Wednesday 18 March 2015

Earthquakes on either side of Loch Carron, Scotland.

The British Geological Survey recorded a Magnitude 1.3 Earthquake at a depth of about 3 km to the north of Loch Carron in Highland County, Scotland, slightly before 8.55 pm GMT on Saturday 14 March 2015. This was followed by a Magnitude 1.0 Earthquake at a depth of 5 km slightly after 11.15 pm on Monday 16 March. Neither of these events are large enough to have caused any damage or presented any threat to human life, but they may have been felt locally.

The approximate locations of the 14 March 2015 (purple) and 16 March 2015 (red) Earthquakes. Google Maps.


Earthquakes become more common as you travel north and west in Great Britain, with the west coast of Scotland being the most quake-prone part of the island and the northwest of Wales being more prone  to quakes than the rest of Wales or most of England. 

The precise cause of Earthquakes in the UK can be hard to determine; the country is not close to any obvious single cause of such activity such as a plate margin, but is subject to tectonic pressures from several different sources, with most quakes probably being the result of the interplay between these forces.

Britain is being pushed to the east by the expansion of the Atlantic Ocean and to the north by the impact of Africa into Europe from the south. It is also affected by lesser areas of tectonic spreading beneath the North Sea, Rhine Valley and Bay of Biscay. Finally the country is subject to glacial rebound; until about 10 000 years ago much of the north of the country was covered by a thick layer of glacial ice (this is believed to have been thickest on the west coast of Scotland), pushing the rocks of the British lithosphere down into the underlying mantle. This ice is now gone, and the rocks are springing (slowly) back into their original position, causing the occasional Earthquake in the process. 

(Top) Simplified diagram showing principle of glacial rebound. Wikipedia. (Bottom) Map showing the rate of glacial rebound in various parts of the UK. Note that some parts of England and Wales show negative values, these areas are being pushed down slightly by uplift in Scotland, as the entire landmass is quite rigid and acts a bit like a see-saw. Climate North East.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. If you felt the 14 March Earthquake, or were in the area but did not (which is also useful information) then you can report it to the British Geological Survey here, and if you felt the 16 March Earthquake then you can report it here.

See also...

The British Geological Survey recorded a Magnitude 1.4 Earthquake at a depth of about 8 km to the northwest of Loch...

Magnitude 2.1 Earthquake in Highland County, Scotland.                             
The British Geological Survey recorded a Magnitude 2.1 Earthquake at a depth of about 7 km to the north of Loch Carron...


The British Geological Survey recorded a Magnitude 2.4 Earthquake at a depth of 4 km northwest if the Isle of Mull off the west coast of Scotland, slightly before...


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