The link between "fracking" and earthquakes was thrown into stark relief over the weekend when a magnitude 4.0 quake struck Youngstown, Ohio – typically not a hot bed of noticeable seismic activity. The quake triggered shaking reportedly felt as as far away as Buffalo, N.Y., and Toronto.
The temblor struck Dec. 31 and was the latest and strongest of 11 minor-to-light quakes that have hit the region since March. The epicenters are clustered around a wastewater injection well for a hydraulic fracturing operation.