The debate over fracking has been long and arduous, but the credibility of some arguments is now coming to a close. Opponents often cite the risk that the process may set off earthquakes, which scientists often discredit in the United States, as these types of earthquakes are uncommon. However, Alberta has seen earthquakes in the past five years attributed to fracking or hydraulic fracturing.
These earthquakes are induced in two ways: by increases in pressure during the fracking and thereafter, by pressure changes brought on by the lingering fracking fluid. Scientists say the most recent earthquakes in parts of the United States, including Oklahoma, have been caused by the burial of wastewater from the different types of oil and gas well – not the fracking process itself. The wastewater is injected under pressure into disposal wells drilled into a permeable formation and flows into the rock. This has the ability to cause a pressure change in the formation, upsetting the equilibrium around the fault zone causing the earthquake as the fault slips.
To improve the fracking process, small underground explosions may be a more stable option. These explosions would deliver shocks that travel into the rock formation and rapidly change the stress patterns.
 Henry Fountain, In Alberta, a Link Between Fracking and Earthquakes, New York Times, Nov. 18, 2016, at A3.