How the ground deformation drives the earth-quake occurrence during the 2005-presenttime unrest at Campi Flegrei - Italy

We investigate the relationship between the cumulative number of earthquakes and ground uplift at the Campi Flegrei caldera (South Italy) during the ongoing unrest (2005–present). While previous studies have explored this correlation, we propose a nonlinear epidemic model that captures new features of the caldera system. More precisely, our model describes earthquake occurrence as a cascading process (similarly to what observed for tectonic earthquakes) influenced by ground deformation. The nonlinearity reflects the reduced efficiency of the triggering mechanism, which contributes to the short duration of seismic swarms. This mechanism, we hypothesize, may represent a general framework for understanding volcanic earthquake occurrence globally.