Bristol Channel earthquake a reminder of Britain’s past

The UK’s biggest earthquake for five years took place in 2014, as seismic activity in the Bristol Channel shook the ground across the West Country and South Wales.

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In Britain, we suffer what is deemed a major earthquake about once a decade, the last being in 2008.

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Yet countries like Italy and Iceland, which are relatively near neighbours in the grand scheme of things, suffer much more volcanic activity and more regular quakes.

Famously, Eyjafjallajökull in Iceland erupted in 2010, producing a mass of ash that caused travel disruption across Europe. Italy meanwhile is home to one of the most famous volcanoes of them all, Vesuvius, which last erupted in 1944. Elsewhere in Italy, Etna and Stromboli both erupted as recently as 2013.

So why does Britain seem to avoid any major geological catastrophe?

We’re, gladly, situated comfortably away from major fault lines. There are a few running through southern England, and some more considerable ones in Scotland including the Great Glen Fault, but they’re nothing like the ones around the Pacific Ocean where most of the world’s earthquakes take place.

Here, the nearest major fault line is north west of Scotland, in the Atlantic. It’s extremely active with earthquakes occurring regularly and volcanoes constantly producing new land.

Iceland sits on top of this fault line, a country that grows each year, added to by the lava flows and eruptions spewing up from the gap between the Eurasian and North American tectonic plates.

This process will continue until, eventually after millions of years, it will become a continent.

Iceland is a country intrinsically linked to the belches and burps of the planet beneath it. It shapes the landscape, the people, their culture and the way they generate energy.

It may have been 300-400 million years since we have anything like that in this country but Britain too has been forged by volcanic and seismic activity over the millennia.

The separating of the continents – the breaking of Pangaea – may have lead to us currently sit in rather a safe place, but you just have to look at Giant’s Causeway and Scotland’s basalt rock formations to see the evidence of our once tumultuous past.

British Volcanoes

The Scottish highlands are part of the same range as the Scandinavian mountains and North America’s Appalachians, all formed about 430 million years ago.

The Ardnamurchan peninsula and the Isle of Mull are remnants of lava flows that would rival anything seen in Iceland and Glen Coe is all that is left of an ancient super-volcano.

Even Edinburgh Castle sits on top of a volcano – the smaller of two long extinct volcanoes in the city – while the Cheviot Hills and the Lake District are also a result of volcanic activity.

In Wales, Mount Snowdon was once at the centre of a furious ring of volcanic activity that was more violent than modern day Indonesia. One such eruption in the region is believed to have been about three times as explosive as Krakatoa.

It may not be active now, but such dramatic happenings are all around us.

Hundreds of earthquakes in Britain each year

Earthquakes still occur, although due to our distance from major fault lines there are rarely large enough to do much damage.

A few of the hundreds of earthquakes that occur in Britain each year have caused damage and killed people though.

The 1931 North Sea quake at Dogger Bank was the largest ever recorded in Britain at 6.1 on the Richter scale. It killed one person in Hull who died of a heart attack cause by the quake.

In 1884 the ‘Great English Earthquake’ killed at least three people and damaged 1200 buildings in and around Colchester.

A quake off the coast of Dover in 1580 measured 5.8 on the Richter scale, killed two people and caused a land slip that exposed new chalk on the famous white cliffs of Dover. It was so deep that the chimneys and a pinnacle on Westminster Abbey came down, while damage was done as far afield at Ely Cathedral, Cambridgeshire and in France.

And most recently, in 2008, the Lincolnshire town of Market Rasen was the epicentre for the country’s biggest earthquake in 25 years, felt in Aberdeen, Ireland and even over in Holland.

Why do we experience earthquakes at all?

Britain is constantly squeezed from the North West by the shifting of the Eurasian plate, clashing with the North American out in the Atlantic as the two pull away from each other.

This results in hundreds of tremors a year in Britain, but only about 20-30 are noticeable. This squeezing explains why the overwhelming majority of tremors and quakes in this country happen on the western side.

According to the British Geological Survey, a magnitude four earthquake happens every couple of years. Research suggests that the strongest earthquake possible in and around Britain would measure 6.5.

Set to the west of the Eurasian tectonic plate, Britain is far enough away from any major fault lines and plate boundaries to suffer a catastrophic quake or eruption, but this land’s violent past is a reminder of just how powerful natural forces can be.

To see evidence of Britain’s fiery past for yourself, take a look at our favourite formerly volcanic countryside sights.

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Main image: Getty