The Mediterranean sea floor is subducted beneath the western Hellenic arc at a gentle angle for about 200 km and then steepens beneath the Gulf of Cornith. The seismic zone extends to a depth of 150 km, but the subducted intact lithosphere could reach 600 km. The present relative motion between Africa and Aegea can be considered as the sum of 2 motions: 1) slow (1 cm/y) relative motion between Africa and Europe, which describes the rate at which the deep slab penetrates the asthenosphere and which started during the upper Cretaceous time when Africa started to converge toward Europe and 2) fast (5 cm/y) relative motion between the southern Aegea and Europe, manifest by internal deformation within the Aegean, which may have been active at present rates only since Pliocene time. I suggest that the increase in the total convergent rates which began about 5 my ago is responsible for the wide, flat slab beneath the Peloponnese.