Multidisciplinary studies of diffuse soil CO2 flux, gas permeability, self-potential, soil temperature highlight the structural architecture of Fondi di Baia craters (Campi Flegrei caldera, Italy)

Antonio Trioano,Roberto Isaia,Stefano Vitale,Francesco Tramparulo,Maria Carapezza,Massimo Ranaldi,Luca Tarchini,Carlo Lucchetti,Maria Di Giuseppe,Ernesto Prinzi

doi:10.4401/ag-7683

Abstract

We present in this paper the results of a geophysical and geochemical survey of self potential, diffuse soil CO 2 flux, soil temperature and gas permeability carried out in the Fondi di Baia craters on the western sector of Campi Flegrei caldera, one of the most hazardous active volcano in Italy, aiming at highlighting the small scale volcano-tectonic structures of this Holocene edifice and at evaluating its state of fracturing. The central sector of Campi Flegrei (Solfatara volcano-Pisciarelli) is the one most affected by ground deformation and intense high-temperature fumarolic activity, nevertheless it cannot be ruled out a future vent opening along the western collapsed margin of the caldera, where Fondi di Baia craters are located. Our results show that the Fondi di Baia craters are characterized by a medium-high release of hydrothermal fluids through fractures that mimic the main volcano-tectonic structures of this portion of the caldera. Moreover, results indicate that, in case of a future volcanic reactivation, these structures could be possible paths for magma ascent. We provide a first estimate of the total flux of CO 2 from Fondi di Baia diffuse degassing structure, quantified in 10.1 ± 1.1 t*d -1

Highlights

Campi Flegrei caldera and Vesuvius volcano are the southernmost active portion of the Quaternary volcanic belt, aligned with the NW-SE trending Tyrrhenian extensional margin of central and southern Italy [e.g. Serri et al, 1993]
Soil temperature was measured at 0.2 m depth with a DeltaOhm HD2301.0 portable thermometer with a PT473P penetration probe (Accuracy ±0.25 °C) on the same points of soil CO2 flux
Self potential varied from -75.0 to 47.0 mV (Table 1)

Summary

Introduction

Campi Flegrei caldera and Vesuvius volcano are the southernmost active portion of the Quaternary volcanic belt, aligned with the NW-SE trending Tyrrhenian extensional margin of central and southern Italy [e.g. Serri et al, 1993]. Campi Flegrei caldera and Vesuvius volcano are the southernmost active portion of the Quaternary volcanic belt, aligned with the NW-SE trending Tyrrhenian extensional margin of central and southern Italy [e.g. Campi Flegrei caldera is one of the most hazardous volcano in the world, due to its young age and the ubiquitous presence of several monogenic and polygenic volcanic centers. The majority of researches and monitoring is focused on the central sector of the caldera where ground deformation and degassing are prevailing, such as in the Solfatara volcano and Pisciarelli area [e.g. We present a geophysical and geochemical study of the Fondi di Baia craters (Figure 1). This multidisciplinary study of self potential, soil CO2 flux, soil temperature and gas permeability of soils, is TARCHINI ET AL

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Conclusion