As many as 11 Ohio earthquakes, to be exact. Pete Spotts reports for the Christian Science Monitor:
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.
Understanding the potential effect hydraulic fracturing or related activities could have on local earthquake risks is one question some researchers hope to answer as they try to develop tools for communities.
Fracking allows energy companies to extract natural gas trapped in shale deposits deep underground.