Another earthquake has been recorded just off the Fylde coast near Fleetwood.
Experts say the latest tremor, early on Saturday morning, could be an aftershock following two earthquakes on August 25.
According to the British Geological Survey, all of the quakes hit in the Irish Sea – around 25km (15.5 miles) west of Fleetwood.
The latest tremor measured 2.6 on the Richter scale, slightly weaker than the 3.3 recorded last month.
It hit at a depth of 10km (six miles) at 6.36am.
Dr Brian Baptie, BGS seismologist, said the earthquakes are not a cause for concern.
He added: “It is quite possible this could be an aftershock.”
Residents previously questioned whether last month’s quakes were the result of a series of controlled explosions being carried out at Knott End by Halite Energy.
However, the firm said its seismic testing was not deep enough to be linked to the recent tremors.
Fracking, the process of getting natural gas from beneath the ground, has previously been linked to earthquakes but the BGS described recent tremors as “natural”.
Dr Baptie said it is possible people would have felt the latest earthquake but no reports were received by the BGS.
He said: “It really does depend what people were doing at the time. It is on the bounds of what might be felt.”
Experts are not unduly alarmed by the latest earthquake to hit the Fylde coast.
Dr Baptie said: “There have been historic earthquakes in this area.
“There have been some quite big earthquakes.
“It is entirely consistent with what we have observed in the past.”
Hundreds of earthquakes are recorded in the UK each year but only 20-30 are felt by people.
The BGS has recorded 17 tremors in the last 50 days but more than half went unnoticed by the public.
Dr Baptie said: “We get earthquakes of the size of 3.3 maybe three times every year.”
It is not unheard of for even larger earthquakes, measuring five on the Richter scale, to occur, he said.
A magnitude four earthquake hits the UK roughly every two years, according to the BGS.
Quakes measuring five on the Richter scale happen on average every 10-20 years.