Analysis of eruptive activity at Stromboli volcano through a continuous monitoring of multi-parameter geophysical data

<p>Recent eruptive activity at Stromboli is mostly characterized by persistent, Strombolian explosive activity from summit craters. Occasionally, so-called major explosions occur, and more rarely paroxysms take place, such as on 3 July and 28 August 2019. We analyze monitoring data recorded between 2016 and 2022 to identify and characterize patterns in multi-parameter time series (considering in particular seismic, geochemical, meteorological, and sea-level gauges), with special interest in analyzing patterns observed before and during the occurrence of major explosions and/or paroxysmal eruptions. In practice, (i) we implement algorithms to automatically identify families of seismic events using waveform features; (ii) we analyze the effect of oceanic microtremor on continuous and discrete amplitude-based measurements; (iii) we study the temporal and size distribution of event occurrences, and use this information to assess likely trends in eruptive behavior. Moreover, (iv) we use noise cross-correlations and auto-correlations to compute seismic velocity variations of the shallow crust.&#160;</p> <p>Multi-parametric measurements provide interesting insights in the temporal evolution of the eruptive activity at Stromboli; for example, correlated changes in the pattern at which events occur in time, patterns in the distribution of extreme, large events, and evidence of a decrease in seismic velocity, seem to be phenomena occurring before paroxysmal eruptions. Detailed analyses of the produced time series, including also pattern recognition techniques, are required for better revealing likely patterns and for better understanding and interpretation of observations.&#160;</p>