Yes, another /.-er said that weakening of the gas-rich strata changes the stress field, causing reacommodation in places that were previously stable. Is there any serious before/after record of displacements / etc (besides seismic events) to build a solid case in court / regulators ?

I learned after posting that comment that some of the quakes happened in places without a significant seismic history. And thar the fracking may have caused a redistribution of stresses by weakening the gas bearing strata. (Which is not the same as crowing "You said you weren't causing quakes and now you can! Which is it, huh? Huh?")

The fun part will be taking Big Oil to court. How well have the areas where they operate been monitored?

I thought all quakes dissipated energy reducing the total stress, but this may still be true while increasing concentration elsewhere as you suggest. Another reply to my comment says that the fractured layer isn't as strong as before, resulting in new shifts and accomodation in faults that were stable. What do you think?

Yes, the "small force triggering a big release" part is alright. The flaw lies in assuming theres a single bowling ball; to follow your analogy, imagine that balls keep coming in at a more or less constant rate until the shelf flexes and all come down (avalanches work like this too). Wouldn't you rather shake the shelf to make one ball fall at a time? (IIRC, avalanches are sometimes triggered on purpose).

Plate movement doesn't stop either, and the fault can accommodate and dissipate its stress in big or small jolts. But again, read the other post I told you about.

So it's not really about faults accommodating plate displacement, but about new dynamics created by collapse in the fractured rock. And the statistics suggest that something is indeed changing. Are there any measurements of the strata backing up this?

Yes, there's a reply to my original post that the fillers do not stabilize the damage well enough, and that's causing new dynamics in faults that were until now quiescent.

That analogy doesn't resemble fault dynamics at all. Perhaps a better one would be pushing a heavy object along a hard floor; as it moves, some points of contact stick, flexing the structure a tiny bit until the stress exceeds the static friction, and every little jolt is like a seismic event. That's how regular fault accommodation causes quakes, and the longer the points of friction are stuck a bigger jolt becomes more likely.

But never mind - there are other replies to my top-level comment that propose other sources of stress / energy.

Now we're talking. There's one thing that doesn't add up to me: does the energy delivered by the process approximate the energy released seismically?

Huh? Don't all quakes release energy?

Both. Since you can't be bothered to read what I wrote attentively, I'll tryoto expand and break it down:

Fracking releases the energy in the faults, thus fracking triggers quakes. But the energy doesn't come from fracking - it comes from plate tectonics. And the quake would have happened anyway, possibly causing more damage like a pressure pot with a defective release valve. So fracking doesn't cause *additional* quaking - it replaces a few (possibly) big quakes with several smaller ones.

If my meager understanding of earthquakes is correct, these small slippages release in small bits the tectonic stress that could otherwise build up until a bigger quake happens. So, frack away?

The air interface may be "free" in a marginal-cost sense. SMSCs (and the associated charging solutions in the case of real-time billing systems) aren't, and companies like Acision make their fortunes selling these.

The term "resolution" predates raster images, and thus it means more than "pixel count":

Optical resolutionÂdescribes the ability of an imaging e system to resolve detail in the object that is being imaged.

http://en.wikipedia.org/wiki/O...

The term "resolution" predates raster images, and thus it means more than "pixel count":

Optical resolutionÂdescribes the ability of an imaging e system to resolve detail in the object that is being imaged.

http://en.wikipedia.org/wiki/O...

To be fair, some behavio(u)rs of the original game were less than reasonable, to the point that taking advantage of them felt like an exploit. One of these was "collective sight", which meant that if anyone on your side (even a controlled alien) can see someone, everyone can target it. You could do the Cydonia mission without leaving the craft by spotting one alien and chain-controlling as many as needed to reach the hive-brain. Others were: stuffing someone (dead/unconscious) in your "backpack" and only suffering some weight encumbrance; unconscious characters not being targetable (I saved more than one soldier by knocking him out); and (this one's debatable) your soldiers' collective "memory" of the map, which e.g. allows any of them to guide the ridiculously fun Blaster Bomb like a Tomahawk Out Of Hell.

Still, those design flaws are more forgivable in their historical context than the needless restrictions that put me off XCOM:EU. Didn't have a chance to enjoy the teleporting Greys.