§ Mrs. Shirley Williams
I have been asked to reply.
The Institute of Geological Sciences has carried out the following regional surveys in the United Kingdom sector of the North Sea:
- (a)Geophysical surveys, including shallow seismic profiling, sonar gravity and magnetic surveys, covering approximately 18,000 square miles; a further 33,000 square miles has been covered by gravity survey alone;
- (b) Geological surveys, to obtain samples of bedrock and sediments to calibrate the geophysical results, including sampling with grabs, gravity corers and vibro-corers, covering approximately 15,000 square miles, and shallow drilling of some 200 boreholes of up to 200 metres depth.
The surveys are planned in conjunction with and are complementary to existing work by commercial companies. It is hoped that they will be completed by about 1986. The results, which are available on request, will then be published in full.