A MINOR earthquake which caused residents to hear ‘a loud boom’ noise took place in the Conwy Valley on Sunday evening.

The British Geological Survey (BGS) confirmed that the region had suffered a small quake, measuring 1.0 on the Richter scale with a depth of 5km, at 8.10pm on October 17.

The BGS added that it was ‘felt by several residents in Dolgarrog’ and that reports from residents included: ‘heard a loud boom’, ‘earthquake was short in duration; no build-up or fade, just start then stop’, ‘noticed by all occupants of the house including the dogs, who all barked’, and ‘window rattled’.

Glenn Ford, a BGS seismologist, added: “The small event on Sunday was a typical small UK earthquake which occur much more frequently than people are actually aware of.

“This event was perhaps unusual in that we do not expect such small events to be actually felt by the public, which we have now received reports for.

“However there are several reasons which probably contributed to this. Essentially, late at night, with not much other background noise, people are still awake but more than likely in a sedentary situation, which is much more favourable to perceive a small earthquake like this.

“North Wales has a long history of experiencing earthquakes and was the area of one of the largest UK events in the last hundred years with a magnitude 5.4 event on the July 19, 1984 (in the Llŷn Peninsula), approximately four million times larger than the small earthquake on Sunday evening.”