Check out this interesting read on fracking being a direct relationship to earchquakes, (Fracking boom could increase California’s earthquake risk) I believe more research is needed to determine if there is a relationship with fracking and earthquakes.
Now, read this aricle Man-Made Earthquakes Update from the USGS that refutes this claim. Th USGS answers this question directly,
Many questions have been raised about whether hydraulic fracturing — commonly known as “fracking”— is responsible for the recent increase of earthquakes. USGS’s studies suggest that the actual hydraulic fracturing process is only very rarely the direct cause of felt earthquakes. While hydraulic fracturing works by making thousands of extremely small “microearthquakes,” they are, with just a few exceptions, too small to be felt; none have been large enough to cause structural damage. As noted previously, underground disposal of wastewater co-produced with oil and gas, enabled by hydraulic fracturing operations, has been linked to induced earthquakes.
Fracking practices neeed to be monitored closely and water wells need to be analyzed for potential contamination, but the suggestion of earthquakes resulting from hydraulic fracking is not true.