North Sea oil has little to do with quakes

As a geography teacher in a local school, I have always taught that earthquakes are caused by the movement of the earth's crust at the junction between two plates. I also teach that the UK does not as a rule have earthquakes. Small tremors are felt due to movement along ancient fault lines but nowhere as big as along the plate boundaries of the world.

And I teach that oil is formed in between sedimentary layers of rock which are part of the earth's crust.

It seems to me an old wive's tale that the removal of oil from these layers could cause earthquakes. To make sure, I went onto the British Geological Society website. Naturally it was full of excitement following the earthquake centred on Birmingham. By reading on I discovered most of our earthquakes are centred on the Great Glen Fault, a line from Carlisle to Leicester, across north Wales, south Wales and in south west England.

The North Sea, it said, had only been monitored since the beginning of oil exploration in the early 1970s. Since then, records showed no increase in earthquakes. If Miss Packer was correct in her thinking, surely they would increase as oil stocks begin to run out. Over the last 30 years, earthquakes of a similar size to last week's show eight in mainland Scotland, four in England, one in Jersey and only two in the North Sea.

It would seem that earthquakes in the UK have nothing to do with North Sea oil. Records clearly show earthquakes of similar magnitude and greater have been happening in the UK since records began over 100 years ago. It is wrong to say that the UK did not have earthquakes until North Sea oil exploration in the 1970s. Indeed, the BGS state that the UK has a quake of 3.7 on the Richter Scale every year, one of 4.7 every 10 years and one of 5.6 every 100 years. Since last week's was less than the latter, it still leaves us waiting for . . . the BIG ONE!

IAN HOWARD

Risingham Mead, Westlea, Swindon