Search results for "Fumarole"
showing 10 items of 71 documents
A New Web-Based Catalog of Earth Degassing Sites in Italy
2008
Italy is a region characterized by intense and widespread processes of Earth degassing. High-temperature gases are released by crater plumes and fumaroles in volcanic environments throughout Italy. Also prevalent are numerous low-temperature gas emissions rich in carbon dioxide (CO2). These low-temperature emissions are located in a large area, mainly in the western sector of central and southern Italy (Figure 1).
Genesis and evolution of the fumaroles of vulcano (Aeolian Islands, Italy): a geochemical model
1981
A geochemical model explaining the presence of fumaroles having different gas composition and temperature at the top of the crater and along the northeastern coast of Vulcano island is proposed. A pressurized biphase (liquid-vapor) reservoir at the depth of about 2 km is hypothesized. Energy and mass balance sheets controlP-T conditions in the system.P-T must vary along a boiling curve of brine as liquid is present. The CO2 content in the steam is governed by the thermodynamic properties of the fluids in the H2-NaCl-CO2 system. On the assumption that oxygen fugacity in the system is between the HM-FMQ oxygen buffers, observed SO2/H2S, CO2/CO, CO/CH4 ratios in the fumarolic gases at the Foss…
UV camera measurements of fumarole field degassing (La Fossa crater, Vulcano Island)
2011
Abstract The UV camera is becoming an important new tool in the armory of volcano geochemists to derive high time resolution SO2 flux measurements. Furthermore, the high camera spatial resolution is particularly useful for exploring multiple-source SO2 gas emissions, for instance the composite fumarolic systems topping most quiescent volcanoes. Here, we report on the first SO2 flux measurements from individual fumaroles of the fumarolic field of La Fossa crater (Vulcano Island, Aeolian Island), which we performed using a UV camera in two field campaigns: in November 12, 2009 and February 4, 2010. We derived ~ 0.5 Hz SO2 flux time-series finding fluxes from individual fumaroles, ranging from…
Thermal anomalies in fumaroles at Vulcano island (Italy) and their relationship with seismic activity
2013
Abstract Fumarole thermal monitoring is a useful tool in the evaluation of volcanic activity, since temperatures strongly relate to the upward flux of magmatic volatiles. Once depurated from meteorological noise, their variations can reflect permeability changes due to crustal stress dynamics eventually associated to seismic activity. In this work, we discuss a fumarole temperature record acquired in the period September 2009–May 2012 at Vulcano island (Italy), during which changes of volcanic state, local seismic activity and teleseisms occurred. Apart from positive thermal anomalies driven by increments in volcanic activity, we observed 3 episodes at least of concurrence between tectonic …
Major and trace element geochemistry of neutral and acidic thermal springs at El Chichón volcano, Mexico
2008
Abstract Four groups of thermal springs with temperatures from 50 to 80 °C are located on the S–SW–W slopes of El Chichon volcano, a composite dome-tephra edifice, which exploded in 1982 with a 1 km wide, 160 m deep crater left. Very dynamic thermal activity inside the crater (variations in chemistry and migration of pools and fumaroles, drastic changes in the crater lake volume and chemistry) contrasts with the stable behavior of the flank hot springs during the time of observations (1974–2005). All known groups of hot springs are located on the contact of the basement and volcanic edifice, and only on the W–SW–S slopes of the volcano at almost same elevations 600–650 m asl and less than 3…
H2S fluxes from Mt. Etna, Stromboli, and Vulcano (Italy) and implications for the sulfur budget at volcanoes
2005
Abstract We present here new measurements of sulfur dioxide and hydrogen sulfide emissions from Vulcano, Etna, and Stromboli (Italy), made by direct sampling at vents and by filter pack and ultraviolet spectroscopy in downwind plumes. Measurements at the F0 and FA fumaroles on Vulcano yielded SO 2 /H 2 S molar ratios of ≈0.38 and ≈1.4, respectively, from which we estimate an H 2 S flux of 6 to 9 t · d −1 for the summit crater. For Mt. Etna and Stromboli, we found SO 2 /H 2 S molar ratios of ≈20 and ≈15, respectively, which combined with SO 2 flux measurements, suggest H 2 S emission rates of 50 to 113 t · d −1 and 4 to 8 t · d −1 , respectively. We observe that “source” and plume SO 2 /H 2 …
Intercomparison of volcanic gas monitoring methodologies performed on Vulcano Island, Italy
2004
[1] Volcanic gas emissions from fumaroles on the rim of La Fossa crater, Vulcano Island, Italy, were measured simultaneously using direct sampling (for H2O, CO2, total sulfur, HCl and HF), filter packs (for SO2, HCl, HF) and short-path active-mode FTIR measurements (for H2O, CO2, SO2, HCl and HF) in an intercomparison study in May 2002. The results show that Cl/F ratios were in good agreement between all three methods, and that FTIR and direct sampling determined comparable proportions of CO2 and H2O. Amounts of total S observed in direct sampling data were approximately double the amounts of SO2 measured with filter packs and FTIR. This difference could be attributed either to the fact FTI…
Tunable diode laser measurements of hydrothermal/volcanic CO<sub>2</sub> and implications for the global CO<sub&am…
2014
Abstract. Quantifying the CO2 flux sustained by low-temperature fumarolic fields in hydrothermal/volcanic environments has remained a challenge, to date. Here, we explored the potential of a commercial infrared tunable laser unit for quantifying such fumarolic volcanic/hydrothermal CO2 fluxes. Our field tests were conducted between April 2013 and March 2014 at Nea Kameni (Santorini, Greece), Hekla and Krýsuvík (Iceland) and Vulcano (Aeolian Islands, Italy). At these sites, the tunable laser was used to measure the path-integrated CO2 mixing ratios along cross sections of the fumaroles' atmospheric plumes. By using a tomographic post-processing routine, we then obtained, for each manifestati…
Chemical and isotopic characterization of the gases of Mount Etna (Italy)
1997
Abstract In the period 1990–1995, 43 samples of dissolved gases in groundwaters (wells, springs and drainage galleries) and 64 samples of free gases (fumaroles, bubbling and soil gases) from the Mount Etna area were collected and analysed. Isotopic analyses were also carried out of both the carbon of the CO 2 in free gases and dissolved inorganic carbon (DIC) in the waters. The chemical composition of the gases depends on the relative abundances of three interacting components. These are gases of (1) atmospheric origin enriched in O 2 and N 2 , present almost exclusively in dissolved gases, (2) deep origin enriched in CO 2 , prevalent in the majority of cases, and (3) more superficial origi…
Fluid geochemistry of the San Vicente geothermal field (El Salvador)
1997
The volcano Chichontepeque (San Vicente) is one of the nine recent volcanoes making up the El Salvador sector of the WNW-ESE-trending active Central American volcanic belt. Thermal activity is at present reduced to a few thermal springs and fumaroles. The most important manifestations (Agua Agria and Los Infernillos Ciegos) are boiling springs and fumaroles located on the northern slope of the volcano (850 m a.s.l.) along two radial faults. The chloride acid waters of the Los Infernillos area are partly fed by a deep hydrothermal aquifer (crossed at 1100–1300 m by a geothermal exploration well), which finds a preferential path to the surface through the radial fault system. C02 is the most …