The earthquake and volcanic activity of the Barcelona region is largely the result of convergence between the Eurasian and African plates, with the Iberian micro plate caught between the two and absorbing much of the impact. The geology is diverse and complex, defying easy tectonic generalizations.
The direction of the relative motion between Africa and Europe is still under debate. Most reconstructions show directions of relative motion between north-west and north-east. Recent space geodesy data confirm this overall trend, in which Africa has a north-south component of convergence relative to Europe of about 5 mm year, but they also show that the absolute plate-motion directions of both Europe and Africa are north-east and not north or north-west as is usually assumed (see the NASA database on present global plate motions).More on: http://geographyfieldwork.com/BarcelonaEarthquake1.htm