Shale Gas "Fracking" Halted After Possible Quake Link

[Parsad]

Might be that shale gas fracking can cause instability leading to earthquakes on occasion.  Cheers!

 

http://www.theglobeandmail.com/report-on-business/international-news/shale-gas-fracking-halted-after-possible-quake-link/article2042598/

[Ross812]

This sounds like a knee jerk reaction to me. I am not familiar with the lithology of the rock in the U.K., but geologically shale should always overlay the continental crust made of granite which rests on a tectonic plate made of basalt.  Earthquakes generally occur in deep in the basalt layer.  The shear strength of shale is extremely low and it would be impossible to build enough stress within the shale layer to contribute to a quake of any significance.  The quakes were recorded with magnitudes of 1.5 and 2.3 which is almost imperceptible to someone standing over the epicenter.  I suppose shallow earth movements are possible;  Earthquakes do not cause damage and are nearly imperceptible below a magnitude 4.0.  A magnitude 4.0 quake is ~350 times ((10^x)^(1.5)) more powerful than the 2.3 magnitude quake measured.  In short, earthquakes are not a reason to discontinue fracking.