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  • 1
    Publikationsdatum: 2021-01-27
    Beschreibung: We report the first combined measurements of the composition and flux of gas emitted from Nyiragongo volcano by ground-based remote-sensing techniques. Ultraviolet spectroscopic measurements made in May/June 2005 and January 2006 indicate average SO2 emission rates of 38 kg s−1 and 23 kg s−1, respectively. Open-path Fourier transform infrared spectroscopic measurements obtained in May/June 2005, January 2006, and June 2007 indicate average molar proportions of 70, 24, 4.6, 0.87, 0.26, 0.11, and 0.0016% for H2O, CO2, SO2, CO, HCl, HF, and OCS, respectively. The composition of the plume was remarkably similar in 2005, 2006, and 2007, with little temporal variation in proportions of CO2, SO2, and CO, in particular, on the scale of seconds or days or even between the three field campaigns that span a period of 24 months. This stability persisted despite a wide range of degassing behaviors on the surface of the summit crater's lava lake (including discrete strombolian bursts and lava fountains) and variations in the SO2 emission rate. We explain these observations by a regime of steady state degassing in which bubbles nucleate and ascend in chemical equilibrium with the convecting magma. Short-term (seconds to minutes) temporal fluctuations in the SO2–HCl–HF composition were observed, and these are attributed to shallow degassing processes.
    Beschreibung: Published
    Beschreibung: Q02017
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Nyiragongo ; volcanic gas emissions ; FTIR ; DOAS ; remote sensing ; spectroscopy ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2020-11-23
    Beschreibung: L’Unità Funzionale Vulcanologia e Geochimica della Sezione di Catania dell’INGV sta sviluppando una nuova tecnologia che permette il monitoraggio in continuo del Radon, un gas che cambia la sua concentrazione in dipendenza del flusso di gas dal suolo. Visto che il tasso di emissione di radon dal suolo è dipendente dalla dinamica sia del magma che delle faglie, si tratta di un parametro che ha una forte potenzialità per la sorveglianza dei vulcani. Per tale motivo l’INGV, nell’ambito della Convenzione 2004-2005 con il Dipartimento della Protezione Civile, ha finanziato un progetto mirato proprio allo sviluppo tecnologico e scientifico di questo tipo di ricerca (progetto V3_6/28 – Etna, coordinatori S. Gresta e P. Papale, resp. M. Neri), la cui prima fase è iniziata il 1° giugno 2005. Questa iniziale fase di lavoro si è concretizzata con l’installazione di una prima sonda tipo “barasol” per la misura continua dell’attività di radon nel suolo presso Torre del Filosofo. Una seconda sonda, acquistata con fondi della Sezione Roma 1 dell’INGV (resp. F. Quattrocchi), è stata installata nei pressi del piano di faglia della Pernicana (quota ~1500 m s.l.m.). Una terza sonda, acquistata con fondi della Sezione Catania dell’INGV, è stata installata nei pressi di Dagala. La presente nota descrive quest’ultima installazione.
    Beschreibung: Istituto Nazionale di Geofisica e Vulcanologia
    Beschreibung: Unpublished
    Beschreibung: open
    Schlagwort(e): NONE ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: report
    Format: 412816 bytes
    Format: application/pdf
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  • 3
    Publikationsdatum: 2021-06-07
    Beschreibung: Stromboli made in July 2002 from fixed positions, using an automated plume scanning technique. Spectral data were collected using a miniature ultraviolet spectrometer, and SO2 column amounts were derived with a differential optical absorption spectroscopy evaluation routine. Scanning through the plume was enabled by a 45 turning mirror affixed to the shaft of a computer controlled stepper motor, so that scattered skylight from incremental angles within the horizon-to-horizon scans was reflected into the field of view of the spectrometer. Each scan lasted _5 min and, by combining these data with wind speeds, average fluxes of 940, 14, and 280 Mg d_1 were obtained for Etna, Vulcano, and Stromboli, respectively. For comparative purposes, conventional road and airborne traverses were also made using this spectrometer, yielding fluxes of 850, 17, and 210 Mg d_1. The automated scanning technique has the advantage of obviating the need for time-consuming traverses underneath the plume and is well suited for longer-term telemetered deployments to provide sustained high time resolution flux data.
    Beschreibung: Gruppo Nazionale per Vulcanolgia (GNV), the EC 5th Framework project ‘‘MULTIMO’’, and NERC grant GR9/04655
    Beschreibung: Published
    Beschreibung: 2455
    Beschreibung: 3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): volcanic gas monitoring, remote sensing, SO2 emissions, DOAS,ultraviolet spectroscopy ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2017-04-04
    Beschreibung: Ground-based thermal imaging is becoming an increasingly important tool for volcano surveillance, however the impact of volcanic plumes on quantitative measurements of surface temperature has not been previously evaluated. Here we use a radiative transfer model to simulate gas (primarily H2O and SO2) and aerosol absorptions over the path between a thermal camera and a heat source on Stromboli volcano, Italy. A FTIR spectrometer was used to quantify path amounts of gases likely to be encountered when making thermal measurements of the active craters. We find that when using a camera sensitive from 7.5 to 13 mm, underestimates of 400 K may be produced when viewing a source with an actual temperature of 1200 K. Cameras that operate between 3 and 5 mm are somewhat less susceptible to these errors.
    Beschreibung: Published
    Beschreibung: L14311
    Beschreibung: reserved
    Schlagwort(e): NONE ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Format: 1098429 bytes
    Format: application/pdf
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  • 5
    Publikationsdatum: 2017-04-04
    Beschreibung: traccia nella troposfera, tende ad accumularsi nei processi biologici che seguono la sua deposizione. Il suo lungo tempo di residenza in atmosfera (circa 1 anno) combinato con la sua elevata tossicità, rendono tale elemento di primaria importanza per l’impatto ambientale, soprattutto nelle aree di maggiore emissione. Le emissioni di mercurio da aree vulcaniche attive sono considerate una delle principali sorgenti di mercurio verso l’atmosfera terrestre, insieme con le emissioni antropogeniche legate all’attività mineraria per l’estrazione del cinabro. L’entità del contributo vulcanico a scala regionale e globale rimane tuttavia altamente incerto. Le emissioni vulcaniche possono essere ricche in mercurio elementare gassoso (Hg0), mercurio gassoso reattivo (HgII) presente soprattutto come solfuro ed altre forme di mercurio che devono essere ancora determinate (Symonds et al., 1992; Nicholson, 1993; Barnes & Seward, 1997). L’Etna rappresenta una delle maggiori sorgenti potenzialmente in grado di fornire grandi quantità di Hg in atmosfera, grazie alle sue notevoli emissioni gassose dal plume craterico e dai fianchi (e.g., Ferrara et al., 2000). A partire dalla metà di Novembre 2005 si è reso disponibile un analizzatore portatile della concentrazione di mercurio in fase gassosa Lumex RA-915+ (Figura 1), in visione temporanea grazie all’accordo tra il distributore per l’Italia (Loccioni srl, Ancona) e la sezione di Catania dell’INGV ottenuto su interessamento personale di M. Burton. L’analizzatore si basa sul principio della spettrometria differenziale Zeeman di assorbimento atomico, ed utilizza la modulazione ad alta frequenza della polarizzazione della luce. Lo strumento è in grado di misurare concentrazioni di Hg in aria o in fase gassosa da 0 a 20.000 ng m-3 nella modalità a cella multi-percorso (limite di rilevabilità = 2 ng m-3), oppure da 500 a 200.000 ng m-3 nella modalità a cella singolo-percorso (limite di rilevabilità = 500 ng m-3). La misura viene effettuata mediante aspirazione del campione di aria o di gas all’interno dello strumento attraverso un tubo che, nel caso di gas del suolo o gorgogliante in acqua, viene opportunamente collegato, rispettivamente, ad una sonda inserita nel suolo o ad un imbuto posto sul punto di campionamento. Nel corso degli ultimi due mesi lo strumento è stato utilizzato sull’Etna per misure di Hg nell’aria in varie zone del vulcano, in gas del suolo emessi in due siti ubicati presso Santa Venerina e presso Paternò, in gas fumarolici presso la Torre del Filosofo e in gas gorgoglianti emessi dalle polle d’acqua delle Salinelle dello Stadio di Paternò. Purtroppo, le spesso avverse condizioni meteorologiche che hanno caratterizzato questo periodo, hanno impedito un più esteso utilizzo dell’analizzatore, così come era stato inizialmente preventivato
    Beschreibung: Istituto Nazionale di Geofisica e Vulcanologia
    Beschreibung: Unpublished
    Beschreibung: open
    Schlagwort(e): NONE ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: report
    Format: 234261 bytes
    Format: application/pdf
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  • 6
    Publikationsdatum: 2017-04-04
    Beschreibung: Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania
    Beschreibung: Published
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): Etna ; Monitoraggio ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: report
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 2017-04-04
    Beschreibung: Quiescent and explosive magma degassing at Stromboli volcano sustain high temperature crater gas venting and a permanent volcanic plume which constitute key sources of information on the magma supply and dynamics, the physical processes controlling the explosive activity and, more broadly, the volcano feeding system. The chemical composition and the mass output of these crater emissions (gases, trace metals, radioactive isotopes) were measured using different methodologies: within-plume airborne measurements, ground-based plume filtering and/or in situ analysis, remote UV and OP-FTIR absorption spectroscopies. The results obtained, summarized in this paper, demonstrate a primary control of the magmatic gas phase on the eruptive regime and the budget of the volcano. The large excess gas discharge, compared to the lava extrusion rate, and the source depth of slug-driven strombolian explosions evidence extensive separate gas transfer across the volcano conduits, promoted by the high gas content (vesicularity) and then permeability of the shallow basaltic magma. Combined with data for volatiles dissolved in olivine-hosted melt inclusions, the results provide updated constraints for the magma supply rate (~0.3 m3 s-1 on average), the extent of intrusive versus extrusive magma degassing (~15), and the amount of un-erupted degassed magma that should be convectively cycled back in conduits and accumulated beneath the volcano over time (~0.25 km3 in last three decades). The results also provide insight into the possible triggering mechanism of intermittent paroxysmal explosions and the geochemical signals that might allow forecasting these events in future.
    Beschreibung: Unpublished
    Beschreibung: 4.4. Scenari e mitigazione del rischio ambientale
    Beschreibung: reserved
    Schlagwort(e): Stromboli ; magma feeding system ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Publikationsdatum: 2017-04-04
    Beschreibung: INGV, Sezione di Catania
    Beschreibung: Published
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: open
    Schlagwort(e): Etna ; Stromboli ; spettro ; SO2 ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: report
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Publikationsdatum: 2017-04-04
    Beschreibung: SO2 fluxes emitted by Stromboli during the 27th February–2nd April 2007 effusive eruption were regularly measured both by an automatic network of scanning ultraviolet spectrometers and by traverse measurements conducted by boat and helicopter. The results from both methodologies agree reasonably well, providing a validation for the automatic flux calculations produced by the network. Approximately 22,000 t of SO2 were degassed during the course of the 35 day eruption at an average rate of 620 t per day. Such a degassing rate is much higher than that normally observed (150–200 t/d), because the cross-sectional area occupied by ascending degassed magma is much greater than normal during the effusion, as descending, degassed magma that would normally occupy a large volume of the conduit is absent. We propose that the hydrostatically controlled magma level within Stromboli's conduit is the main control on eruptive activity, and that a high effusion rate led to the depressurisation of an intermediate magma reservoir, creating a decrease in the magma level until it dropped beneath the eruptive fissure, causing the rapid end of the eruption. A significant decrease in SO2 flux was observed prior to a paroxysm on 15th March 2007, suggesting that choking of the gas flowing in the conduit may have induced a coalescence event, and consequent rapid ascent of gas and magma that produced the explosion.
    Beschreibung: Published
    Beschreibung: 214-220
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): SO2 flux ; Stromboli ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 2017-04-04
    Beschreibung: We performed measurements using an SO2 imaging camera of the SO2 gas mass emitted during five discrete explosive events on Stromboli volcano on 3 October 2006. The SO2 gas mass released during discrete explosions was 15–40 kg per explosion, producing 3–8% of the total daily SO2 gas emission, demonstrating that in terms of gas flux Strombolian explosions are a second-order phenomenon compared with quiescent degassing. Using the typical gas composition measured with OP-FTIR allows us to determine the total gas mass released during an explosion as 360–960 kg with a volume of 1500–4100 m3 at 1 bar. At the probable source pressure of gas slug formation of 75 MPa this gas amount would occupy a volume equivalent to a sphere with a radius of 0.8–1 m, comparable with estimates of Stromboli's conduit geometry.
    Beschreibung: Published
    Beschreibung: 395-400
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): magmatic degassing ; remote sensing ; gas imaging ; Stromboli ; Strombolian explosions ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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