The British Geological Survey says there was a magnitude 5.4 earthquake in the area in 1984.
It describes that year's event as "significant".
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Sheffield Wednesday secured their place in this season's Championship play-offs with a 3-0 victory over their nearest challengers, Cardiff.
Two tries in the last six minutes from Ospreys skipper Rhys Webb won a thrilling Welsh derby at the Principality Stadium.
The oldest ever rugby jersey to ever go on public sale could fetch as much as £20,000 at an auction next month.