Crustal structure in the region of the British Isles

Progress in the application of seismic refraction methods to the determination of crustal structure for the British Isles and surrounding sea areas, is reviewed for the period which follows the publications of 1965. The work has been strongly oriented towards the application of “Time Term” interpretation to land-based observations of explosions in the English Channel, to the south of Ireland, in the Irish Sea, in the North Sea, and off the west coast of Scotland.

All of the surveys have included determinations of velocities for P_n and P_g, with some indication of an increase in P_n-velocity with range. In part of the area, indications of lower-crust velocities ranging from 6.9 to 7.3 km/sec have been found.