ArturoBandini wrote:Interesting topic. I wonder if the technology discussed here could be used to purposefully trigger earthquakes in areas where they cause damage more frequently. The potential energy is already there between the rocks, the water is simply releasing it.
You mean, to reduce the likelihood of a future large earthquake by deliberately triggering swarms of smaller quakes that would reduce the stress on the fault?
That's a creative idea. I've actually had some minor involvement in studies of induced seismicity going back to the 1980s and I never heard anyone suggest that. Intuitively it's a cool idea but there are some problems, both geophysical and social. Probably the biggest one is that you'd be sued left and right by people who claimed that your deliberately induced seismicity had damaged their property. The liability issue would kill this idea, I'm afraid.
Let's say you drill some wells evenly spaced along a major fault and inject water under high pressure. You gently increase the pore pressure to trigger small quakes all along the fault rather than a single big one. Most of the quakes are below 4, but there are a few larger ones including a 5.0 that damages a bunch of houses. Now, in the "world avoided" scenario, there would have been a 6.8 quake at that point, and it would have totally destroyed the same group of houses and killed a few of their occupants. But since we don't know about that alternate universe, the people whose lives and houses you saved are hopping mad about the cracks in their foundation and whatnot.
From what I can tell, none of the earthquakes triggered thus far caused appreciable damage. This might sound crass, but a handful of people killed in accidents, or a collapsed chimney and a cracked driveway don't really count as disasters, especially when compared to the scale of the industrial activity occurring here.
Well, we've only been doing this a few years. Until a couple of years ago, there'd never been a major tsunami that hit a nuclear power plant, either. The statistics of earthquakes are such that there are thousands of small quakes for every large quake. Frankly, if we keep expanding the use of fracking without guidance from seismic studies, sooner or later there's going to be a too-large quake under a town, or a dam, or a nuclear power plant.
In comparison, consider how many roads are utterly destroyed by coal trucks each year, or how often an miner or bystander is killed by coal mining activities.
I'm not sure quite what to make of that argument. Yes, coal mining and coal use in general is more dangerous. In one sense we're better off insofar as we use fracking to reduce our coal consumption.
On the other hand, doesn't it seem a bit strange to use the lax regulation and poor safety record of one industry as justification for overlooking risks in another industry? How about trying to make both coal mining and fracking safer instead?
If the quakes are traced back to oil/gas drilling activities, those companies should be held liable for any damages caused.
I think you know about some of the problems with that. In particular, in the face of any particularly large disaster, the company involved would just shift as much of its resources as possible elsewhere, declare bankruptcy, and leave the victims hanging.
I also think there's a problem with shifting environmental protection from a regulatory model to a litigatory model. My impression is that many of the people who suggest things like this turn out to not exactly be friendly towards environmental litigation. In fact, my impression is that there's been a lot of pressure to try to make it harder for people to litigate environmental issues in the courts.
But I don't see these quakes presenting a risk significant enough to warrant banning fracking or injection wells. Monitoring would probably be sufficient to sort out the limited damages.
Maybe there's some kind of middle-ground between "anything goes!" and "ban it!" How about this:
(1) Require a seismic study before undertaking any well injection for waste disposal. If it's too risky, you don't get to do injection there.
(2) Since there's still a lot of uncertainty in seismic studies, the well owner and the company that does the assessment would be required to have insurance that would recompense injured parties in the area in the event of an earthquake. Perhaps the industry as a whole would maintain a revolving fund to pay claims.
I personally think that groundwater contamination is more concerning than induced seismicity when it comes to risks of fracking, except perhaps in particularly seismically risky locations.