Ohio officials are limiting hydraulic fracturing—or fracking— in a small area of the state after finding that the technique for tapping oil and gas may have triggered a series of minor earthquakes in March. The state regulator is among the first government authorities to impose seismic-related restrictions on fracking, in which drillers shoot water, sand and chemicals down wells to crack open rock and extract fuel. But other states, including Kansas, are looking at the links between oil and gas activity and small quakes. Researchers have previously found such tremors can be triggered by disposal of fracking waste water in deep wells near geologic faults. The Ohio Department of Natural Resources said Friday it was halting fracking within a 3-mile radius of the epicenter of the quakes in northeastern Ohio, and said firms operating in the Utica Shale—a rock formation holding vast quantities of natural gas—must install seismic monitors […]