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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The Conservative Party has been warned over its use of a telephone call centre to contact voters in the run-up to the general election.
A dry start to the night with mist and low cloud, but rain will push into the south by the early hours.
Two people forced their way into a flat in Caerphilly and demanded the victim's car keys. He was assaulted and received cuts to his head.