Does hydraulic fracturing cause earthquakes?
In regions such as Texas and the Cooper Basin (northeast South Australia), fracking is common but earthquakes are rare.
During hydraulic fracturing, the microseismic events are generally less than magnitude minus two (-2) or minus three (-3) on the Richter scale. A study of hydraulic fracturing-related seismic activity in England found the combination of geological factors necessary to create a higher-than-normal seismic event was “extremely rare” and such events would be limited “to around magnitude 3 on the Richter scale as a ‘worst-case scenario’.”
A magnitude three earthquake causes “vibrations similar to the passing of a truck”, according to the United States Geological Survey.