Seismic structure of Iceland along RRISP-profile 1

As part of the RRISP 77 combined land-sea refraction seismic experiment, observations were carried out on Iceland itself with special emphasis on resolving the deep structure beneath Iceland and its transition towards the eastern flank of Reykjanes Ridge. The data, interpretational procedures, and results for the land part are described in this paper. A structural model of Iceland is presented which is characterized by a generalized two-layered crust of variable thickness underlain by anomalous mantle with P-wave velocities of 7.0km/s at the base of the crust increasing to 7.4km/s at 30km depth. Two regions of relatively low velocity have been identified in a lower crust, possibly indicating zones of high melt concentration. -Author