

Gas Fracking may cause earthquakes - chris_gogreen
http://www.sfgate.com/cgi-bin/article.cgi?f=/g/a/2011/11/02/bloomberg_articlesLU1I1C0D9L35.DTL

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hugh3
Magnitude 3. Big deal. That's what happens when you break rocks -- they shake
around a bit. In fact, I'd say gas fracking _is_ earthquakes -- you
characterize what you're doing underground using a seismometer and picking up
the vibrations.

Saying "but if fracking can cause small earthquakes, might it not one day
cause a large one" is a bit like saying "if your cat can devour a mouse, how
do we know it won't one day devour an entire city?"

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libraryatnight
Pretty sure we have the experience to know our cats aren't going to devour our
cities, but it seems like a lot of what happens due to fracking we're still
figuring out.

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mattlong
Old news. A couple weeks ago there was a magnitude 4.8 near San Antonio, TX
caused by fracking[1].

[1]:[http://www.woai.com/news/local/story/Could-fracking-be-at-
fa...](http://www.woai.com/news/local/story/Could-fracking-be-at-fault-for-
the-rare-South/2_3TzfE6gki5VBW8ycy7Ng.cspx)

~~~
ChuckMcM
And most of the information geologists are using comes from investigating the
earthquakes around the Geysers geothermal plan in California.

The conclusion was that removing material from underground and not replacing
it with supporting structure causes subsidence, and depending on the
structure, punctuated subsidence which is basically code for an earthquake.

Draining aquifers has a similar effect although the rate at which an aquifier
is drained is less noticeable.

