Special Issue "Volcanic Plumes: Impacts on the Atmosphere and Insights into Volcanic Processes"

A special issue of Geosciences (ISSN 2076-3263). This special issue belongs to the section "Natural Hazards".

Deadline for manuscript submissions: closed (15 November 2017)

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Guest Editor
Dr. Pasquale Sellitto

Laboratoire de Météorologie Dynamique, École Normale Supérieure, 24, Rue Lhomond 75231, Paris Cedex 05, France
Website | E-Mail
Phone: +33-1-4432-2731
Interests: atmospheric aerosols; air pollution; climate; atmospheric radiative transfer; cirrus clouds; upper troposphere-lower stratosphere; pollution-climate interactions; Asian monsoon; volcanic emissions; remote sensing
Guest Editor
Dr. Giuseppe Salerno

Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Italy
Website | E-Mail
Interests: volcanic dynamics, degassing processes, multidisciplinary integration of geochemical and geophysical data; remote sensing of volcanic gas emissions using ultraviolet spectroscopy, scanning spectrometers, and SO2 camera
Guest Editor
Dr. Andrew McGonigle

Department of Geography, University of Sheffield, UK
Website | E-Mail
Phone: +44 114 222 7961

Special Issue Information

Dear Colleagues,

Volcanoes release plumes of gas and ash to the atmosphere, during episodes of passive and explosive behaviour. These ejecta have important implications for the chemistry and composition of the troposphere and stratosphere, with the capacity to alter Earth's radiation budget and climate system over a range of temporal and spatial scales. In particular, volcanogenic sulphur dioxide reacts to form sulphate aerosols, which increase global albedo, e.g., reducing surface temperatures, in addition to perturbing the formation processes and micro-physics, and therefore the optical/radiative properties, of low and high clouds. In addition, the diabatic radiative processes due to volcanic aerosols and subsequently formed clouds can alter the vertical stability and motion of the atmosphere. Released halogen species can also alter the oxidation capacity of the troposphere, and explosive eruptions cause the depletion of stratospheric ozone. Volcanic degassing, furthermore, played a key role in the formation of Earth’s atmosphere and volcanic plumes can degrade local and regional air quality, generate acid rain, pose hazards to aviation and human health, as well as damaging ecosystems. The chemical compositions and emission rates of volcanic plumes are also monitored, via a range of direct sampling and remote sensing instrumentation, in order to gain insights into subterranean processes, in respect of the magmatic bodies these volatiles exsolve from. Given the significant role these gases play in driving activity, e.g., via pressurisation, this is proving to be an increasingly fruitful means of improving our understanding of volcanic systems, potentially in concert with observations from geophysics and contributions from fluid dynamical modelling of conduit dynamics.

This Special Issue is aimed at presenting state of the art, multi-disciplinary science concerning all aspects of volcanic plumes, of relevance to the volcanology, climatology and atmospheric science communities.

Authors are encouraged to submit articles with respect to the following topics:

  • Novel and improved techniques for direct and remote (including satellite based) observations of gas and aerosols in volcanic plumes;
  • Use of volcanic degassing data to improve our understanding of volcanic and hydrothermal processes;
  • Satellite-based techniques and modelling studies which improve constraints upon the location and spatio-temporal dispersion of volcanic plumes;
  • Chemical processes occurring within volcanic plumes and plume impacts upon atmospheric composition, aerosol and cloud parameters;
  • Impact of volcanic emissions on local and regional air quality;
  • Direct (aerosol-radiation interactions) and indirect (aerosol-cloud-radiation interaction) climatic impacts of volcanic plumes over a range of spatio-temporal scales;
  • Dynamical, chemical and micro-physical modelling tools and their application to refine and better describe the temporal and spatial evolution of volcanic plumes.

We invite you to submit your manuscripts. Both research articles and reviews will be considered for publication.


Dr. Pasquale Sellitto
Dr. Giuseppe Salerno
Dr. Andrew McGonigle
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Geosciences is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 850 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Volcanic plume observation and modelling
  • Volcanic degassing and aerosol
  • Atmospheric impact of volcanic eruption
  • Volcanoes/Climate interactions
  • Eruptive processes
  • Volcanic degassing dynamics
  • In-plume chemical processes
  • Plume dispersion

Published Papers (15 papers)

View options order results:
result details:
Displaying articles 1-15
Export citation of selected articles as:

Editorial

Jump to: Research, Review, Other

Open AccessEditorial
Volcanic Plumes: Impacts on the Atmosphere and Insights into Volcanic Processes
Geosciences 2018, 8(5), 158; https://doi.org/10.3390/geosciences8050158
Received: 22 April 2018 / Revised: 22 April 2018 / Accepted: 24 April 2018 / Published: 30 April 2018
PDF Full-text (180 KB) | HTML Full-text | XML Full-text
Abstract
Here we introduce a Special Issue of Geosciences focused on the scientific research field of ‘Volcanic Plumes: Impacts on the atmosphere and insights into volcanic processes’ [...] Full article

Research

Jump to: Editorial, Review, Other

Open AccessArticle
Proximal Monitoring of the 2011–2015 Etna Lava Fountains Using MSG-SEVIRI Data
Geosciences 2018, 8(4), 140; https://doi.org/10.3390/geosciences8040140
Received: 21 December 2017 / Revised: 7 April 2018 / Accepted: 17 April 2018 / Published: 21 April 2018
Cited by 6 | PDF Full-text (6745 KB) | HTML Full-text | XML Full-text
Abstract
From 2011 to 2015, 49 lava fountains occurred at Etna volcano. In this work, the measurements carried out from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument, on board the Meteosat Second Generation (MSG) geostationary satellite, are processed to realize a proximal [...] Read more.
From 2011 to 2015, 49 lava fountains occurred at Etna volcano. In this work, the measurements carried out from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument, on board the Meteosat Second Generation (MSG) geostationary satellite, are processed to realize a proximal monitoring of the eruptive activity for each event. The SEVIRI measurements are managed to provide the time series of start and duration of eruption and fountains, Time Averaged Discharge Rate (TADR) and Volcanic Plume Top Height (VPTH). Due to its temperature responsivity, the eruptions start and duration, fountains start and duration and TADR are realized by exploiting the SEVIRI 3.9 μm channel, while the VPTH is carried out by applying a simplified procedure based on the SEVIRI 10.8 μm brightness temperature computation. For each event, the start, duration and TADR have been compared with ground-based observations. The VPTH time series is compared with the results obtained from a procedures-based on the volcanic cloud center of mass tracking in combination with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectories. The results indicate that SEVIRI is generally able to detect the start of the lava emission few hours before the ground measurements. A good agreement is found for both the start and the duration of the fountains and the VPTH with mean differences of about 1 h, 50 min and 1 km respectively. Full article
Figures

Figure 1

Open AccessArticle
Ozone Depletion in Tropospheric Volcanic Plumes: From Halogen-Poor to Halogen-Rich Emissions
Geosciences 2018, 8(2), 68; https://doi.org/10.3390/geosciences8020068
Received: 15 November 2017 / Revised: 24 January 2018 / Accepted: 24 January 2018 / Published: 10 February 2018
Cited by 3 | PDF Full-text (2992 KB) | HTML Full-text | XML Full-text
Abstract
Volcanic halogen emissions to the troposphere undergo a rapid plume chemistry that destroys ozone. Quantifying the impact of volcanic halogens on tropospheric ozone is challenging, only a few observations exist. This study presents measurements of ozone in volcanic plumes from Kīlauea (HI, USA), [...] Read more.
Volcanic halogen emissions to the troposphere undergo a rapid plume chemistry that destroys ozone. Quantifying the impact of volcanic halogens on tropospheric ozone is challenging, only a few observations exist. This study presents measurements of ozone in volcanic plumes from Kīlauea (HI, USA), a low halogen emitter. The results are combined with published data from high halogen emitters (Mt Etna, Italy; Mt Redoubt, AK, USA) to identify controls on plume processes. Ozone was measured during periods of relatively sustained Kīlauea plume exposure, using an Aeroqual instrument deployed alongside Multi-Gas SO2 and H2S sensors. Interferences were accounted for in data post-processing. The volcanic H2S/SO2 molar ratio was quantified as 0.03. At Halema‘uma‘u crater-rim, ozone was close to ambient in the emission plume (at 10 ppmv SO2). Measurements in grounding plume (at 5 ppmv SO2) about 10 km downwind of Pu‘u ‘Ō‘ō showed just slight ozone depletion. These Kīlauea observations contrast with substantial ozone depletion reported at Mt Etna and Mt Redoubt. Analysis of the combined data from these three volcanoes identifies the emitted Br/S as a strong but non-linear control on the rate of ozone depletion. Model simulations of the volcanic plume chemistry highlight that the proportion of HBr converted into reactive bromine is a key control on the efficiency of ozone depletion. This underlines the importance of chemistry in the very near-source plume on the fate and atmospheric impacts of volcanic emissions to the troposphere. Full article
Figures

Figure 1

Open AccessArticle
Combining Spherical-Cap and Taylor Bubble Fluid Dynamics with Plume Measurements to Characterize Basaltic Degassing
Geosciences 2018, 8(2), 42; https://doi.org/10.3390/geosciences8020042
Received: 11 October 2017 / Revised: 21 January 2018 / Accepted: 22 January 2018 / Published: 26 January 2018
Cited by 5 | PDF Full-text (1231 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Basaltic activity is the most common class of volcanism on Earth, characterized by magmas of sufficiently low viscosities such that bubbles can move independently of the melt. Following exsolution, spherical bubbles can then expand and/or coalesce to generate larger bubbles of spherical-cap or [...] Read more.
Basaltic activity is the most common class of volcanism on Earth, characterized by magmas of sufficiently low viscosities such that bubbles can move independently of the melt. Following exsolution, spherical bubbles can then expand and/or coalesce to generate larger bubbles of spherical-cap or Taylor bubble (slug) morphologies. Puffing and strombolian explosive activity are driven by the bursting of these larger bubbles at the surface. Here, we present the first combined model classification of spherical-cap and Taylor bubble driven puffing and strombolian activity modes on volcanoes. Furthermore, we incorporate the possibility that neighboring bubbles might coalesce, leading to elevated strombolian explosivity. The model categorizes the behavior in terms of the temporal separation between the arrival of successive bubbles at the surface and bubble gas volume or length, with the output presented on visually-intuitive two-dimensional plots. The categorized behavior is grouped into the following regimes: puffing from (a) cap bubbles; and (b) non-overpressurized Taylor bubbles; and (c) Taylor bubble driven strombolian explosions. Each of these regimes is further subdivided into scenarios whereby inter-bubble interaction does/does not occur. The model performance is corroborated using field data from Stromboli (Aeolian Islands, Italy), Etna (Sicily, Italy), and Yasur (Vanuatu), representing one of the very first studies, focused on combining high temporal resolution degassing data with fluid dynamics as a means of deepening our understanding of the processes which drive basaltic volcanism. Full article
Figures

Figure 1

Open AccessArticle
Aerosol Optical Properties of Pacaya Volcano Plume Measured with a Portable Sun-Photometer
Geosciences 2018, 8(2), 36; https://doi.org/10.3390/geosciences8020036
Received: 14 October 2017 / Revised: 22 December 2017 / Accepted: 22 December 2017 / Published: 23 January 2018
Cited by 1 | PDF Full-text (6292 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, Sun-photometer multichannel measurements of aerosol optical depths (AODs) in the visible and near-infrared spectral ranges, and Ångström parameters of the plume issued from the Pacaya volcano, Guatemala, are presented for the first time. These observations, made during a short-term campaign [...] Read more.
In this paper, Sun-photometer multichannel measurements of aerosol optical depths (AODs) in the visible and near-infrared spectral ranges, and Ångström parameters of the plume issued from the Pacaya volcano, Guatemala, are presented for the first time. These observations, made during a short-term campaign carried out on 29 and 30 January 2011, indicate a diluted (AODs lower than 0.1) volcanic plume composed of small particles (Ångström exponent ∼1.0 on 29 January and ∼1.4 on 30 January). Results are consistent with an ash-free plume. Finally, the impact of the choice of different wavelength pairs for the calculation of the Ångström parameters from the spectral AOD observations is tested and critically discussed. Full article
Figures

Figure 1

Open AccessArticle
Ground-Based Measurements of the 2014–2015 Holuhraun Volcanic Cloud (Iceland)
Geosciences 2018, 8(1), 29; https://doi.org/10.3390/geosciences8010029
Received: 13 November 2017 / Revised: 8 January 2018 / Accepted: 10 January 2018 / Published: 18 January 2018
Cited by 5 | PDF Full-text (5212 KB) | HTML Full-text | XML Full-text
Abstract
The 2014–2015 Bárðarbunga fissure eruption at Holuhraun in central Iceland was distinguished by the high emission of gases, in total 9.6 Mt SO2, with almost no tephra. This work collates all ground-based measurements of this extraordinary eruption cloud made under particularly [...] Read more.
The 2014–2015 Bárðarbunga fissure eruption at Holuhraun in central Iceland was distinguished by the high emission of gases, in total 9.6 Mt SO2, with almost no tephra. This work collates all ground-based measurements of this extraordinary eruption cloud made under particularly challenging conditions: remote location, optically dense cloud with high SO2 column amounts, low UV intensity, frequent clouds and precipitation, an extensive and hot lava field, developing ramparts, and high-latitude winter conditions. Semi-continuous measurements of SO2 flux with three scanning DOAS instruments were augmented by car traverses along the ring-road and along the lava. The ratios of other gases/SO2 were measured by OP-FTIR, MultiGAS, and filter packs. Ratios of SO2/HCl = 30–110 and SO2/HF = 30–130 show a halogen-poor eruption cloud. Scientists on-site reported extremely minor tephra production during the eruption. OPC and filter packs showed low particle concentrations similar to non-eruption cloud conditions. Three weather radars detected a droplet-rich eruption cloud. Top of eruption cloud heights of 0.3–5.5 km agl were measured with ground- and aircraft-based visual observations, web camera and NicAIR II infrared images, triangulation of scanning DOAS instruments, and the location of SO2 peaks measured by DOAS traverses. Cloud height and emission rate measurements were critical for initializing gas dispersal simulations for hazard forecasting. Full article
Figures

Figure 1

Open AccessFeature PaperArticle
A New Degassing Model to Infer Magma Dynamics from Radioactive Disequilibria in Volcanic Plumes
Geosciences 2018, 8(1), 27; https://doi.org/10.3390/geosciences8010027
Received: 15 November 2017 / Revised: 11 January 2018 / Accepted: 14 January 2018 / Published: 18 January 2018
Cited by 2 | PDF Full-text (933 KB) | HTML Full-text | XML Full-text
Abstract
Mount Etna volcano (Sicily, Italy) is the place where short-lived radioactive disequilibrium measurements in volcanic gases were initiated more than 40 years ago. Almost two decades after the last measurements in Mount Etna plume, we carried out in 2015 a new survey of [...] Read more.
Mount Etna volcano (Sicily, Italy) is the place where short-lived radioactive disequilibrium measurements in volcanic gases were initiated more than 40 years ago. Almost two decades after the last measurements in Mount Etna plume, we carried out in 2015 a new survey of 210Pb-210Bi-210Po radioactive disequilibria in gaseous emanations from the volcano. These new results [ ( 210 Po / 210 Pb ) = 42 and ( 210 Bi / 210 Pb ) = 7.5 ] are in fair agreement with those previously reported. Previously published degassing models fail to explain satisfactorily measured activity ratios. We present here a new degassing model, which accounts for 222Rn enrichment in volcanic gases and its subsequent decay into 210Pb within gas bubbles en route to the surface. Theoretical short-lived radioactive disequilibria in volcanic gases predicted by this new model differ from those produced by the former models and better match the values we measured in the plume during the 2015 campaign. A Monte Carlo-like simulation based on variable parameters characterising the degassing process (magma residence time in the degassing reservoir, gas transfer time, Rn-Pb-Bi-Po volatilities, magma volatile content) suggests that short-lived disequilibria in volcanic gases may be of use to infer both magma dynamics and degassing kinetics beneath Mount Etna, and in general at basaltic volcanoes. However, this simulation emphasizes the need for accurately determined input parameters in order to produce unambiguous results, allowing sharp characterisation of degassing processes. Full article
Figures

Figure 1

Open AccessArticle
Assessment of the Combined Sensitivity of Nadir TIR Satellite Observations to Volcanic SO2 and Sulphate Aerosols after a Moderate Stratospheric Eruption
Geosciences 2017, 7(3), 84; https://doi.org/10.3390/geosciences7030084
Received: 20 July 2017 / Revised: 20 August 2017 / Accepted: 24 August 2017 / Published: 13 September 2017
Cited by 2 | PDF Full-text (1922 KB) | HTML Full-text | XML Full-text
Abstract
Monitoring gaseous and particulate volcanic emissions with remote observations is of particular importance for climate studies, air quality and natural risk assessment. The concurrent impact of the simultaneous presence of sulphur dioxide (SO2) emissions and the subsequently formed secondary sulphate aerosols [...] Read more.
Monitoring gaseous and particulate volcanic emissions with remote observations is of particular importance for climate studies, air quality and natural risk assessment. The concurrent impact of the simultaneous presence of sulphur dioxide (SO2) emissions and the subsequently formed secondary sulphate aerosols (SSA) on the thermal infraRed (TIR) satellite observations is not yet well quantified. In this paper, we present the first assessment of the combined sensitivity of pseudo-observations from three TIR satellite instruments (the Infrared Atmospheric Sounding Interferometer (IASI), the MODerate resolution Imaging Spectro radiometer (MODIS) and the Spinning Enhanced Visible and InfraRed Imager (SEVIRI)) to these two volcanic effluents, following an idealized moderate stratospheric eruption. Direct radiative transfer calculations have been performed using the 4A (Automatized Atmospheric Absorption Atlas) radiative transfer model during short-term atmospheric sulphur cycle evolution. The results show that the mutual effect of the volcanic SO2 and SSA on the TIR outgoing radiation is obvious after three to five days from the eruption. Therefore, retrieval efforts of SO2 concentration should consider the progressively formed SSA and vice-versa. This result is also confirmed by estimating the information content of the TIR pseudo-observations to the bi-dimensional retrieved vector formed by the total masses of sulphur dioxide and sulphate aerosols. We find that it is important to be careful when attempting to quantify SO2 burdens in aged volcanic plumes using broad-band instruments like SEVIRI and MODIS as these retrievals present high uncertainties. For IASI, the total errors are smaller and the two parameters can be retrieved as independent quantities. Full article
Figures

Figure 1

Open AccessArticle
Nonlinear Spectral Unmixing for the Characterisation of Volcanic Surface Deposit and Airborne Plumes from Remote Sensing Imagery
Geosciences 2017, 7(3), 46; https://doi.org/10.3390/geosciences7030046
Received: 29 March 2017 / Revised: 16 June 2017 / Accepted: 20 June 2017 / Published: 23 June 2017
Cited by 2 | PDF Full-text (9832 KB) | HTML Full-text | XML Full-text
Abstract
In image processing, it is commonly assumed that the model ruling spectral mixture in a given hyperspectral pixel is linear. However, in many real life cases, the different objects and materials determining the observed spectral signatures overlap in the same scene, resulting in [...] Read more.
In image processing, it is commonly assumed that the model ruling spectral mixture in a given hyperspectral pixel is linear. However, in many real life cases, the different objects and materials determining the observed spectral signatures overlap in the same scene, resulting in nonlinear mixture. This is particularly evident in volcanoes-related imagery, where both airborne plumes of effluents and surface deposit of volcanic ejecta can be mixed in the same observation line of sight. To tackle this intrinsic complexity, in this paper, we perform a pilot test using Nonlinear Principal Component Analysis (NLPCA) as a nonlinear transformation, that projects a hyperspectral image onto a reduced-dimensionality feature space. The use of NLPCA is twofold: (1) it is used to reduce the dimensionality of the original spectral data and (2) it performs a linearization of the information, thus allowing the effective use of successive linear approaches for spectral unmixing. The proposed method has been tested on two different hyperspectral datasets, dealing with active volcanoes at the time of the observation. The dimensionality of the spectroscopic problem is reduced of up to 95% (ratio of the elements of compressed nonlinear vectors and initial spectral inputs), by the use of NLPCA. The selective use of an atmospheric correction pre-processing is applied, demonstrating how individual plume and volcanic surface deposit components can be discriminated, paving the way to future application of this method. Full article
Figures

Figure 1

Open AccessArticle
Volcanic Plume CO2 Flux Measurements at Mount Etna by Mobile Differential Absorption Lidar
Received: 23 January 2017 / Revised: 23 February 2017 / Accepted: 27 February 2017 / Published: 3 March 2017
Cited by 6 | PDF Full-text (5780 KB) | HTML Full-text | XML Full-text
Abstract
Volcanic eruptions are often preceded by precursory increases in the volcanic carbon dioxide (CO2) flux. Unfortunately, the traditional techniques used to measure volcanic CO2 require near-vent, in situ plume measurements that are potentially hazardous for operators and expose instruments to [...] Read more.
Volcanic eruptions are often preceded by precursory increases in the volcanic carbon dioxide (CO2) flux. Unfortunately, the traditional techniques used to measure volcanic CO2 require near-vent, in situ plume measurements that are potentially hazardous for operators and expose instruments to extreme conditions. To overcome these limitations, the project BRIDGE (BRIDging the gap between Gas Emissions and geophysical observations at active volcanoes) received funding from the European Research Council, with the objective to develop a new generation of volcanic gas sensing instruments, including a novel DIAL-Lidar (Differential Absorption Light Detection and Ranging) for remote (e.g., distal) CO2 observations. Here we report on the results of a field campaign carried out at Mt. Etna from 28 July 2016 to 1 August 2016, during which we used this novel DIAL-Lidar to retrieve spatially and temporally resolved profiles of excess CO2 concentrations inside the volcanic plume. By vertically scanning the volcanic plume at different elevation angles and distances, an excess CO2 concentration of tens of ppm (up to 30% above the atmospheric background of 400 ppm) was resolved from up to a 4 km distance from the plume itself. From this, the first remotely sensed volcanic CO2 flux estimation from Etna’s northeast crater was derived at ≈2850–3900 tons/day. This Lidar-based CO2 flux is in fair agreement with that (≈2750 tons/day) obtained using conventional techniques requiring the in situ measurement of volcanic gas composition. Full article
Figures

Figure 1

Review

Jump to: Editorial, Research, Other

Open AccessReview
Volcanic Plume Impact on the Atmosphere and Climate: O- and S-Isotope Insight into Sulfate Aerosol Formation
Geosciences 2018, 8(6), 198; https://doi.org/10.3390/geosciences8060198
Received: 4 May 2018 / Revised: 22 May 2018 / Accepted: 26 May 2018 / Published: 31 May 2018
Cited by 2 | PDF Full-text (2135 KB) | HTML Full-text | XML Full-text
Abstract
The impact of volcanic eruptions on the climate has been studied over the last decades and the role played by sulfate aerosols appears to be major. S-bearing volcanic gases are oxidized in the atmosphere into sulfate aerosols that disturb the radiative balance on [...] Read more.
The impact of volcanic eruptions on the climate has been studied over the last decades and the role played by sulfate aerosols appears to be major. S-bearing volcanic gases are oxidized in the atmosphere into sulfate aerosols that disturb the radiative balance on earth at regional to global scales. This paper discusses the use of the oxygen and sulfur multi-isotope systematics on volcanic sulfates to understand their formation and fate in more or less diluted volcanic plumes. The study of volcanic aerosols collected from air sampling and ash deposits at different distances from the volcanic systems (from volcanic vents to the Earth poles) is discussed. It appears possible to distinguish between the different S-bearing oxidation pathways to generate volcanic sulfate aerosols whether the oxidation occurs in magmatic, tropospheric, or stratospheric conditions. This multi-isotopic approach represents an additional constraint on atmospheric and climatic models and it shows how sulfates from volcanic deposits could represent a large and under-exploited archive that, over time, have recorded atmospheric conditions on human to geological timescales. Full article
Figures

Figure 1

Open AccessReview
Ground-Based Remote Sensing and Imaging of Volcanic Gases and Quantitative Determination of Multi-Species Emission Fluxes
Geosciences 2018, 8(2), 44; https://doi.org/10.3390/geosciences8020044
Received: 15 November 2017 / Revised: 16 January 2018 / Accepted: 17 January 2018 / Published: 26 January 2018
Cited by 9 | PDF Full-text (5282 KB) | HTML Full-text | XML Full-text
Abstract
The physical and chemical structure and the spatial evolution of volcanic plumes are of great interest since they influence the Earth’s atmospheric composition and the climate. Equally important is the monitoring of the abundance and emission patterns of volcanic gases, which gives insight [...] Read more.
The physical and chemical structure and the spatial evolution of volcanic plumes are of great interest since they influence the Earth’s atmospheric composition and the climate. Equally important is the monitoring of the abundance and emission patterns of volcanic gases, which gives insight into processes in the Earth’s interior that are difficult to access otherwise. Here, we review spectroscopic approaches (from ultra-violet to thermal infra-red) to determine multi-species emissions and to quantify gas fluxes. Particular attention is given to the emerging field of plume imaging and quantitative image interpretation. Here UV SO2 cameras paved the way but several other promising techniques are under study and development. We also give a brief summary of a series of initial applications of fast imaging techniques for volcanological research. Full article
Figures

Figure 1

Open AccessReview
Pyplis–A Python Software Toolbox for the Analysis of SO2 Camera Images for Emission Rate Retrievals from Point Sources
Geosciences 2017, 7(4), 134; https://doi.org/10.3390/geosciences7040134
Received: 11 October 2017 / Revised: 27 November 2017 / Accepted: 11 December 2017 / Published: 15 December 2017
Cited by 6 | PDF Full-text (15431 KB) | HTML Full-text | XML Full-text
Abstract
Ultraviolet (UV) SO2 cameras have become a common tool to measure and monitor SO2 emission rates, mostly from volcanoes but also from anthropogenic sources (e.g., power plants or ships). Over the past decade, the analysis of UV SO2 camera data [...] Read more.
Ultraviolet (UV) SO2 cameras have become a common tool to measure and monitor SO2 emission rates, mostly from volcanoes but also from anthropogenic sources (e.g., power plants or ships). Over the past decade, the analysis of UV SO2 camera data has seen many improvements. As a result, for many of the required analysis steps, several alternatives exist today (e.g., cell vs. DOAS based camera calibration; optical flow vs. cross-correlation based gas-velocity retrieval). This inspired the development of Pyplis (Python plume imaging software), an open-source software toolbox written in Python 2.7, which unifies the most prevalent methods from literature within a single, cross-platform analysis framework. Pyplis comprises a vast collection of algorithms relevant for the analysis of UV SO2 camera data. These include several routines to retrieve plume background radiances as well as routines for cell and DOAS based camera calibration. The latter includes two independent methods to identify the DOAS field-of-view (FOV) within the camera images (based on (1) Pearson correlation and (2) IFR inversion method). Plume velocities can be retrieved using an optical flow algorithm as well as signal cross-correlation. Furthermore, Pyplis includes a routine to perform a first order correction of the signal dilution effect (also referred to as light dilution). All required geometrical calculations are performed within a 3D model environment allowing for distance retrievals to plume and local terrain features on a pixel basis. SO2 emission rates can be retrieved simultaneously for an arbitrary number of plume intersections. Hence, Pyplis provides a state-of-the-art framework for more efficient and flexible analyses of UV SO2 camera data and, therefore, marks an important step forward towards more transparency, reliability and inter-comparability of the results. Pyplis has been extensively and successfully tested using data from several field campaigns. Here, the main features are introduced using a dataset obtained at Mt. Etna, Italy on 16 September 2015. Full article
Figures

Figure 1

Open AccessFeature PaperReview
Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology
Geosciences 2017, 7(3), 68; https://doi.org/10.3390/geosciences7030068
Received: 1 April 2017 / Revised: 23 July 2017 / Accepted: 1 August 2017 / Published: 8 August 2017
Cited by 11 | PDF Full-text (2172 KB) | HTML Full-text | XML Full-text
Abstract
Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing [...] Read more.
Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at ≈1 Hz, expediting more holistic investigations of volcanic source-process behaviour. Secondly, there has been the combination of surface observations of gas release with fluid dynamic models (numerical, mathematical, and laboratory) for gas flow in conduits, in attempts to link subterranean driving flow processes to surface activity types. There has also been considerable research and development concerning the technique itself, covering error analysis and most recently the adaptation of smartphone sensors for this application, to deliver gas fluxes at a significantly lower instrumental price point than possible previously. At this decadal juncture in the application of UV imaging in volcanology, this article provides an overview of what has been achieved to date as well as a forward look to possible future research directions. Full article
Figures

Figure 1

Other

Open AccessErratum
Erratum: Gliß, J.; et al. Pyplis–A Python Software Toolbox for the Analysis of SO2 Camera Images for Emission Rate Retrievals from Point Sources. Geosciences 2017, 7, 134
Geosciences 2018, 8(2), 70; https://doi.org/10.3390/geosciences8020070
Received: 7 February 2018 / Revised: 8 February 2018 / Accepted: 8 February 2018 / Published: 13 February 2018
PDF Full-text (127 KB) | HTML Full-text | XML Full-text
Abstract
The Geosciences Editorial Office would like to make the following change to this paper [...] Full article
Geosciences EISSN 2076-3263 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top