Alva Review-Courier -

Pennsylvania environmental regulators have found a likely correlation between a natural gas company's fracking operation and a series of tiny earthquakes in western Pennsylvania last year.

The quakes were recorded last April in Lawrence County, about 50 miles north of Pittsburgh and close to a natural gas well pad owned by Houston-based Hilcorp Energy Co. They were too weak to be felt by humans and no damage was reported.

Fracking, a method to extract gas or oil from underground shale rock, has been tied to earthquakes in neighboring Ohio and other states, but never before in Pennsylvania, the...