On the interpretation of large-scale seismic tomography images in the Aegean sea area

Abstract

A review of the interpretations given to large-scale seismic tomography anomalies in the Aegean area indicates a strong contradiction between these interpretations and the traditional ones based on seismic and tectonic data: 1) the tomographic lithospheric slab penetrates down to at least 400 km which doubles the maximum depth of the Benioff zone seismicity; 2) the resulting minimum time estimates for the subduction process duration at least doubles the seismotectonically calculated maximum time of 13 Ma for the subduction initiation. An alternative interpretation is proposed: the tomography detects not only the South Aegean active Benioff zone but also large remnants of lithospheric material subducted in two phases beneath the Aegean during the Miocene. Given that the geometric features of the paleosubductions are compatible with the features of the tomographic anomalies, it is suggested that the latter represent cool, non-assimilated lithospheric remnants. Then, no contradiction any longer exists and both seismotectonic and tomographic data are well explained.