Modelling and understanding groundwater fluctuation in the volcanic aquifer of Mount Etna, Southern Italy, and its potential relationship with volcanic events and superficial deformation processes identified by a Persistent Scatter Interferometric Synthetic Aperture Radar (PSInSAR) analysis.

  • S. Aveni

    Student thesis: Master's ThesisMaster of Science by Research


    Modelling and understanding groundwater fluctuations is a challenging task, especially in volcanic areas where geodynamic events constantly alter the equilibrium of the system. In this study, the piezometric fluctuations of the Etnean aquifer between 2003 and 2019 were modelled employing the Rainfall Infiltration Breakthrough (RIB) approach. The results revealed remarkable agreements between observed and modelled time series, with errors comprised between 0.04 and 2.69 m, and correlation coefficients ranging from 0.77 to 0.93. After identifying a significant agreement between modelled and observed groundwater levels and, assuming that the aquifer is controlled exclusively by meteorological factors – with the RIB models reflecting the undisturbed aquifer conditions – the modelled groundwater levels were subtracted from the observed time series to identify non-meteorologically induced fluctuations. Due to low resolution and gaps in the time series, this investigation was only applied to the 2003-2007 period. The residual time series revealed significant fluctuations detected up to ~4 months before the flank eruption of September 7th, 2004, and ~1 month prior to the phreatomagmatic explosion of January 12th, 2006. These variations mainly occurred on the southeast flank of the volcano and were consistent with the alteration of geochemical parameters previously investigated by other authors. These fluctuations were suggested to be triggered by the pressurisation of the system caused by the migration of magma and/or by the increased local strain increasing the permeability of the ground, supporting the mixing of water between aquifers. After assessing the effect of volcanic dynamics on the piezometric equilibrium, a mutual interaction between groundwater and geological structures was hypothesised. PSInSAR deformation time series were compared both to filtered and unfiltered groundwater levels, to identify potential associations between the two variables. Significantcorrelations were observed between unfiltered groundwater trends and deformation time seriesfor the southern sector of the volcano, whilst no associations were identified for the northern flanks. These findings suggest that fluctuation of the water table might play a major role in deformation dynamics, despite their physical mechanisms remaining unclear. In contrast, residual groundwaters and deformation time series revealed spatially and temporallyinconsistent associations, and it was not possible to identify a link between the two variables. This work highlights how groundwater variations might offer, from months in advance, evidence of alterations to the geodynamic equilibrium of the Etnean region, providing evidence of the importance of groundwater monitoring and providing suggestions for future research
    Date of AwardMar 2023
    Original languageEnglish
    Awarding Institution
    • Coventry University
    SupervisorCharley Hill-Butler (Supervisor) & Matteo Rubinato (Supervisor)


    • Etna
    • Groundwater levels
    • Groundwater Modelling
    • Volcanic Eruptions
    • PSInSAR

    Cite this