Assessing the volcanic hazard for Rome: Ar-40/Ar-39 and In-SAR constraints on the most recent eruptive activity and present-day uplift at Colli Albani Volcanic District

We present new Ar-40/Ar-39 data which allow us to refine the recurrence time for the most recent eruptive activity occurred at Colli Albani Volcanic District (CAVD) and constrain its geographic area. Time elapsed since the last eruption (36kyr) overruns the recurrence time (31kyr) in the last 100kyr. New interferometric synthetic aperture radar data, covering the years 1993-2010, reveal ongoing inflation with maximum uplift rates (>2mm/yr) in the area hosting the most recent (<200ka) vents, suggesting that the observed uplift might be caused by magma injection within the youngest plumbing system. Finally, we frame the present deformation within the structural pattern of the area of Rome, characterized by 50m of regional uplift since 200ka and by geologic evidence for a recent (<2000years) switch of the local stress-field, highlighting that the precursors of a new phase of volcanic activity are likely occurring at the CAVD.