Fluid Injection's Role in Man-Made Earthquakes Revealed

http://www.caltech.edu/news/fluid-injections-role-man-made-earthquakes-revealed-46986?rp

by jrs235 • 11 years ago

32 12 11 years ago

beloch• 11 years ago

"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.

MiguelHudnandez• 11 years ago

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?

rgbrenner• 11 years ago

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).

igivanov• 11 years ago

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.

cossatot• 11 years ago

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.

mikeash• 11 years ago

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?

protomyth2• 11 years ago

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.

InclinedPlane• 11 years ago

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

aeturnum• 11 years ago

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

glabifrons• 11 years ago

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!

Fluid Injection's Role in Man-Made Earthquakes Revealed

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