BBC News has this story of a significant but not catastrophic earthquake.
http://news.bbc.co.uk/1/hi/england/6602677.stm
Consider this information to see it in context. from a respected UK newspaper after a previous minor quake in the UK
Thursday December 12, 2002
The Guardian .
"They may have fallen out of the news, but earthquakes continue to rock Manchester. Over a hundred shocks have now struck the city since its first large quake on October 21. "Rock" and "struck", of course, are the wrong words. Given the tiny size of most of the quakes, "niggle" (that is, continually finding fault) is more like it. For even the largest event in this swarm of seismic activity would barely raise an eyebrow with those living in Greece and Italy, Europe's earthquake-prone southern border. And yet, the Manchester niggles are an unsettling reminder that Britain's crust remains restless beneath our feet.
A report this week by the Benfield Greig Hazard Research Centre highlights how much of north-west Europe has experienced past earthquakes that are far larger than anything than seismologists have measured in recent times. The main culprit, it seems, is the Rhine valley, a geological rift zone that splits Europe's continental interior like a zipper from the Swiss Alps to the North Sea. And this rift zone caused central Europe's greatest earthquake catastrophe.
On October 18 1356, a large earthquake devastated the city of Basel, Switzerland, damaging large swathes of the Upper Rhine valley. As many as 40 medieval castles close to the city were ruined, and towers and churches up to 200 kilometres away were toppled. The post-mortem suggests that the earthquake had a magnitude of 6.0-6.5, equivalent to the most violent quakes in Greece and Italy. Within the last year, a geological team from Strasbourg and Zurich claim to have found the geological fault responsible for this quake, and it lies just south of Basel at the southern end of the Rhine rift. And it didn't just move in 1356. The same fault may have been capable of triggering between five and eight equivalent-sized earthquakes over the past 10,000 years.
And it's a similar story further north in the Lower Rhine valley. In 1992, a moderately strong (magnitude 5.8) earthquake struck the town of Roermond in the Roer valley, the industrial heartland of western Europe. In terms of economic loss, this modest-sized earthquake inflicted a 100 million ECUs repair bill. With much of the region's infrastructure resting on the loose, wet flood-plain sediments of the Rhine valley, the ground motions in the quake had been amplified, encouraging the ground to crack, liquefy and slide, and causing widespread damage to buildings and structures.
For a long time, most seismologists had felt that this size of earthquake was the largest that the Rhine rift could muster. But then a few years ago, geologists excavated trenches across a fault close to Roermond and found evidence of at least three large prehistoric earthquakes, the most recent of which had ruptured the ground surface between 600 and 900AD. Based on their ground rupture effects, the earth quakes seemed to be over 6.0 in magnitude, possibly even up to magnitude 6.5. An EU-funded research project revealed a similar capability for many other faults bordering the Lower Rhine region. The message emerging from this research is clear - NW Europe is regularly struck by earthquakes that are far larger than those known from recent human history.
But what does all this mean for Britain? Well, a strand of the Lower Rhine earthquake belt swings westward across Belgium and bends northward across the straits of Dover (via the Channel Tunnel rock ridge) to London. And earthquakes are no stranger to the capital. On May 21 1382, a year after reeling from the poll-tax induced Peasants' Revolt, England was rocked by a large earthquake. Strong shaking damaged houses, churches, towers and castles throughout south-east England and northern France. The greatest destruction was in Kent, but the shaking was also particularly intense in London, with St Paul's and Westminster Abbey among the casualties.
The reign of Elizabeth I witnessed a repeat performance. On April 6 1580 a large earth quake inflicted considerable damage was around the straits of Dover, causing part of the cliff at Dover to collapse, bringing a section of the castle wall crashing down. Again the shaking was particularly severe in London, especially close to the river, where two people were killed by falling masonry and people ran in terror from buildings "fearful that the Day of Judgement had come". Even for Shakespeare it was an event of national importance, noting in Romeo and Juliet that "'tis since the earthquake now 11 years".
Modern analysis of the damage reports for 1382 and 1580 suggests that both shocks had magnitudes around 6.0 and both had epicentres in the straits of Dover. Less strong earthquakes in Kent, Northamptonshire and Essex continued to damage London in the following centuries, most notably in 1750 and 1776, culminating in the country's most destructive recent earthquake, the Colchester earthquake of 1884 (a paltry magnitude 4.6!). However in the last century or so, it has all been rather quiet. But, while London has grown into a modern metropolis, the earthquake hazard hasn't gone away.
Today, much of modern London still rests on the flood-plain sediments of the Thames. These loose sediments could mean distant earthquakes can inflict severe shaking in the capital, only today they have been made even more liquefiable by recent rising groundwaters. Strangely, London's greatest structures are probably least at risk, its skyscrapers being designed to be buffeted by winds stronger than the shaking that earthquakes can provoke. As in days gone by, a falling chimney or roof tile rather than the collapsing building is still the main threat to life.
So should we expect a 21st-century London earthquake? Perhaps, but don't lose sleep over it. In 1581, a severe windstorm that swept across the south-east inflicted more damage than the great earthquake had the preceding year.
However, this comforting notion is mired by two slight niggles. First, London hasn't yet had a direct seismic hit. Second, we're still assuming that the largest earthquake we might expect will have a magnitude less than 6.0. The studies along the Rhine rift are a warning that, perhaps even in the UK, the faults beneath our feet may be more capable than we thought.
ยท Iain Stewart is an earthquake geologist in the department of geography and topographic science at Glasgow University and an affiliate researcher at the Benfield Greig Hazard Research Centre, University College London. His report A Rift At The Heart of Europe: reassessing large earthquake potential in NW Europe, is published online at www.bghrc.com"