seem to completely miss the key part of this experiment... The energy has to go somewhere:
Just think of it... Those with the most money to spend, get to be earthquake-free, but everyone else gets their earthquake intensity INCREASED, perhaps DOUBLED.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
Can we somehow make something that turns earthquakes into usable energy like electricity?
Kinda being serious. Feel free to laugh me out of /. for a month.
No, you can't cancel out a freakin earthquake. To generate equal but opposite waves, you need equal but opposite energy.
Now an earthquake might have the energy equivalent of several Megatons of TNT, so unless this scheme is powered by thermonuclear means, then you can forget it.
It can only ever work in a locally contained environment, eg a single building, where a smaller amount of energy can be expended for localized cancellation.
+1
I ask the question since it could be a possibility! How would you know that using such a method wouldn't cause a build up of energy, and while you cancel the quake out, how do you know it wont build up somewhere else and be released at a much larger magnitude, perhaps something well over 10X!
Earthquakes are still something science has yet to fully understand. And trying to create this in a lab, or with a computer [remembering the computer has to be programmed with the knowledge man has] is one thing but going out in the wild and trying it could yield just the opposite.
That seems like that a massive amount of energy to try and cancel out, without expecting your plan not to backfire.
We've been working on the existing of God for between 3,000 and 10,000 years now. The divine entity remains notoriously hard to confirm. News at 11.
Agreed. The energy absolutely has to move somewhere. Noise cancelling headphones don't destroy sound, they just make it undetectable by your eardrums.
This has nothing to do with noise-canceling headphones. The metamaterial is a passive system which does not allow transmission of mechanical power in specific frequency bands (which are called phononic bandgaps). It works like a Bragg filter for electromagnetic waves. Two problems:
1) the spatial scale would be huge. In the article they tested for 50Hz, but seismic waves carry most of the power at 1 Hz and below.
2) the energy is not dissipated, it's reflected back (oops). "Get the most out of your QuakeStop(TM)! Protect your house AND raze down your neighbor's!!"