Fracking Caused Magnitude 5.7 Earthquake In Oklahoma

Scientists have linked the underground injection of oil-drilling wastewater to a magnitude-5.7 earthquake in 2011 that struck the US state of Oklahoma. Wastewater injection from drilling operations has been linked to seismic events in the past, but these have typically been much smaller quakes.

They also have tended to occur in the first weeks or months of injection.The study in Geology suggests that "induced seismicity" can occur years after wastewater injection begins.