Dynamic modelling of stress accumulation in central Italy

Abstract

We develop a viscoelastic dynamic model to calculate the stress distribution in central Italy induced by different geodynamic processes likely active in the region: Africa-Eurasia convergence, Adriatic underthrusting/subduction and asthenospheric upwelling underneath Tuscany. Model results are compared with the hypo central distribution of earthquakes and with the orientation of P and T axes available for the region. The first order characteristics of the seismotectonic observations in central Italy are: subcrustal seismicity, the pair extension-compression in Tuscany and in the outer Apennines, and the flexural behaviour evident in long wavelength orientation of T axes. These features are reproduced by the combination of two processes: underthrusting of the Adriatic plate under the Apennines and asthenospheric upwelling underneath Tuscany. The comparison with available data does not give insights about slab pull as an ongoing process. Copyright 1999 by the American Geophysical Union.