The British Geological Survey (BGS) has recorded a minor earthquake in the county.
People across mid, south and west Norfolk reported feeling their houses shake and hearing a loud rumble at around 7pm on Thursday.
Kim Newman from Santon Downham said: 'Not sure if there was a sonic boom this evening around 7pm.
'I heard a slight noise but thought it was my kids banging upstairs, also my whole house vibrated.
'Slightly puzzled to what it was.'
A BGS graph shows a seismic movement at their West Acre seismic station near King's Lynn on the same evening.
According to the BGS website in an average year the organisation detects about 100 earthquakes around Britain, with about 20pc of them felt by people.
In June people in Norfolk reported feeling the effects of a 3.9-magnitude earthquake which hit Lincolnshire.
There were reports from people in Norwich, King's Lynn and Cromer who said they had felt the effects of the quake.
One person in Norwich, which is about 90 miles from the earthquake's epicentre posted that: 'The house shook slightly twice, about five minutes apart.'
And another in Cromer posted: 'It was a sudden quick judder / nudge. Very short in duration', while somebody in King's Lynn submitted their eyewitness report of 'One door swung shut'.
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