First volatile inventory for Gorely volcano, Kamchatka

We report here the very first assessment of volatile flux emissions from Gorely, an actively degassing volcano in Kamchatka. Using a variety of in situ and remote sensing techniques, we determined the bulk plume concentrations of major volatiles (H2O 93.5%, CO2, 2.6%, SO2 2.2%, HCl 1.1%, HF 0.3%, H2 0.2%) and trace-halogens (Br, I), therefore estimating a total gas release of 11,000 tons·day−1 during September 2011, at which time the target was non-eruptively degassing at 900°C. Gorely is a typical arc emitter, contributing 0.3% and 1.6% of the total global fluxes from arc volcanism for CO2 and HCl, respectively. We show that Gorely's volcanic gas (H2O/SO2 43, CO2/SO2 1.2, HCl/SO2 0.5) is a…

Ludovico Sicardi, an unknown pioneer of the Volcanic Geochemical Monitoring

On December of 1977, almost 100 years since its last eruption, intense volcanic activity took place in Vulcano Island (Sicily). The elevated fluxes and the temperature increase of the fumaroles in La Fossa Crater, as well as the variations in their chemical composition, alarmed the scientific community. During that period, in the city of Palermo, Marcello Carapezza along with his colleagues Mariano Valenza and Mario Nuccio, were studying the fumarolic field of Vulcano. After extended bibliographic research, Valenza discovered the studies of Ludovico Sicardi, which were focused on Vulcano, Stromboli, Vesuvio and Campi Flegrei. Considering the fact that Sicardi’s research was performed 60 yea…

Real-Time Measurements of Hg0 and H2S at Solfatara Crater (Campi Flegrei, Southern Italy): an Innovative Approach to Investigate the Distribution of Gaseous Contaminants in Air.

Catalogue of the main gas manifestation of Greece: Geochemical characterisation and preliminary gas hazard assessment

Quantification of gaseous emissions in geological systems is an important branch because it is a major source of greenhouse gas to the atmospheric budget. Of geological environments, there are two different categories: the first category includes emissions of the predominant carbon dioxide (CO 2), while the second includes emissions of the predominant methane (CH4). The Hellenic territory has a very complex geodynamic setting deriving from a long and complicated geological history. It is strongly characterized by intense seismic activity and enhanced geothermal gradient. This activity, with the contribution of an active volcanic arc, favours the existence of many cold and thermal gas manife…

Mercury concentration, speciation and budget in volcanic aquifers: Italy and Guadeloupe (Lesser Antilles)

Abstract Quantifying the contribution of volcanism to global mercury (Hg) emissions is important to understand the pathways and the mechanisms of Hg cycling through the Earth's geochemical reservoirs and to assess its environmental impacts. While previous studies have suggested that degassing volcanoes might contribute importantly to the atmospheric budget of mercury, little is known about the amount and behaviour of Hg in volcanic aquifers. Here we report on detailed investigations of both the content and the speciation of mercury in aquifers of active volcanoes in Italy and Guadeloupe Island (Lesser Antilles). In the studied groundwaters, total Hg (THg) concentrations range from 10 to 500…

The fluids’ geochemistry along the "Sperchios Basin - Northern Evoikos Gulf" Graben, a geodynamically complex area of Central Greece

Sampling and analysis methodology of atmospheric deposition: a study case form Mount Etna

Understanding volcanoes in the Vanuatu arc

We report the first helium isotope survey of volcanic gases, hot springs and some olivine phenocrysts along the Vanuatu island arc, from Tanna in the south to Vanua Lava in the north. Low CO2 content and low He-3/He-4 ratios in thermal fluids of Epi (4.0 +/- 0.1 R-a), Efate (4.5 +/- 0.1 R-a) and Pentecost (5.3 +/- 0.5 R-a) islands coherently indicate reduced mantle gas leakage and crustal contamination by radiogenic helium on these extinct volcanic systems of the former (Pliocene) arc. Instead, presently active Vanuatu volcanoes display He-3/He-4 and C/He-3 ratios typical of subduction-related volcanic arcs: He-3/He-4 ratios range from 6.4 +/- 0.5 Ra in southernmost Tanna and 7.23 +/- 0.09 …

Development of an active alkaline trap to determine acidic gas ratios in volcanic plumes: sampling technique and analytical methods

Colloidal stability of nanoparticles derived from simulated cloud-processed mineral dusts

AbstractLaboratory simulation of cloud processing of three model dust types with distinct Fe-content (Moroccan dust, Libyan dust and Etna ash) and reference goethite and ferrihydrite were conducted in order to gain a better understanding of natural nanomaterial inputs and their environmental fate and bioavailability. The resulting nanoparticles (NPs) were characterised for Fe dissolution kinetics, aggregation/size distribution, micromorphology and colloidal stability of particle suspensions using a multi-method approach. We demonstrated that the: (i) acid-leachable Fe concentration was highest in volcanic ash (1mMg−1 dust) and was followed by Libyan and Moroccan dust with an order of magnit…

Mercury gas emissions from La Soufrière Volcano, Guadeloupe Island (Lesser Antilles)

Abstract Quantifying mercury (Hg) emissions from active volcanoes is of particular interest for better constraining the global cycle and environmental impact of this highly toxic element. Here we report on the abundance of total gaseous (TGM = Hg 0 (g)  + Hg II (g) ) and particulate (Hg (p) ) mercury in the summit gas emissions of La Soufriere andesitic volcano (Guadeloupe island, Lesser Antilles), where enhanced degassing of mixed hydrothermal-magmatic volatiles has been occurring since 1992 from the Southern summit crater. We demonstrate that Hg in volcanic plume occurs predominantly as gaseous mercury, with a mean TGM/Hg (p) mass ratio of ~ 63. Combining the mean TGM/H 2 S mass ratio of …

Real-time measurements of Hg0 and H2S at La Solfatara Crater (Campi Flegrei, Southern Italy) and Mt. Amiata volcano (Siena, Central Italy): a new geochemical approach to estimate the distribution of air contaminants

Volcanic Lakes in Africa: The VOLADA_Africa 2.0 Database, and Implications for Volcanic Hazard

Volcanic lakes pose specific hazards inherent to the presence of water: phreatic and phreatomagmatic eruptions, lahars, limnic gas bursts and dispersion of brines in the hydrological network. Here we introduce the updated, interactive and open-access database for African volcanic lakes, country by country. The previous database VOLADA (VOlcanic LAke DAta Base, Rouwet et al., Journal of Volcanology and Geothermal Research, 2014, 272, 78–97) reported 96 volcanic lakes for Africa. This number is now revised and established at 220, converting VOLADA_Africa 2.0 in the most comprehensive resource for African volcanic lakes: 81 in Uganda, 37 in Kenya, 33 in Cameroon, 28 in Madagascar, 19 in Ethiop…

Geogenic and atmospheric sources for volatile organic compounds in fumarolic emissions from Mt. Etna and Vulcano Island (Sicily, Italy)

[1] In this paper, fluid source(s) and processes controlling the chemical composition of volatile organic compounds (VOCs) in gas discharges from Mt. Etna and Vulcano Island (Sicily, Italy) were investigated. The main composition of the Etnean and Volcano gas emissions is produced by mixing, to various degrees, of magmatic and hydrothermal components. VOCs are dominated by alkanes, alkenes and aromatics, with minor, though significant, concentrations of O-, S- and Cl(F)-substituted compounds. The main mechanism for the production of alkanes is likely related to pyrolysis of organic-matter-bearing sediments that interact with the ascending magmatic fluids. Alkanes are then converted to alken…

Mafic magma feeds degassing unrest at Vulcano Island, Italy

AbstractThe benign fuming activity of dormant volcanoes is punctuated by phases of escalating degassing activity that, on some occasions, ultimately prelude to eruption. However, understanding the drivers of such unrest is complicated by complex interplay between magmatic and hydrothermal processes. Some of the most comprehensively characterised degassing unrest have recently been observed at La Fossa cone on Vulcano Island, but whether or not these episodes involve new, volatile-rich ascending magma remains debated. Here, we use volcanic gas measurements, in combination with melt inclusion information, to propose that heightened sulphur dioxide flux during the intense fall 2021 La Fossa un…

ENVIRONMENTAL IMPACT OF MT. ETNA’S VOLCANIC EMISSIONS: TRACE METAL BULK-DEPOSITION

CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF ETNEAN VOLCANIC EMISSIONS USING ACTIVE BIOMONITORING TEC HNIQUE (MOSS-BAGS)

Rain-ash interaction during paroxysmal events as potential input of toxic trace element in the environment: example from Mt. Etna Volcano

New insight into halogen release from experimental studies on BrO/Br ratios in volcanic plumes

Multi-component gas emission measurements of the active lava lake of Nyiragongo, DR Congo

Between 2007 and 2011 four measurement campaigns (June 2007, July 2010, June 2011, and December 2011) were carried out at the crater rim of Nyiragongo volcano, DR Congo. Nyiragongo is one of the most active volcanoes in Africa. The ground-based remote sensing technique Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS), which uses scattered sunlight, the in-situ Multi-Component Gas Analyzer System (Multi-GAS) and alkaline impregnated filter were simultaneously applied during all field trips. The bromine monoxide to sulfur dioxide (BrO/SO2) and carbon dioxide to sulfur dioxide (CO2/SO2) molar ratios were determined, among other ratios. During the different field trips variati…

The impact of natural and anthropogenic factors on groundwater quality in an active volcanic/geothermal system under semi-arid climatic conditions: The case study of Methana peninsula (Greece)

Abstract A comprehensive hydrogeochemical study of the cold and thermal groundwaters of the presently quiescent volcanic system at Methana was undertaken that involved collecting 71 natural water samples. Methana is a peninsula in Peloponnesus, Greece whose arid climate and hydrological situation is similar to that of the nearby small islands of the Aegean Sea. Similarly, the chemical and isotopic compositions of its water are dominated by the mixing of seawater with meteoric water both through direct intrusion and meteoric recharge. However, the simple mixing trends at Methana are modified by water–rock interaction processes, enhanced by the dissolution of endogenous CO2, which lead to str…

A geochemical traverse along the “Sperchios Basin e Evoikos Gulf” graben (Central Greece): Origin and evolution of the emitted fluids

The studied area is a 130 km long fast spreading graben in Central Greece. Its complex geodynamical setting includes both the presence of a subduction slab at depth responsible for the recent (Quaternary) volcanic activity in the area and the western termination of a tectonic lineament of regional importance (the North-Anatolian fault). A high geothermal gradient is made evident by the presence of many thermal springs with temperatures from 19 to 82 C, that discharge along the normal faults bordering the graben. In the period 2004e2012, 58 gas and 69 water samples were collected and their chemical and isotopic analysis revealed a wide range of compositions. Two main groups of thermal waters…

Mobility of plume-derived volcanogenic elements in meteoric water at Nyiragongo volcano (Congo) inferred from the chemical composition of single rainfall events

The chemical composition of single rainfall events was investigated at Nyiragongo volcano (Democratic Republic of Congo) with the aim of determining the relative contributions of plume-derived elements. The different locations of the sampling sites allowed both plume-affected samples (hereafter referred to as “fumigated samples”) and samples representative of the local background to be collected. The chemical composition of the local background reflects the peculiar geographic features of the area, being influenced by biomass burning, geogenic dust, and biological activity. Conversely, fumigated samples contain large amounts of volcanogenic elements that can be clearly distinguished from th…

Il Tecnezio: storia, usi e applicazioni.

To bring to the knowledge of all the Italian paternity of the discovery of the first artificial chemical element in history: the Technetium or Technetium (Tc).

Gas geochemistry and CO2 output estimation at the island of Milos, Greece

Abstract Twenty gas samples have been collected from the natural gas manifestations of Milos Island, the majority of which is found underwater along its coast. Furthermore, three anomalous degassing fumarolic areas (Kalamos, Paleochori and Adamas) have been recognized on-land. Almost all the gases are CO2-dominated with CO2 ranging from 88 to 99% vol for the samples taken underwater, while the on-land manifestations show a wider range (15–98%) due to air contamination. Methane reaches up to 1.0% vol, H2 up to 3.2% vol and H2S up to 3.5% vol indicating a hydrothermal origin of the gases. The isotope composition of He points out to mantle contributions up to 45%, while the C-isotope compositi…

Active real-time analyzers vs. passive/diffusive samplers for hydrogen sulfide (H2S) in air: a critical comparison

Hydrogen sulfide (H2S) is a gas pollutant discharged in air from a large number of natural and anthropogenic sources. Its peculiar rotten-egg smell, causing odor nuisance to neighboring communities, is detectable at concentrations between 0.7 and 42 μg/m3 (Schiffman & Williams, 2005). High H2S concentrations could cause eye irritation, damage to the upper respiratory apparatus and loss of smell. The effects of long-term low level (< 2,800 μg/m3) exposures to H2S are still matter of debate (Bates et al., 2013). Hence, the development of techniques for accurate measurements of H2S in air at a wide range of concentrations is a primary issue in environmental monitoring. Two different app…

Atmospheric Deposition around the Industrial Areas of Milazzo and Priolo Gargallo (Sicily–Italy)—Part A: Major Ions

The chemical composition of rainwater was studied in two highly-industrialised areas in Sicily (southern Italy), between June 2018 and July 2019. The study areas were characterised by large oil refining plants and other industrial hubs whose processes contribute to the release of large amounts of gaseous species that can affect the chemical composition of atmospheric deposition As in most of the Mediterranean area, rainwater acidity (ranging in the study area between 3.9 and 8.3) was buffered by the dissolution of abundant geogenic carbonate aerosol. In particular, calcium and magnesium cations showed the highest pH-neutralizing factor, with ~92% of the acidity brought by SO42− and NO…

Origin and evolution of the fluids emitted along the “Sperchios Basin – Evoikos Gulf” Graben (Central Greece)

A biomonitoring study using endemic plants for the evaluation of volcanogenic deposition on Mt. Etna (Italy)

8. A biomonitoring survey using leaves of tree (Betulla aethnensis, Pinus nigra and Populus tremula) and two endemic species (Senecio aethnensis and Rumex aethnensis) above treeline level, was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (800-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analyzed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind se…

Selenium mobilization during Rain-Soil Interaction at Etna volcano

Humans are attracted by the fertile properties of volcanic soils. Currently around 10% of the world population lives within active volcanic areas. Volcanoes emit enormous amounts of potentially toxic elements, even in the absence of obvious volcanic activity. Selenium is particularly interesting due to it geochemical similarities with sulphur, a major compound in volcanic gasses. Although selenium (Se) is an essential element for humans, ingestion of an excess amount of Se can produce adverse effects. Mt. Etna, the biggest volcano in Europe, is persistently active for the last 200,000 years. It is one of the most intensely monitored volcanoes. In the area, volcanic gasses, rainwater and gro…

The flight of Arcadia: spatial CO2/SO2 variations in a cross section above the Nord East crater of Etna volcano

The CO2/SO2 ratio in volcanic plumes of open conduit volcanoes can provide useful information about the magma depth inside a conduit and the possible occurrence of an eruptive event. Moreover, the same CO2 measurement when combined with a SO2 flux measurement, commonly carried out at many volcanoes nowadays, is used to contribute to an improved estimate of global volcanic CO2 budget. Today worldwide at 13 volcanoes automated in-situ instruments (known as Multi-GAS stations) are applied to continuously determine CO2/SO2 ratios and to use this signal as additional parameter for volcanic monitoring. Usually these instruments carry out measurements of half an hour 4 – 6 times/day and thus provi…

Pizzi Deneri Field Trips - Etna 2010-2014

New evidences on mercury emissions from Earth volcanism

Degassing of gaseous (elemental and reactive) and particulate mercury from Mount Etna volcano (Southern Italy)

Abstract There is an urgent need to better constrain the global rates of mercury degassing from natural sources, including active volcanoes. Hitherto, estimates of volcanic fluxes have been limited by the poorly determined speciation of Hg in volcanic emissions. Here, we present a systematic characterisation of mercury partitioning between gaseous (Hg(g)) and particulate (Hg(p)) forms in the volcanic plume of Mount Etna, the largest open-vent passively degassing volcano on Earth. We demonstrate that mercury transport is predominantly in the gas phase, with a mean Hg(p)/Hg(g) ratio of ∼0.01 by mass. We also present the first simultaneous measurement of divalent gaseous mercury ( Hg ( g ) II …

Seawater Trace Metals in acidified condition: an accumulation study in the blue mussel Mytilus galloprovincialis off Vulcano Island submarine vents (Italy)

Volcanic gas and particles monitoring using moss-bags on Vulcano Island, Italy

Preliminary results of biomonitoring survey at Virunga Volcanic Province (D.R. Congo), Eastern Africa.

Biomonitoring techniques have been widely used in environmental studies to monitor anthropogenic pollutants. Recently such techniques have been also applied to ascertain the impact of contaminants naturally released by volcanic activity (Calabrese et al., 2015; Arndt et al., 2017). In the present study a biomonitoring survey has been performed in different sites around Nyiragongo and Nyamulagira (D.R. Congo), active volcanoes in the western branch of the East African Rift. We applied both active and passive biomonitoring techniques in order to investigate the release of some harmful chemical elements by Nyiragongo and Nyamulagira: the former was performed by exposing moss-bags (Sphagnum sp.…

Chemistry of atmospheric depositions over two polluted industrial areas of Sicily (Italy)

Dry and wet depositions provide the pathways through which particles and gases emitted into the atmosphere return to the Earth’s surface. Bulk deposition is defined as the sum of dry and wet deposition, which is characterized by water-soluble and insoluble chemical species. Recent studies (e.g. Castillo et al., 2017) showed that most of the atmospheric deposition in Europe occurs in the wet form, but in southern European regions the role of dry contribution can be as significant as that of wet deposition. In the framework of the multidisciplinary project “CISAS” (Centro Internazionale di Studi Avanzati su Ambiente, ecosistema e Salute umana), bulk depositions were monthly sampled over two p…

Degassing and Cycling of Mercury at Nisyros Volcano (Greece)

Nisyros Island (Greece) is an active volcano hosting a high-enthalpy geothermal system. During June 2013, an extensive survey on Hg concentrations in different matrices (fumarolic fluids, atmosphere, soils, and plants) was carried out at the Lakki Plain, an intracaldera area affected by widespread soil and fumarolic degassing. Concentrations of gaseous elemental mercury (GEM), together with H2S and CO2, were simultaneously measured in both the fumarolic emissions and the atmosphere around them. At the same time, 130 samples of top soils and 31 samples of plants (Cistus creticus and salvifolius and Erica arborea and manipuliflora) were collected for Hg analysis. Mercury concentrations in fum…

Active moss monitoring allows to identify and track distribution of metal(loid)s emitted from fumaroles on Vulcano Island, Italy

Abstract Volatile metal(loid)s are known to be emitted from volcanoes worldwide. We tested the suitability of active moss monitoring for tracking volatile metal(loid)s released from the fumarolic field on Vulcano Island, Italy, and differentiated fumaroles from other sources of gaseous and particulate trace elements such as sea spray and soil. Metal(loid) accumulation on the mosses per day did depend neither on the state of the exposed moss (dead or living) nor exposure time (3, 6, or 9 weeks). After collection, mosses were digested with either HNO3/H2O2 or deionized water and analyzed by ICP-MS. While for most elements both extraction methods yielded similar concentrations, higher concentr…

Monitoring Volcanic Eruptions Using Trace Metals In Tree-Rings: Preliminary Results From Mt. Etna

8. Active volcanoes can influence surrounding vegetation both through passive degassing during quiescent periods and through eruptive degassing, by introducing into the atmosphere several metals as gases and particles. The chemical composition of tree-rings has been generally used to investigate the effects of anthropogenic gas emissions and dendrochemical methods have successfully recorded variations in the pollution levels. The use of tree-rings analysis in active volcanic areas has shown that vascular plants could be used as archives of volcanogenic metals deposition. Tree cores of Pinus Nigra and Populus tremula were collected in sites located both on the downwind (Citelli and Mt. Fonta…

Atmospheric Impacts of Volcanic Volatiles: Trace Elements in Bulk Deposition at Mount Etna (Italy)

FIRST APPLICATION OF ACTIVE BIOMONITORING TECHNIQUES (MOSS-BAGS) TO MAP THE DISPERSION OF VOLCANIC EMISSIONS

Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain informations on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application o…

Flussi di evasione marina del mercurio elementare gassoso (Hg0) nell’atmosfera della Rada di Augusta

Il mercurio (Ilg) è uno dei principali inquinanti emessi in atmosfera. La sua complessità geochimica, unitamente alla tossicità c agli effetti persistenti della sua presenza nell’ecosistema terrestre, lo hanno inserito nella lista delle priorità di un numero sempre crescente di accordi internazionali rivolti alla tutela ambientale e della stiline umana (The Arctic- Monitoring and Assessment Program, AMAR, United Nations - Economie Commission for Europe: Ileavy Metals Protocol, UN- ECE, The Helsinki Commission, IIELCOM, la convenzione OSPAR). I progressi raggiunti neH’ullimo decennio sullo studio del Hg come ‘global poi Intani '(Pirrone et al.. 2001; Hedgecock et al, 2000: Paeyna et al, 2006…

Geothermal mercury output at Nisyros Volcano (Greece)

Nisyros (Greece) is an active volcano in the eastern part of the South Aegean Active Volcanic Arc (SAAVA), hosting a high-enthalpy geothermal system. On June 2013, an extensive survey on Hg concentrations in different types of matrices (fumarolic fluids, atmosphere, soils and plants) was carried out at Lakki plain, an area affected by widespread soil degassing and fumarolic manifestations. To investigate the spatial distribution of mercury emission and its possible relationships with diffuse degassing of hydrothermal fluids, Hg concentrations in soils were related to their physicochemical parameters (e.g. temperature, soil-pH, hydrothermal gases and elemental C, N and S concentrations). Fur…

Sulphur-gas concentrations in volcanic and geothermal areas in Italy and Greece: Characterising potential human exposures and risks

Abstract Passive samplers were used to measure the atmospheric concentrations of SO 2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H 2 S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO 2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (> 1000 μg m − 3 ). H 2 S values measured at Nisyros also exceed the limit considered safe for the same group of …

Composition and distribution of volcanic gases inside the Lakki Caldera (Nisyros, Greece): preliminary results

The use of moss-bags technique to volcanic aerosols investigation on Mt. Etna (Italy)

DEEP RESERVOIR TEMPERATURES OF LOW-ENTHALPY GEOTHERMAL SYSTEMS IN TUNISIA: NEW CONSTRAINTS FROM CHEMISTRY OF THERMAL WATERS

Tunisia is characterized by hot and warm groundwaters (temperature up to 75 °C) which represent the surface manifestation of geothermal systems hosted in carbonate-evaporite rock sequences. The T-conditions of Tunisia deep thermal reservoirs are here evaluated for the first time at the regional scale. The results here shown clearly highlight the limitations inherent in the application of common geothermometric methods in the estimation of equilibrium temperatures in sedimentary environments. The modeling approach proposed by Chiodini et alii (1995), which makes use of the ratios between dissolved HCO3, SO4 and F, provides the most reliable results, and allows us to derive equilibrium temper…

The contribution of volcanic emissions (Etna, Stromboli and Vulcano) to the atmospheric trace metals budget in the Mediterranean basin

Volcanic emissions represent one of the major natural source for several trace metals (Cd, Cu, As, Pb, Hg and Zn) into the atmosphere both as gaseous and aerosol forms. The Mediterranean Sea can be considered a large geochemical sink for these elements whose source are the huge amounts of aerosols of different origin. The industrialized areas located in the northern part of the basin represent a nearly constant source of the anthropogenic-dominated aerosol. By contrast, the arid and desert regions located at the southern and eastern parts of the Mediterranean, are the sources of frequent dust “pulses” perturbing the “steady-state” conditions of the local atmosphere through the input of seve…

Biomonitoring of volcanogenic trace elements using two endemic species (Senecio aethnensis and Rumex aethnensis) on Mt. Etna.

A biomonitoring survey, above treeline level, using two endemic species (Senecio aethnensis and Rumex aethnensis) was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (1500-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analysed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the most impacted b…

Are the Salinelle mud volcanoes threatening human health or are anthropogenic activities threatening the Salinelle mud volcanoes?

Passive samplers were used to measure the atmospheric concentrations of SO2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H2S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (>1000 μg m−3). H2S values measured at Nisyros also exceed the limit considered safe for the same group of people (>3000 μg m−…

Trace element mobility during interaction between rain and volcanic ash on Mt. Etna

Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere, both during and between eruptions. Due to their potential toxicity they may have important environmental impacts from the local to the global scale. Atmospheric precipitation was collected approximately every two weeks, from April 2006 to December 2007, using a network of five rain gauges, located at various altitudes on the upper flanks around the summit craters of Etna volcano. The collected samples were analysed for major (Ca, Mg, K, Na, F, SO4, Cl, NO3) and a large suite of trace elements (Ag, Al, As, Au, B, Ba, Be, Bi, Cd, Co, Cr, Cs, Cu, Fe, Hg, La, Li, Mn, Mo, Ni, Pb, Rb, Si, S…

Trace elements mobility in soils from the active hydrothermal area of Nisyros (Greece)

Nisyros Island, Greece, is a stratovolcano known for its intense hydrothermal activity. On June 2013, during a multidisciplinary field campaign, soil samples were collected in the caldera area to determinate the main mineralogical paragenesis and to investigate the distribution of trace elements concentrations and the possible relationship to the contribution of deep originated fluids. Soil samples were analysed with XRD and for the chemical composition of their leachable (deionized water) and near total (microwave digestion) fraction both for major and trace elements. All data were compared to a local background soil. The results allow to divide the samples in 2 groups: Lakki Plain and Ste…

¿Una nueva vertiente en el Volcán Copahue?: El caso del río Colorado.

El volcán Copahue (37°51′08″S–71°10′03″O) ha sido uno de los más estudiados del cinturón volcánico Argentino-Chileno, desarrollándose numerosos trabajos desde el punto de vista geoquímico, y en particular abarcando el estudio de las aguas del sistema. Dichos trabajos se concentran en su mayoría en las nacientes del sistema volcánico hidrotermal (SVH) (Agusto et al, 2012). Sin embargo, existen varios afluentes que alimentan al rio Caviahue de los cuales no se tiene mayor información. El objetivo de este trabajo es dterminar el origen de uno de ellos, el río Colorado. Desde el flanco E del volcán emanan dos vertientes ácidas (pH 1-2,5) y calientes (35-45°C) que se unen para formar el río Agri…

Environmental impact of Mt. Etna’s degassing: volcanogenic trace elements bioaccumulation in two endemic plant species (Senecio aethnensis and Rumex aethnensis)

A biomonitoring survey, above tree line level, using two endemic species (Senecio aethnensis and Rumex aethnensis)was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic atmospheric emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (1500-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analyzed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the mos…

Application of the moss bag biomonitoring technique in an active volcanic environment (Mt. Etna, Italy).

This paper presents the preliminary results of a biomonitoring study based on the use of moss bags exposed at 24 sites on Etna volcano. Sphagnum mosses were used to study bioaccumulation originating from atmospheric deposition, by measuring the tissue contents of major and a large suite of trace elements. Elements, such as Tl, Bi, As, Se, Cu and Cd, display high concentrations in the exposed samples close to the active vents. This study confirms the effectiveness of the moss bags technique also in active volcanic areas.

First volatile inventory for Gorely volcano, Kamchatka

[1] We report here the very first assessment of volatile flux emissions from Gorely, an actively degassing volcano in Kamchatka. Using a variety of in situ and remote sensing techniques, we determined the bulk plume concentrations of major volatiles (H2O ∼93.5%, CO2, ∼2.6%, SO2 ∼2.2%, HCl 1.1%, HF 0.3%, H20.2%) and trace-halogens (Br, I), therefore estimating a total gas release of ∼11,000 tons·day−1during September 2011, at which time the target was non-eruptively degassing at ∼900°C. Gorely is a typical arc emitter, contributing 0.3% and 1.6% of the total global fluxes from arc volcanism for CO2 and HCl, respectively. We show that Gorely's volcanic gas (H2O/SO2 ∼43, CO2/SO2 ∼1.2, HCl/SO2∼…

Environmental impact of volcanic emissions at Nyiragongo (DRC)

The large amount of trace elements emitted from volcanoes has a strong impact on the close surrounding areas. Nyiragongo Volcano (Democratic Republic of Congo) belongs to the Virunga volcanic chain and is one of the most active volcanoes in Africa. It is characterized by the presence of an active and permanent lava lake with a persistent degassing activity. During a field trip in October-November 2014, we investigated the impact of the volcanogenic deposition in the surrounding of the crater by using different sampling techniques. Rain-gauges were used to collect atmospheric bulk deposition. Active and passive biomonitoring techniques (moss-bags and leaves of endemic plants – Senecio spp. a…

CHEMICAL COMPOSITION OF ATMOSPHERIC BULK DEPOSITION AT THE INDUSTRIAL AREA OF GELA (SICILY, ITALY)

Bulk deposition has been collected at six sampling sites in area of Gela plain (Italy) in the period from February 2008 to May 2009. Samples collected each two weeks were analysed for the major ion and trace elements content. Preliminary results allow identifying three different sources that control the abundance of the elements in atmospheric deposition: (1) sea spray, (2)geogenic dust, and (3) anthropogenic pollution. Due to the closeness of the coast, clear evidence of sea spray input is detectable for most of the samples. The high excess of non sea-salt sulphate(50 - 90% of the total) is prevailingly ascribable to the abundant SO2 emissions of the refinery.The pH values of the collected…

Volcanic soil-rainwater interaction at Mount Etna, Sicily. Preliminary Results

Signature of the 24th December 2018 eruption of Mt. Etna on the chemical composition of bulk deposition in the Siracusa area (Italy)

Mt. Etna, in the eastern coast of Sicily (Italy), is one of the most active and most intensely monitored volcanoes of the planet. It is widely recognized as a big source of volcanic gases, such as CO2, SO2 and halogens, to the troposphere in the Mediterranean basin, and its gas emissions account for a significant percentage respect to the worldwide average volcanic budget. The SO2 flux from Mt. Etna’s plume has been routinely measured by the INGV since 1987. SO2 flux ranges between 600 to 25000 Mg/d; fluxes greater than 100000 Mg/d were prevalently measured during eruptive events. During eruptive periods, Etna’s emissions can be dispersed over long distances and cover wide areas of the Medi…

Steam and gas emission rate from La Soufriere volcano, Guadeloupe (Lesser Antilles): Implications for the magmatic supply during degassing unrest

Abstract Since its last magmatic eruption in 1530 AD, La Soufriere andesitic volcano in Guadeloupe has displayed intense hydrothermal activity and six phreatic eruptive crises. Here we report on the first direct quantification of gas plume emissions from its summit vents, which gradually intensified during the past 20 years. Gas fluxes were determined in March 2006 and March 2012 by measuring the horizontal and vertical distributions of volcanic gas concentrations in the air-diluted plume and scaling to the speed of plume transport. Fluxes in 2006 combine real-time measurements of volcanic H2S concentrations and plume parameters with the composition of the hot (108.5 °C) fumarolic fluid at …

Shallow submarine gas manifestations in the Aegean Sea: preliminary catalogue and geochemical characterization

The Aegean area, like other regions of intense geodynamic activity, is characterised by extensive geogenic degassing. Gas manifestations widespread on land are also very frequent underwater. The present study aims at producing a first catalogue of these manifestations together with the geochemical characterization of the emitted gases. Sixty-one samples at 21 different sites have been collected by diving up to 15 m depth, mainly along the south Aegean active volcanic arc (SAAVA). The sites displayed very different gas fluxes. Most of them showed a very sluggish gas bubbling while a few had spatially large and strong bubbling. The most intense manifestation has been found at Kos Island along…

Preliminary estimates of volcanic gaseous and particulate-phase mercury emissions at Mt. Etna and Vulcano Island

Geosphere-biosphere interactions in bio-activity volcanic lakes: Evidences from Hule and Rìo Cuarto (Costa Rica)

Hule and R ́ıo Cuarto are maar lakes located 11 and 18 km N of Poa ́s volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemica…

Active Moss biomonitoring of mercury in the mine-polluted area of Mt. Amiata (Central Italy)

In the winter 2013, mercury concentrations in air from the mine-polluted area of Mt. Amiata (1738 m a.s.l.), in southern Tuscany (Central Italy), were measured by active moss biomonitoring. This area is part of the geologic anomaly of Hg in the Mediterranean basin, which contains about 65 % of the world’s cinnabar (HgS). Mt. Amiata covers some 400 km2 and is drained by several rivers. Esploitation activity at Abbadia S. Salvatore, in the SE sector of the mountain, sprang up during the 19th century as one of the largest mercury mining and smelting plants in Europe, after those of Almaden Spain. In this area, Sphagnum moss bags were exposed for about two months, from October to December 2013.…

Active alkaline traps to determine acidic-gas ratios in volcanic plumes: Sampling techniques and analytical methods

In situ measurements have been the basis for monitoring volcanic gas emissions for many years and—being complemented by remote sensing techniques—still play an important role to date. Con- cerning in situ techniques for sampling a dilute plume, an increase in accuracy and a reduction of detection limits are still necessary for most gases (e.g., CO2, SO2, HCl, HF, HBr, HI). In this work, the Raschig-Tube tech- nique (RT) is modified and utilized for application on volcanic plumes. The theoretical and experimental absorption properties of the RT and the Drechsel bottle (DB) setups are characterized and both are applied simultaneously to the well-established Filter packs technique (FP) in the …

The use of moss-bags technique for volcanic aerosols investigation on Mt. Etna (Italy)

Explosive eruptions and volcanic passive degassing inject large quantities of gas and particles into the atmosphere that are ultimately deposited at the Earth’s surface through wet or dry deposition processes, affecting the atmosphere, the hydrosphere and the biosphere. Mount Etna (Italy) is one of the most prodigious and persistent sources of gases and particles to the troposphere. Volcanic emissions were studied at Etna volcano by using moss-bags technique. Mosses (Sphagnum species) were exposed around the volcano at different distances from the active vents to evaluate the impact of its emissions into the atmosphere and in the local surrounding. The results confirmed the huge amount of s…

Gas manifestations of Greece: Catalogue, geochemical characterization and gas hazard definition

Like other geodynamically active areas, Greece is affected by a large number of geogenic gas manifestations. These occur either in form of point sources (fumaroles, mofettes, bubbling gases) or as diffuse emanations. We produced a first catalogue of the geogenic gas manifestations of Greece also considering few literature data. Collected samples were analysed for their chemical (He, Ne, Ar, O2, N2, H2, H2S, CO, CH4 and CO2) and isotopic composition (He, C and N). Most of the sampled gas manifestation are found along the South Aegean active volcanic arc (32 sites) and in the majority they belong to the CO2 dominated group. Very few gas manifestations, N2- or CH4- dominated, are found along t…

Distribution and air-sea exchange of mercury (Hg) in polluted marine environments

Mercury (Hg) is emitted in the atmosphere by anthropogenic and natural sources, these last accounting for one third of the total emissions. Since the pre-industrial age, the atmospheric deposition of mercury have increased notably, while ocean emissions have doubled owing to the re-emission of anthropogenic mercury. Exchange between the atmosphere and ocean plays an important role in cycling and transport of mercury. We present the preliminary results from a study on the distribution and evasion flux of mercury at the atmosphere/sea interface in the Augusta basin (SE Sicily, southern Italy), a semi-enclosed marine area affected by a high degree of contamination (heavy metals and PHA) due to…

Measurements of Hg0 (and H2S) at the Solfatara Crater (Southern Italy): Estimating the atmospheric distribution with a real-time approach

Volcanic and geothermal areas are important emitters of natural gas compounds into the atmosphere, which can be of concern when discharging close to densely, populated sites. Mercury has a strong environmental impact, its organic and inorganic complexes being toxic. The dominant form of Hg in the atmosphere is gaseous elemental mercury (GEM), which has high volatility and residence time of 1-2 years. Volcanic degassing accounts for a significant part of the natural mercury emissions. No mercury limits or target values in ambient air are present in the EU legislations, whereas US-EPA and ATSDR impose 300 and 200 ng/m3, respectively, as a limit for chronic exposure. WHO has proposed the annua…

Thermomineral waters of Greece: geochemical characterization

Il Mercurio nel suolo e in ambiente terrestre

Le interazioni del Hg con l'ambiente costituiscono il ciclo geochimico di questo elemento che si esplica per mezzo di complessi processi fisico-chimici differenti per ciascun comparto geochimico. Si stima che circa i due terzi del mercurio presente in ambiente sia stato prodotto durante il ventesimo secolo, e che il carico di mercurio immesso attualmente sia aumentato di circa 3 volte rispetto agli inizi del 1900 (Mason et al.. 1994). Il comparto ambientale certamente più coinvolto dalle emissioni di mercurio è quello atmosferico, da cui poi l’elemento si diffonde anche negli altri comparti, suolo e sedimenti compresi (Filzgerald & Clarkson, 1991). L’Atmosfera costituisce un importante …

Geogenic carbon transport through karst hydrosystems of Greece

The Earth C-cycle is complex, where endogenic and exogenic sources are interconnected, operating in a multiple spatial and temporal scale (Lee et al., 2019). Non-volcanic CO2 degassing from active tectonic structures is one of the less defined components of this cycle (Frondini et al, 2019). Carbon mass-balance (Chiodini et al., 2000) is a useful tool to quantify the geogenic carbon output from regional karst hydrosystems. This approach has been demonstrated for central Italy and may be valid also for Greece, due to the similar geodynamic settings. Deep degassing in Greece has been ascertained mainly at hydrothermal and volcanic areas, but the impact of geogenic CO2 released by active tecto…

A literature review and new data of trace metals fluxes from worldwide active volcanoes

Atmospheric sources and sinks of volcanogenic elements in a basaltic volcano (Etna, Italy)

Abstract This study reports on the first quantitative assessment of the geochemical cycling of volcanogenic elements, from their atmospheric release to their deposition back to the ground. Etna’s emissions and atmospheric depositions were characterised for more than 2 years, providing data on major and trace element abundance in both volcanic aerosols and bulk depositions. Volcanic aerosols were collected from 2004 to 2007, at the summit vents by conventional filtration techniques. Precipitation was collected, from 2006 to 2007, in five rain gauges, at various altitudes around the summit craters. Analytical results for volcanic aerosols showed that the dominant anions were S, Cl, and F, and…

Plume composition and volatile flux from Nyamulagira volcano

Nyamulagira, in the Virunga volcanic province (VVP), Democratic Republic of Congo, is one of the most active volcanoes in Africa. The volcano is located about 25 km north-northwest of Lake Kivu in the Western Branch of the East African Rift System (EARS). The activity is characterized by frequent eruptions (on average, one eruption every 2–4 years) which occur both from the summit crater and from the flanks (31 flank eruptions over the last 110 years). Due to the peculiar low viscosity of its lava and its location in the floor of the rift, Nyamulagira morphology is characterized by a wide lava field that covers over 1100 km2 and contains more than 100 flank cones. Indeed, Nyamulagira is a S…

Monticchio Lakes

The crater lakes are a natural hazard for the population living near them because they can generate liminic explosions, like as the disaster of Nyos lake (Cameroon 1986), in which 1476 people and thousands of animals died. Crater lakes are able to store magmatic and hydrothermal gases and solubilising them into the water. An overpressure of the dissolved gases can generate a limnic eruption. Italy is characterised by an intense volcanic and seismic activity. Evidences of this past volcanism are the numerous crater lakes in Lazio and Campania. The most famous are Bolsena lakes, Vico, Bracciano, Monticchio lakes, Mezzano, Martignano, Albano, Nemi, Averno. The Monticchio lakes (Piccolo Lake (L…

Gas Geochemistry and Fractionation Processes in Florina Basin, Greece

Florina Basin is located in northern Greece, close to Mount Voras where the volcanic activity of Late Messinian age began. In the area, many CO2-rich gas emissions are present as a bubbling free-phase in groundwater (both springs and wells) and soil gases. Volcanism along with the geological and geodynamic regime of the basin, created the ideal conditions for CO2 accumulation in vertically stacked reservoirs. One of these, industrially exploited by the company Air Liquide Greece, produces 30,000 t/a of CO2. Results show that CO2 concentrations in the gases of Florina can arrive up to 99.8% and are mostly above 90%. Moreover, C-isotope composition (-2.1 to + 0.3 h vs. VPDB) indicates a mixed…

Helium-carbon isotopic composition of thermal waters from Tunisia

Bulk deposition at the industrial area of Gela (southern Sicily, Italy): preliminary results

In-situ analysis of the gas-emissions of the Eastern Carpathians (Romania) using the Multi-Gas instrument

The Multi-Gas instrument is an important tool for the investigations and monitoring of volcanic systems world- wide, because it can be easily placed on a volcano and can provide real-time data on the compositional changes of the fluids that are released (Aiuppa et al., 2005, Shinohara et al., 2005). We used a specially designed Multi-Gas to gather in situ compositional information about low-temperature, CO2-rich gases, emerging from different manifestations like dry gas emissions (mofettes), bubbling pools and springs. The instrument is equipped with two IR sensors for CO2 (0-100%) and CH4 (0-7%) and one electrochemical sensor for H2S (0-200 ppm). The Multi-Gas was used during several field…

Magmatic gas flux emissions from Gorelyi volcano, Kamchatka, and implications for volatile recycling in the NW Pacific

The Kamchatka peninsula, in the north-western part of the Pacific ’Ring of Fire’, is one of the most active volcanic realms on Earth, with 29 historically erupting volcanoes along its 700 km-long Eastern Volcanic Belt (EVB). This notwithstanding, volatile input and output fluxes along this arc sector have remained poorly characterised until very recently. We here report on the very first assessment of volatile flux emissions from Gorelyi, a large (25 km3, 1830 m high) and most active shield-like Holocene volcano located on the southern segment of the Kamchatka EVB. By combing results from a variety of in situ and remote sensing techniques (MultiGAS, filter packs, and UV camera), we determine the…

Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): Part 2 – Morphological and mineralogical features

Volcanic emissions were studied at Mount Etna (Italy) by using moss-bags technique. Mosses were exposed around the volcano at different distances from the active vents to evaluate the impact of volcanic emissions in the atmosphere. Morphology and mineralogy of volcanic particulate intercepted by mosses were investigated using scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS). Particles emitted during passive degassing activity from the two active vents, Bocca Nuova and North East Crater (BNC and NEC), were identified as silicates, sulfates and halide compounds. In addition to volcanic particles, we found evidences also of geogenic, anthropogenic and marin…

Catalogue of the main gas manifestation of Greece: a basis for nationwide estimations of gas hazard and total geogenic gas output

SEW – Save the Etna World

At more than 3,330 m high and ~40 km wide, Mount Etna in Sicily, Italy, is the highestvolcano in Europe and one of the most active in the world. Etna stands majesticwherever you look at it, showing a distinctive skyline from each side. More than 200,000people live around its mid-slopes, while another 300,000 are in the biggest city, Catania,located at its southern lower slope. The volcano is so imposing that there are manydifferent landscapes and habitats, often highly dissimilar. Ente Parco dell’Etna (EtnaPark) is the institution, started in 1987, covering the core of the volcano, protecting itsbiodiversity, ecosystems and landscapes, and lastly promoting the sustainabledevelopment of loca…

Real-time measurements of gaseous elemental mercury at the summit area of Mt Etna volcano (Italy): preliminary results

The summit part of Mount Etna revealed by High Resolution DC Electrical Resistivity Tomography coupled with complementary geophysical and soil gas techniques

Between 25 June and 13 July 2015 a very deep ERT profile (Pole-Dipole configuration, 40m spacingbetween electrodes and a remote electrode located at ~10km from the acquisition points) has been performedin the framework of the “MED-SUV” Project. Self-potential, soil gas concentrations (CO2, 222Rn, 220Rn, He,H2 and CH4) and soil temperature measurements were coupled to the ERT profile with a spacing of 20m(except for Rn: 40m). The NE-SW profile crossed Etnas summit craters in the middle of the 5720m ERTtotal length. Six roll along protocols of . of the dispositive (600m out of 2520m tot) have been carried outand, for the first time, a high resolution DC ERT profile reached the noticeable inve…

A christmas gift: Signature of the 24th December 2018 eruption of Mt. Etna on the chemical composition of bulk deposition in eastern sicily

The eruption of Mt. Etna which occurred on December 24th 2018 was characterized by strombolian activity and fire fountains, emitted by the New South-East Crater and along a fissure that propagated towards the SE. The influence of volcanic emissions on atmospheric deposition was clearly detectable at several kilometres from the source. Wet and dry (bulk) deposition samples were collected each month, through a network of eleven collectors, in the areas of Milazzo, and Priolo between June 2018 and June 2019. They were analysed for major ions and trace elements concentrations. The pH values range from 3.9 to 8.3, while the EC values range from 7 to 396 μS cm-1. An extensive neutralization of th…

Risks related to gas manifestations in the Hellenic territory

Like other geodynamically active areas, Greece is affected by a large number of geogenic gas manifestations. These occur either in form of point sources (fumaroles, mofettes, bubbling gases) or as diffuse emanations. We produced a catalogue of the geogenic gas manifestations of Greece also considering few literature data. Collected samples were analysed for their chemical (He, Ne, Ar, O2, N2, H2, H2S, CO, CH4 and CO2) and isotopic composition (He, C and N). Geogenic gases, apart from having important influences on the global climate, could have strong impact on human health. Gas hazard is often disregarded because fatal episodes are often not correctly attributed. Geodynamic active areas re…

Shallow Sea Gas Manifestations in the Aegean Sea (Greece) as Natural Analogs to Study Ocean Acidification: First Catalog and Geochemical Characterization

The concepts of CO2 emission, global warming, climate change, and their environmental impacts are of utmost importance for the understanding and protection of the ecosystems. Among the natural sources of gases into the atmosphere, the contribution of geogenic sources plays a crucial role. However, while subaerial emissions are widely studied, submarine outgassing is not yet well understood. In this study, we review and catalog 122 literature and unpublished data of submarine emissions distributed in ten coastal areas of the Aegean Sea. This catalog includes descriptions of the degassing vents through in situ observations, their chemical and isotopic compositions, and flux estimations. Tempe…

Impact of hydrothermal alteration processes on element mobility and potential environmental implications at the Sousaki solfataric field (Corinthia - Greece)

Abstract Samples of efflorescences and encrustations of hydrothermal origin were collected at Sousaki (Greece) and analysed for their mineralogical (XRD) and chemical composition. Solutions obtained both from mineralization with HNO3 and from leaching with deionised water were analysed for major (ICP-OES), minor and trace metals (ICP-MS) and sulfate contents (IC). Results evidence the dependence of the chemical and mineralogical composition on micro-environmental conditions i.e. humidity, oxygen-rich or -poor environment, exposed or sheltered from meteoric agents. In fact, the presence of highly soluble sulfate minerals with elevated contents of many metals (e.g. Mg, Al, Fe, Mn, Cr, Ni, etc…

Estimation of the geogenic carbon degassing of Greece

Abstract Greece belongs to the most geodynamically active regions of the world and as such it has to be considered an area of intense geogenic degassing. Here we review all the papers already published in the scientific literature on both the geochemistry of gas manifestations and the CO2 and CH4 release, in an attempt to obtain the first nationwide inventory of the natural output of these carbon gases in Greece. The best studied and most exhaling area is the South Aegean Active Volcanic Arc (SAAVA), which releases more than 1.3 × 105 tons of CO2 per year. Continental Greece, on the contrary, is much less studied but may release CO2 in the same order of magnitude in its eastern-central and …

The sea–air exchange of mercury (Hg) in the marine boundary layer of the Augusta basin (southern Italy): Concentrations and evasion flux

Abstract The first attempt to systematically investigate the atmospheric mercury (Hg) in the MBL of the Augusta basin (SE Sicily, Italy) has been undertaken. In the past the basin was the receptor for Hg from an intense industrial activity which contaminated the bottom sediments of the Bay, making this area a potential source of pollution for the surrounding Mediterranean. Three oceanographic cruises have been thus performed in the basin during the winter and summer 2011/2012, where we estimated averaged Hg atm concentrations of about 1.5 ± 0.4 (range 0.9–3.1) and 2.1 ± 0.98 (range 1.1–3.1) ng m −3 for the two seasons, respectively. These data are somewhat higher than the background Hg atm …

Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes

Volcanoes are well known as an impressive large natural source of trace elements into the troposphere. Etna (Italy) and Nyiragongo (D.R. Congo) are two stratovolcanoes located in different geological settings, both characterized by persistent passive degassing from their summit craters. Here, we present some results on trace element composition in volcanic plume emissions, atmospheric bulk deposition (rainwater) and their uptake by the surrounding vegetation, with the aim to compare and identify differences and similarities between these two volcanoes. Volcanic emissions were sampled by using active filter-packs for acid gases (sulfur and halogens) and specific teflon filters for particulat…

Hydrothermal fluid flow structures at Solfatara volcano, Somma-Vesuvius volcanic complex and Mt. Etna

Solfatara (Campi Flegrei):We present the first detailed 3-D Resistivity model of the Solfatara-Pisciarelli area, obtained from numerousERT surveys during the “MED-SUV” Project. This inversion was performed by taking into account 44 000ERT data points, as well as surface e-m resistivity measurements and the magneto-tellurics model from A.Siniscalchi et al. respectively as surface and bottom boundary conditions. The 3-D resistivity structure wellmatches with the CO2 flux, temperature and self-potential variations at the crater surface. This model clearlyhighlights the main geological units of the area (Monte Olibano, Solfatara crypto-dome, layers of eruptivedeposits), and the structures of hy…

Chemical characterisation of the gases released at Gyali Island, Dodecanese, Greece and preliminary estimation of the CO2 output

Greece belongs to the most geodynamically active regions of the world and as such, it has to be considered an area of intense geogenic degassing. In terms of carbon, the territory is characterized by the high hydrothermal and volcanic activity of the South Aegean Active Volcanic Arc (SAAVA), and by widespread geological seeps of buried carbon dioxide and methane. In the present work, we investigate the island of Gyali located in the volcanic system Kos-Gyali-Nisyros. Nine gas samples have been collected on the island of Gyali in areas found both on land, in a small lake (∼2000 m2) along its beach, and in the sea close to the shore at shallow depths (<20 m). Results show that CO2 is the p…

Impact of Volcanic Emissions on Trace Elements Contents Measured in Endemic Plants at Mt. Etna (Italy)

Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes: the chemical characterization of the emissions and assessment of their uptake of trace elements emissions on the local environment

Degassing at the Volcanic/Geothermal System of Kos (Greece): Geochemical Characterization of the Released Gases and CO2 Output Estimation

Forty-five gas samples have been collected from natural gas manifestations at the island of Kos—the majority of which are found underwater along the southern coast of the island. On land, two anomalous degassing areas have been recognized. These areas are mainly characterized by the lack of vegetation and after long dry periods by the presence of sulfate salt efflorescence. Carbon dioxide is the prevailing gas species (ranging from 88 to 99%), while minor amounts of N2 (up to 7.5%) and CH4 (up to 2.1%) are also present. Significant contents of H2 (up to 0.2%) and H2S (up to 0.3%) are found in the on-land manifestations. Only one of the underwater manifestations is generally rich in N2 (up t…

Rapid oxidation of mercury (Hg) at volcanic vents: Insights from high temperature thermodynamic models of Mt Etna's emissions

A major uncertainty regarding the environmental impacts of volcanic Hg is the extent to which Hg is deposited locally or transported globally. An important control on dispersion and deposition is the oxidation state of Hg compounds: Hg(0) is an inert, insoluble gas, while Hg(II) occurs as reactive gases or in particles, which deposit rapidly and proximally, near the volcanic vent. Using a new high temperature thermodynamic model, we show that although Hg in Etna's magmatic gases is almost entirely Hg(0) (i.e., gaseous elemental mercury), significant quantities of Hg(II) are likely formed at Etna's vents as gaseous HgCl2, when magmatic gases are cooled and oxidised by atmospheric gases. Thes…

Measurements of gaseous elemental mercury (GEM) in diffuse soil emission using the static closed-chamber method

Measurements aimed to evaluate the contribution of natural and anthropogenic gaseous elemental mercury (GEM) to the atmosphere are critical for monitoring and mitigating the impact of this highly toxic air contaminant. Notwithstanding, the amounts of GEM originating from different sources are difficult to be estimated, since specific protocols dictating the most appropriate sampling and analytical techniques are lacking. This study was aimed to test a methodological approach enables to measure GEM released through diffuse degassing from the soil, a mechanism that in volcanic and geothermal areas significantly contributes to the discharge of geogenic fluids to the atmosphere. A static closed…

Mount Etna, the major point source of metals in the Mediterranean basin: impact on atmospheric precipitation

Regional variations in the chemical and helium–carbon isotope composition of geothermal fluids across Tunisia

Abstract Tunisia has numerous thermo-mineral springs. Previous studies have shown that their chemical composition and occurrence are strongly influenced by the regional geology. However little work has been done so far to study the isotopic composition of volatiles associated with these geothermal manifestations. Here, we report on the results of an extensive survey of both natural hot springs and production wells across Tunisia, aimed at investigating the spatial distribution of thermal fluids' geochemical characteristics and He–C isotopic composition. The chemistry of the analyzed samples highlights the heterogeneity of the water mineralization processes in Tunisia, as a consequence of th…

A new geochemical approach to estimate the distribution of air pollutants from natural and anthropogenic sources: examples from Solfatara Crater (Campi Flegrei, Southern Italy) and Mt. Amiata Volcano (Siena, Central Italy)

Volcanic and geothermal systems significantly contribute to the input of volatile contaminants, such as mercury and hydrogen sulfide, into the atmosphere. Mercury has a strong environmental impact. In the atmosphere the prevalent elemental form is Hg0 (~98 %), whose main physical-chemical features are: high volatility, low solubility and chemical inertness. Hydrogen sulfide (H2S), one of the most abundant gas compounds in volcanic fluids, is highly poisoning and corrosive and unpleasantly smells of rotten eggs. Measurements of Hg0 and H2S concentrations in air are commonly performed by means of passive samplers. However, real-time measurements, coupled with monitoring of local atmospheric c…

MOBILITY OF MERCURY IN THE VOLCANIC/GEOTHERMAL AREA OF NISYROS (GREECE)

Το καλοκαίρι του 2013, προσδιορίστηκαν οι συγκεντρώσεις υδραργύρου στο έδαφος και τον αέρα του ενεργού ηφαιστείου της Νισύρου (Ελλάδα), το οποίο ανήκει στο ενεργό ηφαιστειακό τόξο του νοτίου Αιγαίου. 102 δείγματα εδάφους συλλέχθηκαν και 2119 αναλύθηκαν για υδράργυρο με τη χρήση ψυχρού ατμού ατομικής απορρόφησης αναλυτή, σύμφωνα με τη μέθοδο ΕΡΑ 7473. Ταυτόχρονα, στα ίδια σημεία πραγματοποιήθηκαν συγκεντρώσεις υδραργύρου στον αέρα, με φορητό φασματοφωτόμετρο (Lumex RA- 915M). Οι τιμές των εδαφικών συγκεντρώσεων υδραργύρου κυμαίνονται από 0.023 έως 13.7 mg/g. Οι συγκεντρώσεις υδραργύρου στον αέρα έδειξαν υψηλότερες τιμές υποβάθρου στην περιοχή Λακκί της καλδέρας, μεταξύ 21 και 36 ng/m3 και μέ…

Dall'ambra siciliana al Tecnezio - Storia per un Museo di Mineralogia

Sweet chestnut (Castanea sativa) leaves as a bio-indicator of volcanic gas, aerosol and ash deposition onto the flanks of Mt Etna in 2005–2007

Sweet chestnut leaves (Castanea sativa) collected from the flanks of Mt Etna volcano in 2005-2007 were analysed by inductively-coupled plasma mass spectrometry to investigate the spatial and temporal variability of element concentrations. The aim of this work was to determine whether these leaves are a bio-indicator for volcanic gas, aerosol and ash deposition and to gain new insights into the environmental effects of quiescent and eruptive volcanic plumes. Results show a positive correlation between sample variability in the concentration of elements in Castanea sativa and enrichment factors of elements in the plume. The spatial and temporal variability of chalcophilic elements (As, Cd, Cu…

Gas emission measurements of the active lava lake of Nyiragongo, DR Congo

Geochemical characterization and health risk assessment in two diversified environmental settings (Southern Italy).

An integrated approach using chemical and microbial indicators has been tested in two different sites of the Campania Plain (Southern Italy) with different land use covering and different hydrogeological features in order: (1) to define the water-rock interaction processes, (2) to differentiate sources of pollution in a detailed way (3) to evaluate the degree of water quality in the studied alluvial aquifer and (4) to identify the most worrying elements for human's health. Groundwater have showed a HCO3-Ca signature for both investigated sites, and a progressive enrichment in alkali ions has been highlighted moving from the boundary of the plain toward the coastal areas, due to groundwater …

Carbon degassing through karst hydrosystems of Greece

Estimation of CO2 degassing from active tectonic structures and regional hydrothermal systems is essential for the quantification of presentday Earth degassing [Frondini et al., 2019 and references therein]. Due to the high solubility of CO2 in water, great amounts of deep inorganic carbon can be dissolved, transported, and released from regional aquifers. By applying a massbalance approach [Chiodini et al., 2000], different sources of the dissolved CO2 can be discriminated. The main source of degassing in Greece is concentrated in hydrothermal and volcanic areas. However, deep CO2 from active tectonic areas has not yet been quantified. A key point of this research is to investigate the pos…

Full scale evaluation of atmospheric mercury budget from persistent volcanic degassing

In the recent years, there has been an increase in environmental concerns related to the pollution of many trace metals emitted from volcanic degassing because of their toxicity and long residence times in the earth’s ecosystems. Among volcanogenic trace elements, mercury (Hg) is one of the most environmentally-significant in light of its potential harmful effects on biological systems. At present, however, the global Hg flux from volcanic sources is still poorly known. We report on Hg levels in volcanic plumes and fumaroles that, in combination with sulphur analyses and SO2 flux data, lead to global Hg estimates. We found that mercury transport in the plume is mainly in the gas-phase, as H…

Gaseous Elemental Mercury (GEM) from mining areas and volcanic and geothermal systems in some Mediterranean areas: a preliminary study

Volcanogenic particulates and gases from Etna volcano (Italy)

Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity they may have important environmental impacts from the local to the global scale and they can severely affect the atmospheric and terrestrial environment also at timescales ranging from a few to million years. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2, and halogens) and particulate matter, including some toxic trace elements. The aim of this study was to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Nine samples were coll…

Mercury concentration and speciation in volcanic aquifers: measurements in Italy and Guadeloupe (Lesser Antilles)

Bioindication of volcanic mercury (Hg) deposition around Mt. Etna (Sicily)

Mt. Etna is a major natural source of Hg to the Mediterranean region. Total mercury concentrations, [Hg] tot, in Castanea sativa (sweet chestnut) leaves sampled 7-13km from Etna's vents (during six campaigns in 2005-2011) were determined using atomic absorption spectroscopy. [Hg] tot in C. sativa was greatest on Etna's SE flank reflecting Hg deposition from the typically overhead volcanic plume. [Hg] tot also showed Hg accumulation over the growing season, increasing with leaf age and recent eruptive activity. [Hg] tot in C. sativa was not controlled by [Hg] tot in soils, which instead was greatest on Etna's NW flank, and was correlated with the proportion of organic matter in the soil (% O…

The scientific instruments of the historical Mineralogical Museum of Palermo: testimonies of almost two centuries of mineralogical and petrographic studies

The scientific collections of the historic Museum of Mineralogy of Palermo are located on the second floor of via Archirafi 36 and are preserved by the Dipartimento di Scienze della Terra e del Mare (DiSTeM) of the University of Palermo. The historical edifice was designed by the architect Antonio Zanca and completed in the years 1933-1934. From the beginning, it has hosted the Institute of Physics at the ground and first floors, today entitled in honour of the famous physicians Emilio Segrè, and the Institute of Mineralogy at the second floor, which has kept one of the richest and ancient collections of Sicilian minerals. Today, the collections are partially exposed and are the subject of …

The impact of volcanogenic emissions of major and trace elements at Mt. Etna, Sicily, on precipitation (rain and snow) chemistry

Catalogue of the main gas manifestations in the Hellenic territory: a first step towards the estimation of the nationwide geogenic gas output

Quantification of gaseous emissions in geological systems is an important branch because it is a major source of greenhouse gas to the atmospheric budget. Of geological environments, there are two different categories: the first category includes emissions of the predominant carbon dioxide (CO2), while the second includes emissions of the predominant methane (CH4). The Hellenic territory has a very complex geodynamic setting deriving from a long and complicated geological history. It is strongly characterized by intense seismic activity and enhanced geothermal gradient. This activity, with the contribution of an active volcanic arc, favours the existence of many cold and thermal gas manifes…

Geogenic element behaviour in soil-rainwater interaction at Mt Etna, Sicily: preliminary results

Active volcanoes emit considerable amounts of contaminants such as As, Se and V. Previous studies have shown that the volcanic activity at Mt Etna (Sicily) has a strong influence on local rainwater compositions. However to date, the behaviour of trace elements in the soils around Mt Etna is poorly understood. 4-hr batch experiments have been performed with 1:5 soil solutions of air-dried soil (fraction <2 mm) and synthetic (acid) rainwater (using either deionized water with a pH of ~6 or a ~500 ppm of sulphuric acid solution with a pH of ~2). In general trace element concentrations are more enriched in soil solutions with low pH (e.g. enrichment factor (EF) acid compared to neutral soil sol…

Volcanogenic particulates and gases from Etna volcano (Italy)

Do Volcanic Eruptions Solve Global Atmospheric Mercury Pollution?

Besides human activities, volcanoes also introduce significant quantities of potentially harmful chemical compounds into the environment, mainly in the forms of gases and particles. High-temperature emissions from persistently degassing volcanoes are a known source of trace metal emissions to the atmosphere which may have important environmental consequences. Among these metals, mercury (Hg) is of particular interest since it is a toxic volatile metal found at elevated concentrations in remote regions of the world. Many natural Hg pathways include a recycled component of anthropogenic material. The anthropogenic contribution to the global atmospheric Hg budget is now well constrained, with …

Methanotrophy in geothermal soils, an overlooked process: The example of Nisyros island (Greece)

Abstract A multidisciplinary field campaign was carried out at Nisyros Island (Greece). Hydrothermal gases were sampled and analysed, and CH4 and CO2 fluxes from the soils were measured with the accumulation chamber method. The sampling area (Lakki plain) covers an area of about 0.08 km2, and includes the main fumarolic areas of Kaminakia, Stefanos, Ramos, Lofos and Phlegeton. Flux values measured at 130 sites range from −3.4 to 1420 mg m−2 d−1 for CH4 and from 0.1 to 383 g m−2 d−1 for CO2. The fumarolic areas show very different CH4 degassing patterns, Kaminakia showing the highest CH4 output values (about 0.8 t a−1 from an area of about 30,000 m2) and Phlegeton the lowest (about 0.01 t a−…

Dissolved major and trace elements in meteoric depositions on the flanks of Mt. Etna (Italy): the impact of volcanic activity on the environment

In the framework of the “Save the Etna World” research project, which investigates the impact of the volcanic activity on the surrounding environment, three bulk collectors were deployed on the flank of the Mt. Etna volcano to collect the meteoric depositions. The sampling sites were at distances between 5.5 and 13 km from the summit vents of the volcano on its eastern flank, that is the most exposed to the volcanic plume due to the high-altitude prevailing winds direction. The sites were selected in order to have a gradient of exposition with respect to the volcanic emissions, the most exposed being CIT, the intermediate ILI and the least NIC. Samples were collected monthly from July 2017 …

Characterization of trace elements in thermal and mineral waters of Greece

: Natural thermal and mineral waters are widely distributed along the Hellenic region and are related to the geodynamic regime of the country. The diverse lithological and tectonic settings they are found in reflect the great variability in their chemical and isotopic composition. The current study presents 276 (published and unpublished) trace element water data and discusses the sources and processes affecting the water by taking into consideration the framework of their geographic distribution. The dataset is divided in groups using temperature- and pH-related criteria. Results yield a wide range of concentrations, often related to the solubility properties of the individual elements and…

Geochemical comparison of natural and anthropogenic metal fluxes in extreme environments: Mt. Etna volcano (Italy) and Šalek Valley (Slovenia)

Geochemical comparison between some metals (As, Cd, Cu, Pb, Se, V, Zn) emissions from an active volcano (Mt. Etna) and a highly industrialized area (Šalek Valley) showed some interesting similarities: in general, most of the elements emitted into the atmosphere do not return to the Earth’s surface and are therefore dispersed into the environment. Exceptions for Šalek Valley are Cd, which probably derives in large part from rock leaching, and in part As and Pb, which fall mostly as ash. Also, Etna’s emissions are richer in Cd and Cu, whereas industrial emissions at Šalek Valley are richer in V and Zn. All other metals have similar fluxes in the two types of emissions.

Intercomparison of gas emissions from the lava lakes of Nyiragongo and Nyamulagira, DR Congo

From 25th of October to 5th of November 2014 field surveys were carried out at Nyiragongo and Nyamulagira volcanoes, DR Congo. These two volcanoes belong to the eight volcanoes in the Virunga volcanic chain. They have an altitude of about 3470 m.a.s.l. and 3060 m.a.s.l., respectively. The craters of the two volcanoes lie within a distance of less than 15 km and both have a diameter of about 1000 m and 2000 m, respectively showing a similar inner geometry containing several terraces inside. The lava lake of Nyamulagira is still under formation while Nyiragongo’s lava lake is known since more than 100 years with short interruptions after the eruptions in 1977 and 2002. However, also Nyamulagi…

Environmental impact of trace metals emission at Mt. Etna area (Italy): preliminary estimates of trace metals in bulk-deposition

Fumarolic alteration products at Sousaki (Greece) : occurrence and environmental impact

Fumarolic alteration crusts and efflorescences have been sampled at the Sousaki solfataric field. Samples have been analysed for mineralogical (XRD) and chemical composition (HNO3 digestion and leaching with distilled water). Results show that mineralogical and chemical compositions (major, minor and trace metals) are controlled by microenvironmental conditions. The sample collected in the anoxic part of a cave is composed almost exclusively by native sulfur. The samples collected in the oxidizing part of the cave and outside in relatively sheltered position are mainly composed by very soluble sulfates. Chemical composition evidence strong enrichments in Al, Ca, Cr, Fe, Mg and Ni which are …

Il risarcimento del danno ambientale da inquinamento: modelli di analisi geochimica valutazione monetaria di un eco-socio-sistema fluviale in Sicilia.

Bromine chemistry of volcanic plumes

Volcanic gas studies are an established tool for volcanic monitoring and enhance the understanding of volcanic manifestations. The central question of the project, which we will introduce here, is whether the ratio between bromine monoxide (BrO) to sulphur dioxide (SO2) can potentially serve as indicator for volcanic activity. Both species have the advantage that they can be remotely measured by Differential Optical Absorption Spectroscopy (DOAS) at safe distances from the emission source. To answer the question above, it is of great importance to link the measurements of halogen oxides to the total emission flux of individual halogen species and to understand the influences of meteorologic…

Selenium mobilization in soils due to volcanic derived acid rain: An example from Mt Etna volcano, Sicily

International audience; The significant amounts of selenium (Se) emitted by volcanoes may have important impact on human health due to the narrow range between nutrition requirement and toxic effects for living organisms upon Se exposure. Although soils play a key role in determining the level in food and water and thereby human health, little is known about the behaviour of Se in volcanic soils. In this work we evaluated the Se release during rainwater–soil interaction under controlled conditions using soils collected on the flanks of Etna volcano and synthetic rain. Selenium concentrations in soil leachate solutions displayed a spatial distribution, which cannot be explained by plume depo…

The hydrothermal system of the Domuyo volcanic complex (Argentina): A conceptual model based on new geochemical and isotopic evidences

The Domuyo volcanic complex (Neuquén Province, Argentina) hosts one of the most promising geothermal systems of Patagonia, giving rise to thermal manifestations discharging hot and Cl−-rich fluids. This study reports a complete geochemical dataset of gas and water samples collected in three years (2013, 2014 and 2015) from the main fluid discharges of this area. The chemical and isotopic composition (δD-H2O and δ18O-H2O) of waters indicates that rainwater and snow melting are the primary recharge of a hydrothermal reservoir located at relative shallow depth (400–600 m) possibly connected to a second deeper (2–3 km) reservoir. Reactive magmatic gases are completely scrubbed by the hydrotherm…

Atmospheric CFCs and geogenic HCFCs in gas discharges from Mt Etna and Vulcano Island (Italy)

Hydrogen sulfide measurements in air by passive/diffusive samplers and high-frequency analyzer: A critical comparison

In this study, hydrogen sulfide (H2S) measurements in air carried out using (a) passive/diffusive samplers (Radiello® traps) and (b) a high-frequency (60 s) real-time analyzer (Thermo® 450i) were compared in order to evaluate advantages and limitations of the two techniques. Four different sites in urban environments (Florence, Italy) and two volcanic areas characterized by intense degassing of H2S-rich fluids (Campi Flegrei and Vulcano Island, Italy) were selected for such measurements. The concentrations of H2S generally varied over 5 orders of magnitude (from 101e103 mg/m3), the H2S values measured with the Radiello® traps (H2SR) being significantly higher than the average values measure…

Etna International Training School of Geochemistry. Science meets Practice

Also this year, the “Etna International Training School of Geochemistry. Science meets practice” took place at Mt. Etna, now in its fourth edition. The school was hosted in the historical Volcanological Observatory “Pizzi Deneri”, one of the most important sites of the INGV - Osservatorio Etneo for geochemical and geophysical monitoring. Mount Etna, located in eastern Sicily, is the largest active volcano in Europe and one of the most intensely degassing volcanoes of the world [Allard et al., 1991; Gerlach, 1991]. Mt Etna emits about 1.6 % of global H2O fluxes from arc volcanism [Aiuppa et al., 2008] and 10 % of global average volcanic emission of CO2 and SO2 [D’Alessandro et al., 1997; Cal…

Impacts of volcanic hazards on rural communities and adaptative strategies: A case study of the Virunga Volcanic Province (Democratic Republic of Congo)

co auteur étranger; International audience; Active volcanoes are a continuous threat for several regions worldwide and cause socio-economic and environmental issues, including the Virunga Volcanic Province (D.R. Congo). There, more than 2 million people are permanently exposed to the hazards of the most active volcanoes in Africa: Nyiragongo and Nyamulagira. However, there is a clear lack of information regarding the impacts of these hazards and how they may be affected by social vulnerability. In this study, a household survey based on semi-structural interviews was performed for rural communities in Virunga. This research aims to (i) investigate the impacts of volcanic hazards on rural co…

Preliminary data on trace element emissions from Nyiragongo volcano (DR Congo)

Steam and gas emission rates from La Soufrière of Guadeloupe (Antilles arc): implications for the magmatic supply degassing during unrest

Since its last magmatic eruption in 1530 AD, La Soufrière andesitic volcano in Guadeloupe has displayed intense hydrothermal activity and six phreatic eruptive crises (the last of which, in 1976-1977, with 73000 evacuees). Here we report on the first direct quantification of gas plume emissions from La Soufrière summit vents, which gradually intensified during the past 20 years. Gas fluxes were determined in 2006 then 2012 [1] by measuring the horizontal and vertical distribution of volcanic gas concentrations in the air-diluted plume, the composition of the hot fumarolic fluid at exit (108°C), and scaling to the speed of plume transport (in situ measurements and FLIR imaging). We first dem…

Tellurium in active volcanic environments: Preliminary results

The cycle of major and trace elements in a volcanic environment

A geochemical traverse along the “Sperchios Basin – Evoikos Gulf” graben (Central Greece): Origin and evolution of the emitted fluids

The studied area is a 130 km long fast spreading graben in Central Greece. Its complex geodynamical setting includes both the presence of a subduction slab at depth responsible for the recent (Quaternary) volcanic activity in the area and the western termination of a tectonic lineament of regional importance (the North-Anatolian fault). A high geothermal gradient is made evident by the presence of many thermal springs with temperatures from 19 to 82 °C, that discharge along the normal faults bordering the graben. In the period 2004–2012, 58 gas and 69 water samples were collected and their chemical and isotopic analysis revealed a wide range of compositions. Two main groups of thermal water…

Another kind of “volcanic risk”: the acidification of sea-water. Vulcano Island (Italy) a natural laboratory for ocean acidification studies

Characterization of the Etna volcanic emissions through an active biomonitoring technique (moss-bags): Part 1 – Major and trace element composition

Active biomonitoring using moss-bags was applied to an active volcanic environment for the first time. Bioaccumulation originating from atmospheric deposition was evaluated by exposing mixtures of washed and air-dried mosses (Sphagnum species) at 24 sites on Mt. Etna volcano (Italy). Concentrations of major and a large suite of trace elements were analysed by inductively coupled mass and optical spectrometry (ICP-MS and ICP-OES) after total acid digestion. Of the 49 elements analysed those which closely reflect summit volcanic emissions were S, Tl, Bi, Se, Cd, As, Cu, B, Na, Fe, Al. Enrichment factors and cluster analysis allowed clear distinction between volcanogenic, geogenic and anthropo…

Geochemical characterisation of the alkaline and hyperalkaline groundwater in the Othrys Ophiolite Massif, central Greece

The complex geology of Greece includes two important parallel running ophiolitic belts. The Othrys Massif in central Greece belongs to the westernmost of them. In the current study, 33 water samples from cold hyperalkaline and hypothermal (T &lt; 40°C) alkaline springs and 30 gas samples (either dissolved or free) were collected at 17 different sites in and around this wide ophiolite outcrop, aiming to determine the origin of fluids and evidence gas-water-rock interaction processes taking place in the area. Water samples were analysed for their chemical (major ions and trace elements) and isotope (d18O-H2O, d2H-H2O) composition. They can be subdivided into alkaline (pH &lt;11) of both Mg-Ca…

Real-time measurements of Hg0 in volcanic, geothermal and anthropogenic systems: a multi-methodological approach using Lumex® instrumentation

Mercury represents a pollutant of global concern and strong environmental impact since is highly toxic. Hg is present in air in the oxidation states of 0 and +2, the former being the dominant species with a residence time of 1-2 years due to its high volatility, relatively low solubility and chemical inertness. Both volcanic/geothermal and anthropogenic systems are crucial contributor to the release of Hg0 in the atmosphere. In this work, a Lumex® (RA-915M) was used to evaluate the environmental impact in air of Hg0 from: i) the abandoned Hg mining site and geothermal areas from Mt. Amiata (Siena, Central Italy) and ii) selected Mediterranean volcanic and geothermal systems. The Lumex® inst…

Active biomonitoring (moss-bags) of volcanic emissions on Mt. Etna

Biomonitoring may be defined as the use of organisms and biomaterials (biomonitors) to obtain information on certain characteristics of a particular medium (atmosphere, hydrosphere etc.). In particular, mosses accumulate large amounts of trace metals, making them good bioaccumulators to estimate atmospheric pollution. The moss-bags technique, introduced in the early 1970’, has become very popular. Such active biomonitoring technique is particularly useful in highly polluted areas and has been extensively used in industrial and/or urban areas to examine deposition patterns and to recognize point sources of pollution. The main objective of this study, which represents the first application of…

Using mosses as biomonitors to study trace element emissions and their distribution in six different volcanic areas

Volcanoes emit SO2, CO2, and H2S, but also trace elements gases and particles such as As, Cd, Cr, Cu, Hg, Ni, Pb, and Sb. Active moss bag biomonitoring, an easy to apply and low budget method, was used to determine trace element release from volcanic areas of different geological context and climates. Exposure height variations (0.7–1.6 m above ground) due to different availability of natural tie points did not affect the results. Accumulation was linear for exposure durations from three days to nine weeks, so values were comparable by normalization to moss exposure time. Uncovered moss bags showed higher accumulation than co-exposed covered ones because of additional dust and wet deposit…

The Cycle of volcanogenic trace elements at Mt Etna (Italy): From volcanic emissions to atmospheric deposition

Atmospheric Deposition Of Volcanogenic Major And Trace Elements On Mt. Etna (Italy)

There are a variety of natural and anthropogenic sources of trace elements into the environment, and human activity has drastically changed the biogeochemical cycles and balance of several elements. In the last twenty years many efforts have been spent by the scientific community to better outline the levels of pollutants in the environment on a long-term basis, and to evaluate global large-scale changes. It is generally accepted that volcanic emissions are an important source of gases and particles to the atmosphere, contributing significantly to the natural geochemical cycles of all elements (Nriagu, 1989; Hinkley et al., 1999; Oppenheimer, 2003). Many studies have been carried out on the…

The Fate of Volcanogenic Major and Trace Elements emitted from the plume of Mount Etna

Mercury’s Distribution in the Atmosphere, Soils and Plants of the Active Hydrothermal Area of Nisyros (Greece).

GEOCHEMISTRY OF THE GAS MANIFESTATIONS OF GREECE: METHANE AND LIGHT HYDROCARBONS

Το σύνθετο γεωδυναμικό καθεστώς της Ελλάδας πηγάζει από την πολύπλοκη γεωλογική της ιστορία, η οποία χαρακτηρίζεται από έντονη σεισμική δραστηριότητα και ενισχυμένη γεωθερμική βαθμίδα. Αυτή η δραστηριότητα σε συνδυασμό με το ενεργό ηφαιστειακό τόξο, ευνοεί την ύπαρξη πολλών εκπομπών αερίων, με αποτέλεσμα την κατηγοριοποίηση σε CO2-, N2- και CH4-αέρια, ανάλογα με το επικρατών είδος. Η παρούσα εργασία επικεντρώνεται στο μεθάνιο και τους ελαφρούς υδρογονάνθρακες (C2-C6) με σκοπό τον προσδιορισμό της προέλευσή τους. Οι συγκεντρώσεις του CH4 (&lt;2 έως 915,200 μmol/mol) και η ισοτοπική του αναλογία (δ13C -79.8 έως +16.9 ‰, δD -298 έως +264‰) καλύπτουν ένα ευρύ φάσμα τιμών, που υποδεικνύει διαφορ…

The precious treasure of Mariano Valenza: The history of Ludovico Sicardi and the birth of geochemical volcano monitoring

I was lucky enough to meet Mariano Valenza in September 1995. I was hitchhiking on the highway that leads from Cefalu to Palermo to go back home. I had spent my summer holidays in the beautiful and wild Madonie mountains. An off-road vehicle (a Land Rover Defender) stopped and a refined gentleman with a curious and charismatic gaze offered me a ride. During our journey, we chatted pleasantly and he told he was originally from that area. When I told him, I was a Geology student, he smiled at me and said Then we will meet again soon, I am going to be your Teacher of Geochemistry!. After a few weeks the lessons began and I met again Professor Valenza in Via Archirafi 36, at the University of P…

Impact of acidic volcanic emissions on ash leaching and on the bioavailability and mobility of trace metals in soils of Mt Etna

We report on original geochemical data, which combine the rainfall trace metal contents from three different areas of Mt. Etna, variably fumigated by the volcanic plume, and those from soils, collected over the whole volcano. Trace element contents in rainfall appear mostly related to acidic ash leaching, while only for the most volatile elements (Cu, Zn, Cd, Pb, As, Sb, Tl, Se) we suggest a derivation from magmatic degassing. We analyzed separately the labile fraction of soil samples, considered the fraction bioavailable to plants and soil organisms living in. The complexing medium used to extract the bioavailable fraction simulates the growth environment of plant roots.The contents of tra…

Plume composition and volatile flux of Nyamulagira volcano, Democratic Republic of Congo, during birth and evolution of the lava lake, 2014-2015

Very little is known about the volatile element makeup of the gaseous emissions of Nyamulagira volcano. This paper tries to fill this gap by reporting the first gas composition measurements of Nyamulagira’s volcanic plume since the onset of its lava lake activity at the end of 2014. Two field surveys were carried out on 1 November 2014, and 13–15 October 2015. We applied a broad toolbox of volcanic gas composition measurement techniques in order to geochemically characterize Nyamulagira’s plume. Nyamulagira is a significant emitter of SO2, and our measurements confirm this, as we recorded SO2 emissions of up to ~ 14 kt/d during the studied period. In contrast to neighbouring Nyiragongo volc…

Rainwater-induced leaching of selenium, arsenic and vanadium from Etnean volcanic soils

Active volcanoes emit considerable amounts of contaminants such as As, Se and V. Mount Etna is the biggest volcano of Europe and an excellent geochemical site to study water-soil processes. Due to its volcanic activity, the rainwater has a strong compositional gradient, both in time and space. At present, the behaviour of trace elements in the soils around Mt Etna is poorly understood. To determine the influence of the rainwater pH on the potential mobilization of geogenic pollutants, batch experiments have been performed with synthetic rainwater for 25 soils collected along the flanks of the volcano. Our results show that: i) The maximum concentrations in the leaching solutions are higher …

Experimental studies on BrO/Br ratios at Stromboli, Etna, Masaya, Gorely and Nyiragongo

Mount Etna volcano (Italy) as a major “dust” point source in the Mediterranean area

Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity, they may have important environmental impacts from local to global scale. They can also severely affect the atmospheric and terrestrial environment at timescales ranging from a few to millions of years. Mt. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2 and halogens) and particulate matter, including some toxic trace elements. The aim of this study is to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Twenty-five samples were c…

Helium isotopes distribution in groundwater and thermal waters of Tunisia: relationship to tectonics and geology

Selenium around Etna Volcano, Italy

Humans are attracted by the fertile properties of volcanic soils and currently around 10% of the world population lives within active volcanic areas. Volcanoes emit significantly amounts of potentially toxic elements such as selenium (Se), even in the absence of obvious volcanic activity. Although Se is an essential element for humans, ingestion of an excess amount of Se can produce adverse effects. Mt. Etna, the biggest volcano in Europe, is persistently active for the last 200,000 years and one of the most intensely monitored volcanoes. We have studied selenium in rainwater and soils from Mt Etna volcano. Bulk depositions were collected from April 2006 to December 2007, using a network of…

Geochemical characterization of trace elements in thermomineral waters of Greece

Trace elements have a fundamental role in natural and anthropogenic systems. In waters, they present a great variability of concentrations that mostly depends on the degree of gaswaterrock interactions and geochemical conditions such as pH, temperature, redox and/or exchange reactions, etc. Even though, they are present in very low contents in hostrocks, elevated concentrations in ground or surface waters may have a hazardous impact on human and animal health and thus, it is important to both quantify and try to understand their behaviour in natural systems. Here we present the results of about 300 cold and thermal mineral waters collected along the entire Hellenic territory. Physicochemica…

Determination and comparison of acidic gas ratios at the Stromboli Volcano and Mount Etna obtained by various active alkaline traps

THE IMPACT OF VOLCANIC EMISSIONS ON ETNA’S SNOW COVER

New results and review of major and trace element output from worldwide passive degassing volcanoes

Estudio Hidrogeoquimico De Las Áreas Termales Del Complejo Volcánico Copahue-Caviahue

Hydrogeochemical study on Thermal areas of the Copahue-Caviahue Volcanic Complex The hydrothermal system hosted in the Copahue- Caviahue Volcanic Complex consists of different geothermal areas around the Copahue volcano, whose last eruptive cycle started on December 22 of 2012. This work presents new data from the samplings of November 2012 and march 2013 in Las Maquinas, Las Maquinitas, villa de Copahue and Chancho-Có areas. These acid-sulfate and steam heated waters, presented changes in their SO4-2 concentrations, especially in Las Maquinas and Las Maquinitas areas. Meanwhile, SO4-2/Cl- ratios presented a strong decrease in the samples from November 2012, regarding the samples from 2013.…

Atmospheric Deposition around the Industrial Areas of Milazzo and Priolo Gargallo (Sicily–Italy)—Part B: Trace Elements

The concentrations of trace elements in atmospheric bulk depositions (wet plus dry) were investigated from two highly industrialised areas of Sicily (southern Italy) from June 2018 to July 2019, in order to recognise the main natural and anthropogenic sources. A side objective of this study was to improve the common sampling procedures and analytical methods used for monitoring trace elements in atmospheric deposition. The trace element VWM (Volume-Weighted Mean) concentrations ranged from less than 0.01 &mu;g L&minus;1 for trace elements such as Cs, Tl, and U, up to 24 &mu;g L&minus;1 for minor elements (Al, Zn, Sr), in the filtered aliquot, while they reached concentrations up to 144 &mu;…

Volcanic health hazard: the acidification of seawater and trace metals accumulation study in Blue Mussels (Mytilus galloprovincialis). Vulcano Island (Italy)

Preliminary results of systematic sampling of gas manifestations in geodynamically active areas of Greece

Greece is located on a convergent plate boundary comprising the subduction of the African Plate beneath the Eurasian, while the Arabian plate approaches the Eurasian in a northwestward motion. It is considered to be one of the most tectonically active regions of Earth with a complex geodynamic setting, deriving from a long and complicated geological history. Due to this specific geological background, conditions for the formation of many thermal springs are favoured. In the past years, almost all the already known sites of degassing (fumaroles, soil gases, mofettes, gas bubbling in cold and thermal waters) located in the Hellenic area were sampled at least one time. Collected samples were a…

Application and evaluation of biomagnetic and biochemical monitoring of the dispersion and deposition of volcanically-derived particles at Mt. Etna, Italy

article i nfo Article history: Received 6 August 2009 Accepted 4 January 2010 Available online xxxx Biomagnetic monitoring, using tree leaves as passive surfaces for particle collection, has been shown to be a promising technique for assessing the dispersion and deposition of particles in the context of anthropogenic pollution. By comparing leaves' magnetic properties with trace metal levels measured in the leaves, we here assess the utility of the biomagnetic technique as a sensitive, fast and inexpensive method for assessment of volcanic plume deposition. Samples of sweet chestnut leaves (Castanea sativa) were collected from the area surrounding Mt. Etna volcano in Sicily during the 2008 …

Water chemistry and abiogenic methane content of a hyperalkaline spring related to serpentinization in the Argolida ophiolite (Ermioni, Greece)

Abstract Hyperalkaline mineral springs related to active continental serpentinization are a theme of growing interest since they may contain significant amounts of abiotic gas and have important implications for energy resource exploration, subsurface microbiology and astrobiology. We report the discovery of a new hyperalkaline (pH∼12) spring issuing in the Agioi Anargyroi monastery at Ermioni (Greece), connected to serpentinization of peridotites of the Argolis ophiolite. Two water samples have been collected from separated springs and analysed for the chemical composition of major, minor and trace elements, and isotopic composition (2H and 18O) of water by IC, ICP-OES, ICP-MS and IRMS, an…

Origin of methane and light hydrocarbons in natural fluids emissions: A study from Greece.

Abstract Greece, a country characterised by intense seismic and volcanic activity, has a complex geodynamic and geological setting that favours the occurrence of many gas manifestations. In this study, we address the origin of CH 4 and light hydrocarbons in cold and thermal emissions discharging along the Hellenic territory. Also, we investigate their possible relationship with the main geochemical composition of the gases and the different geological settings of the sampling sites. For this purpose we collected 101 new samples that were analysed for their chemical (O 2 , N 2 , CH 4 , CO 2 , He, Ne, Ar, H 2 , H 2 S and C 2 -C 6 hydrocarbons) and isotopic (R/R A , δ 13 C-CO 2 , δ 13 C-CH 4 a…

The contribution of volcanoes to the atmospheric trace metals budget in the Mediterranean basin

Volcanic emissions represent one of the major natural source for several trace metals (Cd, Cu, As, Pb, Hg and Zn) into the atmosphere both as gaseous and aerosol forms. The Mediterranean Sea can be considered a large geochemical sink for these elements whose source are the huge amounts of aerosols of different origin. The industrialised areas located in the northern part of the basin represent a nearly constant source of the anthropogenic-dominated aerosol. By contrast, the arid and desert regions located at the southern and eastern parts of the Mediterranean, are the sources of frequent dust “pulses” perturbing the “steady-state” conditions of the local atmosphere through the input of seve…

Origin and distribution of methane and C2-C6 hydrocarbons in hydrothermal and cold gaseous emissions in Greece

The Hellenic territory has a very complex geodynamic setting from a long and composite geological history, giving rise to an intense seismic activity deriving and favoring the occurrence of many cold and thermal gas manifestations. Geogenic sources release huge amounts of gases, which have a significant impact on the global balance of the subaerial Carbon Cycle. The study of the geochemistry of the natural gas emissions of the Greek territory is actually underway. In the present work, we focus on methane and light hydrocarbons (C2-C6) to define their origin. Concentrations of methane range from &lt; 2 to 915,200 mmol/mol and its isotopic ratios cover a wide range (d13C from -79.8‰ to +16.9‰…

Geochemical characterisation of the thermo-mineral waters of Greece

AbstractGeothermal areas of Greece are located in regions affected by recent volcanism and in continental basins characterised by elevated heat flow. Many of them are found along the coast, and thus, water is often saline due to marine intrusion. In the current study, we present about 300 unpublished and literature data from thermal and cold mineral waters collected along Greece. Samples were analysed for major ions, Li, SiO2 and isotopes in water. Measured temperatures range from 6.5 to 98 °C, pH from 1.96 to 11.98, while Total Dissolved Solutes (TDS) from 0.22 to 51 g/L. Waters were subdivided into four main groups: (1) thermal; (2) cold; (3) acidic (pH &lt; 5); and (4) hyperalkaline (pH …

A wider view on possible causes of observed BrO/SO2 – CO2/SO2 correlations – during volcanic degassing variations

Preliminary results of trace elements mobility in soils and plants from the active hydrothermal area of Nisyros island (Greece)

Volcanic signature of volatile trace elements on atmospheric deposition at Mt. Etna, Italy

Volcanic volatiles and aerosol emitted into the atmosphere ultimately fall on the Earth’s surface as wet or dry deposition, and they can influence the environment and the ecosystems at local and regional scales. Therefore, atmospheric deposition plays a key-role in the geochemical cycles, redistributing volcanogenic elements to the ground. For this reason, estimating the volcanogenic trace element fluxes from the atmosphere to the surface is necessary for a better knowledge of the environmental impact of the volcanic emissions. Nevertheless, from a literature review, we have recognized the scarcity of investigation on trace element deposition in the surroundings of active volcanoes. Here, w…

Sustainable Management Of Natural Resources And Natural Hazards Related Problems

Active volcanoes as emission point sources of atmospheric mercury

ercury emissions from active volcanoes are of interest for estimating the volcanogenic contribution of Hg to the atmosphere and for monitoring volcanic activity. The global Hg flux from natural sources is poorly known and considerable uncertainty still exists with respect to the complex physical and chemical reactions taking place in the atmosphere among the various Hg forms. The environmental hazard of Hg have been widely demonstrated for its high toxicity. Previous estimates from volcanic plumes are based on limited measurements and poorly determined speciation of Hg in volcanic emissions which is crucial for making reliable estimates of volcanic Hg source strengths and for predicting atm…

Chemical-physical parameters, major, minor and trace elements composition of thermo-mineral groundwaters of Greece

This dataset comprises samples of thermo-mineral waters collected by the same team over the period from October 2004 to March 2020 and analysed in the same laboratory. Samples were collected on the whole territory of Greece.

Chemical-physical parameters, major, minor and trace elements compositions of big karst springs of Greece

This database consists of samples of karst springs collected in Greece and selected on the base of their water flow (&gt; 50 L s-1), over the period from May 2016 to October 2022