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Di Martino, Roberto Maria Rosario
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Di Martino, Roberto Maria Rosario
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Di Martino Roberto M. R.
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Di Martino, Roberto M. R.
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roberto.dimartino@ingv.it
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robertomr.dimartino@gmail.com
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Roberto M.R. Di Martino
23 results
Now showing 1 - 10 of 23
- PublicationOpen AccessContinuous monitoring of hydrogen and carbon dioxide at Stromboli volcano(2015-04)
; ; ; ;Valenza, M. ;Di Martino, R. M. R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Camarda, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Gurrieri, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Valenza, M.; Dipartimento DiSTeM, Università di Palermo, Palermo, Italy; ; ; Dipartimento DiSTeM, Università di Palermo, Palermo, ItalyGeochemical monitoring of fumarole and soil gases is a powerful tool for volcano surveillance, for investigating the subsurface magma dynamics, and for hazard assessment in volcanic areas. The monitoring of both carbon dioxide (CO2) flux, and hydrogen (H2) concentration in active volcanic areas helps to improve the understanding of the processes linking the surface gas emissions, the chemistry of the magmatic gases, and the volcanic activity. The CO2 flux measurement is a routine technique for volcano monitoring purposes, because of CO2 is the secondabundant component of the gas phase in silicate magmas, attaining saturation at the mantle to deep crustal level. The H2 concentration has provided indications concerning the oxygen fugacity of magmatic gases, a parameter that changes over a wide range of low values (1016 – 108 bar), and affects the redox state of multivalent elements. This study reports on the use a tailor-made automatic system developed for continuous monitoring purposes of H2 concentration and CO2 flux in the summit area of Stromboli volcano (Aeolian islands). The automatic device consists of an H2-selective electrochemical sensor, and two IR-spectrophotometers for measuring the CO2 flux in agreement with the dynamic concentration method. The data collected by the automatic system deployed at Stromboli from 19 May 2009 to 15 December 2010 are presented herein. The data processing provides a better understanding of the relationships between the evolution of the low temperature fumarolic emissions, and the volcanic activity. The results of the data analysis indicates that the high frequency variations exhibited by CO2 flux and H2 concentration are positively correlated with the eruptive activity of Stromboli, typically changing on time scale of hours or days. Furthermore, the investigation of the relationships between CO2 flux and H2 concentration provides an evaluation of the depth of the degassing source, by which the gas mixture containing H2 and CO2 starts to move through the rock fractures. Our data indicates that the depth of the degassing source ranges between 2 and 4 km in the volcano plumbing system, in agreement with the magma storage zone that has been proposed by other geochemical, volcanological, petrological and geophysical investigations120 88 - 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 - PublicationRestrictedTemporal and spatial correlations between soil CO2 flux and crustal stress(2016-10)
; ; ; ; ;Camarda, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;De Gregorio, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Di Martino, R. M. R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; ; ; In seismically active areas, tectonic stress deforms and breaks the rocks of the crust. Ongoing deformation produces detectable modifications in the shallower portions of the crust, resulting in a wide variety of changes in several parameters. In this paper, we report the results of a large-scale spatial (across an area of 15,000 km2) and temporal (up to 3 years) investigation of the relationship between active crustal stress and soil CO2 flux. We deployed a network of 10 automatic stations in most of the seismically active districts of southern Italy to monitor the soil CO2 fluxes, and we used seismicity data to track crustal stress. The results of the investigation show that the CO2 flux signals varied independently in the districts with low and sporadic seismicity. Conversely, in the only district with nearly continuous seismic activity, almost all of the CO2 flux signals were well correlated with each other, and we recorded a clear synchronous sharp increase of the seismicity and signals recorded by several stations. The high spatial and temporal correlation between seismicity and gas discharge evidenced in this study prove that the crustal stress associated with the seismogenic process is able to effectively modulate the gas release in a seismically active area.860 29 - PublicationEmbargoTheoretical principles and application to measure the flux of carbon dioxide in the air of urban zonesAtmospheric carbon dioxide (CO2) concentrations increase due to volcanic emissions, diffuse degassing from fault zones, and various human-caused gas emissions, especially in densely populated urban zones, which play a pivotal role in the ongoing climate change. This study aims to examine changes in the concentration and stable isotopic composition of atmospheric CO2. A laser-based analyzer provided the δ13C and δ18O values based on concentration measurements for various CO2 isotopologues. Multiple linear regression (MLR) showed that almost 30% of the atmospheric CO2 changes are caused by weather variations, while ~70% of the changes involve CO2 from various gas sources related to human activities. The Keeling plot approach was used to identify the isotopic signature of the extra CO2, which points to the gas produced by hydrocarbon combustion. An isotopic mass balance model was designed to show the relation between excess atmospheric CO2 and the flux of human-related gas emissions. Calculating the CO2 flux in the atmosphere based on this isotopic mass balance model showed that several tons of CO2 move daily between geospheres. This study shows that surveying atmospheric CO2 in urban zones allows quantifying the CO2 emissions from various sources.
369 2 - PublicationRestrictedDeep CO2 release revealed by stable isotope and diffuse degassing surveys at Vulcano (Aeolian Islands) in 2015–2018(2020)
; ; ; ; ; ; ; ; ; The partitioning of carbon dioxide (CO2) released by soils at Vulcano Island (Aeolian Islands, Italy) was performed by combining the CO2 flux and the carbon isotope measurements. Based on this method, the amount of CO2 of volcanic origin was quantified six times during the period 2015–2018. The data analysis allowed us to establish the correlation between CO2 soil degassing and changes in the contribution of volcanic fluids. Carbon isotope determinations were performed in situ to enhance the coverage of data collection in space and time. These data were combined with both the CO2 contents in the ground gases and the soil CO2 flux. The amount of volcanic CO2 was distinguished from that of biogenic origin by implementing a three-component mixing model. The results of this study indicate that the increase in CO2 output in September 2018 reflects the increase in volcanic gas emissions. The measurement method and analysis presented in this work are sufficiently general to be applicable to the monitoring programs of active volcanoes.909 8 - PublicationOpen AccessA multi-instrumental geochemical approach to assess the environmental impact of CO2-rich gas emissions in a densely populated area: the case of Cava dei Selci (Latium, Italy)(2019)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;; ; ; ; ;; ; The Colli Albani volcanic complex (Lazio, Italy) hosts areas characterized by anomalously high emissions of CO2-rich gases (e.g. Tivoli, Cava dei Selci, Tor Caldara, Solforata). The source of these gases is a regional aquifer within the Mesozoic carbonate rock sequences. These degassing zones release significant concentrations of H2S and other toxic gases (e.g. GEM: Gaseous Elemental Mercury, and Rn) and represent a serious hazard for local inhabitants, especially for those living at Cava dei Selci (near Rome, Italy), where the emitting areas are nested inside residential neighborhoods. In April 2016, a comprehensive geochemical survey was carried out in an abandoned stone quarry nearby the urban settlement aimed to: (i) investigate the gas composition from both punctual discharges and anomalously high diffuse soil degassing sites, and (ii) evaluate their environmental impact on the local air quality. The spatial distribution of the soil CO2 fluxes was mainly dependent on the local geostructural setting, whereas shallow secondary processes (e.g. oxidation and gas-water interaction) likely represent the main controlling factor on reactive and/or water-soluble gas species, such as CH4 and H2S. The total output of CO2 from the abandoned stone quarry accounted for 0.53% of total CO2 discharged from the whole Colli Albani volcanic district. The naturally emitted toxic gases (e.g. CO2, H2S, CH4, GEM) largely affect the air quality and pose a serious threat for the health of the local residents. A mobile multi-instrumental station able to continuously and simultaneously acquire CO2, H2S, SO2, CH4, GEM and CO was deployed to verify the concentrations of both the main deep-originated gas compounds and potential secondary gaseous contaminants (i.e. SO2) around and inside the urban settlement most exposed to the lethal gases. Hydrogen sulfide was found to be the most impacting gas, occasionally exceeding the 24-h air quality guideline for ambient air and causing odor annoyance at a distance up to more than 250 m downwind from the emitting area. In poorly ventilated basements, toxic gas accumulations up to hazardous levels were measured, producing anomalous outdoor air concentrations at the street level in front of the descending vehicular access to private garages and relatively far from the main emitting area. The geochemical survey, carried out via mobile station and soil gas measurements, resulted to be particularly efficient for evaluating the potential effects caused by gas emissions in inhabited areas. The multi-measurement approach adopted in the present study is of paramount importance for managing future urban development plans.1081 104 - PublicationOpen AccessContinuous monitoring of hydrogen and carbon dioxide at Stromboli volcano (Aeolian Islands, Italy)(2021)
; ; ; ; ; The geochemistry of volcanic gases has been fruitfully applied to identify important changes in the volcanic activity. This study reviews the dataset of the volcanic gas survey performed during 2009 and 2010 at Stromboli (Aeolian Islands – Italy). Dry gas collection occurred discontinuously at the crater fumaroles for subsequent chemical and isotopic (δ13C-CO2) analyses in the laboratory. A tailor-made device enabled continuous survey of H2 molar fraction and CO2 flux on the same site. Evaluation of the raw data was performed in accordance with air temperature, atmospheric pressure, wind speed and wind direction dataset. Both MLR (Multiple Linear Regression) and FFT (Fast Fourier Transform) analyses allowed filtering the dataset from the environmental effects. The MLR analysis indicated that wind speed and air temperature affected the CO2 flux. Changes in the atmospheric pressure promoted pumping effect of the fumarole gas and caused changes in the H2 molar fraction. The power spectral analysis revealed daily cycles in both gases. A digital signal filtering procedure enabled minimizing the environmental effects. This study confirmed that gas emissions from the crater fumaroles have both chemical ad isotopic composition similar to the magmatic gas phase. The results of the continuous survey showed that changes of both H2 and CO2 correlated with changes of the volcanic activity. Therefore, H2 and CO2 resulted effective tracers of the dynamics involving the plumbing system of Stromboli. Identification of changes in the gas emissions at open conduit volcanoes offers a great advance over the ground gas survey. The results of the continuous survey at Stromboli showed that H2 could apply as an auxiliary parameter of the CO2 flux in the surveillance programs of active volcanoes.791 272 - PublicationOpen AccessQuantification of the Volcanic Carbon Dioxide in the Air of Vulcano Porto by Stable Isotope SurveysInjecting volcanic gas into the air leads to an increase in carbon dioxide (CO2) levels compared with background concentrations and may establish gas hazard conditions. This study reports the results of five stable isotope (i.e., δ13C-CO2 and δ18O-CO2) surveys of airborne CO2 on Vulcano from August 2020 to November 2021. To measure CO2 in the air, a mobile laboratory was equipped with a laser-based spectrophotometer that can selectively detect different CO2 isotopologues. Volcanic CO2 has a different isotopic signature than atmospheric CO2 and both δ13C-CO2 and δ18O-CO2 can help trace the injections of volcanic gases into the air. An isotopic mass balance model was developed for partitions CO2 between atmospheric background and volcanic CO2. The results of these studies show that volcanic CO2 emissions and atmospheric circulation deeply affected the concentration of CO2 in the air at Vulcano Porto. Studies of δ13C-CO2 and δ18O-CO2 provide an estimate of volcanic CO2 in the air. These results help identify spatially some points of interest for mitigating volcanic gas emission-related hazards on Vulcano.
245 19 - PublicationOpen AccessHeavy Metal Concentrations in the Groundwater of the Barcellona-Milazzo Plain (Italy): Contributions from Geogenic and Anthropogenic Sources(2019)
; ; ; ; ; ; ; ; ;; ; ; ; ; ;We collected and analysed 58 samples of groundwater from wells in the Barcellona-Milazzo Plain, one of the most important coastal aquifers of Sicily (Italy), to determine major, minor, and trace element concentrations. In this area, geogenic and anthropogenic sources of heavy metals and other pollutants co-act, making the individuation of the main pollution sources difficult. Our work was aimed at the application of geostatistical criteria for discriminating between these pollution sources. We used probability plots for separating anomalous values from background concentrations, which were plotted on maps and related to possible sources of pollutants. Our results indicate that hydrothermal fluid circulation and the water–rock interaction of country rocks that host mineralized ore deposits generate a significant flux of heavy metals to groundwater, as well as anthropogenic sources like intense agriculture and industrial activities. In particular, NO3, F, and Ni exceed the Maximum Admitted Concentrations (MACs) established by the WHO and Italian legislation for drinking-water. The spatial distributions of geogenic and anthropogenic sources were so deeply interlocked that their separation was not easy, also employing geostatistical tools. This complex scenario makes the implementation of human health risk mitigation actions difficult, since the flow of pollutants is in many cases controlled by simple water–rock interaction processes.601 84 - PublicationOpen AccessAsynchronous changes of CO2, H2 and He concentrations in soil gases: a theoretical model and experimental results(2016)
; ; ; ; ;Di Martino, R. M. R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Camarda, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Gurrieri, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Valenza, M.; Università Degli Studi di Palermo; ; ; This paper focuses on the chemical composition changes in soil gases through both a theoretical model and laboratory experiments. The model describes the one-dimensional mass transfer process, which is triggered by changes in the flux parameters of the system, and the time-dependent evolution of the composition of the soil gases as a function of i) the pristine gas mixture, ii) the diffusivity of the chemicals, and iii) the thickness of the transited medium. Carbon dioxide (CO2), hydrogen (H2), and helium (He) were used in a laboratory-scale flux simulator to investigate the evolution of the gas composition profile in an artificial soil of constant thickness. The agreement between the theoretical calculations and the experimental results supports the validity of the model. Our results indicate a good reproducibility of the transient changes in the concentrations of CO2, He, and H2 in CO2-rich gas mixtures that contain He and H2 as trace gases. Finally, the theoretical results were used to analyze the H2 and CO2 continuous monitoring data collected at Etna volcano in 2010796 137
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