Developing long-term probability time models for the episodic volcanism of Campi Flegrei caldera (Italy)

Abstract

After the large scale event of Neapolitan Yellow Tuff (~15 ka BP), intense and mostly explosive volcanism has occurred within and along the boundaries of the Campi Flegrei caldera (Italy). Eruptions occurred closely spaced in time, over periods from a few centuries to a few millennia, and were alternated by periods of quiescence lasting up to several millennia. Often events also occurred closely in space thus generating a cluster of events. The most recent eruption was that of Monte Nuovo in AD 1538. There is a remarkable uncertainty on the eruptive record, affecting the time of eruptions, location of vents as well as the erupted volume estimates. This study had two main objectives: 1) to describe the record uncertainty by using a quantitative model and 2) to develop, based on the uncertainty assessment, a temporal probability model to describe the temporal and spatial eruptive behaviour of the caldera. In particular, the study adopts a time-space double stochastic non-homogeneous Poisson-type model with a local self-exciting feature able to generate clustering of events which are consistent with the reconstructed record of Campi Flegrei. Results allow to evaluate similarities and differences between the three epochs of activity as well as to derive eruptive base-rate of the caldera and its capacity to generate clusters of events. The temporal probability model is also used to investigate the effect of Monte Nuovo event on a possible reactivation of the caldera and to estimate the time to the next eruption under different volcanological and modelling assumptions.