scholarly journals CO2 and H2S Degassing at Fangaia Mud Pool, Solfatara, Campi Flegrei (Italy): Origin and Dynamics of the Pool Basin

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1051
Author(s):  
Dmitri Rouwet ◽  
Giancarlo Tamburello ◽  
Tullio Ricci ◽  
Alessandra Sciarra ◽  
Francesco Capecchiacci ◽  
...  
Keyword(s):  
Hydrothermal System ◽  
Co2 Flux ◽  
Campi Flegrei ◽  
Gas Migration ◽  
Campi Flegrei Caldera ◽  
Active Crater ◽  
Physical And Chemical ◽  
Solfatara Crater

The Fangaia mud pool provides a “window” into the hydrothermal system underlying the degassing Solfatara crater, which is the most active volcanic centre inside the restless Campi Flegrei caldera, Southern Italy. The present study aimed at unravelling the degassing dynamics of CO2 and H2S flushing through the pH 1.2 steam-heated Fangaia mud pool, an ideal field laboratory as a proxy of an active crater lake. Our results from MultiGAS measurements above Fangaia’s surface show that H2S scrubbing, demonstrated by high CO2/H2S ratios, was most efficient in the portions of the basin affected by diffusive degassing. Convective bubbling degassing instead was the most effective mechanism to release gas in quantitative terms, with lower CO2/H2S ratios, similar to the Solfatara crater fumaroles, the high-T end member of the hydrothermal system. Unsurprisingly, total estimated CO2 and H2S fluxes from the small Fangaia pool (~184 m2 in June 2017) were at least two orders of magnitude lower (CO2 flux < 64 t/d, H2S flux < 0.5 t/d) than the total CO2 flux of the Campi Flegrei caldera (up to 3000 t/d for CO2), too low to affect the gas budget for the caldera, and hence volcano monitoring routines. Given the role of the rising gas as “sediment stirrer”, the physical and chemical processes behind gas migration through a mud pool are arguably the creating processes giving origin to Fangaia. Follow-up studies of this so far unique campaign will help to better understand the fast dynamics of this peculiar degassing feature.

scholarly journals Study of Surface Emissions of 220Rn (Thoron) at Two Sites in the Campi Flegrei Caldera (Italy) during Volcanic Unrest in the Period 2011–2017

2021 ◽  
Vol 11 (13) ◽  
pp. 5809
Author(s):  
Fabrizio Ambrosino ◽  
Carlo Sabbarese ◽  
Flora Giudicepietro ◽  
Walter De Cesare ◽  
Mariagabriella Pugliese ◽  
...  
Keyword(s):  
Surface Layer ◽  
Surface Soil ◽  
Co2 Flux ◽  
Good Evidence ◽  
Campi Flegrei ◽  
Measuring Point ◽  
Volcanic Unrest ◽  
Campi Flegrei Caldera ◽  
Carrier Effect ◽  
Geochemical Parameters

The study concerns the analysis of 220Rn (thoron) recorded in the surface soil in two sites of the Campi Flegrei caldera (Naples, Southern Italy) characterized by phases of volcanic unrest in the seven-year period 1 July 2011–31 December 2017. Thoron comes only from the most surface layer, so the characteristics of its time series are strictly connected to the shallow phenomena, which can also act at a distance from the measuring point in these particular areas. Since we measured 220Rn in parallel with 222Rn (radon), we found that by using the same analysis applied to radon, we obtained interesting information. While knowing the limits of this radioisotope well, we highlight only the particular characteristics of the emissions of thoron in the surface soil. Here, we show that it also shows some clear features found in the radon signal, such as anomalies and signal trends. Consequently, we provide good evidence that, in spite of the very short life of 220Rn compared to 222Rn, both are related to the carrier effect of CO2, which has significantly increased in the last few years within the caldera. The hydrothermal alterations, induced by the increase in temperature and pressure of the caldera system, occur in the surface soils and significantly influence thoron’s power of exhalation from the surface layer. The effects on the surface thoron are reflected in both sites, but with less intensity, the same behavior of 222Rn following the increasing movements and fluctuations of the geophysical and geochemical parameters (CO2 flux, fumarolic tremor, background seismicity, soil deformation). An overall linear correlation was found between the 222−220Rn signals, indicating the effect of the CO2 vector. The overall results represent a significant step forward in the use and interpretation of the thoron signal.

scholarly journals A roadmap for amphibious drilling at the Campi Flegrei caldera: insights from a MagellanPlus workshop

2019 ◽  
Vol 26 ◽  
pp. 29-46 ◽  
Author(s):  
Marco Sacchi ◽  
Giuseppe De Natale ◽  
Volkhard Spiess ◽  
Lena Steinmann ◽  
Valerio Acocella ◽  
...  
Keyword(s):  
Hydrothermal System ◽  
In Situ Monitoring ◽  
Campi Flegrei ◽  
Magma Chambers ◽  
Pyroclastic Deposits ◽  
Campi Flegrei Caldera ◽  
Magma Reservoirs ◽  
Campanian Plain ◽  
International Ocean Discovery Program

Abstract. Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100–200 km3 Campanian Ignimbrite (CI) eruption at ∼39 ka and the 40 km3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25–28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore–offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sediments, and (d) the geological expression of the phreatic and hydromagmatic eruptions, hydrothermal degassing, sedimentary structures, and other records of these phenomena. The deployment of a multiparametric in situ monitoring system at depth will enable near-real-time tracking of changes in the magma reservoir and hydrothermal system.

scholarly journals Temperature and pressure gas geoindicators at the Solfatara fumaroles (Campi Flegrei)

2011 ◽  
Vol 54 (2) ◽  
Author(s):  
Giovanni Chiodini ◽  
Rosario Avino ◽  
Stefano Caliro ◽  
Carmine Minopoli
Keyword(s):  
Hydrothermal System ◽  
Fluid Pressure ◽  
Critical Conditions ◽  
Campi Flegrei ◽  
Gas System ◽  
Show Evidence ◽  
Long Time ◽  
Compositional Variations ◽  
Pressure Changes ◽  
Solfatara Crater

Long time series of fluid pressure and temperature within a hydrothermal system feeding the Solfatara fumaroles are investigated here, on the basis of the chemical equilibria within the CO2&ndash;H2O&ndash;H2&ndash;CO gas system. The Pisciarelli fumarole external to Solfatara crater shows an annual cycle of CO contents that indicates the occurrence of shallow secondary processes that mask the deep signals. In contrast, the Bocca Grande and Bocca Nova fumaroles located inside Solfatara crater do not show evidence of secondary processes, and their compositional variations are linked to the temperature&ndash;pressure changes within the hydrothermal system. The agreement between geochemical signals and the ground movements of the area (bradyseismic phenomena) suggests a direct relationship between the pressurization process and the ground uplift. Since 2007, the gas geoindicators have indicated pressurization of the system, which is most probably caused by the arrival of deep gases with high CO2 contents in the shallow parts of the hydrothermal system. This pressurization process causes critical conditions in the hydrothermal system, as highlighted by the increase in the fumarole temperature, the opening of new vents, and the localized seismic activity. If the pressurization process continues with time, it is not possible to rule out the occurrence of phreatic explosions.<br />

scholarly journals Increasing CO<sub>2</sub> flux at Pisciarelli, Campi Flegrei, Italy

2017 ◽  
Author(s):  
Manuel Queiβer ◽  
Domenico Granieri ◽  
Mike Burton ◽  
Fabio Arzilli ◽  
Rosario Avino ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Vapor ◽  
Co2 Flux ◽  
Scanning Laser ◽  
Campi Flegrei ◽  
Magmatic Source ◽  
Campi Flegrei Caldera ◽  
Co2 Concentrations ◽  
Laser Remote Sensing

Abstract. Campi Flegrei caldera is located in the metropolitan nucleus of Naples (Italy), and has been undergoing different stages of unrest since 1950, evidenced by episodes of significant ground uplift followed by minor subsidence, increasing and fluctuating emission strengths of water vapor and CO2 from fumaroles, and periodic seismic crises. We deployed a scanning laser remote sensing spectrometer (LARSS) that measures path integrated CO2 concentrations at the Pisciarelli area in May 2017. The resulting mean CO2 flux is 578 ± 246 t d−1. Our data suggest a significant increase in CO2 flux at this site since 2015. Together with recent geophysical observations, this suggests a greater contribution of the magmatic source to the degassing and/or an increase of permeability at shallow levels. Thanks to the integrated path soundings, LARSS proves to give representative measurements from large regions containing different CO2 sources, including fumaroles, low-T vents, and degassing soils, helping to constrain the contribution of deep gases and their migration mechanisms towards the surface.

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