With the risk of the moderator killing the thread for me knocking it off the rails, no one has show fracturing to cause earthquakes. Meaning turning them on, then off and predicting when quakes would start based on restarting fracturing.
However, fluid injection has been show to create quakes. Evans, 1966 The Denver Area Earthquakes and the Rocky Mountain Arsenal Disposal Well (Our government was injecting waste water from weapons) and Raleigh, 1976 An Experiment in Earthquake Control (Oilfield waterflood). Both demonstrated cause and effect with long term fluid injections. They could even predict when quakes would restart, based on restarting fluid injection. As best I know, even in Oklahoma, where injection wells are blamed for the quakes, no one has done a controlled study to establish the link. Although I think the oil and gas industry should consider not injecting into the Arbuckle formation.
So what I am saying, is that fracturing does not cause the quakes, but long term fluid injection can in the right (wrong) formations. It is common to inject all oilfield waste water into wells. Other types of disposal wells can have the same effect. Also, in the US it is not normal to inject into fractured disposal wells. Your permit usually should require that fluid pressure in the well never exceed fracturing (parting) pressure.
Also note how old and moldy those papers are. Very few people in the press or the Petroleum industry are even aware of the work by Evans, Raleigh et. al. All that is old, shall be new again. Or is that those who ignore history are doomed to repeat it.
