Agnès Mazot

GNS Science

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Salvatore Inguaggiato

Istituto Nazionale di Geofisica e Vulcanologia

Fabio Vita

Istituto Nazionale di Geofisica e Vulcanologia

Claudio Inguaggiato

Center for Scientific Research and Higher Education at Ensenada

Alain Bernard

Université Libre de Bruxelles

Marianna Cangemi

Istituto Nazionale di Geofisica e Vulcanologia

Iole Serena Diliberto

Istituto Nazionale di Geofisica e Vulcanologia

Bruce Christenson

GNS Science

Karen Britten

GNS Science

B. J. Scott

GNS Science

Geoff Kilgour

GNS Science

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GNS Science

Istituto Nazionale di Geofisica e Vulcanologia

Universidad Nacional Autónoma de México

University of Canterbury

Crown Research Institutes

University of Palermo

University of Auckland

University of Toronto

Centre National de la Recherche Scientifique

INGV Sezione di Palermo

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CO2 output discharged from Stromboli Island (Italy)

Chemical Geology (2012)

Salvatore Inguaggiato Mariana Patricia Jácome Paz Agnès Mazot Hugo Delgado Granados Claudio Inguaggiato

10.1016/j.chemgeo.2012.10.008

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Citations (39)

Environmental and Volcanic Implications of Volatile Output in the Atmosphere of Vulcano Island Detected Using SO2 Plume (2021–23)

Remote Sensing (2023)

Fabio Vita Benedetto Schiavo Claudio Inguaggiato Salvatore Inguaggiato Agnès Mazot

The volatiles released by the volcanic structures of the world contribute to natural environmental pollution both during the passive and active degassing stages. The Island of Vulcano is characterized by solfataric degassing mainly localized in the summit part (Fossa crater) and in the peripheral part in the Levante Bay. The normal solfataric degassing (high-temperature fumarolic area of the summit and boiling fluids emitted in the Levante Bay area), established after the last explosive eruption of 1888–90, is periodically interrupted by geochemical crises characterized by anomalous degassing that are attributable to increased volcanic inputs, which determine a sharp increase in the degassing rate. In this work, we have used the data acquired from the INGV (Istituto Nazionale di Geofisica e Vulcanologia) geochemical monitoring networks to identify, evaluate, and monitor the geochemical variations of the extensive parameters, such as the SO2 flux from the volcanic plume (solfataric cloud) and the CO2 flux from the soil in the summit area outside the fumaroles areas. The increase in the flux of volatiles started in June–July 2021 and reached its maximum in November of the same year. In particular, the mean monthly flux of SO2 plume of 22 tons day−1 (t d−1) and of CO2 from the soil of 1570 grams per square meter per day (g m2 d−1) increased during this event up to 89 t d−1 and 11,596 g m2 d−1, respectively, in November 2021. The average annual baseline value of SO2 output was estimated at 7700 t d−1 during normal solfataric activity. Instead, this outgassing increased to 18,000 and 24,000 t d−1 in 2021 and 2022, respectively, indicating that the system is still in an anomalous phase of outgassing and shows no signs of returning to the pre-crisis baseline values. In fact, in the first quarter of 2023, the SO2 output shows average values comparable to those emitted in 2022. Finally, the dispersion maps of SO2 on the island of Vulcano have been produced and have indicated that the areas close to the fumarolic source are characterized by concentrations of SO2 in the atmosphere higher than those permitted by European legislation (40 μg m−3 for 24 h of exposition) on human health.

Fumarole

10.3390/rs15123086

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Citations (2)

Long-time variation of soil CO2 fluxes at the summit crater of Vulcano (Italy)

Bulletin of Volcanology (2012)

Salvatore Inguaggiato Lorenzo Calderone Claudio Inguaggiato Agnès Mazot Sabina Morici

Fumarole

Soil gas

Summit

10.1007/s00445-012-0637-6

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Citations (30)

Twenty years of volcano data at GeoNet—collection, custodianship, and evolution of open data on New Zealand’s volcanoes

Bulletin of Volcanology (2024)

J. B. Hanson Steven Sherburn Yannik Behr Karen M. Britten Ery Hughes

10.1007/s00445-024-01769-x

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Citations (0)

Soil CO2 flux baseline in an urban monogenetic volcanic field: the Auckland Volcanic Field, New Zealand

Bulletin of Volcanology (2013)

Agnès Mazot Elaine R. Smid Luitgard Schwendenmann Hugo Delgado Granados Jan M. Lindsay

Soil gas

Volcanic ash

10.1007/s00445-013-0757-7

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Citations (19)

The volcanic activity changes occurred in the 2021–2022 at Vulcano island (Italy), inferred by the abrupt variations of soil CO2 output

Scientific Reports (2022)

Salvatore Inguaggiato Fabio Vita Iole Serena Diliberto Claudio Inguaggiato Agnès Mazot

Abstract The active cone of La Fossa is a close conduit volcano characterized by solphataric activity, manifested by discharging fluids through fumaroles and soil degassing. Since 1978 several degassing crises have been observed and interpreted as early signals of volcanic unrests. Recently, from June 2021 to May 2022, we measured the changes in soils CO 2 release to evaluating the level and duration of the actual exhaling crises. The CO 2 output has been evaluated by surveys carried out in anomalously degassing areas, located both in the La Fossa cone summit area and in other peripheral zones, coupled to near-real time monitoring data acquired by three automated stations. The strong and deep input of volatiles released from an underlying magma batch modified the chemical composition of the shallow plumbing system, bringing the system to a higher level of CO 2 total pressure. This work highlights that a geochemical networks of stations, located at some distance from the fumaroles release and/or from eruptive conduits, is useful and can be applied to characterizing and monitoring any other active volcanic system. This type of studies can be useful to contribute to forecast the next evolution of the studied systems.

Fumarole

10.1038/s41598-022-25435-4

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Citations (18)

Measurement of Atmospheric Mercury over Volcanic and Fumarolic Regions on the North Island of New Zealand Using Passive Air Samplers

ACS Earth and Space Chemistry (2020)

Meng Si David S. McLagan Agnès Mazot Natalie Szponar Bridget A. Bergquist

The estimation of mercury (Hg) emission fluxes from geothermal sources has a large uncertainty due to the paucity of relevant measurements. Using a high-precision, easy-to-deploy, and cost-effective passive air sampling method, we assessed the spatial concentration variability of gaseous elemental Hg (GEM) at three locations at or near geothermal sources in the Taupo Volcanic Zone on the North Island of New Zealand: Karapiti, Ngapouri, and Whakaari/White Island. GEM concentrations, averaged over periods of 1–4 months, were elevated above Southern Hemisphere background levels at all locations. Fumaroles were identified as major point sources of Hg, with levels in their vicinity exceeding background by up to 2 orders of magnitude (4.0–110 ng m–3). From a spatial GEM concentration map at Karapiti, we estimate an area-normalized Hg emission flux of ∼60 μg m–2 d–1. Contamination of samplers during storage was identified and corrected using field blanks. While this rendered the results for background samples semiquantitative, the main conclusions regarding spatial concentration variability and emission strength were unaffected. Isotopic analysis showed that the isotopic signatures of samples collected in the vicinity of fumaroles had negative mass-dependent fractionation (MDF, δ202Hg) and near-zero odd mass-independent fractionation (MIF, Δ199Hg) values compared to samples collected at a distance from geothermal sources, which had positive MDF and negative odd MIF values. With the ability for high spatial resolution measurement and reliable isotopic characterization of GEM, the passive air sampler is a useful tool to characterize Hg emissions from geothermal sources.

Fumarole

Mercury

10.1021/acsearthspacechem.0c00274

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Citations (18)

The Extensive Parameters as a Tool to Monitoring the Volcanic Activity: The Case Study of Vulcano Island (Italy)

Remote Sensing (2022)

Salvatore Inguaggiato Fabio Vita Iole Serena Diliberto Agnès Mazot Lorenzo Calderone

On Vulcano Island (Italy), many geochemical crises have occurred during the last 130 years of solfataric activity. The main crises occurred in 1978–1980, 1988–1991, 1996, 2004–2007, 2009–2010 and the ongoing 2021 anomalous degassing activity. These crises have been characterized by early signals of resuming degassing activity, measurable by the increase of volatiles and energy output emitted from the summit areas of the active cone, and particularly by increases of gas/water ratios in the fumarolic area at the summit. In any case, a direct rather than linear correspondence has been observed among the observed increase in the fluid output, seismic release and ground deformation, and is still a subject of study. We present here the results obtained by the long-term monitoring (over 13 years of observations) of three extensive parameters: the SO2 flux monitored in the volcanic plume, the soil CO2 flux and the local heat flux, monitored in the mild thermal anomaly located to the east of the high-temperature fumarole. The time variations of these parameters showed cyclicity in the volcanic degassing and a general increase in the trend in the last period. In particular, we focused on the changes in the mass and energy output registered in the period of June–December 2021, to offer in near-real-time the first evaluation of the level and duration of the actual exhalative crisis affecting Vulcano Island. In this last event, a clear change in degassing style was recorded for the volatiles emitted by the magma. For example, the flux of diffused CO2 from the soils reached the maximum never-before-recorded value of 34,000 g m−2 d−1 and the flux of SO2 of the plume emitted by the fumarolic field on the summit crater area reached values higher than 200 t d−1. The interpretation of the behavior of this volcanic system, resulting from the detailed analyses of these continuous monitoring data, will complete the framework of observations and help in defining and possibly forecasting the next evolution of the actual exhaling crisis.

Fumarole

Summit

10.3390/rs14051283

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Citations (37)

Fluid geochemistry and soil gas fluxes (CO2–CH4–H2S) at a promissory Hot Dry Rock Geothermal System: The Acoculco caldera, Mexico

Journal of Volcanology and Geothermal Research (2014)

Loïc Peiffer R. Bernard Agnès Mazot Yuri Taran Mirna Guevara

Caldera

Soil gas

Fumarole

10.1016/j.jvolgeores.2014.07.019

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Citations (36)

The acid volcanic lake of Santa Ana volcano, El Salvador

Geological Society of America eBooks (2004)

Alain Bernard C. Demetrio Escobar Agnès Mazot R. E. Gutierrez

Physical and chemical parameters were obtained from the crater lake of Santa Ana during a two-year monitoring program between 2000 and 2002. The lake contains cool (20 °C) acid-sulfate-chloride waters with a pH ∼1, SO4 = 11,000 mg/kg, Cl = 7000 mg/kg, and total dissolved solids concentration = 23,000 mg/kg. A bathymetric survey revealed a shallow lake with a maximum depth of 27 m and a volume of 0.47 million m3. Chemical data obtained from the lake show that the major cations are derived essentially from the congruent dissolution of the basaltic andesite host rock. Thermodynamic modeling shows that the acid waters last equilibrated with the host andesite at low temperature, ∼100 °C. Stable isotopic data of the lake waters indicate that D/H and 18O/16O isotopic ratios reflect the combination of evaporation effects at the lake surface and the contribution of deep magmatic fluids. δ34SHSO4 = 16.3‰ suggests that the main source of dissolved bisulfate ions is magmatic SO2. No δ18O equilibrium is observed between water and bisulfate ion, suggesting slow kinetics of the isotopic exchange at the low-temperature environment of the lake. Gas emissions from the fumarolic field increased in May 2000; lake temperature increased to 30 °C, and dissolved chloride and sulfate increased as well. Following this change in activity, deuterium and oxygen isotopic ratios shifted toward heavier compositions due to enhanced evaporation at the lake surface.

Crater lake

δ18O

10.1130/0-8137-2375-2.121

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Citations (34)