A series of earthquakes near Gatwick Airport, which led to mass protests, were not caused by fracking, according to scientists.
A report found no evidence that fracking is responsible for the string of quakes in Sussex and Surrey, that were known as the "Surrey Swarm."
The string of 34 earthquakes, the strongest reaching magnitudes of 3.2 on the Richter scale, shook homes within a few miles of two active oil extraction sites at Brockham and Horse Hill in Surrey.
Green campaigners called for a ban on fracking following the earthquakes, between April 2018 and May this year.
The British Isles are not by a tectonic plate boundary and earthquakes are rare, leading to fears they were triggered by nearby drilling and extraction.
Scientists at Imperial College London believe natural causes were behind the quakes and said their proximity to fracking sites was "probably a coincidence."
Dr Stephen Hicks, of Imperial’s Department of Earth Science and Engineering, said: “The quakes seem to have occurred naturally and our findings suggest their closeness to oil extraction sites is probably a coincidence.
“This is not the first time earthquakes have come seemingly from nowhere and without human input.
"The swarm, like most natural earthquakes in the UK, could have been caused by ongoing collision of the African and Eurasian tectonic plates in the Mediterranean Sea – the UK’s nearest plate boundary – which stresses the crust and causes earthquakes across Europe."
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The team used seismometers to track the timing, strength and distribution of the quakes and mapped the distance between the epicentre and extraction sites.
The data showed the quakes were in a tight cluster more than 3km away from the fracking sites which "was too far away" to link them.
Most natural earthquakes cause rocks either side of faults, to move horizontally while earthquakes from extraction sites cause rocks to move vertically.
Dr Hicks said: "The ground vibrations recorded from earthquakes provide clues that hint at their cause.
"There are increasing examples worldwide of human activity causing earthquakes, but it can be difficult to work out which newer cases are natural, and which are human-caused.”
He added: "Decades of instrumental recordings and hundreds of years of historical accounts of earthquakes show that similar seismic swarms have happened in the UK before due to long-term tectonic stresses and without any clear link to human activities."
The study was conducted in collaboration with the University of Bristol and the British Geological Survey, and was published in the journal Seismological Research Letters.
