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Favara, Rocco
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Favara, Rocco
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rocco.favara@ingv.it
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- PublicationRestrictedGas hazard assessment at the Monticchio Mt. Vulture, a volcano in Southern Italy(2009)
; ; ; ; ; ;Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Nuccio, P. M.; Dipartimento Chimica e Fisica della Terra e Applicazioni, Universita` di Palermo, Via Archirafi 36, 90100, Palermo, Italy ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Nicolosi, M.; Dipartimento Chimica e Fisica della Terra e Applicazioni, Universita` di Palermo, Via Archirafi 36, 90100, Palermo, Italy ;Paternoster, M.; Dipartimento Scienze Geologiche, Universita` della Basilicata, Via dell’Ateneo 10, 85100, Potenza, Italy; ; ; ; Geochemical investigations have shown that there is a considerable inflow of gas into both crater lakes of Monticchio, Southern Italy. These lakes are located in two maars that formed 140 000 years ago during Mt. Vulture volcano s last eruptive activity. Isotopic analyses suggest that CO2 and helium are of magmatic origin; the latter displays 3He ⁄ 4He isotope ratios similar to those measured in olivines of the maar ejecta. In spite of the fact that the amount of dissolved gases in the water is less than that found in Lake Nyos (Cameroon), both the results obtained and the historical reports studied indicate that these crater lakes could be highly hazardous sites, even though they are located in a region currently considered inactive. This could be of special significance in very popular tourist areas such as the Monticchio lakes, which are visited by about 30 000 people throughout the summer, for the most part on Sundays.264 26 - PublicationOpen AccessA novel infrastructure for the continuous monitoring of soil CO2 emissions: a case study at the alto Tiberina near fault observatory in Italy(2023)
; ; ; ; ; ; ; ; ; ; ; Static and dynamic stress, along with earthquakes, can trigger the emission and migration of crustal fluids, as frequently observed on the surface and within the upper crust of tectonically active areas such as the northern Apennines of Italy. To investigate the origin of these fluids and their interconnection with the seismogenic process, we complemented The Alto Tiberina Near Fault Observatory (TABOO-NFO), a multidisciplinary monitoring infrastructure composed of a dense array of seismic, geodetic, strain, and radon sensors, with a proper geochemical network grounded on four soil CO2 flux monitoring stations and weather sensors, placed near the main vents of the superficial manifestations. The TABOO-NFO is a state-of-the-art monitoring infrastructure, which allows for studying various geophysical parameters connected to the deformation processes active along a crustal fault system dominated by the Alto Tiberina fault (ATF), which is a 60 km long normal fault dipping at a low angle (<15°–20°). The region is favourable for conducting geochemical studies, as it is characterised by the presence of over-pressurised fluids trapped at certain depths and superficial manifestations associated with the emission of large quantities of fluids. After describing the theoretical framework and the technological aspects based on which we developed the geochemical monitoring network, we described the data recorded in the first months. Over the studied period, the results showed that soil CO2 flux was primarily influenced by environmental parameters, and that the selected sites received a regular supply of deep-origin CO2.290 26 - PublicationRestrictedChemical characterisation of rainwater at Stromboli Island (Italy): The effect of post-depositional processes(2017-02-20)
; ; ; ;Cangemi, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Madonia, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; Volcanoes emit fluids and solid particles into the atmosphere that modify the chemical composition of natural precipitation. We have investigated the geochemistry of Stromboli's rainfall during the period from November 2014 to March 2016 using a network of a new type of sampler specifically designed for operations on volcanic islands.Wefound thatmost of the chemicalmodifications are due to processes occurring after the storage of rainwater in the sampling bottles. These processes include dissolution of volcanogenic soluble salts encrusting volcanic ash and a variable contribution of sea spray aerosol. Our data showed noticeably less scatter than has previously been achieved with a different sampling systemthat wasmore open to the atmosphere. This demonstrates the improved efficacy of the new sampler design. The data showed that post-depositional chemical alteration of rain samples dominates over processes occurring during droplet formation ad precipitation. This has important implications for the calculation of fluxes of chemicals from rainfall in volcanic regions.161 11 - PublicationRestrictedIsotopic, chemical and dissolved gas constraints on spring water from Popocatepetl volcano (Mexico): evidence of gas–water interaction between magmatic component and shallow fluids(2005)
; ; ; ; ; ;Inguaggiato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Martin-Del Pozzo, A.L.; Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico DF, 04510 Mexico ;Aguayo, A.; Instituto de Geofisica UNAM, Ciudad Universitaria, Mexico DF, 04510 Mexico ;Capasso, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; Geochemical research was carried out on cold and hot springs at Popocatepetl (Popo) volcano (Mexico) in 1999 to identify a possible relationship with magmatic activity. The chemical and isotopic composition of the fluids is compatible with strong gas–water interaction between deep and shallow fluids. In fact, the isotopic composition of He and dissolved carbon species is consistent with a magmatic origin. The presence of a geothermal system having a temperature of 80–1008 C was estimated on the basis of liquid geothermometers. A large amount of dissolved CO2 in the springs was also detected and associated with high CO2 degassing.366 94 - PublicationOpen AccessOn-field measurements of CO2 isotope composition of diffuse degassing from soils in volcanic areas: Delta-ray setup for direct measurements in the 0-100% vol. range.(2019-04-10)
; ; ; ; ; ; ; Volcanoes release carbon dioxide in the atmosphere and have been targeted as potential contributors to the global warming. Despite the evidences lay against these conjectures, the accurate estimation of the release of CO2 of volcanic origin in the atmosphere is currently unavailable because both not all the volcanoes of the world are satisfactorily monitored, and the estimations available for monitored volcanoes are often discordant. At the same time, the available estimate for the monitored volcanoes can be different according to the state of activity of the volcano.Multiple sources can be effective in the release of CO2 in volcanic zones as demonstrated by the isotopic fingerprinting of CO2. Better estimates of the amount of carbon dioxide released by different sources represent one means of improving the accuracy of the estimation of the CO2 budget in environmental systems and reducing the knowledge gaps related to the effects of the carbon cycle in the Earth-climate system. The coupled approach of carbon isotope and CO2 flux measurements allows the precise identification of different sources, and enables the evaluation of the mass contribution of each source to the carbon dioxide emissions. From a volcanological perspective, it is well known that the amount of CO2 released by soils before and during periods of unrest increases appreciably, similar to the amount of carbon dioxide released from the craters of the volcanoes. This study focuses on the application of a DeltaRayTM from Thermo Scientific, and reports the development of an innovative method for directly determining in the field the isotope composition of carbon dioxide discharged by soils at concentrations from atmospheric to 100 vol %. To settle the DeltaRayTM to the determination of the isotope composition of soil gases, a sampling method has been designed to analyse the isotope composition of the CO2 in a gas sample of unknown CO2 concentration, reduce the measurement operation time without loss of accuracy, and measure the isotope composition of the CO2 without changing the instrument configuration. The results of the first application on Vulcano (Aeolian Islands) are reported in order to evaluate the amount of hydrothermal CO2 discharged by soils. The amount of hydrothermal CO2 released by soils is not negligible because of the specific extent of the degassing surface. For the first time, the budget of the CO2 of hydrothermal origin discharged by soils on Vulcano was computed separately from the contribution of the biogenic source, and the data indicate a degassing area that is wider than that previously reported in the literature. Furthermore, the synchronous and extensive investigation of both the spatial distribution of the carbon isotope composition of CO2 and the CO2 flux provides a better assessment of the amount of CO2 of deep origin. Monitoring of this type of CO2 represents a step forward in the evaluation of the volcanic hazard.35 6 - PublicationRestrictedEvoluzione tettonica mesozoico-terziaria della Sicilia centrosettentrionale(2009)
; ; ; ; ;Nigro, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Salvaggio, G.; Dipartimento di Geologia e Geodesia, Università di Palermo, Italy - Via Archirafi, 22, 90123, Palermo ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Renda, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; Sicily owes its complex geological structure to a switch in tectonic regime from the Mesozoic to the Tertiary. A set of tectonic units outcrops in the northern portion of the island that originated during the Tertiary at the expense of paleogeographic domains of the African Mesozoic continental margin. The pre-orogenic successions show different types of deformation (extensional and transcurrent) related to the Jurassic paleotectonic evolution of the southern Neotethys margin. The history of the tectonic inversion of the Neotethys shear zone is recorded in the Cretaceous strata. Extension occurred during late Cretaceous and may be compatible with the tensile stress field related to the Sicilide basin opening. The Neogene deformations are linked to collisional processes and are mostly represented by thrusts and folds. Since the late Miocene onwards, the formation of the Tyrrhenian basin has driven the recent tectonic evolution of Northern Sicily. Its basin formation was realised through extension, followed by transcurrent tectonics along its southern margin.314 52 - PublicationRestrictedHydrothermal processes governing the geochemistry of the crater fumaroles at Mount Etna volcano (Italy)(2010-11-02)
; ; ; ; ; ; ;Liotta, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Paonita, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Martelli, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Rizzo, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; ; ; We investigated the geochemistry of the fumaroles at the summit area of Mt. Etna, including sulfur speciation and the content of acidic gases. The carbon-isotope composition of the Etnean plume was also measured in order to compare it to that of fumaroles. Two types of fumaroles were identified: (i) low-temperature fumaroles, which are dominated by CO2 with minor amounts of SO2 and H2S, and negligible chlorine contents, and (ii) high-temperature fumaroles, which are strongly air-contaminated and characterized by appreciable amounts of volcanogenic carbon, sulfur, and chlorine. As recognized by Martelli et al. (2008), both groups of fumaroles are fed by the degassing of an underlying magma; nevertheless, compositional data clearly show that secondary processes affect the composition of the fluids once they leave the magma body. Here a model of cooling and condensation of fluids is proposed to explore such postmagmatic processes. The model, which uses Etnean plume geochemistry as starting composition of fluids exsolved from magma, shows that SO2 and H2S control the redox conditions of the gas mixture during the cooling, until the reactions involving CO/CO2 and H2/H2O ratios are fully quenched at temperatures around 350–450 °C. The dissolution of gases in water, subsequent to condensation, must occur at thermobaric conditions over 50 bar and 260 °C, which allows (a) total removal of HCl, (b) partial removal of sulfur species while preserving the SO2/H2S ratio, and (c) the C/S ratio to increase by almost 10-fold relative to that in the plume. The observed CH4/CO2 ratios are higher than those calculated for the Etnean magmatic gas, and hence they provide evidence of modest contributions from peripheral hydrothermal fluids during the migration of magmatic gases toward the surface in both low- and high-temperature fumaroles. Due to the peculiar thermodynamic conditions, the model predicts that carbon isotopes do not experience any postmagmatic fractionation, and hence the isotopic composition of the fumaroles is representative of magmatic carbon. Measurements of the carbon-isotope composition of the plume corroborate these findings.247 39 - PublicationRestrictedGeochemical characterization of groundwaters from the Hyblean aquifers, South-Eastern Sicily.(2001-07-10)
; ; ; ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Grassa, F.; Dipartimento CFTA Università di Palermo, 90123 Palermo-Italia ;Valenza, M.; Dipartimento CFTA Università di Palermo, 90123 Palermo-Italia; ; Groundwaters hosted within unconfined aquifers were collected from sixty-five cold and slightly thermal springs and wells. The studied aquifers are mainly constituted of a thick sequence of carbonates, Meso-Cenozoic in age. Basic volcanic intercalations, occurring during several episodes, are also present. Except for the samples located near the coast where seawater contribution plays an important role, the chemical composition of studied groundwaters is controlled by water-rock interaction. The proposed geochemical mass balance model suggests that Ca+Mg/HCO3 groundwaters evolve toward a Na-HCO3 type due to interaction with volcanic rocks, thus forming secondary minerals. pCO2 values up to 0.1 atm suggest a contribution of a CO2-gas source. The 13CTDIC values range between –15 to -8 ‰ vs PDB, indicating mixed organic-inorganic carbon sources.180 72 - PublicationRestrictedMoisture source in the Hyblean Mountains region (south-eastern Sicily, Italy): evidence from stable isotopes signature(2006)
; ; ; ;Grassa, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Valenza, M.; Dipartimento CFTA, Universita` di Palermo, Palermo; ; Here the authors present results of an isotope study on precipitation collected during a 2-a period from a rain-gauge network consisting of 6 stations located at different elevations in the Hyblean Mountains (HM) region, in south-eastern Sicily. The slope of the local meteoric water line (dD = 6.50 d18O + 9.87) obtained for the region suggests that precipitation is affected by evaporation during rainfall events. The main variations in rainwater isotope composition are due to seasonal effects and elevation. An average 2H excess value of +21.2&was found for precipitation events less affected by evaporation (i.e. when the rainfall was >65 mm/month). The spatial distribution of O isotope composition of precipitation shows a negative gradient from east and south to the inner areas. The depositional rate of Cl, used as a tracer of the origin of air masses, is highest at the coastal rain-gauges (SR and MRG stations) and lowest on the northern flank of the HM region (SC station). Based on these findings, a model is proposed for the origin of precipitation in the HM region, which assumes that a Mediterranean-derived component is the main source of moisture in the studied area. D/H and 18O/16O ratios of inferred meteoric recharge waters were also compared with the isotope composition of waters collected from the main local springs and wells. The best linear fit of the d18O vs dD relationship for Hyblean groundwater is dD = 4.85 d18O–2.01. The enrichment of heavy isotopes in Hyblean groundwater is probably due to evaporation occurring after precipitation events or to a recharging contribution from surface waters (lakes or rivers) enriched in heavy isotopes.142 20 - PublicationOpen AccessCO2 Degassing in Sicily (Central Mediterranean) as Inferred from Groundwater Composition(2020-07-10)
; ; ; ; ; ; ; The circulation of groundwater is influenced by several factors, including permeability changes due to the dynamics of the stress field acting along tectonic discontinuities. Open faults can act as preferential pathways for the escape of crustal and subcrustal gases, such as CO2, towards the surface, allowing their chemical interaction with meteoric fluids. Here, we present the first map of dissolved CO2 partial pressure in the groundwater of Sicily, Italy. Based on the chemical analysis of 557 samples of groundwater, which were collected in wells and springs, we calculated the related CO2 partial pressure (PCO2) using PHREEQC software. The spatial distribution of the calculated PCO2 values highlights a general homogeneity at the regional scale, interrupted by positive anomalies linked to the main seismogenic or volcanic areas. Faults work as preferential escape pathways for deep CO2. The subsequent CO2–water–rock interaction determines the chemical composition of circulating water. As a consequence, groundwater composition can be successfully used to identify anomalous degassing areas.152 43