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 1.39pm on Tuesday afternoon, just over four hours after a 3.0 tremor was felt in the Bedfordshire town at 9.32am.
Geologists said they were likely to be aftershocks of the first quake felt in the area on 8 September.
“There’s obviously been some stress been building up in that particular area and we’ve had the initial earthquake,” said Glenn Ford, a seismologist with the British Geological Survey (BGS). “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.”
The 8 September tremor was magnitude 3.5 and the first aftershock five days later measured 2.1.
According to the BGS, residents said Tuesday’s first tremor “only lasted a couple of seconds” and that they “felt a single jolt, a bit like being in a car that has done an emergency stop”.
The most profound quake to hit the UK in the past three decades was recorded in Market Rasen, in Lincolnshire, in 2008. One person was injured but damage caused by the 5.2-magnitude quake was otherwise slight, with reports of a collapsed chimney and a cross falling off the church.
The effects of the 2008 quake were nevertheless felt as far away as Wales, Scotland and London, and emergency services across England received more than 1,000 calls from people who had woken up to find their homes shaking.
On Tuesday, Ford the recent activity was “typical behaviour” that had been seen in different areas of the UK “on many occasions”.
Dr Richard Luckett, a BGS seismologist, added: “The ground beneath us is constantly under stress, it has been for geological time, and also under stress because of the plate boundaries in the mid-Atlantic.
“You can measure the whole of the UK moving eastwards on GPS. There is a certain level of stress permanently and, every now and again through natural buildup, a fault ruptures and we get a little earthquake. We get about two magnitude 3s per year.”