Fluid Injection's Role in Man-Made Earthquakes Revealed | Hacker News Reader

Fluid Injection's Role in Man-Made Earthquakes Revealed

caltech.edu

32 pointsjrs23512 comments

"The experiment revealed that fluid injection itself did not directly provoke an earthquake. Instead, the aseismic slip likely built up stress at the edges of the creeping zone of rock. Eventually, the stress overcame the friction between the rock faces within the fault, triggering earthquakes."

It's worth asking if this could be used to deliberately set off minor earthquakes that relieve stress in such a way as to prevent larger ones.

Sort of like the straw breaking the camel's back...

I have been wondering why oil companies have not been making the smaller-quake argument -- the link between hydraulic fracturing and earthquakes has been clear for some time.

I think 1,000 4.0 earthquakes have the same energy as a single 8.0 earthquake. The thousand 4.0's would be much more survivable. Even better, ten thousand 3.0's or a hundred thousand 2.0's spread out over decades...

I am wondering if fracking in California will slow down now that a finger can be pointed at a corporation after a quake, instead of being shrugged off as an "act of god." The earthquake would occur eventually & naturally, of course, but what if oil & gas exploitation triggered it?

Oklahoma has an earthquake catalog for each year: http://www.okgeosurvey1.gov/pages/earthquakes/catalogs.php

I picked a random year (pre-fracking): 1989. There were 62 quakes with magnitudes between 1.7 and 3.1.

Now lets pick a year with fracking: 2014. There were 5417 quakes with magnitudes between ~1 and 4.4. (Edit: for comparison purposes: 4923 were at 1.7 or above.)

13 out of 20 of the largest earthquakes since 1897 have been in the past 5 years. http://www.okgeosurvey1.gov/pages/earthquakes/information.ph...

So no oil company is going to make that argument.. because there's no evidence it reduces the likelihood of larger quakes.. and people would start asking questions about why they're causing thousands of quakes each year (not to mention the liability).

1 mag 8 = 1,000,000 of mag 4

https://en.wikipedia.org/wiki/Richter_magnitude_scale#Richte...

On top of that major quakes happen deep below, not where humans do their thing.

It's a question that lots of geophysicists have asked. Unfortunately, the answer is that we don't know much accumulated stress there is in the earth, especially in regions that are already at high seismic risk. So the risk is that in doing this, you could potentially trigger the much larger earthquake you were trying to prevent.

Even just knowing when it would happen would be valuable. This is getting into crazy-pants territory, but what if you knew it would trigger a big earthquake but did it anyway, at an appointed day and time, when people could all take shelter?

This reminds me of Welcome To Night Vale (a podcast about a community radio broadcast in a fictional town where every conspiracy theory and mythology is true and everything is weird and bizarre):

> And now, a public service announcement from the Night Vale Seismological Society, who have released their schedule of upcoming municipally-planned earthquakes.

> On Sunday, from 8:00am to 8:30am, there will be a small series of minor tremors. “It’s likely you will feel nothing,” the seismologists say, as these quakes are just to test some new equipment.

> At 3:00pm on Tuesday, there will be an enormous earthquake, rating upwards of 7 to 8 on the Richter scale, so, wear long sleeves, or goggles, or gloves... whatever it is you do to be safe during an earthquake. “We’re not entirely sure,” the Night Vale Seismological Society said.

> The following Saturday, be ready for anything. They’re not sure what’s going to happen. Maybe nothing! Probably nothing. But... hopefully, something really, really cool. They don’t want to get your hopes up, so just be on the lookout, but... no promises.

> “Oh, man! Fingers crossed! This could be super amazing!” the Night Vale Seismological Society said.

http://cecilspeaks.tumblr.com/post/100062639486/episode-56-h...

> It's worth asking if this could be used to deliberately set off minor earthquakes that relieve stress in such a way as to prevent larger ones.

BBC Radio on SirusXM (cannot find the link) had someone talking about that exact question. He said that in theory you could relive the pressure and let the fault slide without causing a real earthquake, but their is no way anyone is going to try it because of the liability.

There are tons of quake-prone faults that are well outside of even sparsely populated areas.

I'm guessing that permission to pump a lot of fluid into a fault line with the intention of sliding two giant land masses anywhere in the world is going to be hard to come by.

No. The USGS has a FAQ item covering this [1]. The quakes are too small to dissipate the stress and may cause damage anyway.

[1] http://www.usgs.gov/faq/categories/9830/3353

I'm amazed that I'm reading in the same article talking about faults in limestone and "underground trapping of carbon dioxide emitted by power stations".

The water we're pumping down there isn't the only water deep in the earth. Water + C02 = carbonic acid, commonly known to dissolve limestone (frequently the cause of sinkholes when it happens near the surface). Am I the only one who thinks pumping enormous amounts of C02 deep into the ground (where it's going to come into contact with water and limestone) is a really, really bad idea?

Outside of that, very interesting article. Fantastic that they have access to a fault via an old military installation!

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