People in Snowdonia had their Sunday night interrupted by an earthquake which caused a "big rumble sound".
Communities in the Conway Valley reported hearing a "strange noise" shortly after 8pm on Sunday, which some thought could be a sonic boom, thunder or even a large vehicle passing.
But the British Geological Survey (BGS) confirmed the area had suffered a mini earthquake measuring 1.0 on the Richter scale, North Wales Live reports.
It was recorded at a depth of 6km with the epicentre given as "3km north-north-east of the village of Dolgarrog, Conwy".
This suggests the quake was centred near Llyn Syberi towards Eglwysbach.
The BGS said no local residents reported the incident, which was picked up by its network of seismic sensors at 8.10pm on Sunday.
Did the earth move for you during this very British quake? Let us know in the comments
However numerous Facebook users, from Rowen down to Llanrwst, said they had heard the event.
One woman said her husband shouted down the hall, “what the hell was that?”
Another said: “I just muted TV in Trefriw wondering what I heard.”
A number of people said their dogs started growing and barking at the “strange” noise.
A Rowen resident suspected it was the neighbour’s motorbike starting up, while a woman in Dolgarrog thought someone was putting the bins out nearby.
One person suggested it was a sonic boom. “Phew, Glad it wasn’t just me that heard it!” she added.
At 1.0 on the Richter scale, it is considered to be a “micro earthquake” which are relatively commonplace in the UK.
However it is the largest in North Wales since September 2019 when a 1.5 quake rattled the village of Beddgelert, Gwynedd.
A similar magnitute earthquake hit the Treuddyn area of Flintshire in November 2018.
The most recent was 0.9 tremor in the Dolbenmaen area of Gwynedd in January 2020.
Another, with the same magnitude, was recorded in Dolgarrog the previous November.
Most small quakes go unnoticed and unreported.
A BGS spokesperson said of the Dolgarrog quake: “To date, the BGS has received no direct reports that it was felt.”
It is inviting people to record what they felt via a questionnaire on the BGS website.
