McGarr and his team studied seven cases of quakes induced by fluid injection. They included the Oklahoma fracking site where 8,900 cubic metres were injected; a scientific bore hole in Germany, where an injection of 200 cubic metres of salt water caused a magnitude 1.4 earthquake; a geothermal-energy project on the outskirts of Basel, Switzerland, that was terminated after an injection of 11,600 cubic metres of water triggered a series of quakes of magnitude up to 3.4; another in Cooper Basin, Australia, where a 20,000-cubic-metre injection resulted in a magnitude 3.7 quake; and a liquid-waste-disposal project in Colorado in the 1960s, where an injection of 631,000 cubic metres triggered earthquakes of magnitude up to 5, the largest yet seen as a result of fluid injection.