Air Guns Shake Up Earthquake Monitoring 38
sciencehabit writes "Petroleum geologists have long used air guns in their search for oil and gas deposits. Sudden blasts from the devices generate seismic waves that they use to map underground rock formations. Could the same technique be used to study earthquakes? A team of Chinese scientists thinks so. The researchers have designed an air gun that could be useful in monitoring changes in stress buildup along fault zones."
Re: (Score:2, Insightful)
Do you have to practice being this obnoxious, or does it come naturally?
Let me be the first to say... (Score:5, Funny)
Re:Let me be the first to say... (Score:5, Funny)
OTOH, Just imagine this conversation:
Engineer 1: Man, this is boring.
Engineer 2: Yep, nothing happening.
Engineer 1: How many of those guns do we have around here anyway?
Engineer 2: Dunno, couple dozen. Home office just dropped off a bunch last week.
Engineer 1: How many of these things can we tie together anyway?
Engineer 2: Dunno, probably all of them, they just hook up with that cable.
Engineer 1: Think those guys at the Earthquake Monitoring Program [usgs.gov] are awake yet?
Engineer 2: Dunno, we could find out, I suppose.
Blowing a rock (Score:2)
Well, if they blow hard enough, they might be able to rock somebody.
Study earthquakes? (Score:2)
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Impressive, and probably cheaper and less risky (Score:5, Insightful)
"None of the lake's fish were killed or stunned by the shots, and instruments installed at a dam 1.4 kilometers away from the test site showed that peak ground accelerations were far below those detectable by humans"
Impressive, and probably cheaper and less risky than dynamite. No animals were harmed.
Good work!
Re:Impressive, and probably cheaper and less risky (Score:5, Informative)
... probably cheaper and less risky than dynamite.
Dynamite's pretty safe. Blasting caps can be dangerous. However, most of the blowback wrt using dynamite in this application is it annoys the neighbours, is environmentally unfriendly, and bad guys love to steal the stuff.
As for TFA, it depends. Shear waves (the twisty kind) travel quite a ways, but don't tell you much. Pressure waves don't travel very far but do tell you a lot, dependent upon the range of frequencies transmitted by the wave, and the medium through which they're transmitted. An 8 Hz p-wave will travel farther than a 500 Hz p-wave, but you won't learn much of any interest at 8 Hz.
Unfortunately, TFA says nothing about the frequency range produced by these air guns. I doubt it's anywhere near the range produced by dynamite.
BTW, it's geophysicists who do this stuff, not geologists. The latter are the guys with rock hammers and sample bags.
Holy shit (Score:1)
What is that really
Measuring Something Changes It (Score:5, Interesting)
Is there any scientific study showing how much these seismic impulses, from air guns or from other giant synthetic "pings", increase the rate and/or intensity of earthquakes? There's some data from fracking and other injection wells, but those also introduce (possibly lubricating) newly active materials. How about just an energetic impulse? Or are we just blindly pulling the dragon's tail?
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Is there any scientific study showing how much these seismic impulses, from air guns or from other giant synthetic "pings", increase the rate and/or intensity of earthquakes?
According to the article, that's part of the field tests they're doing now.
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It's sort of on the scale of "Is there any scientific study showing how much knocking on front doors, with fists or with synthetic "knocking devices", increase the rate and/or intensity of houses collapsing? Or are we just blindly pulling the dragon's tail?"
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Where's your scientific evidence to show that's the "scale"? Or aren't you just making it up?
Re: (Score:2)
Why does he bear the burden of proving your original question is relevant?
Hint: he doesn't.
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I think the default assumption would be that anything we do would DECREASE the intensity of earthquakes.
(explanation: earthquakes are the huge release of energy when pent-up forces are released; anything that lets it be released earlier in smaller amounts would decrease that).
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I dunno - the natural system might be prone to releasing the energy more gradually, over a longer time series of quakes. "Popping" a quake outside its own rhythm might bypass natural mitigating mechanisms.
But I don't know. That's why I'm looking for scientific evidence.
I would like to believe there's at least a scientific model, based on measured data, that indicates it's safe. Not just oil/gas corps assuring us it's OK.
Re: (Score:3)
If the air gun pulses can measure tension, perhaps some other method could be used to cause the plates to slip while there is little tension. Would that not be similar to avalanche control on mountains? Avalanche control entails causing smaller slides in areas that are troublesome. Perhaps in the same way the air gun measurements and intentional blasts could be used to help manage plate tension below a certain level of tension. Many smaller tremors, instead of "the big one" all at once.
This type of management would require measuring other faults and surrounding plates, as a small slip here may have a larger effect elsewhere. I'll admit that this is getting into an area where we really don't know what the long or even short term affects of this type of management would cause, if it would work at all.
Given the relative energies, it would be more like attempting to control avalanches by shooting spitwads at the slopes.
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Except the triggering event need not be at the scale of the energy increased. It's not the additional energy from the trigger, it's what mechanical configuration that energy acts upon. You're saying that no straw can break a camel's back, because the camel is so much bigger than the straw. I'm not so sure.
Re:Measuring Something Changes It (Score:4, Informative)
While measuring something indeed influences it, there are fundamental energetic limits below which this influence is negligible (i.e., shining light on a truck to measure it's position. I believe these air guns fall into this category
Re: (Score:2)
That's a pretty cool thought. Probably completely unfeasable but cool nonetheless.
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They travel very far. But bandwidth sucks.
Thumper trucks (Score:5, Interesting)
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They had a similar thingy for oceans that would blast high pressure air into the sea floor.
Wouldn't that attract Kraken?
What's the frequency? (Score:5, Interesting)
I worked in seismic data processing for a couple of years - there's a MOUNTAIN of data out there. The big problem for researchers is that it's mostly locked away as trade secrets. There are a few firms that can license you a few shot lines - but they are pretty limited compared to the big companies.
This sort of geological study is already used for 4D studies, where shots are compared over a period of time. The hydrophone shot technology has been pretty stable for 20 years now - but older data may have limited depth and frequency.
They're great for Antlion outbreaks (Score:2)
They're indispensible for Antlion outbreaks.
Who's going to fix it (Score:2)
This is really going to piss off the Silurians.