THERMO-MECHANICAL MODELING OF GROUND DEFORMATION IN VOLCANIC AREAS

Materials surrounding a long-lived magmatic source are significantly heated above the brittle-ductile transition and rocks no longer behave in a purely elastic manner. A thermo-mechanical numerical model is performed for evaluating the temperature dependency of the rheological behaviour. The inclusion of viscoelastic and elasto-plastic material around the volcanic source considerably reduces the magmatic pressure necessary to produce the observed surface deformation with respect to elastic model. The assumption on the medium rheology strongly affects the ground deformation and, hence, the estimate of source pressure, which is an important issue for improving the knowledge of the physics of volcano deformation and eruption hazard.