The UK hasn't got a history of catastrophic earthquakes.

This earthquake swarm - the name for a number of earthquakes - is unusual for the UK but we've had other swarms in the past.

For instance in Perthshire in 1788 and in Cornwall in 1981, 1986 and 1992.

And this shouldn't really be interpreted as a precursor to larger earthquakes.

The UK is not located near a plate boundary like Turkey, California or Japan, and that's where destructive earthquakes happen.

Twelve earthquakes and aftershocks have been registered

Most people don't really associate earthquakes with the UK - a lot of people are alarmed and surprised.

I wouldn't be worried about the Manchester earthquake.

The largest onshore earthquake in the UK was in 1984 in North Wales and a minor one in Dudley recently was felt.

These were a lot bigger in energy than the earthquake in Manchester.

As far as the causes of the Manchester earthquake are concerned - it's complete chance.

We get 250 earthquakes in the UK per year and they are spread throughout the country.

Constant vigilance

The British Geographical Survey has got a network of stations throughout the UK.

We're constantly monitoring the earth's movement 365 days a year.

Every day we will come in and check where earthquakes happen throughout the UK.

There are 200 to 250 on average a year and about 30 of those are felt.

An earthquake is the sudden release of strain energy in the earth's crust resulting in waves of shaking that radiate outwards from the earthquake source.

When stresses in the crust exceed the strength of the rock, it breaks along lines of weakness.