Saturday, September 1, 2007

UK:Folkestone Earthquake 28 April 2007 07:18 UTC (08:18 BST) 4.2 ML

Detailed analysis of all available seismic data from Saturday's 4.2 magnitude earthquake by the British Geological Survey shows that the epicentre was less than 1 km east of Folkestone and close to the area of maximum reported damage. However, uncertainties in epicentre determination are still of the order of 5 km. The event occurred at shallow depth, less than 5 km below the surface.Over one thousand replies have been received to our online macroseismic survey inviting the public to report the shaking and damage they experienced. The preliminary map of the results can be seen at http://www.earthquakes.bgs.ac.uk
The maximum intensity is currently assessed as 6-7 EMS (European Macroseismic Scale). This is the highest recorded intensity for a British earthquake in over 100 years. Acceleration levels at the nearest station (about 5km from the earthquake) were about 0.1g, also the highest recorded in the UK.The worst damage is concentrated within one area of Folkestone. In the most affected group of streets, serious structural damage to a few houses was observed, including large cracks in load-bearing walls. There have been many cases of damage to chimneys, with fall of chimney pots and fall of brickwork from the upper part of the chimney stacks, with secondary damage to roofs from falling masonry. A detailed damage survey is being carried out by BGS. The damage seems to have been exacerbated by local site conditions. The BGS are installing a number of additional sensors in southeast England to study any possible aftershocks or further earthquake activity.This is the largest earthquake in this region since a magnitude 4.4 ML earthquake in 1950. Significant earthquakes also struck the Dover Straits in 1776 and 1580; the latter had an magnitude of 5.7 ML and caused damage as far as London where two people were killed by falling masonry. Earthquakes of magnitude 4.2 ML occur in mainland UK roughly every 5 years although are more common in offshore areas. A magnitude 4.7 ML earthquake struck Dudley, West Midlands in 2002 and was widely felt across England and Wales....
To read more go to:
http://www.earthquakes.bgs.ac.uk/earthquakes/reports/folkestone/folkestone_28_april_2007.htm


As in the days of Noah...

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