The Mediterranean Sea is the location of a number of inactive or failing subduction systems. Confined between the slowly converging landmasses of Eurasia and Africa, the Mediterranean microplates and their subduction systems can move independently only for a limited time before a collision ensues and forces a reorganization of the system. Of the complex, retreating, stalling and foundering subduction zones of the Mediterranean, Calabria is one of the most intriguing. It continues to subduct oceanic lithosphere, yet convergence appears to have stalled and uplift appears to have accelerated in the Pleistocene. Modern uplift rates are some of the highest in the Adriatic subduction systems. This project will focus an array of modern analysis techniques (quaternary geochronology, geomorphology, sedimentology, structural geology, seismicity, thermochronology, and GPS geodesty) on this problem; first, by refining the observations of horizontal and vertical motions back through time and second, by linking these to geodynamic models of upper mantle, lithospheric and crustal deformation. The key will be to connect the surface observations to the underlying geodynamics.
The Calabrian arc represents an outstanding example of subduction and continental platform collision leading to rapid uplift and deformation of the upper plate. Its small size makes it a tractable field laboratory in which to study processes important to all subduction zones, including analysis of the forces driving and resisting subduction and their manifestations on plate motion and surface uplift. The international PI team will integrate and extend the field observations and modeling necessary to (1) understand why Calabria is undergoing sustained rapid uplift, and (2) explore the implications for processes at depth. These surface and near-surface observations will be combined with analysis of the deeper structure provided by the previously funded CD CAT/SCAN passive seismic experiment. Understanding the puzzle of why Calabria is being uplifted and why it has slowed its horizontal motion has broad implications for the processes that drive and impede plate motions.
