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Donnini, Marco
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- PublicationOpen AccessLong term variations at Campi Flegrei (Italy) volcanic system highlighted by the monitoring of hydrothermal activity(2009-04-19)
; ; ; ; ; ; ; ; ;Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Caliro, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Cardellini, C.; Dipartimento scienze della Terra Università di Perugia, Italy ;Granieri, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia ;Avino, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Baldini, A.; Dipartimento scienze della Terra Università di Perugia, Italy ;Donnini, M.; Dipartimento scienze della Terra Università di Perugia, Italy ;Minopoli, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; ; ; Long time-series of chemical composition of fumaroles and of soil CO2 flux reveal that important variations in the activity of Solfatara fumarolic field, the most important hydrothermal site of Campi Flegrei, occurred in the 2000- 2008 period. A continuous increase of the CO2 concentration and a general decrease of the CH4 concentration are interpreted as the consequence of the increment of the relative amount of magmatic fluids, rich in CO2 and poor in CH4, hosted by the hydrothermal system. Contemporaneously the H2O-CO2-He-N2 gas system shows remarkable compositional variations in the samples collected after July 2000 with respect to the previous ones, indicating the progressive arrival at the surface of a magmatic component different from that involved in the 1983-84 bradyseism. The change starts in 2000 concurrently with the occurrence of relatively deep long periods seismic events which, in our interpretation, were the indicator of the opening of an easy pathway for the transfer of magmatic fluids towards the shallower, brittle domain hosting the hydrothermal system. Since 2000 this magmatic gas source is active and causes ground deformations, seismicity as well as the expansion of the area interested by diffuse soil degassing of deeply derived CO2.151 78 - PublicationRestrictedLong term variations of the Campi Flegrei (Italy) volcanic system as revealed by the monitoring of hydrothermal activity(2010)
; ; ; ; ; ; ; ; ;Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Caliro, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Cardellini, C.; Dipartimento di Scienze della Terra, Università di Perugia, Perugia,Italy ;Granieri, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia ;Avino, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Baldini, A.; Dipartimento di Scienze della Terra, Università di Perugia, Perugia,Italy ;Donnini, M.; Dipartimento di Scienze della Terra, Università di Perugia, Perugia,Italy ;Minopoli, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; ; ; Long duration time-series of the chemical composition of fumaroles and of soil CO2 flux reveal that important variations in the activity of the Solfatara fumarolic field, the most important hydrothermal site of Campi Flegrei, occurred in the 2000-2008 period. A continuous increase of the CO2 concentrations, and a general decrease of the CH4 concentrations are interpreted as the consequence of the increment of the relative amount of magmatic fluids, rich in CO2 and poor in CH4, hosted by the hydrothermal system. Contemporaneously, the H2O-CO2-He-N2 gas system shows remarkable compositional variations in the samples collected after July 2000 with respect to the previous ones, indicating the progressive arrival at the surface of a magmatic component different from that involved in the 1983-84 episode of volcanic unrest (1983-1984 bradyseism). The change starts in 2000 concurrently with the occurrence of relatively deep, long-period seismic events which were the indicator of the opening of an easy-ascent pathway for the transfer of magmatic fluids towards the shallower, brittle domain hosting the hydrothermal system. Since 2000, this magmatic gas source is active and causes ground deformations, seismicity as well as the expansion of the area affected by soil degassing of deeply derived CO2. Even though the activity will most probably be limited to the expulsion of large amounts of gases and thermal energy, as observed in other volcanoes and in the past activity of Campi Flegrei, the behavior of the system in the future is, at the moment, unpredictable.242 29 - PublicationOpen AccessLevel of carbon dioxide diffuse degassing from the ground of Vesuvio: comparison between extensive surveys and inferences on the gas source(2013)
; ; ; ; ; ; ; ; ; ; ; ;Granieri, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia ;Carapezza, M. L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Avino, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Caliro, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Cardellini, C.; Università di Perugia, Dipartimento di Scienze della Terra, Perugia, Italy ;Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Donnini, M.; Università di Perugia, Dipartimento di Scienze della Terra, Perugia, Italy ;Minopoli, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Ranaldi, M.; Università di Roma Tre, Dipartimento di Scienze, Rome, Italy ;Ricci, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia ;Tarchini, L.; Università di Roma Tre, Dipartimento di Scienze, Rome, Italy; ; ; ; ; ; ; ; ; ; An extensive campaign of diffuse CO2 soil flux was carried out at the cone of Vesuvio in October 2006 with two main objectives: 1) to provide an estimation of CO2 diffusely discharged through the soils in the summit area and 2) to evidence those sectors of the volcano where structural and morphological conditions could favour the gas output. The survey consisted of 502 measurements of soil CO2 flux homogenously distributed over an area of about 1.8 km2. Results of this survey were compared with those obtained during a similar campaign carried out by Frondini et al. in 2000, from which we have taken and reinterpreted a subset of data belonging to the common investigated area. Graphical statistical analysis showed three overlapping populations in both surveys, evidencing the contribution of three different sources feeding the soil CO2 degassing process. The overall CO2 emission pattern of 2006 is coherent with that observed in 2000 and suggests that a value between 120 and 140 t/day of CO2 is representative of the total CO2 discharged by diffuse degassing from the summit area of Vesuvio. The preferential exhaling area lies in the inner crater, whose contribution resulted in 45.3% of the total CO2 emission in 2006 (with 62.8 t/day) and in 57.4% (with 70.3 t/day) in 2000, although its extension is only 13% of the investigated area. This highly emissive area correlated closely with the structural discontinuities of Vesuvio cone, mainly suggesting that the NW-SE trending tectonic line is actually an active fault leaking deep gas to the bottom of the crater. The drainage action of the fault could be enhanced by the “aspiration” effect of the volcanic conduit.605 393 - PublicationOpen AccessThe hydrothermal system of Bagni San Filippo (Italy): fluids circulation and CO2 degassing(2020)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Bagni San Filippo area is characterized by the discharge of thermal waters and deeply produced CO2-rich gases both from vents and soil diffuse degassing. The thermal waters are the results of the mixing between meteoric waters and hot fluids deriving from the condensation, at depth, of vapours uprising from a deep hydrothermal reservoir. This process gives rise to a relatively shallow thermal system at temperature close to 50°C, characterized by SO4-rich and Cl-poor waters and elevated PCO2 (~7 bar). Most of the incondensable gas of deep originated vapour is released as a free gas phase forming cold gas vents and localized spots of anomalous CO2 diffuse degassing. The location and the shape of these degassing zones are strongly controlled by the main tectonic structures of the area. Through detailed soil diffuse degassing surveys and hydrogeochemical modelling, we estimate at 226-326 t d-1 and at 965 t d-1 the deep CO2 emission and the amount of condensates discharged by the thermal springs, respectively. The thermal energy associated to the process results at ~ 29 MW, most of which (~ 25 MW) is associated with condensation occurring at depths greater than groundwater circulation.393 12 - PublicationOpen AccessAn Endorheic Lake in a Changing Climate: Geochemical Investigations at Lake Trasimeno (Italy)(2019-06-26)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Lake Trasimeno is a shallow, endorheic lake located in central Italy. It is the fourth Italian largest lake and is one of the largest endorheic basins in western Europe. Because of its shallow depth and the absence of natural outflows, the lake, in historical times, alternated from periods of floods to strong decreases of the water level during periods of prolonged drought. Lake water is characterised by a NaCl composition and relatively high salinity. The geochemical and isotopic monitoring of lake water from 2006 to 2018 shows the presence of well-defined seasonal trends, strictly correlated to precipitation regime and evaporation. These trends are clearly highlighted by the isotopic composition of lake water (δ18O and δD) and by the variations of dissolved mobile species. In the long term, a progressive warming of lake water and a strong increase of total dissolved inorganic solids have been observed, indicating Lake Trasimeno as a paradigmatic example of how climate change can cause large variations of water quality and quantity. Furthermore, the rate of variation of lake water temperature is very close to the rate of variation of land-surface air temperature, LSAT, suggesting that shallow endorheic lakes can be used as a proxy for global warming measurements.215 55 - PublicationRestrictedDiffuse soil emission of hydrothermal gases (CO2, CH4, and C6H6) at Solfatara crater (Campi Flegrei, southern Italy)(2013)
; ; ; ; ; ; ; ; ;Tassi, F.; Department of Earth Sciences, University of Florence, Via La Pira 4, 50121 Florence, Italy ;Nisi, B.; CNR-IGG Institute of Geosciences and Earth Resources, Via G. Moruzzi 1, 56124 Pisa, Italy ;Cardellini, C.; Department of Earth Sciences, University of Perugia, P.zza dell’Università, 06100 Perugia, Italy ;Capecchiacci, F.; CNR-IGG Institute of Geosciences and Earth Resources, Via La Pira 4, 50121 Florence, Italy ;Donnini, M.; Department of Earth Sciences, University of Perugia, P.zza dell’Università, 06100 Perugia, Italy ;Vaselli, O.; Department of Earth Sciences, University of Florence, Via La Pira 4, 50121 Florence, Italy ;Avino, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; ; ; ; ; ; ; Measurements of soil fluxes of hydrothermal gases, with special emphasis on C6H6, as well as chemical composition of mono-aromatic compounds in fumaroles and air, were carried out in April 2012 at the Solfatara crater (Campi Flegrei, Southern Italy) to investigate the distribution and behavior of these species as they migrate through the soil from their deep source to the atmosphere. Soil fluxes of CO2, CH4 and C6H6 exhibit good spatial correlation, suggesting that diffuse degassing is mainly controlled by local fractures. The calculated total output of diffuse C6H6 from Solfatara is 0.10 kg day 1, whereas fluxes of CO2 and CH4 are 79 103 and 1.04 kg day 1, respectively. A comparison between soil gas fluxes and fumarole composition reveals that within the crater soil CH4 is significantly affected by oxidation processes, which are more efficient for low gas fluxes, being dependent on the residence time of the uprising hydrothermal gases at shallow depth. Benzene degradation, mainly proceeding through oxidation via benzoate, seems to be strongly controlled by the presence of a shallow SO2 4 -rich aquifer located in the central and southwestern sectors of the crater, suggesting that the process is particularly efficient when SO2 4 acts as terminal electron acceptor (SO4 reduction). Relatively high C6H6/C7H8 ratios, typical of hydrothermal fluids, were measured in air close to the main fumarolic field of Solfatara crater. Here, C6H6 concentrations, whose detection limit is 0.1 lgm 3, are more than one order of magnitude higher than the limit value for ambient air (5 lgm 3). This suggests that hydrothermal fluids have a strong impact on air quality in the immediate surroundings of the fumarolic vents. Significant concentrations of endogenous mono-aromatics were also detected in air samples collected from the northern and western sides of the crater, where these gas compounds are mostly fed by diffuse degassing through the crater bottom soil.372 26