First multiparametric observation of a mud volcano eruption

Abstract. Mud volcanoes (MVs) are geological structures emitting a mixture of gas (mostly methane), water, clayey sediments and rock fragments. Their background activity is sometimes interrupted by paroxysmal events, consisting of violent expulsions of huge amounts of these materials, determining geohazard conditions. Although MV eruptions have been reported to have caused damages and casualties worldwide, their surveillance protocols are poorly developed, and multiparametric instrumental recordings of paroxysmal phases have never been documented. Here we show the first-ever multiparametric dataset capturing the pre-, syn-, and post-eruptive evolution of a paroxysmal event at Maccalube di Aragona (Italy) on 29 August 2025. Seismic, geodetic, geomorphological, hydro-meteorological and geochemical data, acquired before, during and after the event allowed to reconstruct the eruption dynamics, identifying indicators for the implementation of monitoring protocols. In particular, variations of physical-chemical parameters of mud pools, soil electric conductivity, seismic tremor and ground deformation shed light on possible precursors, from days to minutes, of the paroxysmal phase.