The 2.2-magnitude quake was centred just outside the village of Roybridge, near Spean Bridge in the Highlands, at around 9.30pm.
A small number of people reported feeling the tremor, which had a depth of 7.5km, the British Geological Survey (BGS) said.
It followed the 3.3-magnitude earthquake which hit Lochgilphead in Argyll and Bute at around 2am on Tuesday and was felt as far away as Edinburgh and Ballycastle in Northern Ireland. The BGS also detected two smaller tremors near Roybridge later the same morning, with magnitudes of 0.9 and 1.6.
Glenn Ford, a seismic analyst for the BGS, said there had “obviously been a little bit of stress built up in that area”.
Between 200 and 300 earthquakes are detected in the UK every year, with tremors of between 3.0 and 3.9 magnitude occurring on the mainland once every three years on average.
The seismologist described Friday’s tremor as “absolutely tiny” by comparison to major earthquakes experienced in other parts of the world.
“The fact that this one was actually felt was unusual because approximately 90 per cent of them are so small nobody actually perceives them,” said Mr Ford.
“Because people are not used to earthquakes in the UK, they put a small earthquake, because it could just be a small tremor, down to traffic noise.
“So if somebody is in a very remote area like this which occurred last night there is much better opportunity to actually feel it because they are nice and still, it was late at night, and probably in a sedentary position.
“Normally if the roads had been busy or you’re near a motorway, you’d just put it down to traffic.”
Iain MacDonald, who was staying in the village, described it as “like a train rumbling past the house”.
He said: “It was about 9.30pm and I felt the tremor, but I heard it much more. It was really quite loud. I knew what it was straight away, I have heard it before and felt the tremor before.”
Resident Michael Sillars said he “heard a big rumble and the house shook”. He added: “It did feel like a really loud, close passing train.”
Additional reporting by Press Association