Argyll is Britain’s earth tremor hotspot
A SEISMIC rumble rocking Kintyre and Mid Argyll has confirmed the region as the nation’s hotspot when it comes to earthquakes.
Last week’s quake, which measured 2.4 on the Richter Scale from a depth of 11km, shook the ground and caused alarm among a number of pets.
The effects were heard and felt by witnesses as a muffled ‘bang’ followed by a prolonged rumbling which lasted for around 10 seconds.
After the Argyllshire
Advertiser queried the rumble on Facebook, it was discovered that the earthquake occurred near Lephinmore, opposite Lochgair, at 4.35pm on Tuesday January 24, with some people even wondering if they experienced the tremors in Campbeltown. In response to The
Courier’s post about the quake, Isabel Scott reported: ‘Definitely a bang and the house shook.’
James Maclean commented: ‘It shook the coconuts of our tree.’
Not everyone was convinced, however, as Barbara Johnson said: ‘Was out walking, never heard a thing!’
Last year a bookmaker was offering odds on when the next earthquake would strike, with Argyll installed as favourite.
McBookie had offshore Argyll at 6/4 with the region’s mainland at 7/2.
Spokesman Paul Petrie said: ‘Luckily, we’re not a country where earthquakes are a life-and-death matter.
‘The worst that can happen is that your best china ends up in pieces on the floor.
‘People often think they’re just things that occur in other countries, so I think the public would be amazed at how many tremors Argyll and Scotland as a whole actually do get.’
Since last year, the island of Mull and its surrounding waters have seen 13 earthquakes, while Islay has felt eight. There have been four recorded at each of Oban, Strontian and Achallader.
Meanwhile, tremors have also been detected at, among other places, Dunoon, Kilmelford, Tarbert, Acharacle, Skipness and Ballachulish.
Earthquakes are caused when masses of rock in the planet’s crust move against each other, often along fault lines. Scotland has dozens of these cracks though they are mostly dormant.
Another reason Scotland is afflicted by quakes is that 20,000 years ago, the country was under a two kilometre-thick sheet of ice.
Re-adjusting
The glaciers melted long ago but the earth below us is still re-adjusting with some areas – including Oban – raising by two millimetres a year while parts of England are sinking lower.
Ian Main, professor of seismology at Edinburgh University, said: ‘Imagine you pushed your finger into a football and took it out again but the football had a gloopy filling – it would take time for the ball to recover its shape.
‘Some parts of it would have to rise and others fall until it became its normal shape again.
‘That’s what is happening here. And some earthquakes may also be triggered by human activity such as collapses in abandoned coal mines.’
Prof Main added: ‘It’s impossible to be definitive about why there has been this apparent increase in seismicity in Scotland.
‘It could be due to improved detection or the clustered nature of a random process – you wait half an hour and three buses arrive at once.
‘One tremor triggering another would also be a plausible explanation.’
Those caught in a quake will usually only notice the earth moving if it registers above 1.5 on the Richter Scale, the scorecard that measures a tremor’s strength.
Lives are only usually lost at six and above, as is common in Italy.
In 2015, the most violent in Scotland measured 2.4 at Durness in Sutherland, though Strontian saw one of 2.2. In 2016, there were three of 1.9 at Oban, Loch Goil and Mull.
Scotland’s strongest recorded tremor was a 5.2 that hit Loch Awe in 1880 and was felt across Scotland and Northern Ireland.
Another of 5.1, with its epicentre at Inverness, shook most of the country in August 1816.
Eyewitness Thomas Lauder described how ‘the fabric of the whole building shook from its foundation.
‘Dogs howled and poultry on the roost manifested much dismay. A horse started with his rider, and would not move forward.’
The government-funded British Geological Survey has more than 100 seismograph stations across the UK – including one at Loch Avich, near Taynuilt – all ‘listening’ for quakes 24 hours a day with the results collated at its Edinburgh data centre.