9:20am Wednesday 1st September 2010
By Richard Harris
Updated: TWO earthquakes hit North Yorkshire over the bank holiday weekend.
The epicentre of the first, at 5.12pm on Saturday, was Long Marston, west of York, while the second occurred yesterday at 12.20am in the Leyburn area.
But rather than the ground-shaking experience by York residents in February 2008 when a 5.3 earthquake struck, these two geological events were rather more low key.
Both measured only 1.6 on the Richter scale, with the Long Marston quake occurring six kilometres below the ground and the Leyburn event taking place nine kilometres down.
Davie Galloway, a seismologist with the British Geological Survey (BGS), said it was unlikely anyone would have felt the Earth move – although had they been closer to the surface their knees might have trembled.
Mr Galloway said: “Both measured 1.6, which is not a significant earthquake. In world terms it’s very small.
“We’ve not had any reports from members of the public, but for earthquakes of this size we would not expect any. We get about 150 to 200 earthquakes every year in the UK, and occasionally we get a bigger one that is felt by the local population.”
He said the tremors had been picked up by the BGS’s seismographs in Leeds, but also in their instruments as far away as Hereford.
Although the UK does not sit on the fault line of two tectonic plates – it is actually in the middle of a plate – stresses are still produced in the rocks far below by the plate’s movement and it is when this stress is released that an earthquake occurs.
And just because there have been two earthquakes in the space of three days, it does not mean there will not be another one very soon.
Mr Galloway said: “We can’t predict when they will be. There might be one tomorrow, next month or there might not be one for another year.
“It’s the nature of the planet we live on, the plates are jostling all the time at the rate your fingernails grow at.”
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