Silverdale is at the centre of a geological mystery.

Over the course of the past 12 months, 25 earthquakes have been recorded in the Lancashire village, the largest of which - in December - had a 3.2 magnitude and was powerful enough to be felt by people living up to 12 miles (20km) away.

CCTV footage showed cameras shaking, lights flickering, and sleeping dogs jumping out of their baskets.

Other tremors have been felt in the village this year too.

Andrew Smith said his house shook after December's quake.

"I was upstairs, just sorting out some stuff and, all of a sudden, there was this almighty crash," he told the BBC.

"I thought something had hit the house or exploded somewhere."

Smith said he was concerned the tremor may not have been a one-off.

"It does seem to be a continuing theme," he said. "There is always that concern - will there be worse ones?"

On the other side of the village, Tom Bradfield said he had felt the tremors on more than once occasion.

"The first one, I thought a truck had crashed into our house," he said. "The bed was shaking upstairs, the dog woke up."

The most recent earthquake happened on 21 September.

So what is going on?

Seismologists at the British Geological Survey (BGS) in Edinburgh are keeping a close eye on Silverdale and its surrounding area.

Dr Brian Baptie - who leads the BGS's earthquake seismology team - explained: "We do get earthquakes in the UK.

"We get around 200-300 every year - and about 20-30 of them are felt by people - so it's actually quite normal."

He said western parts of England, north-west Wales and the west of Scotland "are all, what we might call, earthquake hot spots".

Baptie explained earthquakes "usually happen in clusters - so when there is one earthquake, we usually get lots of others".

He said: "People are probably familiar with the idea of when there is a big earthquake around the world we get these aftershocks which can, maybe, last for days, or weeks, or even months.

"Usually those aftershocks are smaller than the first event, but very rarely they can actually be bigger.

"So we can't rule out a bigger earthquake, but it's really quite unlikely."

While Silverdale residents may be reassured by this, some fears remain.

Smith, who moved to the village relatively recently, said: "It is obviously a concern - you don't expect that sort of thing.

"It wasn't on our list when we were looking for a property: 'Avoid an earthquake zone'!"