Frack the San Andreas

With the continuing slump in oil prices, a lot of drilling and fracking equipment is idle. What better use to put it to than triggering earthquakes?

There have been reports of this happening: in Oklahoma, some fracking operations were discontinued after they seemed to be triggering earthquakes. And it stands to reason that they could: injecting liquid directly into a seismic fault lubricates it, encouraging the fault to slip.

Avoiding this seems to usually be easy enough: there aren’t all that many major seismic faults in the world, and most oil and gas deposits that people want to frack aren’t next to one. The wells that seemed to be causing the trouble in Oklahoma were wastewater disposal wells; for that, injecting into a fault probably makes things easier since the water doesn’t have to crack rock to make its own paths away from the injection point; cracks already exist.

But though earthquakes are normally something to avoid, they also could be provoked on purpose. The way earthquakes work is that motion along a fault is interrupted by the rocks sticking. The stress builds up until the sticking points give way, which happens suddenly and with little or no warning, yielding an earthquake. In areas where the sticking is weak, earthquakes happen more often but are smaller. Lubricating the fault would push things in this direction: instead of decades of quiet followed by “The Big One”, there’d be a lot of little ones, which in sum total would not be nearly as damaging. At least that’d be the long-term goal.

In the short term there is of course a hitch with this: if it’s about time for the Big One, lubricating the fault for the first time will bring it on. This is not necessarily as bad as it sounds, because with deliberate lubrication the timing would be predictable. Injection wells would be drilled; injection pumps would be prepositioned at them; and at an appointed time the pumps would all be turned on. The public would have been warned ahead of time to bolt things down and to evacuate the area. If after a week or so of injection no earthquake resulted, the pumps would be stopped and people could return and relax. Or if The Big One happened they could return and rebuild. Either way they would know (at least this would be the hope) that they were no longer living on top of a hair trigger: if the fracking didn’t provoke it, it probably wouldn’t go off any time soon. After a couple of years, the exercise could be repeated; if it had not provoked anything, one might try increasing the amount of fluid injected.

Of course there are lots of things that could go wrong with this; the only real way to know whether it’d work would be to try it. And while the San Andreas Fault, the best known fault in the United States, would likely be the most valuable target, it’d be prudent to first try it on a fault that wasn’t valuable, so as to establish parameters like how many injection wells were necessary without having to issue too many evacuation warnings to too many people.

And of course this is not just the sort of thing people call “politically impossible”; it’s way beyond that. Even Mr. “Make America Great Again” would be most unlikely to advocate for it; it’s not his sort of big construction project. In today’s political environment, many things that work well and reliably are under attack, and this actually would be adventurous.