§ Mr. Peter Reesasked the Secretary of State for Transport what account he took of the possibility of earth tremors in approving plans for the Channel tunnel.
§ Mr. MooreThe possibility of earth tremors affecting the tunnel was examined in detail for the 1973 Channel tunnel project by distinguished geologists from the Institute of Geological Science (now the British Geological Survey), the Bureau de Recherches Geologiques et Minieres, and the British and French consulting engineers employed on the project. After examining all the historical evidence of earthquakes in the area, including the one in 1580 referred to in a recent article in theNew Scientist, and undertaking sophisticated measurements of the present geology of the area, the conclusion was that the risk to a bored tunnel was very low indeed.
This evidence was reviewed again by consultants to the present promoters, who included a special section on seismicity in their proposal. The Government assessors who examined the engineering aspects of all the proposals put forward agreed with the view that the risk was very slight, and stated that
displacements during a very large earthquake would be in the order of millimetres and damage would be nominal only.