Dr Susanne Sergeant of the British Geological Survey told ITV News earthquakes like today's 4.1 magnitude "tend to happen in the UK once every two-three years on average".
The largest earthquake recorded in the UK was a 6.1 magnitude, hitting Dogger Bank in the North Sea in June 1931.
"It released approximately 900 times more energy than today's earthquake," Dr Sergeant said.
Speaking of today's earthquake, she said: "I am not aware of any reports of damage - because the earthquake happened in the Bristol Channel (about 20 km north of Ilfracombe), the area of strongest shaking would have been under the sea.
"It would not be unusual for this earthquake to be followed by aftershocks".
This graph shows real-time Seismogram data from a sub-station in North Devon at the time the 4.1-magnitude earthquake struck the Bristol Channel.
The earthquake that struck the Bristol Channel at 1.21pm today measured 4.1 magnitude, the British Geological Survey (BGS) has confirmed.
It's epicentre was located around 18 km (11 miles) north of Ilfracombe in North Devon and 30 km (18.6 miles) southwest of Swansea.
"The earthquake was widely felt in North Devon and South Wales", the BGS added.
Did you feel an earthquake this afternoon in Swansea, Llanelli or another area of south-west Wales?
The British Geological Survey is asking people to share their experiences to help them build a better picture of the quake.
The map above, in its early stages, shows the intensity of the earthquake felt in different areas.
You can add your observations by visiting the British Geological Survey's website here.
There has been an earthquake in the Bristol Channel, the British Geological Survey has confirmed.
The quake was felt by people living in parts of Swansea and Devon.
A BGS spokesperson told ITV News they are investigating.
No further information is available at this time.
Did we just have a little earthquake in Swansea? The walls of my house & all my furniture just shook for like 3 seconds. Weird.
At least seven people were killed in an earthquake near the Iranian city of Bushehr today, state news agency IRNA reported.
The quake struck near the country's sole nuclear power plant, but no damage to the plant was reported.
A magnitude 5.6 earthquake has struck close to the Iranian city of Bushehr, site of the country's sole nuclear power plant, US Geological Survey data showed.
Buildings were shook in Tokyo today when a 5.5 magnitude earthquake hit the city, Reuters reported.
An earthquake with a preliminary magnitude of 5 jolted eastern Japan including the capital, Tokyo, on Sunday, the NHK public broadcaster and witnesses said.
There were no immediate reports of injuries or damage, and no tsunami warning was issued.