A NEW APPROACH TO THE RELIEF OF GREAT-BRITAIN - I - THE MACHINE-READABLE DATABASE

We describe a simple, if fairly large, database of relief and geology for Great Britain and the surrounding shelf based on the kilometre squ ares of the National Grid. The area covered is 560,000 km(2), 319,490 km(2) classified as sea and 240,510 km2 as land (squares which include d the coastline were classed as land). The database affords a new appr oach to establishing the importance of rock resistance to erosion as a factor affecting the form of the present land surface, the legacy of older tectonic movements, and the role of neotectonics. It can be used to test existing hypotheses, or propose new ones, which can then be t ested against other evidence. Initial data on land/shelf contrasts are presented. The current coastal zone is found to be a sector of relati vely abrupt transition from shelf depths between -60 and -70 m, to lan d elevations exceeding an average of over 100 m, even within a few kil ometres of the coast. This transition zone is attributed to the isosta tic buoyancy of a land area steadily unloaded by denudation and attack ed by the transgressing sea as water levels rise after each glacial st age. The database is a novel and powerful way to tackle some fundament al aspects of the evolution of the relief of Great Britain and further papers will explore issues such as relative rock resistance and evide nce for neotectonic movement. (C) 1998 Elsevier Science B.V. All right s reserved.