Experts are claiming that a series of earthquakes that struck Ohio last year were caused by fracking. Hydraulic fracturing triggered the seismic activity
They discovered hydraulic fracturing had activated a previously unknown fault that triggered the seismic activity.
Fracking involves extracting gas and oil from shale rock by injecting a high-pressure water mix into the rock. The process normally creates micro-earthquakes far smaller than could be felt by humans.
Previous research has linked earthquakes with fracking. Last October, researchers connected 400 micro-earthquakes to fracking in Harrison County in Ohio between September and October 2013.
In July, another study found fracking was responsible for hundreds of earthquakes across Oklahoma. It found the rate of earthquakes increased from about one per year before the 2008 oil and gas boom to about 240 small earthquakes less than five years later.
Two earthquakes in the UK in 2011 were also found to have been caused by nearby fracking.