A NUMERICAL MODEL OF THE HELLENIC SUBDUCTION ZONE - ACTIVE STRESS FIELD AND SEA-LEVEL CHANGES

摘要

A 2-D viscoelastic finite element model for subduction in the southern Aegean Sea allows us to study the distribution of stress and surface velocities in a vertical cross section through the island of Crete. Recent tomographic results constrain the geometry of the slab and the structure of the crust, lithosphere and mantle. Two models are considered, the first for passive subduction driven solely by slab pull, and the second one where active convergence between the African and Aegean plates is also included. Both models predict subsidence of the Hellenic trench and of Cretan trough; uplift of Crete and of the Aegean volcanic are. The island of Crete is subject to differential uplift, highest in the southern part, with maximum rates of 1.5 and of 3.2 mm/yr for the two models, respectively. These results agree with the tectonic uplift inferred from Holocene sea-level changes in the island. The style of stress within the modeled African acid Aegean plates is in general agreement with the focal mechanisms of the largest earthquakes along the subduction zone. [References: 21]