A second 1.6 magnitude tremor was recorded in the village of Roybridge in the Scottish Highlands at around 2.42am – less than an hour after a 3.3 magnitude earthquake near the town of Lochgilphead
Scotland was rocked by a second earthquake just an hour after its first tremor on Tuesday morning.
The first 3.3 magnitude quake took place near the town of Lochgilphead, in Argyll and Bute, at 1.44am.
Locals compared the noise to an explosion, with one person saying it felt ‘like a freight train’.
Less than an hour later – at 2.42am – a second 1.6 magnitude tremor was recorded at a depth of 7km in the village of Roybridge in the Highlands.
The British Geological Survey said the first quake was felt by more than 30 people at Achnamara, Tayvallich, Lochgilphead, Tarbert, Ardrishaig and many other villages and hamlets the region.
Some residents said they were awoken by a ‘loud bang’, while others said ‘the house and windows shook’ and ‘it was like rolling thunder’, said the BGS.
The agency said the quake happened 12km below the Earth’s surface.
Rosemary Neagle, who lives on a farm in Kilmartin Glen near Lochgilphead, said the noise of the tremor was so loud that she initially thought something had exploded in one of her sheds.
She told BBC Radio’s Good Morning Scotland programme: “It kept on intensifying and the house vibrated. It rumbled on for about 10 seconds afterwards, so it was quite frightening.
“I have experienced them before here but never to that extent. The house has never shook like that in the past.”
Victoria Winters, 53, also felt the earthquake rumble through her home – and described it as “like a freight train”.
She said: “We were woken with a bit of a start. It sounds like a freight train appearing all of a sudden and then it starts shaking.
“It sounds like something really big is hurtling towards you. I live in a big echo-y old stone house, so it makes quite a noise when it comes through.
“It’s not the first time I’ve experienced one here, so I knew what it was.
“I can imagine if you hadn’t experienced it before then it could be quite scary.
“I’ve felt about four in the last ten years. It lasted five or six seconds, enough to wake me up, carry on and then I could tell when it was coming through the house.
“It came through where the bedroom is. It got louder and then the bed shook from side to side and the noise carried on veered up the ridge.
“Nothing feel but it is a creaky house so it made a few noises.”
In comparison, the largest known Scottish earthquake occurred near Loch Awe in 1880, with a magnitude of 5.2.
There are roughly 200-300 quakes in Britain every year, but the vast majority are so small that no one notices them. However between 20-30 are over 2.0 magnitude which can be felt over a wider area.
Earthquakes in Scotland are most often attributed to glacial rebound. Until about 10,500 years ago much of the north of the UK was covered by a thick layer of ice – which pushed the rocks down into the underlying mantle.
These rocks have been slowly rising back up ever since the ice melted, causing occasional earthquakes in the process.
The UK is also subject to tectonic stresses caused by the expansion of the Atlantic Ocean, which is slowly pushing the entire of Eurasia to the east, and from the northward motion of Africa, which is pushing into Europe from the south.
The most damaging UK earthquake was in the Colchester area in 1884. Some 1,200 buildings needed repairs, chimneys collapsed and walls were cracked.