Leighton Buzzard has been hit by two aftershocks in the space of a few hours – taking the total number of earthquakes felt in the area over the last two weeks to four.
A magnitude 2.1 event struck at 1.39 on Tuesday afternoon, just over four hours after a magnitude 3.0 tremor was felt in the Bedfordshire town at 9.32 in the morning.
They follow the initial quake on September 8 and a first aftershock on September 13, which were magnitude 3.5 and 2.1 respectively.
Glenn Ford, a seismologist with the British Geological Survey, said that while earthquakes have not occurred frequently in the area in the past, the activity was “typical behaviour” which had been seen in different areas of the UK “on many occasions”.
He told the PA news agency: “There’s obviously been some stress been building up in that particular area and we’ve had the initial earthquake.
“It’s maybe just still rebalancing the stress regime in that particular part of the world and we’re getting these little aftershocks occurring as well.”
Sheila O’Connell, an NHS worker who lives in Leighton Buzzard, said Tuesday’s first quake felt similar to the event two weeks ago.
“It was a bang and it was a shake, a real shake,” she told PA. “I felt the building shake.
“It was almost the same as the first one.
“My instinct was, ‘Is that another earthquake? What is going on in Leighton Buzzard?’.”
She said she did not feel unsafe, but added: “If they carry on it might well come to that.”
Jo Reggelt, who lives in nearby Bletchley, said it was similar to the September 8 quake “but on a lesser scale”.
“The conservatory rattled again, there was that sort of muffled sound of a gas explosion,” he told PA.
Mr Ford said there are 200-300 earthquakes in the UK each year.
“They’re a frequent feature of the UK, it’s just that 90% go unnoticed by the public,” he said.
And while the Leighton Buzzard earthquakes are small compared to quakes felt elsewhere in the world, they can be unsettling to people who have not felt them before.
“It’s not an area that’s had a lot of earthquakes previously, though we have got records of them,” Mr Ford added. “Obviously happening in an area of large population, it can be very startling and alarming to people when they’re not very used to them happening, and this is what we might be seeing as well.”
Mr Ford dismissed suggestions from some residents that the events may have been linked in some way to building work for the new HS2 rail link.
“I can categorically say that is not true,” he said. “These are natural tectonic earthquakes that we’ve been seeing in the UK for thousands of years.”