Dispersion of surface waves in the iberian Peninsula and the adjacent atlantic and Mediterranean areas

Abstract

Fourier analysis techniques have been applied to determine the phase and group velocity of surface waves through the following regions: a) the Iberian Peninsula, b) the Atlantic Sea between Azores and Portugal and c) the Alboran Sea. The crust-mantle structure corresponding to the dispersion curves obtained has been determined by the normal inversion methods, applied to several theoretical crust-mantle models. Comparison of theoretical and empirical curves leads to fix the most probable type of structure for those three regions. The paths studied between Ebro-Porto and Ebro-Malaga turn out to be of similar structure to that of the triangle Toledo-Porto-Malaga.
The paths Azores-Porto and Azores-Malaga are of clear oceanic type with a crust thickness of only 6 km, including the sediments. Finally, the structure of the Alboran Sea and that of the Balearic Basin, between Algeria and Spain, presents some oceanic features. This supports the idea that the Alboran Sea is a part of a small plate of the type described as "buffer plate" that, in this case, is being squeezed between the two large African and Euroasiatic plates.