Quake sets seismographs - and imaginations - twitching

In full working order, Joe Guest's ears would have exposed the 83-year-old to what the West Midlands was calling yesterday the "Dudley Quake" – Britain's most severe tremor for 13 years, which left him and his neighbours marvelling at the strength of their red-brick bungalows.

As it was, his ears are due for a syringing, and so Mr Guest knew nothing until he awoke to survey the "damage" – the six-inch displacement of his brass clock on the mantlepiece. "Thank God we're here to tell the tale," he said. "I've already rung my daughter in Blackpool and put her mind at rest."

His wife Marjorie, 81, thought Joe was having "one of those nervous turns" when she heard the rumble at 12.54am and experienced the effects of the earthquake. Seismologists said it measured 4.8 on the Richter scale and was centred 6.1 miles beneath the Guests' street in Gormal Wood, a few miles west of Dudley.

Norman Harper, 77, lives next to the Guests. "The end of the bed was rising as if somebody was under it," he said. "The wardrobe left the wall and came back again. For a time I thought the roof had come in."

He was not the only one to fear the worst. The tremor lasted only 15 seconds, but it provoked 5,000 calls to West Midlands Police in the space of an hour, caused prison officers in distant Salford to report a suspected jail-break and brought 12 residents out in their pyjamas to the front desk at Dudley police station.

Quake stories filled the Radio West Midlands airwaves until lunchtime, many describing the sense that the tremor was passing from one side of the house to another and detailing the premonitions of animals. (Geologists agree that their extra-sensory perceptions make them capable of detecting quakes first.)

Paul, calling from his seventh-floor flat in Walsall, found his African grey parrot "panicking" before the rumbling started, while Lee of Cradley Heath was advised to see a vet about one of his four rabbits which "came over all floppy" as early as Sunday afternoon.

Emma of West Bromwich, returning home with her husband at midnight, settled down for some carnal pleasure as neither of them was tired enough to sleep. "Just as we were about to get down to it the quake happened," she explained. "A jug of water fell off the side table and spilt over the cat, who jumped on the bed and dug her claws into my husband."

The quake, felt by people as far afield as south and west Wales, Northamptonshire, South Yorkshire and Oxfordshire, appears to have been caused by the north-west to south-east movement of tectonic plates forcing a landslip on the north-south fault lines that created the Black Country's coalfields.

Though cracks at Dudley Castle were a cause for concern yesterday, the depth of the slip meant there was minimal damage, compared with the previous serious quake when much of Shrewsbury was sealed off after a tremor measuring 5.2 in April 1990. Dr Jonathan Turner, a structural geologist at the University of Birmingham, said: "Tectonically speaking, we are about as quiescent as you can get in the UK. It's one of the safest places to be."

Alex Potter of south Birmingham will take some convincing of that, having been one of several locals whose anxieties about terrorism were aroused in the early hours. "My immediate thought was, 'Oh God, they've bombed Birmingham," he said.

But nobody at the Crooked House pub was complaining. The 237-year-old building near the Guests' house is four feet lower on one side than the other after a mine shaft collapsed beneath it in the mid 1800s – just the kind of subterranean activity that caused the Dudley quake – and was doing a roaring trade. "Didn't expect this. Business will be booming all this week," grinned the landlady, Sue Hollaway.

Why earthquakes shake Britain

The earthquake early yesterday had a very simple cause: Britain is being squashed by gigantic forces acting on the tectonic plate – a giant piece of the Earth's crust – upon which it sits.

Add to that the fact that the island has a turbulent geological past, being repeatedly raised from and submerged in the sea, and you have what seems like the perfect recipe for an unstable existence.

But experts say Britain is unlikely to suffer any quakes more powerful than about 6 on the Richter scale – about 15 times more powerful than yesterday's – because it is so far from the edge of its tectonic plate.

"Britain has relatively few earthquakes because we're not in an active seismic zone," said David Booth, a principal seismologist at the British Geological Survey. "Unlike places like Iceland, where the plate is being created, or the seas off Chile and Japan where it's being destroyed by being pushed down into the Earth's crust, we are pretty much in the middle of the Eurasian plate."

The Eurasian plate extends north beyond Scandinavia, to the west into the mid-Atlantic, east to Turkey and south to the Mediterranean. Earthquakes happen when one or two plates try to move but are blocked by their own rigidity.

"Britain is being squashed from the north-east and south-west," said Dr Booth. "There are tiny faults all over the UK, some near the surface, such as in Scotland's Midland Valley. This one appears to have been almost dormant.''

An earthquake is the release and sudden movement of the plate. The largest occur at the margins of those plates, where a movement of a few centimetres may occur in an instant.

Often a quake releases other tensed-up plates, causing "aftershocks". Britain had an aftershock, at about 4am yesterday measuring 2.7 on the Richter scale.

Charles Arthur