27th February 2008. When the Earth Shook.
In 1580 a strong earthquake referred to in Romeo and Juliet was felt in London and the Dover Straits: one of the largest to be recorded in England. When the Channel Tunnel was under construction the British Geological Survey (BGS), estimated it at 5.6-5.9 on the Richter Scale.(1)
In recent times it was Today at 1 am on 27th February 2008 that an earthquake with a magnitude of 5.3 according to the BGS, had an epicentre in Market Rasen, Lincolnshire. It was felt over much of the country causing some damage to chimneys.
It was said to be the biggest since 1984 when an earthquake with an epicentre was detected on the Llyn Peninsula, North Wales with a magnitude of 5.4 on the Richter Scale. This was to constitute the largest known onshore quake in the UK since the use of instrumental recording.
On 2nd April 1990 Bishops Castle in Shropshire experienced a 5.1 quake, and in September 2002 an earthquake caused consternation in the Midlands, when the Author, in Burton-0n-Trent. experienced a thud and rushing wind sensation in the early hours.
English seismic occurrences are seen in a line from Leicestershire and Carlisle in Cumbria with the most repeating problems in the upper end of Wensleydale from 1768 to 1970, and to a lesser extent at Skipton, Yorks.
There is another fault on the Welsh borders with Herefordshire and Shropshire experiencing large earthquakes in 1863, 1896, 1926, 1990, but none shared a common epicentre. Ireland on the other hand is earthquake free, though can experience the effects of those in England.
The average seismic force in the UK ranges exponentially for occurrences from 3.7 plus, every year to 4.7 plus, every ten years and every hundred years over 5.6.
However the largest quake in recent time off-shore was that in the North Sea in 1931 which was said to be 6.1, with an epicentre on the Dogger Bank, and to cause damage, on the east-coast, at Filey, Bridlington, Beverley and Hull.(2)
(1) 6.April, 1580. The Nurse in Romeo and Juliet: ‘Tis since the earthquake now eleven years; And she was wean’d – I never shall forget it’. It was caused by subterranean weakness in the Dover Straits.
Ref: English Geology of Channel Tunnel; BGS. Website.