Fracking causes as much seismic activity as 'jumping off a ladder', study concludes Fracking is blasting underground rock deposits with water and chemicals It releases trapped gas pockets and was blamed for starting earthquakes But study says it's very unlikely we'll feel earthquakes caused by fracking A controversial process used to extract shale gas causes tremors equivalent to someone "jumping off a ladder." Fracking, which involves blasting underground rock deposits with water and chemicals to release trapped pockets of gas, has been blamed for triggering earthquakes. But a study has concluded "it is extremely unlikely that any of us will ever be able to feel an earthquake caused by fracking." Process: Fracking involves blasting underground rock deposits with water and chemicals to release trapped pockets of gas. The Cuadrilla shale fracking facility in Preston, Lancashire, is pictured After examining hundreds of thousands of gas extraction operations, the scientists found only three instances where resulting shocks could be detected by residents above ground. In contrast, they found other man-made activities, such as mining and waste-disposal, are much more likely to trigger noticeable seismic activity. Lead researcher Professor Richard Davies from Durham University's Energy Institute, said the risk of fracking resulting in seismic activity that could be felt on the surface is "not significant." In almost all cases, the seismic events caused by hydraulic fracturing have been undetectable other than by geoscientists. It is also low compared to other man-made triggers," he said. By comparison, most fracking-related events release a negligible amount of energy roughly equivalent to or even less than someone jumping off a ladder onto the floor. He added: "It is extremely unlikely that any of us will ever be able to feel an earthquake caused by fracking." Making a point: Demonstrators in London to protest against hydraulic fracturing for shale gas last December A forthcoming report by the British Geological Survey is expected to announce that shale gas deposits are far larger than previously predicted. Industry experts say we could be sitting on enough gas reserves to supply the nation for more than a century. David Cameron wants to see Britain at the heart of the "shale gas revolution," and Chancellor George Osborne has pledged to offer lucrative tax breaks and a simplified regulatory regime to the industry in a bid to promote investment. Prime Minister: David Cameron wants to see Britain at the heart of the 'shale gas revolution' Fracking was temporarily halted at Britain's only test drill site in 2011, after two small earthquakes woke some residents in Blackpool - they were 2.3 in magnitude. Operations were allowed to resume in December after Energy Secretary Ed Davey announced greater restrictions aimed at limiting the likelihood of tremors. Critics say any shale gas energy boom will scar the countryside and pollute water supplies. Lawrence Carter of Greenpeace said: "People's apprehensions about fracking go well beyond earth tremors. Communities are concerned about industrialisation of the English countryside, including noise, increased traffic, falling house prices and environmental damage. The Durham team compared data from all earthquakes resulting from human industrial activity since 1929. They found the largest fracking tremor was at Horn River Basin in Canada in 2011 and had a magnitude of 3.8 on the Richter scale. "A tremor of 3.8 would feel like a little shudder to most people, like a lorry going down the road or someone jumping off a ladder," said Professor Davies. He added: "Earthquakes caused by mining can range from a magnitude of 1.6 to 5.6, reservoir-filling from 2.0 to 7.9 and waste disposal from 2.0 to 5.7." A Department of Energy and Climate Change spokesman said: "An independent panel of experts commissioned by DECC concluded there was a small risk that fracking could cause relatively minor seismic activity. As a result, the Government has set out that any fracking must be carefully monitored and will be stopped at the first sign of seismic activity.