Saturday 28 March 2015

Magnitude 1.9 Earthquake in North Yorkshire, England.

The British Geological Survey recorded a Magnitude 1.9 Earthquake at an uncertain depth near the village of Wormersley in North Yorkshire, slightly before midday GMT on Friday 27 March 2015. There is no danger of any damage or casualties from an event of this size, though people have reported feeling it in the village of Hensall, about 10 km to the east of the epicenter, as well as underground at mines in the area.

The approximate location of the 27 March 2015 North Yorkshire Earthquake. 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. However, while quakes in southern England are less frequent, they are often larger than events in the north, as tectonic presures tend to build up for longer periods of time between events, so that when they occur more pressure is released.

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 this quake, or were in the area but did not (which is also useful information) then you can report it to the British Geological Survey here.

See also...

The British Geological Survey recorded a Magnitude 1.9 Earthquake at a depth of 2 km near the village of Redmire in...

The British Geological Survey recorded a Magnitude 1.9 Earthquake at a depth of 1 km in southern North Yorkshire slightly after 11.30 pm British...

Three homes were evacuated after a 7.5 m wide sinkhole oppened up in Rippon, North Yorkshire, on Monday 16 February 2014. Two...

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