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  • Artikel  (79)
  • 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk  (45)
  • 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques  (28)
  • 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
  • 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
  • American Geophysical Union  (56)
  • Springer Berlin Heidelberg  (15)
  • Copernicus  (5)
  • ELSEVIER
  • Institute of Electrical and Electronics Engineers (IEEE)
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  • Artikel  (79)
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  • 1
    Publikationsdatum: 2020-11-26
    Beschreibung: We propose a long-term probabilistic multi-hazard assessment for El Misti Volcano, a composite cone located 〈20 km from Arequipa. The second largest Peruvian city is a rapidly expanding economic centre and is classified by UNESCO as World Heritage. We apply the Bayesian Event Tree code for Volcanic Hazard (BET_VH) to produce probabi- listic hazard maps for the predominant volcanic phenomena that may affect c.900,000 people living around the volcano. The methodology accounts for the natural variability displayed by volcanoes in their eruptive behaviour, such as different types/sizes of eruptions and possible vent locations. For this purpose, we treat probabilistically several model runs for some of the main hazardous phenomena (lahars, pyroclastic density currents (PDCs), tephra fall and ballistic ejecta) and data from past eruptions at El Misti (tephra fall, PDCs and lahars) and at other volcanoes (PDCs). The hazard maps, although neglecting possible interactions among phenomena or cascade effects, have been produced with a homogeneous method and refer to a common time window of 1 year. The probability maps reveal that only the north and east suburbs of Arequipa are exposed to all volcanic threats except for ballistic ejecta, which are limited to the uninhabited but touristic summit cone. The probability for pyroclastic density currents reaching recently expanding urban areas and the city along ravines is around 0.05 %/year, similar to the probability obtained for roof-critical tephra load- ing during the rainy season. Lahars represent by far the most probable threat (around 10 %/year) because at least four radial drainage channels can convey them approximately 20 km away from the volcano across the entire city area in heavy rain episodes, even without eruption. The Río Chili Valley repre- sents the major concern to city safety owing to the probable cascading effect of combined threats: PDCs and rockslides, dammed lake break-outs and subsequent lahars or floods. Although this study does not intend to replace the current El Misti hazard map, the quantitative results of this probabilistic multi-hazard assessment can be incorporated into a multi-risk analysis, to support decision makers in any future improvement of the current hazard evaluation, such as further land-use planning and possible emergency management.
    Beschreibung: Published
    Beschreibung: 771
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): BET_VH ; TITAN2D ; TEPHRA2 ; Probabilistic volcanic hazard ; Multi-hazard assessment ; El Misti Arequipa ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2020-12-14
    Beschreibung: Explosive volcanic eruptions are defined as the violent ejection of gas and hot fragments from a vent in the Earth's crust. Knowledge of ejection velocity is crucial for understanding and modeling relevant physical processes of an eruption, and yet direct measurements are still a difficult task with largely variable results. Here we apply pioneering high-speed imaging to measure the ejection velocity of pyroclasts from Strombolian explosive eruptions with an unparalleled temporal resolution. Measured supersonic velocities, up to 405 m/s, are twice higher than previously reported for such eruptions. Individual Strombolian explosions include multiple, sub-second-lasting ejection pulses characterized by an exponential decay of velocity. When fitted with an empirical model from shock-tube experiments literature, this decay allows constraining the length of the pressurized gas pockets responsible for the ejection pulses. These results directly impact eruption modeling and related hazard assessment, as well as the interpretation of geophysical signals from monitoring networks.
    Beschreibung: INGV-DPC “V2” and “Paroxysm”, FIRB-MIUR “Research and Development of New Technologies for Protection and Defense of Territory from Natural Risks”, and FP7-PEOPLE-IEF-2008 – 235328 Projects
    Beschreibung: Published
    Beschreibung: L02301
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): strombolian ; ejection velocity ; explosive eruption ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 3
    Publikationsdatum: 2021-03-01
    Beschreibung: A new period of eruptive activity started at Turrialba volcano, Costa Rica, in 2010 after almost 150 years of quiescence. This activity has been characterized by sporadic explosions whose frequency clearly increased since October 2014. This study aimed to identify the mechanisms that triggered the resumption of this eruptive activity and characterize the evolution of the phenomena over the past 2 years. We integrate 3He/4He data available on fumarole gases collected in the summit area of Turrialba between 1999 and 2011 with new measurements made on samples collected between September 2014 and February 2016. The results of a petrological investigation of the products that erupted between October 2014 and May 2015 are also presented. We infer that the resumption of eruptive activity in 2010 was triggered by a replenishment of the plumbing system of Turrialba by a new batch of magma. This is supported by the increase in 3He/4He values observed since 2005 at the crater fumaroles and by comparable high values in September 2014, just before the onset of the new eruptive phase. The presence of a number of fresh and juvenile glassy shards in the erupted products increased between October 2014 and May 2015, suggesting the involvement of new magma with a composition similar to that erupted in 1864–1866. We conclude that the increase in 3He/4He at the summit fumaroles since October 2015 represents strong evidence of a new phase of magma replenishment, which implies that the level of activity remains high at the volcano.
    Beschreibung: Published
    Beschreibung: 3V. Proprietà dei magmi e dei prodotti vulcanici
    Beschreibung: 4V. Dinamica dei processi pre-eruttivi
    Beschreibung: 5V. Dinamica dei processi eruttivi e post-eruttivi
    Beschreibung: JCR Journal
    Schlagwort(e): Turrialba volcano ; eruptive activity ; 3He/4He ; fumarole gases ; glassy shards ; juvenile component ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.08. Volcanic arcs ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 4
    Publikationsdatum: 2021-06-25
    Beschreibung: Uncertainties in modelling volcanic hazards are often amplified in geographically large systems and in volcanoes which have a diverse eruption history that comprises variable eruption compositions and styles from different vent locations. The large ~ 700 km2 Okataina Volcanic Centre (OVC) is a large silicic caldera complex in a geodynamic region of New Zealand which has displayed a range of eruption styles and compositions over its current phase of activity (26 ka - present), including one basaltic maar-forming eruption, one basaltic Plinian eruption, and nine rhyolitic Plinian eruptions. All three of these eruption styles have occurred within the past 3.5 ky, and any of these styles could occur in the event of a future eruption. The location of a future eruption is also unknown. Future vents could potentially open in one of three different possible areas of the OVC: the Tarawera linear vent zone (LVZ) (5 eruptions over the past 26 ky), the Haroharo LVZ (5 eruptions over the past 26 ky), or outside of these LVZs (1 eruption over the past 26 ky). A future rhyolitic or basaltic Plinian eruption from the OVC is likely to generate widespread tephra fall in loads that will cause significant disruption and socio- economic impacts throughout the surrounding region. Past OVC tephra studies have focused on evaluating hazard from a rhyolitic Plinian eruption at select vent locations in the OVC's Tarawera LVZ. Here, we expand upon these past studies by evaluating tephra hazard for all possible OVC eruption vent areas and for both rhyolitic and basaltic Plinian eruption styles, and exploring how these parameters influence tephra hazard forecasts. Probabilistic volcanic hazard model BET_VH and advection-diffusion tephra hazard model TEPHRA2 were used to assess the hazard of accumulating ≥ 10 kg m-2 of tephra from both basaltic Plinian and rhyolitic Plinian eruption styles, occurring from within the Tarawera LVZ, the Haroharo LVZ, and other potential vent areas within the caldera. We present the results of these analyses as a first-order tephra hazard assessment for the entire OVC. Our results highlight the importance of considering all the potential vent locations of a volcanic system, in order to capture the full eruption catalogue in analyses (e.g., 11 eruptions over 26 ky for the OVC, versus only 5 eruptions over 26 ky for the Tarawera LVZ), as well as the full potential distribution of tephra hazard. Although the Tarawera LVZ has been prominently discussed in studies of OVC hazard because of is recent activity (1886 and ~1315 AD), we find that, in the event of future eruption, the likelihood of a vent opening within the Haroharo LVZ (last eruption 5.6 ka) is equivalent (〈 1% difference) to that for the Tarawera LVZ (31.8% compared to 32.5%). We also find that an eruption from within the Haroharo LVZ presents a relatively higher hazard to several localities, such as the town of Kawerau, where the average absolute probability of accumulating ≥ 10 kg m-2 of tephra is 1.3 times greater than for an eruption from within the Tarawera LVZ. While the absolute probabilities of accumulating ≥ 10 kg m-2 of tephra in the next one year from a basaltic Plinian eruption are on average 7.2 times lower than for a rhyolitic Plinian eruption throughout the surrounding region, our results suggest that the hazard posed by a basaltic Plinian eruption does contribute to the overall OVC tephra hazard, raising absolute probabilities for the entire OVC by an order of 0.14, which may have implications when considering sensitive decision-making thresholds.
    Beschreibung: Published
    Beschreibung: 38
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): PVHA ; Okataina Volcanic Centre ; BET_VH ; TEPHRA2 ; volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 5
    Publikationsdatum: 2021-04-07
    Beschreibung: The flow of ground water in a buried permeable paleochannel can be observed at the ground surface through its self-potential signature. We apply this method to delineate the Saint-Ferréol paleo-channel of the Rhone River located in Camargue, in the South East of France. Negative potentials, 30 mV (reference taken outside the paleochannel),are associated with ground water flow in this major sand-filled channel (500 m wide). Electrical resistivity is primarily controls by the salinity of the pore water. Electrical resistivity tomography and in situ sampling show the salinity of the water inside the paleo-channel is ten times smaller by comparison with the pore water of the surrounding sediments. Combining electrical resistivity surveys, self-potential data, and a minimum of drilling information, a 3-D reconstruction of the architecture of the paleo-channel is obtained showing the usefulness of this methodology for geomorphological reconstructions in this type of coastal environment.
    Beschreibung: - Observatoire de Recherche en Environnement (ORE)
    Beschreibung: Published
    Beschreibung: L07401
    Beschreibung: partially_open
    Schlagwort(e): Self-potential ; electrical resistivity tomography ; hydrogeology ; tomography ; 01. Atmosphere::01.01. Atmosphere::01.01.02. Climate ; 03. Hydrosphere::03.02. Hydrology::03.02.02. Hydrological processes: interaction, transport, dynamics ; 03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 04. Solid Earth::04.02. Exploration geophysics::04.02.04. Magnetic and electrical methods ; 04. Solid Earth::04.06. Seismology::04.06.07. Tomography and anisotropy ; 05. General::05.02. Data dissemination::05.02.04. Hydrogeological data
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Format: 503 bytes
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  • 6
    Publikationsdatum: 2021-06-25
    Beschreibung: By using BET_VH, we propose a quantitative probabilistic hazard assessment for base surge impact in Auckland, New Zealand. Base surges resulting from phreatomagmatic eruptions are among the most dangerous phenomena likely to be associated with the initial phase of a future eruption in the Auckland Volcanic Field. The assessment is done both in the long-term and in a specific short-term case study, i.e. the simulated pre-eruptive unrest episode during Exercise Ruaumoko, a national civil defence exercise. The most important factors to account for are the uncertainties in the vent location (expected for a volcanic field) and in the run-out distance of base surges. Here, we propose a statistical model of base surge run-out distance based on deposits from past eruptions in Auckland and in analogous volcanoes. We then combine our hazard assessment with an analysis of the costs and benefits of evacuating people (on a 1km x 1km cell grid). In addition to stressing the practical importance of a cost-benefit analysis in creating a bridge between volcanologists and decision makers, our study highlights some important points. First, in the Exercise Ruaumoko application, the evacuation call seems to be required as soon as the unrest phase is clear; additionally, the evacuation area is much larger than what is recommended in the current Contingency Plan. Secondly, the evacuation area changes in size with time, due to a reduction in the uncertainty in the vent location and increase in the probability of eruption. It is the tradeoff between these two factors that dictates which cells must be evacuated, and when, thus determining the ultimate size and shape of the area to be evacuated.
    Beschreibung: Published
    Beschreibung: 705-723
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Auckland Volcanic Field ; Base surge ; Bayesian event tree ; Volcanic hazard ; Cost benefit analysis ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 7
    Publikationsdatum: 2021-06-15
    Beschreibung: To assess ways in which the products of explosive eruptions interact with human settlements, we performed volcanological and rock magnetic analyses on the deposits of the A.D. 79 eruption at the Pompeii excavations (Italy). During this eruption the Roman town of Pompeii was covered by 2.5 m of fallout pumice and then partially destroyed by pyroclastic density currents (PDCs). Anisotropy of magnetic susceptibility measurements performed on the fine matrix of the deposits allowed the quantification of the variations in flow direction and emplacement mechanisms of the parental PDCs that entered the town. These results, integrated with volcanological field investigations, revealed that the presence of buildings, still protruding through the fallout deposits, strongly affected the distribution and accumulation of the erupted products. All of the PDCs that entered the town, even the most dilute ones, were density stratified currents in which interaction with the urban fabric occurred in the lower part of the current. The degree of interaction varied mainly as a function of obstacle height and density stratification within the current. For examples, the lower part of the EU4pf current left deposits up to 3 m thick and was able to interact with 2- to 4-m-high obstacles. However, a decrease in thickness and grain size of the deposits across the town indicates that even though the upper portion of the current was able to decouple from the lower portion, enabling it to flow over the town, it was not able to fully restore the sediment supply to the lower portion in order to maintain the deposition observed upon entry into the town.
    Beschreibung: Published
    Beschreibung: B05213
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Pompeii ; facies ; magnetic fabric ; pyroclastic density currents ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 8
    Publikationsdatum: 2021-06-15
    Beschreibung: During the A.D. 79 eruption of Vesuvius, Italy, the Roman town of Pompeii was covered by 2.5 m of pyroclastic fall pumice and then partially destroyed by pyroclastic density currents (PDCs). Thermal remanent magnetization measurements performed on the lithic and roof tile fragments embedded in the PDC deposits allow us to quantify the variations in the temperature (Tdep) of the deposits within and around Pompeii. These results reveal that the presence of buildings strongly influenced the deposition temperature of the erupted products. The first two currents, which entered Pompeii at a temperature around 300–360°C, show drastic decreases in the Tdep, with minima of 100–140°C, found in the deposits within the town. We interpret these decreases in temperature as being the result of localized interactions between the PDCs and the city structures, which were only able to affect the lower part of the currents. Down flow of Pompeii, the lowermost portion of the PDCs regained its original physical characteristics, emplacing hot deposits once more. The final, dilute PDCs entered a town that was already partially destroyed by the previous currents. These PDCs left thin ash deposits, which mantled the previous ones. The lack of interaction with the urban fabric is indicated by their uniform temperature everywhere. However, the relatively high temperature of the deposits, between 140 and 300°C, indicates that even these distal, thin ash layers, capped by their accretionary lapilli bed, were associated with PDCs that were still hot enough to cause problems for unsheltered people.
    Beschreibung: Published
    Beschreibung: B05214
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Pompeii ; temperature ; magnetic fabric ; pyroclastic density currents ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 9
    Publikationsdatum: 2017-04-04
    Beschreibung: The recent eruption of Mount Etna (July 2001) offered the opportunity to analyze magma-derived volatiles emitted during preand syn-eruptive phases, and to verify whether their composition is affected by changes in volcanic dynamics. This paper presents the results of analyses of F, Cl and S in the volcanic plume collected by filter-packs, and interprets variations in the composition based on contrasting solubility in magmas. A Rayleigh-type degassing mechanism was used to fit the acquired data and to estimate Henryâ s solubility constant ratios in Etnean basalt. This model provided insights into the dynamics of the volcano. Abundances of sulfur and halogens in eruptive plumes may help predict the temporal evolution of an ongoing effusive eruption.
    Beschreibung: -Gruppo Nazionale per la Vulcanologia.
    Beschreibung: Published
    Beschreibung: 1559
    Beschreibung: partially_open
    Schlagwort(e): magmatic degassing ; acidic gases ; plume chemistry ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 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
    Format: 503 bytes
    Format: 275912 bytes
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  • 10
    Publikationsdatum: 2017-04-04
    Beschreibung: Sulphur speciation in volcanic gases acts as a major redox buffer, and H2S/SO2 ratios represent a valuable indicator of magmatic conditions and interactions between magmatic and hydrothermal fluids. However, measurement of H2S/SO2 even by direct sampling techniques, is not straightforward. We report here on application of a small ultraviolet spectrometer for real-time field measurement of H2S and SO2 concentrations, using open-path and extractive configurations. The device was tested at fumaroles on Solfatara and Vulcano, Italy, in November 2002. H2S concentrations of up to 220ppmm(400 ppmv) were measured directly above the Bocca Grande fumarole at Solfatara, and H2S/SO2 molar ratios of 2 and 2.4, respectively, were determined for the ‘F11’ and ‘F0’ fumaroles at Vulcano. In comparison with other optical techniques capable of multiple volcanic gas measurements, such as laser and FTIR spectroscopy, this approach is considerably simpler and cheaper, with the potential for autonomous, sustained hightime resolution operation.
    Beschreibung: Published
    Beschreibung: 1652
    Beschreibung: partially_open
    Schlagwort(e): Remote monitoring ; Plume chemistry ; sulphur species ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Format: 503 bytes
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  • 11
    Publikationsdatum: 2017-04-04
    Beschreibung: Soil temperature and total dissolved gas pressure(TDGP) data were recorded by two continuous monitoring stations on the volcano of Stromboli (Italy) between March and October 2006. During this period several TDGP and soil temperature anomalies, unrelated to external causes and characterized by a similar shape and occurrence time, were recorded. These anomalies were interpreted as transients due to changes in the degassing regime of the volcano,which was in turn related to changes in the partition ratio of the volcanic fluidsbetweenthe conduitandthe soil. In thesame period Stromboli experienced an anomalous phase of volcanic and tectonic activity. The close correlation found between volcano-tectonic activity and variations in anomalousmonitored parameters suggests that their continuous monitoring may be a useful tool for the surveillance of volcanic activity on the island.
    Beschreibung: Published
    Beschreibung: L08301
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Dissolved gases ; Soil temperature ; Total dissolved gas pressure ; Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 12
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    Unbekannt
    American Geophysical Union
    Publikationsdatum: 2017-04-04
    Beschreibung: One of the most critical practical actions to reduce volcanic risk is the evacuation of people from threatened areas during volcanic unrest. Despite its importance, this decision is usually arrived at subjectively by a few individuals, with little quantitative decision support. Here, we propose a possible strategy to integrate a probabilistic scheme for eruption forecasting and cost-benefit analysis, with an application to the call for an evacuation of one of the highest risk volcanoes: Vesuvius. This approach has the following merits. First, it incorporates a decision-analysis framework, expressed in terms of event probability, accounting for all modes of available hazard knowledge. Secondly, it is a scientific tool, based on quantitative and transparent rules that can be tested. Finally, since the quantitative rules are defined during a period of quiescence, it allows prior scrutiny of any scientific input into the model, so minimizing the external stress on scientists during an actual emergency phase. Whilst we specifically report the case of Vesuvius during the MESIMEX exercise, the approach can be generalized to other types of natural catastrophe.
    Beschreibung: Published
    Beschreibung: L22310
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: partially_open
    Schlagwort(e): evacuation ; probabilistic eruption forecasting ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 13
    Publikationsdatum: 2017-04-04
    Beschreibung: In this paper we integrate stratigraphic and sedimentological analyses of the volcaniclastic deposits, emplaced during initial opening and later widening of the Valle del Bove depression, with the available stratigraphy of the inner walls, and marine offshore data, structural data, and magnetic surveys to develop a comprehensive model for the opening of the Valle del Bove depression. The resulting model adds new insight into the triggering mechanisms of the flank collapse. Additionally, it suggests a three-stage evolution of the eastern flank of Etna. (1) About 10 Kyr ago, the extinct Ellittico volcano (60 80 (per uniformità anche con Acireale) to 15 Kyr) collapsed, forming the early Valle del Bove. The collapse produced an avalanche deposit that spread ESE and formed the base of the Milo Lahar and the Chiancone deposits. (2) The second stage involved instability-related minor collapses within the valley, causing southward and westward enlargement of the depression and the emplacement of the debris flow sequence that comprises the upper part of the Milo Lahar deposit. (3) Available debris that accumulated within the Valle del Bove from smaller subsequent collapses was deposited at the mouth of the Valle del Bove in the fluvial sequence that forms most of the exposed part of the Chiancone deposit. The emplacement of the whole volcaniclastic sequence occurred between 10 and 2 Kyr ago. Since then, the Valle del Bove has acted as a basin protecting the lower eastern flank of Etna from lava flows or inundations of volcaniclastic debris.
    Beschreibung: Published
    Beschreibung: 65-75
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: open
    Schlagwort(e): Etna ; flank collapse ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
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  • 14
    Publikationsdatum: 2017-04-04
    Beschreibung: Stromboli is a 3000-m-high, conical island-arc volcano rising to 900 m above sea level. It is the most active volcano of the Aeolian Archipelago in the Tyrrhenian Sea (Italy). In the last 13 Kr four large-volume (1 km3) flank collapses have played an important role in shaping the northwestern flank (Sciara del Fuoco- SdF) of the volcano. These flank collapses have the potential to cause hazardous tsunamis in the Aeolian islands and farther afield along the Italian coast. In addition, smaller volume, much more frequent partial collapses of the SdF have been shown to be tsunami generating, potentially hazardous events One such partial collapse occurred on 30/12/2002, on the north-western flank of the island. The resulting landslide generated a 10-m-high tsunami that impacted the island. Multibeam bathymetry, side-scan sonar and seabed visual observations reveal that 25-30 x 106 m3 of sediments were deposited on the offshore from the Sciara del Fuoco landslide. Sediment samples have led to the recognition of a proximal coarse-grained landslide deposit on the volcano slope and a distal, cogenetic, sandy turbidite 24 km from the Stromboli shoreline. The proximal landslide deposit consists of two contiguous facies: (1) a chaotic, coarse grained (meter- to centimetre-sized clasts) deposit and (2) a sand deposit containing a lower, cross bedded sand layer and an upper structureless, pebbly sand bed, capped by seafloor ripple bedforms. The ubiquitous sand facies develops laterally with and over the coarse-grained deposits. Distally, a capping 2-3 cm-thick sand layer, not present in a pre-landslide September 2002 core, is interpreted as the finer grained turbidite equivalent of the proximal deposits. Characteristics of the SdF landslide deposits suggest that they derive from cohesionless, sandy-matrix, density flows. Flow rheology resulted in segregation of the density flow into sand-rich and clast-rich regions. Our results show that a range of density flow transitions, based principally on particle concentration and grain-size partitioning of cohesionless parent flows, can be identified in the proximal and distaldeposits of this relatively small-scale landslide event on Stromboli.
    Beschreibung: Unpublished
    Beschreibung: 23
    Beschreibung: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: open
    Schlagwort(e): Stromboli ; flank collapse ; tsunami ; submarine landslide deposits ; 04. Solid Earth::04.04. Geology::04.04.04. Marine geology ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
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  • 15
    Publikationsdatum: 2017-04-04
    Beschreibung: Spectral properties of volcanic materials in the optical region (350–2500 nm) of the electromagnetic spectrum are analyzed. The goal is to characterize air-fall deposits, recent lava flows, and old lava flows based on their spectral reflectance properties and on the textural characteristics (grain size) of pyroclastic deposits at an active basaltic volcano. Data were acquired during a spectroradiometric field survey at Mt. Etna (Italy) in summer 2003 and combined with hyperspectral satellite (Hyperion) and airborne LiDAR (Light Detection and Ranging) data. In addition, air-fall deposits produced by the highly explosive 2002–2003 eruption have been sampled and spectrally characterized at different distances from the new vents. The spectral analysis shows that air-fall deposits are characterized by low reflectance values besides variations in grain size. This distinguishes them from other surface materials. Old lava flows show highest reflectance values due to weathering and vegetation cover. The spectral data set derived from the field survey has been compared to corrected satellite hyperspectral data in order to investigate the Hyperion capabilities to differentiate the surface cover using the reflectance properties. This has allowed us to identify the 2002–2003 air-fall deposits in a thematic image just few months after their emplacement. Moreover, the observed differences in the field spectra of volcanic surfaces have been compared with differences in the signal intensity detected by airborne LiDAR survey showing the possibility to include information on the texture of volcanic surfaces at Mt. Etna. The approach presented here may be particularly useful for remote and inaccessible volcanic areas and also represents a potentially powerful tool for the exploration of extraterrestrial volcanic surfaces.
    Beschreibung: Italian National Group of Volcanology
    Beschreibung: Published
    Beschreibung: 142-155
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Mt. Etna ; Lava ; Reflectance spectra ; Hyperion ; LiDAR ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods ; 04. Solid Earth::04.02. Exploration geophysics::04.02.07. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 16
    Publikationsdatum: 2017-04-04
    Beschreibung: On 16 November 2006 a flank collapse affected the unstable eastern slope of the South-East Crater (SEC) of Mount Etna. The collapse occurred during one of the paroxysmal events with sustained strombolian activity that characterized the August–December 2006 eruption and was triggered by erosion of loose, hydrothermally altered material of the steep south-east sector of SEC from the outpour of lava. The collapse produced a debris avalanche that involved both lithic and juvenile material and resulted in a deposit emplaced on the eastern flank of the volcano up to 1.2 km away from the source. The total volume of the deposit was estimated to be in the order of 330,000–413,000 m3. The reconstruction of the collapse event was simulated using TITAN2D software designed to model granular avalanches and landslides. This approach can be used to estimate areas that may be affected by similar collapse events in the future. The area affected by the 16 November 2006 lateral collapse of SEC was a small portion of the Mount Etna summit area, but the fact that no one was killed or injured should be considered fortuitous. The summit and adjacent areas of the volcano, in fact, are usually visited by many tourists who are not prepared to face this type of danger. The 16 November 2006 collapse points to the need to be prepared for similar events through scientific investigation (analysis of flank instability, numerical simulation of flows) and development of specific civil protection plans.
    Beschreibung: Published
    Beschreibung: B02204
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Mount Etna ; flank instability ; volcaniclastic deposit ; granular flows ; numerical simulation ; volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 17
    Publikationsdatum: 2017-04-04
    Beschreibung: Methane plays an important role in the Earth’s atmospheric chemistry and radiative balance being the second most important greenhouse gas after carbon dioxide. Methane is released to the atmosphere by a wide number of sources, both natural and anthropogenic, with the latter being twice as large as the former (IPCC, 2007). It has recently been established that significant amounts of geological methane, produced within the Earth’s crust, are currently released naturally into the atmosphere (Etiope, 2004). Active or recent volcanic/geothermal areas represent one of these sources of geological methane. But due to the fact that methane flux measurements are laboratory intensive, very few data have been collected until now and the contribution of this source has been generally indirectly estimated (Etiope et al., 2007). The Greek territory is geodynamically very active and has many volcanic and geothermal areas. Here we report on methane flux measurements made at two volcanic/geothermal systems along the South Aegean volcanic arc: Sousaki and Nisyros. The former is an extinct volcanic area of Plio-Pleistocene age hosting nowadays a low enthalpy geothermal field. The latter is a currently quiescent active volcanic system with strong fumarolic activity due to the presence of a high enthalpy geothermal system. Both systems have gas manifestations that emit significant amounts of hydrothermal methane and display important diffuse carbon dioxide emissions from the soils. New data on methane isotopic composition and higher hydrocarbon contents point to an abiogenic origin of the hydrothermal methane in the studied systems. Measured methane flux values range from –48 to 29,000 (38 sites) and from –20 to 1100 mg/mˆ2/d (35 sites) at Sousaki and Nisyros respectively. At Sousaki measurement sites covered almost all the degassing area and the diffuse methane output can be estimated in about 20 t/a from a surface of about 10,000 mˆ2. At Nisyros measurements covered the Stephanos and Kaminakia areas, which represent only a part of the entire degassing area. The two areas show very different methane degassing pattern with latter showing much higher flux values. Methane output can be estimated in about 0.25 t/a from an area of about 30,000 mˆ2 at Stephanos and about 1 t/a from an area of about 20,000 mˆ2 at Kaminakia. The total output from the entire geothermal system of Nisyros probably should not exceed 2 t/a.
    Beschreibung: Published
    Beschreibung: Vienna, Austria
    Beschreibung: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Beschreibung: open
    Schlagwort(e): methane output ; diffuse degassing ; volcanic/hydrothermal systems ; Greece ; 01. Atmosphere::01.01. Atmosphere::01.01.03. Pollution ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Poster session
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  • 18
    Publikationsdatum: 2017-04-04
    Beschreibung: 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 most impacted by volcanic emissions. Leaves collected along two radial transects from the active vents on the eastern flank, highlight that the levels of metals decrease one or two orders of magnitude with increasing distance from the source. This variability is higher for volatile elements (As, Bi, Cd, Cs, Pb, Sb, Tl) than for more refractory elements (Al, Ba, Sc, Si, Sr, Th, U). The two different species of plants do not show significant differences in the bioaccumulation of most of the analyzed elements, except for lanthanides, which are systematically enriched in Rumex leaves. The high concentrations of many toxic elements in the leaves allow us to consider these plants as highly tolerant species to the volcanic emissions, and suitable for biomonitoring researches in the Mt. Etna area.
    Beschreibung: Published
    Beschreibung: Vienna, Austria
    Beschreibung: 4.4. Scenari e mitigazione del rischio ambientale
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; biomonitoring ; Trace elements ; 01. Atmosphere::01.01. Atmosphere::01.01.03. Pollution ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Poster session
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Publikationsdatum: 2017-04-04
    Beschreibung: Etna volcano, Italy, hosts one of the major groundwater systems of the island of Sicily. Waters circulate within highly permeable fractured, mainly hawaiitic, volcanic rocks. Aquifers are limited downwards by the underlying impermeable sedimentary terrains. Thickness of the volcanic rocks generally does not exceed some 300 m, preventing the waters to reach great depths. This is faced by short travel times (years to tens of years) and low thermalisation of the Etnean groundwaters. Measured temperatures are, in fact, generally lower than 25 °C. But the huge annual meteoric recharge (about 0.97 kmˆ3) with a high actual infiltration coefficient (0.75) implies a great underground circulation. During their travel from the summit area to the periphery of the volcano, waters acquire magmatic heat together with volcanic gases and solutes through water-rock interaction processes. In the last 20 years the Etnean aquifers has been extensively studied. Their waters were analysed for dissolved major, minor and trace element, O, H, C, S, B, Sr and He isotopes, and dissolved gas composition. These data have been published in several articles. Here, after a summary of the obtained results, the estimation of the magmatic heat flux through the aquifer will be discussed. To calculate heat uptake during subsurface circulation, for each sampling point (spring, well or drainage gallery) the following data have been considered: flow rate, water temperature, and oxygen isotopic composition. The latter was used to calculate the mean recharge altitude through the measured local isotopic lapse rate. Mean recharge temperatures, weighted for rain amount throughout the year, were obtained from the local weather station network. Calculations were made for a representative number of sampling points (216) including all major issues and corresponding to a total water flow of about 0.315 kmˆ3/a, which is 40% of the effective meteoric recharge. Results gave a total energy output of about 140 MW/a the half of which is ascribable to only 13 sampling points. These correspond to the highest flow drainage galleries with fluxes ranging from 50 to 1000 l/s and wells with pumping rates from 70 to 250 l/s. Geographical distribution indicates that, like magmatic gas leakage, heat flow is influenced by structural features of the volcanic edifice. The major heat discharge through groundwater are all tightly connected either to the major regional tectonic systems or to the major volcanic rift zones along which the most important flank eruptions take place. But rift zones are much more important for heat upraise due to the frequent dikes injection than for gas escape because generally when dikes have been emplaced the structure is no more permeable to gases because it becomes sealed by the cooling magma.
    Beschreibung: Published
    Beschreibung: Vienna, Austria
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): groundwaters ; volcanic surveillance ; water chemistry ; dissolved gases ; 03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters ; 03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Oral presentation
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Publikationsdatum: 2017-04-04
    Beschreibung: Volcanic gas emissions from fumaroles on the rim of La Fossa crater, Vulcano Island, Italy, were measured simultaneously using direct sampling (for H2O, CO2, total sulfur, HCl and HF), filter packs (for SO2, HCl, HF) and short-path active-mode FTIR measurements (for H2O, CO2,SO2, HCl and HF) in an intercomparison study in May 2002. The results show that Cl/F ratios were in good agreement between all three methods, and that FTIR and direct sampling determined comparable proportions of CO2 and H2O. Amounts of total S observed in direct sampling data were approximately double the amounts of SO2 measured with filter packs and FTIR. This difference could be attributed either to the fact FTIR and filter packs do not measure reduced sulfur species (e.g., H2S) or to sublimation of elemental S upon exit from the fumarole, after collection by direct sampling but before detection with FTIR and filter packs.
    Beschreibung: Published
    Beschreibung: L02610
    Beschreibung: partially_open
    Schlagwort(e): volcanic gas techniques ; gas geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 21
    Publikationsdatum: 2017-04-04
    Beschreibung: Constraining fluxes of volcanic bromine and iodine to the atmosphere is important given the significant role these species play in ozone depletion. However, very few such measurements have been made hitherto, such that global volcanic fluxes are poorly constrained. Here we extend the data set of volcanic Br and I degassing by reporting the first measurements of bromine and iodine emissions from Mount Etna. These data were obtained using filter packs and contemporaneous ultraviolet spectroscopic SO2 flux measurements, resulting in time-averaged emission rates of 0.7 kt yr 1 and 0.01 kt yr 1 for Br and I, respectively, from April to October 2004, from which we estimate global Br and I fluxes of order 13 (range, 3â 40) and 0.11 (range, 0.04â 6.6) kt yr 1. Observed changes in plume composition highlight the coherent geochemical behavior of HCl, HF, HBr, and HI during magmatic degassing, and strong fractionation of these species with respect to SO2.
    Beschreibung: Published
    Beschreibung: Q08008
    Beschreibung: partially_open
    Schlagwort(e): bromine and iodine in volcanic gases ; halogen atmospheric chemistry ; volcanic degassing ; volcanic plumes ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 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
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  • 22
    Publikationsdatum: 2017-04-04
    Beschreibung: A new method for extracting dissolved gases in natural waters has been developed and tested, both in the laboratory and in the field. The sampling device consists of a polytetrafluroethylene (PTFE) tube (waterproof and gas permeable) sealed at one end and connected to a glass sample holder at the other end. The device is pre-evacuated and subsequently dipped in water, where the dissolved gases permeate through the PTFE tube until the pressure inside the system reaches equilibrium. A theoretical model describing the time variation in partial gas pressure inside a sampling device has been elaborated, combining the mass balance and ‘‘Solution-Diffusion Model’’ which describes the gas permeation process through a PTFE membrane). This theoretical model was used to predict the temporal evolution of the partial pressure of each gas species in the sampling device. The model was validated by numerous laboratory tests. The method was applied to the groundwater of Vulcano Island (southern Italy). The results suggest that the new sampling device could easily extract the dissolved gases from water in order to determine their chemical and isotopic composition.
    Beschreibung: - European Social Fund.
    Beschreibung: Published
    Beschreibung: Q09005
    Beschreibung: partially_open
    Schlagwort(e): dissolved gases ; helium isotope ; PTFE membrane ; Vulcano Island ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 03. Hydrosphere::03.02. Hydrology::03.02.07. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
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    Materialart: article
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  • 23
    Publikationsdatum: 2017-04-04
    Beschreibung: Ground-based measurements of volcanic sulfur dioxide fluxes are important indicators of volcanic activity, with application in hazard assessment, and understanding the impacts of volcanic emissions upon the environment and climate. These data are obtained by making traverses underneath the volcanic plume a few kilometers from source with an ultraviolet spectrometer, measuring integrated SO2 concentrations across the plume’s cross section, and multiplying by the plume’s transport speed. However, plume velocities are usually derived from ground-based anemometers, located many kilometers from the traverse route and hundreds of meters below plume altitude, complicating the experimental design and introducing large flux (can be 〉100%) errors. Here we present the first report of a single instrument capable of (accurate) volcanic SO2 flux measurements. This device records integrated SO2 concentrations and plume heights during traverses. Between traverses, two in-plume SO2 time series are measured from underneath the plume with the instrument, corresponding to zenith and inclined (user-specified angle from vertical in the direction of the volcano) fields of view, respectively. The distance between the points of intersection of the two views with the plume is found on the basis of the determined plume height, and the two signals are cross-correlated to determine the lag between them, enabling accurate derivation of the wind speed. We present flux data (with errors ±12%) obtained in this way at Mt. Etna during July 2004.
    Beschreibung: Published
    Beschreibung: Q02003
    Beschreibung: partially_open
    Schlagwort(e): DOAS ; volcanic SO2 emissions. ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 24
    Publikationsdatum: 2017-04-04
    Beschreibung: Volcanoes represent an important natural source of several trace elements to the atmosphere. For some species (e.g., As, Cd, Pb and Se) they may be the main natural source and thereby strongly influencing geochemical cycles from the local to the global scale. Mount Etna is one of the most actively degassing volcanoes in the world, and it is considered to be, on the long-term average, the major atmospheric point source of many environmental harmful compounds. Their emission occurs either through continuous passive degassing from open-conduit activity or through sporadic paroxysmal eruptive activity, in the form of gases, aerosols or particulate. To estimate the environmental impact of magma-derived trace metals and their depositions processes, rainwater and snow samples were collected at Mount Etna area. Five bulk collectors have been deployed at various altitudes on the upper flanks around the summit craters of the volcano; samples were collected every two week for a period of one year and analyzed for the main chemical-physical parameters (electric conductivity and pH) and for major and trace elements concentrations. Chemical analysis of rainwater clearly shows that the volcanic contribution is always prevailing in the sampling site closest to the summit crater (about 1.5 km). In the distal sites (5.5-10 km from the summit) and downwind of the summit craters, the volcanic contribution is also detectable but often overwhelmed by anthropogenic or other natural (seawater spray, geogenic dust) contributions. Volcanic contribution may derive from both dry and wet deposition of gases and aerosols from the volcanic plume, but sometimes also from leaching of freshly emitted volcanic ashes. In fact, in our background site (7.5 km in the upwind direction) volcanic contribution has been detected only following an ash deposition event. About 30 samples of fresh snow were collected in the upper part of the volcano, during the winters 2006 and 2007 to estimate deposition processes at high altitude during cold periods. Some of the samples were collected immediately after a major explosive event from the summit craters to understand the interaction between snow and fresh erupted ash. Sulphur, Chlorine and Fluorine, are the major elements that prevailingly characterize the volcanic contribution in atmospheric precipitation on Mount Etna, but high concentrations of many trace elements are also detected in the studied samples. In particular, bulk deposition samples display high concentration of Al, Fe, Ti, Cu, As, Rb, Pb, Tl, Cd, Cr, U and Ag, in the site most exposed to the volcanic emissions: median concentration values are about two orders of magnitude higher than those measured in our background site. Also in the snow samples the volcanic signature is clearly detectable and decreases with distance from the summit craters. Some of the analysed elements display very high enrichment values with respect to the average crust and, in the closest site to the summit craters, also deposition values higher than those measured in polluted urban or industrial sites.
    Beschreibung: Published
    Beschreibung: Vienna, Austria
    Beschreibung: 4.5. Degassamento naturale
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; trace elements ; rainwater ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 03. Hydrosphere::03.03. Physical::03.03.01. Air/water/earth interactions ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Oral presentation
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  • 25
    Publikationsdatum: 2017-04-04
    Beschreibung: Volcanoes deform as a consequence of the rise and storage of magma; once magma reaches a critical pressure, an eruption occurs. However, how the edifice deformation relates to its eruptive behavior is poorly known. Here, we produce a joint interpretation of spaceborne InSAR deformation measurements and volcanic activity at Mt. Etna (Italy), between 1992 and 2006. We distinguish two volcano-tectonic behaviors. Between 1993 and 2000, Etna inflated with a starting deformation rate of 1 cm yr 1 that progressively reduced with time, nearly vanishing between 1998 and 2000; moreover, low-eruptive rate summit eruptions occurred, punctuated by lava fountains. Between 2001 and 2005, Etna deflated, feeding higher-eruptive rate flank eruptions, along with large displacements of the entire East-flank. These two behaviors, we suggest, result from the higher rate of magma stored between 1993 and June 2001, which triggered the emplacement of the dike responsible for the 2001 and 2002–2003 eruptions. Our results clearly show that the joint interpretation of volcano deformation and stored magma rates may be crucial in identifying impending volcanic eruptions.
    Beschreibung: This work was partly funded by INGV and the Italian DPC and was supported by ASI, the Preview Project and CRdC-AMRA. DPC-INGV Flank project providing the funds for the publication fees.
    Beschreibung: Published
    Beschreibung: L02309
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: 4.5. Degassamento naturale
    Beschreibung: JCR Journal
    Beschreibung: partially_open
    Schlagwort(e): deformation ; eruptions ; Mt. Etna ; eruptive cycle ; InSAR ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 26
    Publikationsdatum: 2017-04-04
    Beschreibung: Assessment of the hazard from lava flow inundation at the active volcano of Mount Etna, Italy, was performed by calculating the probability of lava flow inundation at each position on the volcano. A probability distribution for the formation of new vents was calculated using geological and volcanological data from past eruptions. The simulated lava flows from these vents were emplaced using a maximum expected flow length derived from geological data on previous lava flows. Simulations were run using DOWNFLOW, a digital-elevation-model-based model designed to predict lava flow paths. Different eruptive scenarios were simulated by varying the elevation and probability distribution of eruptive points. Inundation maps show that the city of Catania and the coastal zone may only be impacted by flows erupted from low-altitude vents (〈1500 m elevation) and that flank eruptions at elevations 〉2000 m preferentially inundate the northeast and southern sectors of the volcano as well as the Valle del Bove. Eruptions occurring in the summit area (〉3000 m elevation) pose no threat to the local population. Discrepancies between the results of simple, hydrological models and those of the DOWNFLOW model show that hydrological approaches are inappropriate when dealing with Etnean lava flows. Because hydrological approaches are not designed to reproduce the full complexity of lava flow spreading, they underestimate the catchment basins when the fluid has a complex rheology.
    Beschreibung: Published
    Beschreibung: F01019
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): volcanic hazard ; lava flow ; Mount Etna ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 27
    Publikationsdatum: 2017-04-04
    Beschreibung: Forecasting the time, nature, and impact of future eruptions is difficult at volcanoes such as Mount Etna, in Italy, where eruptions occur from the summit and on the flanks, affecting areas distant from each other. Nonetheless, the identification and quantification of areas at risk from new eruptions are fundamental for mitigating potential human casualties and material damage. Here, we present new results from the application of a methodology to define flexible high‐resolution lava invasion susceptibility maps based on a reliable computational model for simulating lava flows at Etna and on a validation procedure for assessing the correctness of susceptibility mapping in the study area. Furthermore, specific scenarios can be extracted at any time from the simulation database, for land use and civil defense planning in the long term, to quantify, in real time, the impact of an imminent eruption, and to assess the efficiency of protective measures.
    Beschreibung: This work was sponsored by the Italian Ministry for Education, University and Research, FIRB project RBAU01RMZ4 “Lava flow simulations by Cellular Automata,” and by the National Civil Defense Department and INGV (National Institute of Geophysics and Volcanology), project V3_6/09 “V3_6 – Etna.”
    Beschreibung: Published
    Beschreibung: B04203
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: 4.4. Scenari e mitigazione del rischio ambientale
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): lava flows ; volcanic hazard ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.02. Cellular automata, fuzzy logic, genetic alghoritms, neural networks ; 05. General::05.01. Computational geophysics::05.01.05. Algorithms and implementation ; 05. General::05.02. Data dissemination::05.02.99. General or miscellaneous ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 05. General::05.08. Risk::05.08.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 28
    Publikationsdatum: 2012-02-03
    Beschreibung: A simple linear relation can be used to link time averaged discharge rate (TADR) and lava flow area (A). The relation applies to given insulation conditions, as described by the characteristic flow surface temperature (Te), and will vary from case-to-case depending on rheological and topographic influences on flow spreading. Most flows have insulation conditions that change through time, modifying the relationship between TADR and area as insulation conditions evolve. Using lidar data we can define TADR, the flow area that the discharge feeds and Te, allowing generation of a case-specific relation to convert satellite-data-derived flow areas to TADR. For Etna's 2006 lava flow field we obtain a relation whereby TADR = 5.6 × 10−6 A for well insulated conditions (Te = 100°C) and TADR = 1.5 × 10−4 A for poorly insulated conditions (Te = 600°C).
    Beschreibung: Published
    Beschreibung: L20308
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): lava flow ; discharge rate ; area ; surface temperature ; lidar ; Etna. ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 29
    Publikationsdatum: 2017-04-04
    Beschreibung: From December 2002 to July 2003, Stromboli volcano was characterized by a new effusive stage of eruption after a period of extraordinary strombolian activity. Signals recorded in two continuous monitoring stations during the eruption, which have already been presented in very recent papers, evidenced anomalies in the CO2 flux just before the onset of the eruption. A more detailed analysis carried out on the data subset acquired during the eruption, integrated by daily field observations of the scientific personnel working at the volcanological observatory in Stromboli, showed that CO2 flux and soil temperature are strictly related to volcanic events. Furthermore, the relative minima and maxima of the two parameters showed a strong correlation with wind speed and direction. This fact was especially true at the summit station, whereas at the coastal sites seasonal and meteorological effects masked the volcanic signal. The analysis of the wind data, particularly the relationships between wind speed and direction, air and soil temperature, and local circulation of atmospheric air masses revealed that during the eruption, in the summit area of Stromboli air movements were not only related to atmospheric circulation but were also significantly affected, and in certain cases caused, by volcanic activity. This conclusion was reached by observing several anomalies, such as the discrepancies in the wind direction between the two stations, higher air temperatures at the summit site, and inversion of direction for wind before and after the reopening of the conduit in a major explosion on 5 April 2003. The relationships found between volcanic activity, soil temperatures, CO2 fluxes, and wind speed and direction indicate that soil temperature measurements, in an open conduit volcano such as in this case, could be used to monitor the level of volcanic activity, along with CO2 flux. Furthermore, the possible volcanic origin of a peculiar type of air circulation identified in the summit area of Stromboli suggests that the separation between volcanic and atmospheric signals might not be obvious, requiring monitoring over a wide area, rather than a single location.
    Beschreibung: Published
    Beschreibung: Q12001
    Beschreibung: partially_open
    Schlagwort(e): carbon dioxide flux ; continuous monitoring ; soil temperature ; wind ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
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  • 30
    Publikationsdatum: 2017-04-04
    Beschreibung: Marked increases of CO2, H2 and He dissolved in thermal waters and changes in the dissolved carbon isotopic composition, were observed at Stromboli before the 28 December 2002 eruption and before a violent explosive paroxysm occurred on 5 April 2003. High anomalous CO2 flux values were recorded at the crater rim since a week before the eruption onset. The first anomalies in the thermal waters (dissolved CO2 amount) appeared some months before the eruption, when magma column rose at a very high level in the conduit. High peaks of dissolved H2 and He were recorded a few days before the paroxysm. Carbon isotopic composition indicates a magmatic origin of the dissolved CO2 whose increase, together with those of H2 and He, is attributed to an increasing output of deep gases likely produced by depressurization of a rising batch of a deep gas-rich magma, whose fragments have been emitted during the explosion.
    Beschreibung: Italian Civil Protection
    Beschreibung: Published
    Beschreibung: L07620
    Beschreibung: partially_open
    Schlagwort(e): Stromboli ; geochemical precursors ; CO2 flux ; pH ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters ; 03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
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  • 31
    Publikationsdatum: 2017-04-04
    Beschreibung: The performance of a newly-developed portable gas analyzer, capable of real-time measurement of CO2, SO2 and H2S concentrations in volcanic gases, was tested at La Fossa Crater, Vulcano Island. The gas analyzer was used to acquire about 3000 determinations over the fumarolic field, allowing the definition of its chemical structure and heterogeneity. Our high-resolution analysis reveals that, in December 2004, the La Fossa fumarolic field was characterized by an oxidized inner core (SO2/H2S ratios of 3), and by more reducing conditions on its northern edge (SO2/H2S ratios of 1; range: 0.2–3.3). CO2/(SO2+H2S) molar ratios averaged 35 ± 21, with overlapping compositions for rim and inner crater fumaroles. S-poor compositions (CO2/(SO2+H2S) 50) characterized the field margins, probably due to deposition of native sulfur. Based on the above data and an SO2 flux of 18 ± 3 t.d-1, we estimate CO2 and H2S output rates from the volcano of 420 ± 250 and 4 ± 2 t.d-1, respectively.
    Beschreibung: Published
    Beschreibung: L13309
    Beschreibung: partially_open
    Schlagwort(e): electrochemical sensors ; fumarolic gases ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
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  • 32
    Publikationsdatum: 2017-04-04
    Beschreibung: We present the first regional map of CO2 Earth degassing from a large area (most of central and south Italy) derived from the carbon of deep provenance dissolved in the main springs of the region. The investigation shows that a globally significant amount of deeply derived CO2 (10% of the estimated global CO2 emitted from subaerial volcanoes) is released by two large areas located in western Italy. The anomalous flux of CO2 suddenly disappears in the Apennine in correspondence to a narrow band where most of seismicity concentrates. Here, at depth, the gas accumulates in crustal traps generating CO2 overpressurized reservoirs which induce seismicity.
    Beschreibung: Published
    Beschreibung: 1-4
    Beschreibung: partially_open
    Schlagwort(e): Carbon dioxide ; Central Italy ; Southern Italy ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 03. Hydrosphere::03.04. Chemical and biological::03.04.02. Carbon cycling ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
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  • 33
    Publikationsdatum: 2017-04-04
    Beschreibung: Improving the constraints on the atmospheric fate and depletion rates of acidic compounds persistently emitted by non-erupting (quiescent) volcanoes is important for quantitatively predicting the environmental impact of volcanic gas plumes. Here, we present new experimental data coupled with modelling studies to investigate the chemical processing of acidic volcanogenic species during tropospheric dispersion. Diffusive tube samplers were deployed at Mount Etna, a very active open-conduit basaltic volcano in eastern Sicily, and Vulcano Island, a closed-conduit quiescent volcano in the Aeolian Islands (northern Sicily). Sulphur dioxide (SO2), hydrogen sulphide (H2S), hydrogen chloride (HCl) and hydrogen fluoride (HF) concentrations in the volcanic plumes (typically several minutes to a few hours old) were repeatedly determined at distances from the summit vents ranging from 0.1 to ~10 km, and under different environmental conditions. At both volcanoes, acidic gas concentrations were found to decrease exponentially with distance from the summit vents (e.g., SO2 decreases from ~10,000 μg/m3 at 0.1 km from Etna’s vents down to ~7 _μg/m3 at ~10km distance), reflecting the atmospheric dilution of the plume within the acid gas-free background troposphere. Conversely, SO2/HCl, SO2/HF, and SO2/H2S ratios in the plume showed no systematic changes with plume aging, and fit source compositions within analytical error. Assuming that SO2 losses by reaction are small during short-range atmospheric transport within quiescent (ash-free) volcanic plumes, our observations suggest that, for these short transport distances, atmospheric reactions for H2S and halogens are also negligible. The one-dimensional model MISTRA was used to simulate quantitatively the evolution of halogen and sulphur compounds in the plume of Mt. Etna. Model predictions support the hypothesis of minor HCl chemical processing during plume transport, at least in cloud-free conditions. Larger variations in the modelled SO2/HCl ratios were predicted under cloudy conditions, due to heterogeneous chlorine cycling in the aerosol phase. The modelled evolution of the SO2/H2S ratios is found to be substantially dependent on whether or not the interactions of H2S with halogens are included in the model. In the former case, H2S is assumed to be oxidized in the atmosphere mainly by OH, which results in minor chemical loss for H2S during plume aging and produces a fair match between modelled and measured SO2/H2S ratios. In the latter case, fast oxidation of H2S by Cl leads to H2S chemical lifetimes in the early plume of a few seconds, and thus SO2 to H2S ratios that increase sharply during plume transport. This disagreement between modelled and observed plume compositions suggests that more in-detail kinetic investigations are required for a proper evaluation of H2S chemical processing in volcanic plumes.
    Beschreibung: Published
    Beschreibung: 1441-1450
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 4.5. Degassamento naturale
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; volcanic gas plumes ; tropospheric processing ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 34
    Publikationsdatum: 2017-04-04
    Beschreibung: We applied a new simulation model, based on multiphase transport laws, to describe the 4D (3D spatial coordinates plus time) dynamics of explosive eruptions. Numerical experiments, carried out on a parallel supercomputer, describe the collapse of the volcanic eruption column and the propagation of pyroclastic density currents (PDCs), for selected medium scale (sub-Plinian) eruptive scenarios at Vesuvius, Italy. Simulations provide crucial insights into the effects of the generation mechanism of the flows - partial collapse vs boiling-over - on their evolution and hazard potential, the unstable dynamics of the fountain, and the influence of Mount Somma on the propagation of PDCs into the circum-Vesuvian area, one of the world's most hazardous volcanic settings. Results also show that it is possible to characterize the volcanic column behavior in terms of percentage of the mass of pyroclasts collapsed to the ground and how this parameter strongly influences the dynamics and hazard of the associated PDCs.
    Beschreibung: Published
    Beschreibung: L04309
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): explosive eruption ; numerical modeling ; Vesuvius ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 35
    Publikationsdatum: 2017-04-04
    Beschreibung: Field evidence reveals that the Neolithic village of Atlit-Yam (Israeli coast) was destroyed in an event which also caused the sudden death of tens of inhabitants. Archaeological evidence and numerical simulations support the notion that the village was destroyed, ~8.3 ka B.P., by a tsunami triggered by a known Holocene flank collapse of Mt. Etna volcano (Italy). The filling of a water well within the village confirms inundation by a tsunami wave train and a sediment layer, composed of a clayed-sandy matrix and other detritus including reworked marine sediment, indicates tsunami inundation. This scenario shows that tsunamis generated by sector collapses from coastal volcanoes can seriously threaten near-shore settlements thousands of kilometres distant from the tsunami source.
    Beschreibung: Published
    Beschreibung: L16317
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): tsunami ; Mt. Etna ; Atlit-Yam ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 36
    Publikationsdatum: 2017-04-04
    Beschreibung: Repeated phenomena of flank instability accompanied the 28 December 2002 to 21 July 2003 eruption of Stromboli volcano. The major episodes were two tsunamigenic landslides on 30 December 2002, 2 d after the volcano unrest. After 30 December, sliding processes remodeled the area affected by slope instability.We propose analyses of 565 sliding episodes taking place from December 2002 to February 2003.We try to shed light on their main seismic features and links with the ongoing seismic and volcanic activity using variogram analysis as well. A characterization of the seismic signals in the time and frequency domains is presented for 185 sliding episodes. Their frequency content is between 1 Hz and 7 Hz. On the basis of the dominant peaks and shape of the spectrum, we identify three subclasses of signals, one of which has significant energy below 2 Hz. Low-frequency signatures were also found in the seismic records of the landslides of 30 December, which affected the aerial and submarine northwestern flank of the volcano. Accordingly, we surmise that spectral analysis might provide evidence of sliding phenomena with submarine runouts.We find no evidence of sliding processes induced by earthquakes. Additionally, a negative statistical correlation between sliding episodes and explosion quakes is highlighted by variogram analysis. Variograms indicate a persistent behavior, memory, of the flank instability from 5 to 10 d.We interpret the climax in the occurrence rate of the sliding processes between 24 and 29 January 2003 as the result of favorable conditions to slope instability due to the emplacement of NW-SE aligned, dike-fed vents located near the scarp of the landslide area. Afterward, the stabilizing effect of the lava flows over the northwestern flank of the volcano limited erosive phenomena to the unstable, loose slope not covered by lava.
    Beschreibung: This work was supported financially by Istituto Nazionale di Geofisica e Vulcanologia and Dipartimento per la Protezione Civile, project INGV-DPC V4/02.
    Beschreibung: Published
    Beschreibung: Q04022
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): rockfalls ; seismicity ; volcanoes ; volcano collapses ; Stromboli ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
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  • 37
    Publikationsdatum: 2017-04-04
    Beschreibung: We report the first measurements of volcanic gases with an unmanned aerial vehicle (UAV). The data were collected at La Fossa crater, Vulcano, Italy, during April 2007, with a helicopter UAV of 3 kg payload, carrying an ultraviolet spectrometer for remotely sensing the SO2 flux (8.5 Mg d 1), and an infrared spectrometer, and electrochemical sensor assembly for measuring the plume CO2/SO2 ratio; by multiplying these data we compute a CO2 flux of 170 Mg d 1. Given the deeper exsolution of carbon dioxide from magma, and its lower solubility in hydro-thermal systems, relative to SO2, the ability to remotely measure CO2 fluxes is significant, with promise to provide more profound geochemical insights, and earlier eruption forecasts, than possible with SO2 fluxes alone: the most ubiquitous current source of remotely sensed volcanic gas data.
    Beschreibung: Published
    Beschreibung: L06303
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Plume measurements ; carbon dioxide fluxes ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 38
    Publikationsdatum: 2017-04-04
    Beschreibung: An edited version of this paper was published by AGU. Copyright (2009) American Geophysical Union.
    Beschreibung: Despite volcanic risk having been defined quantitatively more than 30 years ago, this risk has been managed without being effectively measured. The recent substantial progress in quantifying eruption probability paves the way for a new era of rational science-based volcano risk management, based on what may be termed ‘‘volcanic risk metrics’’ (VRM). In this paper, we propose the basic principles of VRM, based on coupling probabilistic volcanic hazard assessment and eruption forecasting with cost-benefit analysis. The VRM strategy has the potential to rationalize decision making across a broad spectrum of volcanological questions. When should the call for evacuation be made? What early preparations should be made for a volcano crisis? Is it worthwhile waiting longer? What areas should be covered by an emergency plan? During unrest, what areas of a large volcanic field or caldera should be evacuated, and when? The VRM strategy has the paramount advantage of providing a set of quantitative and transparent rules that can be established well in advance of a crisis, optimizing and clarifying decision-making procedures. It enables volcanologists to apply all their scientific knowledge and observational information to assist authorities in quantifying the positive and negative risk implications of any decision.
    Beschreibung: Published
    Beschreibung: B03213
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): risk assessment ; decision making ; campi flegrei ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 39
    Publikationsdatum: 2017-04-04
    Beschreibung: Long duration time-series of the chemical composition of fumaroles and of soil CO2 flux reveal that important variations in the activity of the Solfatara fumarolic field, the most important hydrothermal site of Campi Flegrei, occurred in the 2000-2008 period. A continuous increase of the CO2 concentrations, and a general decrease of the CH4 concentrations are interpreted as the consequence of the increment of the relative amount of magmatic fluids, rich in CO2 and poor in CH4, hosted by the hydrothermal system. Contemporaneously, the H2O-CO2-He-N2 gas system shows remarkable compositional variations in the samples collected after July 2000 with respect to the previous ones, indicating the progressive arrival at the surface of a magmatic component different from that involved in the 1983-84 episode of volcanic unrest (1983-1984 bradyseism). The change starts in 2000 concurrently with the occurrence of relatively deep, long-period seismic events which were the indicator of the opening of an easy-ascent pathway for the transfer of magmatic fluids towards the shallower, brittle domain hosting the hydrothermal system. Since 2000, this magmatic gas source is active and causes ground deformations, seismicity as well as the expansion of the area affected by soil degassing of deeply derived CO2. Even though the activity will most probably be limited to the expulsion of large amounts of gases and thermal energy, as observed in other volcanoes and in the past activity of Campi Flegrei, the behavior of the system in the future is, at the moment, unpredictable.
    Beschreibung: Published
    Beschreibung: B03205
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 2.4. TTC - Laboratori di geochimica dei fluidi
    Beschreibung: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Campi Flegrei ; CO2 ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 40
    Publikationsdatum: 2012-02-03
    Beschreibung: An edited version of this paper was published by AGU. Copyright (2010) American Geophysical Union
    Beschreibung: Seismic, deformation, and volcanic gas observations offer independent and complementary information on the activity state and dynamics of quiescent and eruptive volcanoes and thus all contribute to volcanic risk assessment. In spite of their wide use, there have been only a few efforts to systematically integrate and compare the results of these different monitoring techniques. Here we combine seismic (volcanic tremor and long‐period seismicity), deformation (GPS), and geochemical (volcanic gas plume CO2/SO2 ratios) measurements in an attempt to interpret trends in the recent (2007–2008) activity of Etna volcano. We show that each eruptive episode occurring at the Southeast Crater (SEC) was preceded by a cyclic phase of increase‐decrease of plume CO2/SO2 ratios and by inflation of the volcano’s summit captured by the GPS network. These observations are interpreted as reflecting the persistent supply of CO2‐rich gas bubbles (and eventually more primitive magmas) to a shallow (depth of 1–2.8 km asl) magma storage zone below the volcano’s central craters (CCs). Overpressuring of the resident magma stored in the upper CCs’ conduit triggers further magma ascent and finally eruption at SEC, a process which we capture as an abrupt increase in tremor amplitude, an upward (〉2800 m asl) and eastward migration of the source location of seismic tremor, and a rapid contraction of the volcano’s summit. Resumption of volcanic activity at SEC was also systematically anticipated by declining plume CO2/SO2 ratios, consistent with magma degassing being diverted from the central conduit area (toward SEC).
    Beschreibung: Published
    Beschreibung: Q09008
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): volcano monitoring ; Mt. Etna volcano ; geochemistry and geophysics ; volcanic tremor ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 41
    Publikationsdatum: 2012-02-03
    Beschreibung: An edited version of this paper was published by AGU. Copyright (2010) American Geophysical Union.
    Beschreibung: Volcano deformation may occur under different conditions. To understand how a volcano deforms, as well as relations with magmatic activity, we studied Mt. Etna in detail using interferometric synthetic aperture radar (InSAR) data from 1994 to 2008. From 1994 to 2000, the volcano inflated with a linear behavior. The inflation was accompanied by eastward and westward slip on the eastern and western flanks, respectively. The portions proximal to the summit showed higher inflation rates, whereas the distal portions showed several sectors bounded by faults, in some cases behaving as rigid blocks. From 2000 to 2003, the deformation became nonlinear, especially on the proximal eastern and western flanks, showing marked eastward and westward displacements, respectively. This behavior resulted from the deformation induced by the emplacement of feeder dikes during the 2001 and 2002–2003 eruptions. From 2003 to 2008, the deformation approached linearity again, even though the overall pattern continued to be influenced by the emplacement of the dikes from 2001 to 2002. The eastward velocity on the eastern flank showed a marked asymmetry between the faster sectors to the north and those (largely inactive) to the south. In addition, from 1994 to 2008 part of the volcano base (south, west, and north lower slopes) experienced a consistent trend of uplift on the order of ∼0.5 cm/yr. This study reveals that the flanks of Etna have undergone a complex instability resulting from three main processes. In the long term (103–104 years), the load of the volcano is responsible for the development of a peripheral bulge. In the intermediate term (≤101 years, observed from 1994 to 2000), inflation due to the accumulation of magma induces a moderate and linear uplift and outward slip of the flanks. In the short term (≤1 year, observed from 2001 to 2002), the emplacement of feeder dikes along the NE and south rifts results in a nonlinear, focused, and asymmetric deformation on the eastern and western flanks. Deformation due to flank instability is widespread at Mt. Etna, regardless of volcanic activity, and remains by far the predominant type of deformation on the volcano.
    Beschreibung: ESA provided the SAR data (Cat‐1 no. 4532 and GEO Supersite initiative). The DEM was obtained from the SRTM archive, while the ERS‐1/2 orbits are courtesy of the TU‐Delft, The Netherlands. This work was partially funded by INGV and the Italian DPC (DPCINGV project V4 “Flank”), the Italian DPC (under special agreement with IREA‐CNR), and the Italian Space Agency under contract “sistema rischio vulcanico (SRV).” The authors thank Francesco Casu, Paolo Berardino, and Riccardo Lanari for their support and Geoff Wadge and Michael Poland for their helpful and constructive review of the manuscript.
    Beschreibung: Published
    Beschreibung: B10405
    Beschreibung: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Flank instability ; InSAR ; volcanoes ; Etna ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 05. General::05.04. Instrumentation and techniques of general interest::05.04.99. General or miscellaneous ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 42
    Publikationsdatum: 2017-04-04
    Beschreibung: On 2nd/3rd November 2002, a huge amount of gas, mainly composed of CO2, was suddenly released from the sea bottom off the coast of Panarea, producing a ‘‘crater’’20 by 10 meters wide and 7 meters deep. The gas output was estimated to be 109 l/d, two orders of magnitude higher than that measured in the 1980s. The anomalous degassing rate lasted for some weeks, slowly decreasing to an almost constant rate of about 4 x 107 l/d after two months. The geothermo- barometric estimations revealed an increase of both the temperature and pressure in the geothermal system feeding the sampled vents. The 3He/4He ratios were similar to those measured in nearby Stromboli. We have monitored the area for the last two decades, and based on our intensive and extensive geochemical measurements, have ascertained that the geothermal reservoir has lost its steady state. We maintain that a new magmatic input caused these phenomena.
    Beschreibung: - Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Vesuviano, Naples, Italy. - Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Palermo, Italy. - Dipartimento Chimica e Fisica della Terra ed Applicazioni, Palermo, Italy.
    Beschreibung: Published
    Beschreibung: L07619
    Beschreibung: partially_open
    Schlagwort(e): Submarine degassing ; magmatic fluids ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.04. Thermodynamics ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 43
    Publikationsdatum: 2017-04-04
    Beschreibung: Numerical simulation of pyroclastic density currents has developed significantly in recent years and is increasingly applied to volcanological research. Results from physical modeling are commonly taken into account in volcanic hazard assessment and in the definition of hazard mitigation strategies. In this work, we modeled pyroclastic density currents in the Phlegrean Fields caldera, where flows propagating along the flat ground could be confined by the old crater rims that separate downtown Naples from the caldera. The different eruptive scenarios (mass eruption rates, magma compositions, and water contents) were based on available knowledge of this volcanic system, and appropriate vent conditions were calculated for each scenario. Simulations were performed along different topographic profiles to evaluate the effects of topographic barriers on flow propagation. Simulations highlighted interesting features associated with the presence of obstacles such as the development of backflows. Complex interaction between outward moving fronts and backflows can affect flow propagation; if backflows reach the vent, they can even interfere with fountain dynamics and induce a more collapsing behavior. Results show that in the case of large events ( 108 kg/s), obstacles affect flow propagation by reducing flow velocity and hence dynamic pressure in distal regions, but they cannot stop the advancement of flows. Deadly conditions (in terms of temperature and ash concentration) characterize the entire region invaded by pyroclastic flows. In the case of small events (2.5 107 kg/s), flows are confined by distal topographic barriers which provide valuable protection to the region beyond.
    Beschreibung: Published
    Beschreibung: Q11003
    Beschreibung: open
    Schlagwort(e): Phlegrean Fields ; multiphase flow ; pyroclastic flows ; dynamic pressure ; volcanic hazard ; caldera ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 44
    Publikationsdatum: 2017-04-04
    Beschreibung: An application of light detection and ranging (lidar) intensity for the identification and mapping of different lava flows from the Mount Etna (Italy) active volcano is described. In September 2004 an airborne lidar survey was flown over summit sectors of Mount Etna. The information derived from lidar intensity values was used to compare the lava flows with respect to their age of emplacement. Analyzed lava flows vary in age between those dating prior to A.D. 1610 and those active during the survey (2004–2005 eruptions). The target-emitter distance, as well as surface roughness and texture at the lidar footprint scale, is the main parameter controlling the intensity response of lava flows. Variations in the roughness and texture of surfaces at a meter scale result from two main processes, initial lava cooling and subsequent surface weathering; both lead to variations in the original surface roughness of the flow. In summary: (1) initially, from the time of emplacement, the lidar intensity of lava flow surfaces decreases and (2) about 6 years after emplacement the lidar intensity of lava surfaces starts to increase with the age of flows. Lidar capability in terms of geometric (accuracy of ∼1 m in plan position and less than 1 m in elevation) and spectral (lidar intensity depends on surface reflection at λ = 1.064 μm) information can thus be effectively used to map lava flows and to define a relative chronology of lava emplacement.
    Beschreibung: Published
    Beschreibung: B02201
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): lava flows ; mapping ; lidar ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 45
    Publikationsdatum: 2017-04-04
    Beschreibung: The 2002–2003 Etna eruption is studied through earthquake distributions and surface fracturing. In September 2002, earthquake-induced surface rupture (sinistral offset 0.48 m) occurred along the E-W striking Pernicana Fault (PF), on the NE flank. In late October, a flank eruption accompanied further ( 0.77 m) surface rupturing, reaching a total sinistral offset of 1.25 m; the deformation then propagated for 18 km eastwards to the coastline (sinistral offset 0.03 m) and southwards, along the NW-SE striking Timpe (dextral offset 0.04 m) and, later, Trecastagni faults (dextral offset 0.035 m). Seismicity (〈4 km bsl) on the E flank accompanied surface fracturing: fault plane solutions indicate an overall ESEWNWextension direction, consistent with ESE slip of the E flank also revealed by ground fractures. A three-stage model of flank slip is proposed: inception (September earthquake), climax (accelerated slip and eruption) and propagation (E and S migration of the deformation).
    Beschreibung: Published
    Beschreibung: 2286
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): volcano seismology ; surface fracturing ; flank slip ; eruption ; Etna ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.02. Earthquake interactions and probability ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 46
    Publikationsdatum: 2017-04-04
    Beschreibung: This work is aimed at estimating the sulfur dioxide emission of Mt. Etna volcano (Sicily, Italy) using the thermal infrared images remotely sensed by the Advanced Spacebome Thermal Emission and Reflection Radiometer (ASTER). A new procedure (named FUN) is presented based on approximating functions which represent the atmospheric terms of the radiative transfer equation: transmittance, up-welling and down-welling radiances. The parameters of the approximating functions have been computed through the MODTRAN simulations performed using atmospheric monthly mean profiles measured at Trapani (1989-2003). Trapani (WMO station 16429) is located at the western tip of Sicily and is the closest station to Mt. Etna volcano. With these functions MODTRAN is no longer necessary to compute the SO2 abundance in the plume emitted from Mt. Etna and seen by ASTER. Only an atmospheric radiosounding and a digital elevation model (DEM) registered to the ASTER image are required. This new procedure is compared with the known look-up tables (LUT) procedure proposed by other authors. An interesting aspect of the FUN procedure derives from its combined use with a split window (SW) algorithm. In this case only radiosounding is required to compute the SO2 map. The FUN procedure presented in this paper is a rapid, simple and accurate means of generating SO2 map estimates from the ASTER view of Mt. Etna. The proposed scheme can easily be adapted to another sensor and another volcano. In this paper the results from two ASTER images, 19 July 2003 and 29 July 2001, are presented. In July 2003, a ground truth campaign was deployed, SO2 emission was very low (10-25 kg s(-1); Etna baseline is about 50 kg s(-1)). In July 2001, Mt. Etna erupted and a strong SO2 emission (about 140 kg s(-1)) was measured.
    Beschreibung: Published
    Beschreibung: 74-90
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Mt. Etna volcano ; sulfur dioxide ; ASTER ; radiative transfer ; TIR ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 47
    Publikationsdatum: 2017-04-04
    Beschreibung: The 5 April 2003 explosive eruption at Stromboli emplaced typical basaltic scoria, pumice, and lithic blocks. This paper reports a detailed set of mineralogical, geochemical, and isotopic data on the juvenile ejecta and fresh subvolcanic blocks, including micro-Sr isotope analyses and major and dissolved volatile element contents in olivine-hosted melt inclusions. The juvenile ejecta have compositions similar to those of their analogs from previous paroxysms; the 2003 pumice, however, does not contain stable high-MgO olivine, usually typical of large-scale paroxysms and has lower compatible element contents. Texture, composition, and Sr isotope disequilibrium of crystals in pumice indicate that most of them are inherited from the shallow crystal-rich magma and/or crystal mush. The most primitive magma is recorded as rare melt inclusion in olivine Fo85–86. It has a typical S/Cl (1.1) and a total volatile content of 3.1 wt % from which the total fluid pressure was evaluated ≥240 MPa. Hence, moderate pressure conditions can be envisaged for the mechanism triggering the April 2003 paroxysm. The subvolcanic blocks are shoshonitic basalts with 45–50 vol % of phenocrysts (plagioclase + clinopyroxene + olivine). The late-stage crystallization of the crystal-rich magma lead to the formation of Na-sanidine with plagioclase An60–25 + olivine Fo68–49 + Timagnetite ± apatite ± phlogopite ± ilmenite assemblage. Mineralogy, chemistry, and Sr–Nd isotopic signatures of the subvolcanic blocks indicate they represent the slowly cooled equivalents of batches of crystal-rich basaltic magma stored in the uppermost subvolcanic feeding system. Cooling might be facilitated by short breaks in the summit crater activity.
    Beschreibung: Unpublished
    Beschreibung: 17
    Beschreibung: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: open
    Schlagwort(e): Stromboli volcano ; Paroxysmal activity ; Basaltic pumice ; Volatile content ; Mineralogy ; Geochemistry ; Sr isotope ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
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  • 48
    Publikationsdatum: 2017-04-04
    Beschreibung: Two-dimensional cross sections of the sulphur dioxide (SO2) distribution in the volcanic gas plume of Mt. Etna were reconstructed using tomographic techniques. The data for these projections were generated by a network of five automated scanning spectrometers, positioned on the flanks of the volcano. These measure slant-column amounts of SO2 at 105 different angles, every four minutes. Stable wind conditions allow the plume to be monitored on 82% of days. A time-series of plume cross sections was computed, revealing the potential of this method to track variations in plume position and structure on timescales of minutes to hours, a result of potential importance for air traffic and civil defence in case of eruption, when copious amounts of fine ash can be transported.
    Beschreibung: Published
    Beschreibung: L17811
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): tomography ; SO2 ; DOAS ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 49
    Publikationsdatum: 2017-04-04
    Beschreibung: The ocean bottom seismometer with hydrophone deployed on the flat top of the Marsili submarine volcano (790 m deep) by the Gibilmanna OBS Lab (CNT–INGV) from 12th to 21st July, 2006, recorded more than 1000 transient seismic signals. Nineteen of these signals were associated with tectonic earthquakes: 1 teleseismic, 8 regional (located by INGV) and 10 small local seismic events (non located earthquakes). The regional events were used to determine sensor orientation. By comparing the signals recorded with typical volcanic seismic activity, we were able to group all the other signals into three categories: 817 volcano–tectonic type B (VT-B) events, 159 occurrences of high frequency tremor (HFT) and 32 short duration events (SDE). Smallmagnitude VT-B swarms, having a frequency band of 2–6 Hz and a mean length of about 30 s, were almost all recorded during the first 7 days. During the last 2 days, the OBS/H mainly recorded HFT events with frequencies of over 40 Hz and of a few minutes in length. Signals that have similar features in frequency and time domain are generally associated with hydrothermal activity. During the last two days a signal was recorded that had a frequency content similar to that of VT-B events was recorded. It will be referred to as continuous volcanic tremor (CVT). The SDE signals, characterized by a quasi-monochromatic waveform and having an exponential decaying envelope, may have been generated by oscillations of resonant bodies excited by magmatic or hydrothermal activity. By applying polarization and parametric spectral analyses, we inferred that the VT-B were probably multi P-phase events having shallow sources that were situated in narrow azimuthal windows in relation to the positions of the OBS/H. The parametric spectral analysis of the SDE signals allowed us to determine their dominant complex frequencies with high accuracy; these frequencies are distributed in two distinct clusters on the complex plane.
    Beschreibung: Published
    Beschreibung: 17-29
    Beschreibung: 2.5. Laboratorio per lo sviluppo di sistemi di rilevamento sottomarini
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Marsili Seamount OBS/H Transient volcano–seismic signals Continuous volcanic tremor Polarization analysis Spectral analysis ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 50
    Publikationsdatum: 2017-04-04
    Beschreibung: Forecasting the time, nature and impact of future eruptions is difficult at volcanoes such as Mount Etna, in Italy, where eruptions occur from the summit and on the flanks, affecting areas distant from each other. Nonetheless, the identification and quantification of areas at risk from new eruptions is fundamental for mitigating potential human casualties and material damage. Here, we present new results from the application of a methodology to define flexible high-resolution lava invasion susceptibility maps based on a reliable computational model for simulating lava flows at Etna and on a validation procedure for assessing the correctness of susceptibility mapping in the study area. Furthermore, specific scenarios can be extracted at any time from the simulation database, for land-use and civil defence planning in the long-term, to quantify, in real-time, the impact of an imminent eruption, and to assess the efficiency of protective measures.
    Beschreibung: This work was sponsored by the Italian Ministry for Education, University and Research, FIRB project n° RBAU01RMZ4 “Lava flow simulations by Cellular Automata”, and by the National Civil Defence Department and INGV (National Institute of Geophysics and Volcanology), project V3_6/09 “V3_6 – Etna”.
    Beschreibung: In press
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: 4.4. Scenari e mitigazione del rischio ambientale
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): lava flows ; Etna ; hazard evaluation ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous ; 05. General::05.01. Computational geophysics::05.01.02. Cellular automata, fuzzy logic, genetic alghoritms, neural networks ; 05. General::05.02. Data dissemination::05.02.99. General or miscellaneous ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 05. General::05.08. Risk::05.08.99. General or miscellaneous ; 05. General::05.09. Miscellaneous::05.09.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 51
    Publikationsdatum: 2017-04-04
    Beschreibung: This is a parametric study that was carried out to investigate the signals generated by a hydrothermal system fed by a pulsating source of magmatic fluids. This study focuses on the effects that selected properties of the source have on the evolution of hydrothermal activity at Campi Flegrei, Italy. Numerical simulations are carried out to describe a multiphase and multicomponent hydrothermal system. Each simulation describes a short unrest phase, followed by a prolonged quiet period. During the unrest, specific properties of the fluid source (flow rate, fluid composition, source size, and unrest duration) are modified with respect to selected baseline values. The evolution of the system is tracked by looking at two parameters that can be monitored in active volcanic areas: the composition of fumarolic gases and gravity changes. The results describe the temporal evolution of these two observables and allow comparisons of the effects of different source properties. All of the simulated unrest events cause measurable changes in gas composition and gravity. For the geometry and system properties considered, these changes always last beyond the end of the unrest period, and can often persist for decades. Fluid flow rate is the source property that mostly affects the observable evolution. Gravity is more sensitive to source properties than gas composition, and it undergoes the largest and quickest changes. The results also highlight the major role that rock properties and initial conditions have in the evolution of these observable signals.
    Beschreibung: Department of Civil Protection
    Beschreibung: Published
    Beschreibung: B05201
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): hydrothermal fluids ; modeling ; monitoring ; signals ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 52
    Publikationsdatum: 2017-04-04
    Beschreibung: We produce a spatial probability map of vent opening (susceptibility map) at Etna, using a statistical analysis of structural features of flank eruptions of the last 2 ky. We exploit a detailed knowledge of the volcano structures, including the modalities of shallow magma transfer deriving from dike and dike-fed fissure eruptions analysis on historical eruptions. Assuming the location of future vents will have the same causal factors as the past eruptions, we converted the geological and structural data in distinct and weighted probability density functions, which were included in a non-homogeneous Poisson process to obtain the susceptibility map. The highest probability of new eruptive vents opening falls within a N-S aligned area passing through the Summit Craters down to about 2,000 ma.s.l. on the southern flank. Other zones of high probability follow the North-East, East-North-East, West, and South Rifts, the latter reaching low altitudes (∼400 m). Less susceptible areas are found around the faults cutting the upper portions of Etna, including the western portion of the Pernicana fault and the northern extent of the Ragalna fault. This structuralbased susceptibility map is a crucial step in forecasting lava flow hazards at Etna, providing a support tool for decision makers.
    Beschreibung: This study was performed with the financial support from the V3-LAVA project (DPC-INGV 2007–2009 contract).
    Beschreibung: Published
    Beschreibung: 2083–2094
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Flank eruption ; Dike ; Volcano structure ; Susceptibility map ; Spatial clustering ; Back analysis ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    facet.materialart.
    Unbekannt
    Springer Berlin Heidelberg
    Publikationsdatum: 2017-04-04
    Beschreibung: Any effective volcanic risk mitigation strat- egy requires a scientific assessment of the future evo- lution of a volcanic system and its eruptive behavior. Some consider the onus should be on volcanologists to provide simple but emphatic deterministic forecasts. This traditional way of thinking, however, does not deal with the implications of inherent uncertainties, both aleatoric and epistemic, that are inevitably present in observations, monitoring data, and interpretation of any natural system. In contrast to deterministic pre- dictions, probabilistic eruption forecasting attempts to quantify these inherent uncertainties utilizing all avail- able information to the extent that it can be relied upon and is informative. As with many other natural hazards, probabilistic eruption forecasting is becoming established as the primary scientific basis for planning rational risk mitigation actions: at short-term (hours to weeks or months), it allows decision-makers to pri- oritize actions in a crisis; and at long-term (years to decades), it is the basic component for land use and emergency planning. Probabilistic eruption forecasting consists of estimating the probability of an eruption event and where it sits in a complex multidimensional time–space–magnitude framework. In this review, we discuss the key developments and features of models that have been used to address the problem.
    Beschreibung: Published
    Beschreibung: 1777-1805
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): eruption forecasting ; volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 54
    Publikationsdatum: 2017-04-04
    Beschreibung: Volcanic rift zones, characterized by repeated dike emplacements, are expected to delimit the upper portion of unstable flanks at basaltic edifices. We use nearly two decades of InSAR observations excluding wintertime acquisitions, to analyze the relationships between rift zones, dike emplacement and flank instability at Etna. The results highlight a general eastward shift of the volcano summit, including the northeast and south rifts. This steadystate eastward movement (1-2 cm/yr) is interrupted or even reversed during transient dike injections. Detailed analysis of the northeast rift shows that only during phases of dike injection, as in 2002, does the rift transiently becomes the upper border of the unstable flank. The flank's steady-state eastward movement is inferred to result from the interplay between magmatic activity, asymmetric topographic unbuttressing, and east-dipping detachment geometry at its base. This study documents the first evidence of steady-state volcano rift instability interrupted by transient dike injection at basaltic edifices.
    Beschreibung: Partially funded by INGV and the Italian DPC (DPC-INGV project V4 “Flank”). ERS and ENVISAT SAR data were provided by ESA through the Cat-1 project no. 4532 and the GEO Supersite initiative. The DEM was obtained from the SRTM archive. ERS-1/2 orbits are courtesy of the TU-Delft, The Netherlands. SAR data processing has been done at IREACNR, partially carried out under contract “Volcanic Risk System (SRV)” funded by the Italian Space Agency (ASI).
    Beschreibung: Published
    Beschreibung: L20311
    Beschreibung: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): flank instability ; rift zones ; 04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.03. Geodesy::04.03.09. Instruments and techniques ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 55
    Publikationsdatum: 2017-04-04
    Beschreibung: To better understand the mechanisms leading to different radon background levels in volcanic settings, we have performed two long-term deformation experiments of 16 days using a real-time setup that enables us to monitor any variation of radon activity concentration during rock compression. Our measurements demonstrate that, in the case of highly porous volcanic rocks, the emanating power of the substrate changes as a function of the volcanic stress conditions. Constant magmatic pressures, such as those observed during dike intrusions and hydrothermal fluid injections, can result in pervasive pore collapse that is mirrored by a significant radon decrease until a constant emanation is achieved. Conversely, repeated cycles of stress due to, for example, volcano inflation/deflation cycles, cause a progressive radon increase a few days (but even weeks and months) before rupture. After rock failure, however, the formation of new emanation surfaces leads to a substantial increase of the radon signal. Our results suggest that surface deformation in tectonic and volcanic settings, such as inflation/ deflation or constant magmatic pressures, have important repercussions on the emanating power of volcanic substrates.
    Beschreibung: Published
    Beschreibung: 751
    Beschreibung: 2R. Laboratori sperimentali e analitici
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Radon monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    Publikationsdatum: 2017-04-04
    Beschreibung: The performances of two absolute gravimeters at three different sites in Italy between 2009 and 2011 is presented. The measurements of the gravity acceleration g were performed using the absolute gravimeters Micro-g LaCoste FG5#238 and the INRiM prototype IMGC-02, which represent the state of the art in ballistic gravimeter technology (relative uncertainty of a few parts in 10 9 ). For the comparison, the measured g values were reported at the same height by means of the vertical gravity gradient estimated at each site with relative gravimeters. The consistency and reliability of the gravity observations, as well as the performance and efficiency of the instruments, were assessed by measurements made in sites charac- terized by different logistics and environmental conditions. Furthermore, the various factors affecting the measurements and their uncertainty were thoroughly investigated. The measurements showed good agree- ment, with the minimum and maximum differences being 4.0 and 8.3 µGal. The normalized errors are very much lower than 1, ranging between 0.06 and 0.45, confirming the compatibility between the results. This excellent agreement can be attributed to several factors, including the good working order of gravimeters and the correct setup and use of the instruments in different conditions. These results can contribute to the standardization of absolute gravity surveys largely for applications in geophysics, volcanology and other branches of geosciences, allowing achieving a good trade-off between uncertainty and efficiency of gravity measurements.
    Beschreibung: Published
    Beschreibung: 38
    Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): absolute gravimeter ; gravity acceleration ; comparison of absolute gravimeters ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 57
    Publikationsdatum: 2020-02-24
    Beschreibung: We present unprecedented data of real-time measurements of the concentration and isotope composition of CO2 in air and in fumarole-plume gases collected in 2013 during two campaigns at Mount Etna volcano, which were made using a laser-based isotope ratio infrared spectrometer. We performed approximately 360 measurements/h, which allowed calculation of the δ13C values of volcanic CO2. The fumarole gases of Torre del Filosofo (2900mabove sea level) range from 3.24 ± 0.06‰to 3.71 ± 0.09‰, comparable to isotope ratio mass spectrometry (IRMS) measurements of discrete samples collected on the same dates. Plume gases sampled more than 1 km from the craters show a δ13C= 2.2 ± 0.4‰, in agreement with the crater fumarole gases analyzed by IRMS. Measurements performed along ~17km driving track from Catania to Mount Etna show more negative δ13C values when passing through populated centers due to anthropogenic-derived CO2 inputs (e.g., car exhaust). The reported results demonstrate that this technique may represent an important advancement for volcanic and environmental monitoring.
    Beschreibung: Published
    Beschreibung: 2382–2389
    Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Real-time data of CO2 content and δ13C in atmospheric/volcanic gases ; This study opens new perspective for the community for volcanic surveillance ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 58
    Publikationsdatum: 2017-04-04
    Beschreibung: Near-infrared room temperature tunable diode lasers(TDL) have recently found increased usage in atmospheric chemistry and air monitoring research, but applications in volcanology are still limited to a few examples. Here, we explored the potential of a commercial infrared laser unit (GasFinder 2.0 from Boreal Laser Ltd) for measurement of volcanic CO2 mixing ratios, and ultimately for estimating the volcanic CO2 flux. Our field tests were conducted at Campi Flegrei near Pozzuoli, Southern Italy, where the GasFinder was used during three campaigns in October 2012, January 2013 and May 2013 to repeatedly measure the path-integrated mixing ratios of CO2 along cross sections of the atmospheric plumes of two major fumarolic fields (Solfatara and Pisciarelli). By using a tomographic post-processing routine, we resolved, for each of the two fields, the contour maps of CO2 mixing ratios in the atmosphere, from the integration of which (and after multiplication by the plumes’ transport speeds) the CO2 fluxes were finally obtained. We evaluate a total CO2 output from the Campi Flegrei fumaroles of ∼490 Mg/day, in line with independent estimates based on in situ (Multi-GAS) observations. We conclude that TDL technique may enable CO2 flux quantification at other volcanoes worldwide.
    Beschreibung: 1- Progetto V2 “Precursori” DPC-INGV research agreement 2012-2013; 2- Miur (PRIN 2009; PI M.V.), and 3-European Research Council under the European Union’s Seventh Framework Programme (FP7/2007/2013)/ERC grant agreement n1305377 (PI, A.A).
    Beschreibung: Published
    Beschreibung: 812
    Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Beschreibung: 5V. Sorveglianza vulcanica ed emergenze
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Tunable diode lasers ; Atmospheric CO2 monitoring ; gas sensing ; spectroscopy ; Volcanic CO2 fluxes ; Campi Flegrei ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 59
    Publikationsdatum: 2017-04-04
    Beschreibung: Mt. Cameroon is one of the most active effusive volcanoes in Africa. About 500,000 people living or working around its fertile flanks are subject to significant threat from lava flow inundation. Lava flow hazard and risk were assessed by simulating probable lava flow paths using the DOWNFLOW code. The vent opening probability density function and lava flow length distribution were determined on the basis of available data from past eruptions at Mt. Cameroon volcano. Code calibration was performed through comparison with real lava flow paths. The topographic basis for simulations was the 90-m resolution SRTM DEM. Simulated lava flows from about 80,000 possible vents were used to produce a detailed lava flow hazard map. The lava flow risk in the area was mapped by combining the hazard map with digitized infrastructures (i.e., human settlements and roads). Results show that the risk of lava flow inundation is greatest in the most inhabited coastal areas comprising the town of Limbe, which constitutes the center of Cameroon’s oil industry and an important commercial port. Buea, the second most important town in the area, has a much lower risk although it is significantly closer to the summit of the volcano. Non-negligible risk characterizes many villages and most roads in the area surrounding the volcano. In addition to the conventional risk mapping described above, we also present (1) two reversed risk maps (one for buildings and one for roads), where each point on the volcano is classified according to the total damage expected as a consequence of vent opening at that point; (2) maps of the lava catchments for the two main towns of Limbe and Buea, illustrating the expected damage upon venting at any point in the catchment basin. The hazard and risk maps provided here represent valuable tools for both medium/long-term land-use planning and real-time volcanic risk management and decision making.
    Beschreibung: Published
    Beschreibung: 423-439
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Lava flow simulation ; Lava flow hazard ; Lava flow risk ; Mt. Cameroon ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Publikationsdatum: 2017-04-04
    Beschreibung: High-speed imaging of explosive eruptions at Stromboli (Italy), Fuego (Guatemala), and Yasur (Vanuatu) volcanoes allowed visualization of pressure waves from seconds-long explosions. From the explosion jets, waves radiate with variable geometry, timing, and apparent direction and velocity. Both the explosion jets and their wave fields are replicated well by numerical simulations of supersonic jets impulsively released from a pressurized vessel. The scaled acoustic signal from one explosion at Stromboli displays a frequency pattern with an excellent match to those from the simulated jets. We conclude that both the observed waves and the audible sound from the explosions are jet noise, i.e., the typical acoustic field radiating from high-velocity jets. Volcanic jet noise was previously quantified only in the infrasonic emissions from large, sub-Plinian to Plinian eruptions. Our combined approach allows us to define the spatial and temporal evolution of audible jet noise from supersonic jets in small-scale volcanic eruptions.
    Beschreibung: INGV-DPC “V2” and “Paroxysm,” FIRB-MIUR “Research and Development of New Technologies for Protection and Defense of Territory from Natural Risks,” and FP7-PEOPLE-IEF-2008–235328 “NEMOH” ITN projects
    Beschreibung: Published
    Beschreibung: 3096–3102
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): jet noise ; volcano acoustics ; Stromboli ; Yasur ; Fuego ; strombolian eruption ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 61
    Publikationsdatum: 2017-04-04
    Beschreibung: The fumarolic gas output has not been quantified for any of the currently deforming calderas worldwide, due to the lack of suitable gas flux sensing techniques. In view of resumption of ground uplift (since 2005) and the associated variations in gas chemistry, Campi Flegrei, in southern Italy, is one of the restless calderas where gas flux observations are especially necessary. Here we report the first ever obtained estimate of the Campi Flegrei fumarolic gas output, based on a set of MultiGAS surveys (performed in 2012 and 2013) with an ad-hoc-designed measurement setup. We estimate that the current Campi Flegrei fumarolic sulphur (S) flux is low, on the order of 1.5–2.2 tons/day, suggesting substantial scrubbing of magmatic S by the hydrothermal system. However, the fumarolic carbon dioxide (CO2) output is ∼460±160 tons/day (mean±SD), which is surprisingly high for a dormant volcano in the hydrothermal stage of activity, and results in a combined (fumaroles + soil) CO2 output of ∼1560 tons/day. Assuming magma to be the predominant source, we propose that the current CO2 output can be supplied by either (i) a large (0.6–4.6 km3), deeply stored (〉7 km) magmatic source with low CO2 contents (0.05–0.1 wt%) or (ii) by a small to medium-sized (∼0.01–0.1 km3) but CO2-rich (2 wt%) magma, possibly stored at pressures of ∼100 to 120 MPa. Independent geophysical evidence (e.g., inferred from geodetic and gravity data) is needed to distinguish between these two possibilities.
    Beschreibung: Published
    Beschreibung: 4153–4169
    Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Campi Flegrei ; calderas ; gas output ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 62
    facet.materialart.
    Unbekannt
    American Geophysical Union
    Publikationsdatum: 2017-04-04
    Beschreibung: Many accounts, anecdotal and statistical, have noted a causal effect on volcanic eruptions from large, not too distant, earthquakes. Physical mechanisms have been proposed that explain how small static stress changes, or larger transient dynamic stress changes, can have observable effects on a volcano. While only ∼0.4% of eruptions appear to be directly triggered within a few days of an earthquake, these physical mechanisms also imply the possibility of delayed triggering. In the few regional studies conducted, data issues (selection bias and scarcity, inhomogeneity, and cleaning of data) have tended to obscure any clear signal. Using a perturbation technique, we first show that the Indonesian volcanic region possesses no statistically significant coupling for the region as a whole. We then augment a number of point process models for eruption onsets by a time‐, distance‐, and earthquake magnitude–dependent triggering term and apply this to the individual volcanoes. This method weighs both positive and negative (i.e., absence of eruptions following an earthquake) evidence of triggering. Of 35 volcanoes with at least three eruptions in the study region, seven (Marapi, Talang, Krakatau, Slamet, Ebulobo, Lewotobi, and Ruang) show statistical evidence of triggering over varying temporal and spatial scales, but only after the internal state of the volcano is accounted for. This confirms that triggering is fundamentally a property of the internal magma plumbing of the volcano in question and that any earthquake can potentially “advance the clock” toward a future eruption. This is further supported by the absence of any dependence on triggering of the eruption size
    Beschreibung: Published
    Beschreibung: B05204
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): earthquake eruption interaction ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 63
    Publikationsdatum: 2017-04-03
    Beschreibung: Total CO2 output from fumaroles, soil gas, bubbling gas discharges and water dissolved gases discharged from the island, was estimated for Vulcano island, Italy. The CO2 emission from fumaroles from the La Fossa summit crater was estimated from the SO2 crater output, while CO2 discharged through diffuse soil emission was quantified on the basis of 730 measurements of CO2 fluxes from the soil of the island, performed by using the accumulation chamber method. The results indicate an overall output of ≅500 t/day of CO2 from the island. The main contribution to the total CO2 output comes from the summit area of the La Fossa cone (453 t/day), with 362 t/day from crater fumaroles and 91 t/day from crater soil degassing. The release of CO2 from peripheral areas is ≅20 t/day by soil degassing (Palizzi and Istmo areas mainly), an amount comparable to both the contribution of water dissolved CO2 (6 t/day), as well as to seawater bubbling CO2 (4 t/day measured in the Istmo area). Presented data (September 2007) refer to a period of moderate solphataric activity, when the fumaroles temperature were 450°C and gas/water molar ratio of fumaroles was up to 0.16. The calculated total CO2 emission allows the estimation of the mass release and related thermal energy from the volcanic-hydrothermal system.
    Beschreibung: Published
    Beschreibung: Q02012
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): CO2 flux, SO2 flux, Vulcano island ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 64
    Publikationsdatum: 2017-04-04
    Beschreibung: The Campi Flegrei caldera is a restless structure affected by general subsidence and ongoing resurgence of its central part. The persistent activity of the system and the explosive character of the volcanism lead to a very high volcanic hazard that, combined with intense urbanization, corresponds to a very high volcanic risk. One of the largest sources of uncertainty in volcanic hazard/risk assessment for Campi Flegrei is the spatial location of the future volcanic activity. This paper presents and discusses a long- term probability hazard map for vent opening in case of renewal of volcanism at the Campi Flegrei caldera, which shows the spatial conditional probability for the next vent opening, given that an eruption occurs. The map has been constructed by building a Bayesian inference scheme merging prior information and past data. The method allows both aleatory and epistemic uncertainties to be evaluated. The probability map of vent opening shows that two areas of relatively high probability are present within the active portion of the caldera, with a probability approximately doubled with respect to the rest of the caldera. The map has an immediate use in evaluating the areas of the caldera prone to the highest volcanic hazard. Furthermore, it represents an important ingredient in addressing the more general problem of quantitative volcanic hazards assessment at the Campi Flegrei caldera.
    Beschreibung: Published
    Beschreibung: 497-510
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcanic hazards assessment . Campi Flegrei . Vent opening probability map . Bayesian inference ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 65
    Publikationsdatum: 2017-04-04
    Beschreibung: We investigated the structure and evolution of the 2010 Eyjafjallajökull volcanic cloud and its dispersal over Iceland and Europe integrating satellite multispectral images and numerical simulations. Data acquired by Medium Resolution Imaging Spectrometer (MERIS)and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) have been analyzed to quantify the cloud extent and composition. The VOL-CALPUFF dispersal code was applied to reconstruct the transient and 3-D evolution of the cloud. Source parameters estimated on the base of available a posteriori volcanological data sets have been used. Quantitative comparisons between satellite retrievals and modeling results were performed for two selected instants of time during the first and third eruptive phases on a regional scale. Sensitivity of the model to initial volcanological conditions has been analyzed at continental scale. Several complex non intuitive features of cloud dynamics have been highlighted and strengths and limitations of the adopted methods identified. The main findings are: the level of quantitative agreement between satellite observations and numerical results depends on ash cloud composition (particle sizes and concentration) with better agreement for smaller particles and higher concentrations; the agreement between observations and modeling outcomes also depends on the temporal stability of volcanological conditions and the complexity of the meteorological wind field; the irregular dispersion of ash, as reconstructed from satellite data and numerical modeling, can be well explained by the different response of particle sizes to strong vertical wind-shear, and by resuspension processes acting at ground level; eruptive source conditions are the main source of uncertainty in modeling, especially during an ongoing crisis and at long-range scales.
    Beschreibung: Published
    Beschreibung: 4729–4747
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Volcanic ash cloud ; Satellite retrieval ; Numerical modelling ; Eyjafjallajokull ; Ash dispersal and deposition ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 66
    Publikationsdatum: 2017-04-04
    Beschreibung: Over the last four decades Etna has shown a high output rate through numerous eruptions. The volcano has displayed two eruptive behaviors. The first is characterized by effusive eruptions that efficiently drained the storage system and emitted large volumes of magma, the second behavior is related to lava fountains, erupting small magma batches, which are normally with high frequency and have been considered as precursors of major effusive eruptions. In this paper, we present an updated estimation of emitted volumes from Etna eruptions, which include the 38 lava fountain episodes that occurred from January 2011 to April 2013. These recent explosive episodes have been frequent, discharging significant magma volumes. Observing the steady trend of magma output over time, we present insights on expected erupted volumes. We highlight that the January 2011 –April 2013 lava fountains, efficiently drained the intermediate-shallow storage system and favored a balance between the incoming and outgoing magma.
    Beschreibung: Published
    Beschreibung: 6069–6073
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Eruption mechanisms and flow emplacement ; Volcanic hazards and risks ; volcano monitoring ; erupted volumes ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 67
    Publikationsdatum: 2017-04-04
    Beschreibung: The results of three-dimensional discrete element modeling (DEM) presented in this paper confirm the grain size and flow volume effects on granular flow mobility that were observed in laboratory experiments where batches of granular material traveled down a curved chute. Our numerical simulations are able to predict the correct relative mobility of the granular flows because they take into account particle interactions and, thus, the energy dissipated by the flows. The results illustrated here are obtained without prior fine tuning of the parameter values to get the desired output. The grain size and flow volume effects can be expressed by a linear relationship between scaling parameters where the finer the grain size or the smaller the flow volume, the more mobile the centre of mass of the granular flows. The numerical simulations reveal also the effect of the initial compaction of the granular masses before release. The larger the initial compaction, the more mobile the centre of mass of the granular flows. Both grain size effect and compaction effect are explained by different particle agitations per unit of flow mass that cause different energy dissipations per unit of travel distance. The volume effect is explained by the backward accretion of the deposits that occurs wherever there is a change of slope (either gradual or abrupt). Our results are relevant for the understanding of the travel and deposition mechanisms of geophysical flows such as rock avalanches and pyroclastic flows.
    Beschreibung: Published
    Beschreibung: 2350–2366
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Pyroclastic Flows ; Mobility ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 68
    Publikationsdatum: 2017-04-04
    Beschreibung: We present the results of laboratory experiments on the aggregation and disaggregation of colliding volcanic ash particles. Ash particles of different composition and size 〈90 µm were held in turbulent suspension and filmed in high speed while colliding, aggregating, and disaggregating, forming a growing layer of electrostatically bound particles along a vertical plate. At room conditions and regardless of composition, 60–80% of the colliding particles smaller than 32 µm remained aggregated. In contrast, aggregation of particles larger than 63 µm was negligible, and, when a layer formed, periods when disaggregation (mainly by collisions or drag) exceeded aggregation occurred twice as frequently than for smaller particles. An empirical relationship linking the aggregation index, i.e., the effective fraction of aggregated particles surviving disaggregation, to the mean particle collision kinetic energy is provided. Our results have potential implications on the dynamics of volcanic plumes and ash mobility in the environment.
    Beschreibung: INGV-DPC project V1 “Probabilistic evaluation of volcanic hazard”; EU Seventh Programme FP7 “MED-SUV” grant agreement 308665
    Beschreibung: Published
    Beschreibung: 1068–1075
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: 2IT. Laboratori sperimentali e analitici
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): volcanic ash ; disaggregation ; experimental modeling ; volcanic plumes ; aggregation processes ; colliding particles ; sticking rate ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 69
    Publikationsdatum: 2017-04-04
    Beschreibung: Pyroclastic density currents (PDC) related to paroxysmal eruptions have caused a large number of casualties in the recent history of Stromboli. We combine here a critical review of historical chronicles with detailed stratigraphic,textural, and petrographic analyses of PDC deposits emplaced at Stromboli over the last century to unravel the origin of currents, their flow mechanism and the depositional dynamics. We focus on the 1930 PDC as they are well described in historical accounts and because the 1930 eruption stands as the most voluminous and destructive paroxysm of the last 13 centuries. Stromboli PDC deposits are recognizable from their architecture and the great abundance of fresh, well-preserved juvenile material. General deposit features indicate that Stromboli PDC formed due to the syn-eruptive gravitational collapse of hot pyroclasts rapidly accumulated over steep slopes. Flow channelization within the several small valleys cut on the flanks of the volcano can enhance the mobility of PDC, as well as the production of fine particles by abrasion and comminution of hot juvenile fragments, thereby increasing the degree of fluidization. Textural analyses and historical accounts also indicate that PDC can be fast (15–20 m/s) and relatively hot (360–700 °C). PDC can thus flow right down the slopes of the volcano, representing a major hazard. For this reason, they must be adequately taken into account when compiling risk maps and evaluating volcanic hazard on the Island of Stromboli.
    Beschreibung: Published
    Beschreibung: 827-840
    Beschreibung: 1V. Storia e struttura dei sistemi vulcanici
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Stromboli, Pyroclastic density currents, Paroxysms, Basaltic explosive volcanism,Volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 70
    Publikationsdatum: 2020-02-05
    Beschreibung: The definition of probabilistic models as mathematical structures to describe the response of a volcanic system is a plausible approach to characterize the temporal behavior of volcanic eruptions, and constitutes a tool for long-term eruption forecasting. This kind of approach is motivated by the fact that volcanoes are complex systems in which a com- pletely deterministic description of the processes preceding eruptions is practically impos- sible. To describe recurrent eruptive activity we apply a physically-motivated probabilistic model based on the characteristics of the Brownian passage-time (BPT) distribution; the physical process defining this model can be described by the steady rise of a state variable from a ground state to a failure threshold; adding Brownian perturbations to the steady load- ing produces a stochastic load-state process (a Brownian relaxation oscillator) in which an eruption relaxes the load state to begin a new eruptive cycle. The Brownian relaxation os- cillator and Brownian passage-time distribution connect together physical notions of unob- servable loading and failure processes of a point process with observable response statistics. The Brownian passage-time model is parameterized by the mean rate of event occurrence, μ , and the aperiodicity about the mean, α . We apply this model to analyze the eruptive his- tory of Miyakejima volcano, Japan, finding a value of 44.2(±6.5 years) for the μ parameter and 0.51(±0.01) for the (dimensionless) α parameter. The comparison with other models often used in volcanological literature shows that this pysically-motivated model may be a good descriptor of volcanic systems that produce eruptions with a characteristic size. BPT is clearly superior to the exponential distribution and the fit to the data is comparable to other two-parameters models. Nonetheless, being a physically-motivated model, it provides an insight into the macro-mechanical processes driving the system.
    Beschreibung: INGV - Sezione di Bologna; Universita' di Bologna - Marco Polo program
    Beschreibung: Published
    Beschreibung: 545-558
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Probabilistic models; Brownian passage-time distribution; ; Hazard function; Miyakejima volcano ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis ; 05. General::05.08. Risk::05.08.01. Environmental risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 71
    Publikationsdatum: 2020-02-05
    Beschreibung: Eruption forecasting refers, in general, to the assessment of the occurrence probability of a given erup- tive event, whereas volcanic hazards are normally associated with the analysis of superficial and evident phenomena that usually accompany eruptions (e.g., lava, pyroclastic flows, tephra fall, lahars, etc.). Nevertheless, several hazards of volcanic origin may occur in noneruptive phases dur- ing unrest episodes. Among others, remarkable examples are gas emissions, phreatic explosions, ground deforma- tion, and seismic swarms. Many of such events may lead to significant damages, and for this reason, the “risk” associ- ated to unrest episodes could not be negligible with respect to eruption-related phenomena. Our main objective in this paper is to provide a quantitative framework to calculate probabilities of volcanic unrest. The mathematical frame- work proposed is based on the integration of stochastic mod- els based on the analysis of eruption occurrence catalogs into a Bayesian event tree scheme for eruption forecast- ing and volcanic hazard assessment. Indeed, such models are based on long-term eruption catalogs and in many cases allow a more consistent analysis of long-term tem- poral modulations of volcanic activity. The main result of this approach is twofold: first, it allows to make inferences about the probability of volcanic unrest; second, it allows to project the results of stochastic modeling of the eruptive history of a volcano toward the probabilistic assessment of volcanic hazards. To illustrate the performance of the pro- posed approach, we apply it to determine probabilities of unrest at Miyakejima volcano, Japan.
    Beschreibung: Published
    Beschreibung: 689
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Volcanic unrest ; Eruption forecasting ; Bayesian event tree ; Stochastic models ; Miyakejima volcano ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 72
    Publikationsdatum: 2017-04-04
    Beschreibung: A new 2D/3D Lagrangian particle model (named LPAC) for the dynamics of clasts ejected during explosive eruptions is presented. The novelty of the model lies in the one-way coupling of the carrier flow field, given by a Eulerian multiphase flow code, and the particles. The model is based on a simplification of the Basset-Boussinesq-Oseen equation, expressing the Lagrangian equation of a particle as the sum of the forces exerted on it along its trajectory. It is assumed that particles are non-interacting and do not affect the background carrier flow and that the drag coefficient is constant. The model was applied to large clasts produced by Vulcanian explosions, in particular those occurring in August 1997 at Soufrière Hills Volcano, Montserrat (West Indies, UK). Simulation results allowed parametric studies as well as semi-quantitative comparisons between modeling results and field evidence. Major results include (1) the carrier flow was found to play a fundamental role even for meter-sized particles—a 1 m diameter block is predicted to reach a distance that is about 70% greater than that predicted without the effect of the carrier flow (assuming the same initial velocity), (2) assumption of the initial velocity of the particle was dropped thanks to the description of both the acceleration and deceleration phases along the particle trajectory, (3) by adopting experimentally based drag coefficients, large particles were able to reach greater distances with respect to smaller particles consistently with field observations and (4) the initial depth of the particle in the conduit was found to mainly influence the ejection velocity while the initial radial position with respect to the conduit axis was found to play a major role on the distance reached by the particle.
    Beschreibung: Published
    Beschreibung: B08206
    Beschreibung: 3.7. Dinamica del clima e dell'oceano
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): ballistic dynamics ; Lagrangian modeling ; explosive volcanism ; Montserrat ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.05. Algorithms and implementation
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 73
    Publikationsdatum: 2017-04-04
    Beschreibung: Flank instability is common at volcanoes, even though the subsurface structures, including the depth to a detachment fault, remain poorly constrained. Here, we use a multidisciplinary approach, applicable to most volcanoes, to evaluate the detachment depth of the unstable NE flank of Mt. Etna. InSAR observations of Mount Etna during 1995–2008 show a trapdoor subsidence of the upper NE flank, with a maximum deformation against the NE Rift. The trapdoor tilt was highest in magnitude in 2002–2004, contemporaneous with the maximum rates of eastward slip along the east flank. We explain this deformation as due to a general eastward displacement of the flank, activating a rotational detachment and forming a rollover anticline, the head of which is against the NE Rift. Established 2D rollover construction models, constrained by morphological and structural data, suggest that the east‐dipping detachment below the upper NE flank lies at around 4 km below the surface. This depth is consistent with seismicity that clusters above 2–3 km below sea level. Therefore, the episodically unstable NE flank lies above an east‐dipping rotational detachment confined by the NE Rift and Pernicana Fault. Our approach, which combines short‐term (InSAR) and long‐term (geological) observations, constrains the 3D geometry and kinematics of part of the unstable flank of Etna and may be applicable and effective to understand the deeper structure of volcanoes undergoing flank instability or unrest.
    Beschreibung: This work was partially funded by INGV and the DPC‐INGV project “Flank”, and partially by the ASI (SRV project).
    Beschreibung: Published
    Beschreibung: L16304
    Beschreibung: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): flank instability ; fault ; InSAR ; Etna ; rollover ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.04. Geology::04.04.11. Instruments and techniques ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 74
    Publikationsdatum: 2023-01-16
    Beschreibung: The 5 April 2003 eruption of Stromboli volcano (Italy) was the most violent in the past 50 years. It was also the best documented due to the accurate geophysical monitoring of the ongoing effusive eruption. Detailed field studies carried out a few hours to a few months after the event provided further information that were coupled with visual documentation to reconstruct the explosive dynamics. The eruption consisted of an 8-min-long explosive event preceded by a short-lived precursory activity that evolved into the impulsive ejection of gas and pyroclasts. Meter-sized ballistic blocks were launched to altitudes of up to 1400 m above the craters falling on the volcano flanks and on the village of Ginostra, about 2 km far from the vent. The vertical jet of gas and pyroclasts above the craters fed a convective plume that reached a height of 4 km. The calculated erupted mass yielded values of 1.1–1.4 × 108 kg. Later explosions generated a scoria flow deposit, with an estimated mass of 1.0–1.3 × 107 kg. Final, waning ash explosions closet the event. The juvenile fraction consisted of an almost aphyric, highly vesicular pumice mingled with a shallow-derived, crystal-rich, moderately vesicular scoria. Resuming of the lava emission a few hours after the paroxysm indicate that the shallow magmatic system was not significantly modified during the explosions. Combination of volume data with duration of eruptive phases allowed us to estimate the eruptive intensity: during the climactic explosive event, the mass discharge rate was between 106 and 107 kg/s, whereas during the pyroclastic flow activity, it was 2.8–3.6 × 105 kg/s. Strong similarities with other historical paroxysms at Stromboli suggest similar explosion dynamics.
    Beschreibung: Unpublished
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: open
    Schlagwort(e): Stromboli ; paroxysm ; explosive dynamics ; pyroclastic deposits ; ballistic ejecta ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Publikationsdatum: 2023-01-16
    Beschreibung: The April–May 2010 eruption of the Eyjafjallajökull volcano (Iceland) was characterized by a nearly continuous injection of tephra into the atmosphere that affected various economic sectors in Iceland and caused a global interruption of air traffic. Eruptive activity during 4–8 May 2010 was characterized based on short-duration physical parameters in order to capture transient eruptive behavior of a long-lasting eruption (i.e., total grain-size distribution, erupted mass, and mass eruption rate averaged over 30 min activity). The resulting 30 min total grain-size distribution based on both ground and Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) satellite measurements is characterized by Mdphi of about 2 and a fine-ash content of about 30 wt %. The accumulation rate varied by 2 orders of magnitude with an exponential decay away from the vent, whereas Mdphi shows a linear increase until about 18 km from the vent, reaching a plateau of about 4.5 between 20 and 56 km. The associated mass eruption rate is between 0.6 and 1.2 × 105 kg s−1. In situ sampling showed how fine ash mainly fell as aggregates of various typologies. About 5 to 9 wt % of the erupted mass remained in the cloud up to 1000 km from the vent, suggesting that nearly half of the ash 〉7 settled as aggregates within the first 60 km. Particle sphericity and shape factor varied between 0.4 and 1 with no clear correlation to the size and distance from vent. Our experiments also demonstrate how satellite retrievals and Doppler radar grain-size detection can provide a real-time description of the source term but for a limited particle-size range.
    Beschreibung: Published
    Beschreibung: B12202
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): MSG-SEVIRI, PLUDIX ; particle aggregation ; settling velocity ; tephra deposits ; weak plumes ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 76
    Publikationsdatum: 2024-05-09
    Beschreibung: In January 2002, Nyiragongo volcano erupted 14–34 × 106 m3 of lava from fractures on its southern flanks. The nearby city of Goma was inundated by two lava flows, which caused substantial socioeconomic disruption and forced the mass exodus of the population, leaving nearly 120,000 people homeless. Field observations showed marked differences between the lava erupted from the northern portion of the fracture system and that later erupted from the southern part. These observations are confirmed by new 238U and 232Th series radioactive disequilibria data, which show the presence of three different phases during the eruption. The lavas first erupted (T1) were probably supplied by a residual magma batch from the lava lake activity during 1994–1995. These lavas were followed by a fresh batch erupted from fissure vents as well as later (May–June 2002) from the central crater (T2). Both lava batches reached the surface via the volcano's central plumbing system, even though a separate flank reservoir may also have been involved in addition to the main reservoir. The final phase (T3) is related to an independent magmatic reservoir located much closer (or even beneath) the city of Goma. Data from the January 2002 eruption, and for similar activity in January 1977, suggest that the eruptive style of the volcano is likely to change in the future, trending toward more common occurrence of flank eruptions. If so, this would pose a significant escalation of volcanic hazards facing Goma and environs, thus requiring the implementation of different volcano-monitoring strategies to better anticipate where and when future eruptions might take place.
    Beschreibung: Published
    Beschreibung: B09202
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Nyiragongo ; forecasting ; volcanic hazard ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 77
    Publikationsdatum: 2024-05-09
    Beschreibung: Abstract A geochemical survey of fumarolic and submerged gases from fluid discharges located in the Nea Kameni and Palea Kameni islets (Santorini Island, Greece) was carried out before, during, and after the unrest related to the anomalously high seismic and ground deformation activity that affected this volcanic system since January 2011. Our data show that from May 2011 to February 2012, the Nea Kameni fumaroles showed a significant increase of H2 concentrations. After this period, an abrupt decrease in the H2 contents, accompanied by decreasing seismic events, was recorded. A similar temporal pattern was shown by the F−, Cl−, SO4 2−, and NH4 + concentrations in the fumarolic condensates. During the sharp increase of H2 concentrations, when values up to 158 mmol/ mol were measured, the δ13C–CO2 values, which prior to January 2011 were consistent with a dominant CO2 thermometamorphic source, have shown a significant decrease, suggesting an increase of mantle CO2 contribution. Light hydrocarbons, including CH4, which are controlled by chemical reactions kinetically slower than H2 production from H2O dissociation, displayed a sharp increase in March 2012, under enhanced reducing conditions caused by the high H2 concentrations of May 2011–February 2012. The general increase in light hydrocarbons continued up to July 2012, notwithstanding the contemporaneous H2 decrease. The temporal patterns of CO2 concentrations and N2/Ar ratios increased similarly to that of H2, possibly due to sealing processes in the fumarolic conduits that diminished the contamination related to the entrance of atmospheric gases in the fumarolic conduits. The compositional evolution of the Nea Kameni fumaroles can be explained by a convective heat pulse from depth associated with the seismic activation of the NE–SW-oriented Kameni tectonic lineament, possibly triggered by either injection of new magma below Nea Kameni island, as apparently suggested by the evolution of the seismic and ground deformation activity, or increased permeability of the volcanic plumbing system resulting from the tectonic movements affecting the area. The results of the present study demonstrate that the geophysical and geochemical signals at Santorini are interrelated and may be precursory signals of renewed volcanic activity and encourage the development of interdisciplinary monitoring program to mitigate the volcanic risk in the most tourist-visited island of the Mediterranean Sea.
    Beschreibung: Published
    Beschreibung: 711
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 2.4. TTC - Laboratori di geochimica dei fluidi
    Beschreibung: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Santorini Island . ; Fluid geochemistry ; Geochemical monitoring ; Seismic crisis ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 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
    Standort Signatur Erwartet Verfügbarkeit
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  • 78
    Publikationsdatum: 2024-05-09
    Beschreibung: We carried out a combined geophysical and gas-geochemical survey on an active fault strand along the North-Anatolian Fault (NAF) system in the Gulf of İzmit (eastern Sea of Marmara), providing for the first time in this area data on the distribution of methane (CH4) and other gases dissolved in the bottom seawater, as well as the CH4 isotopic composition. Based on high-resolution morphobathymetric data and chirp-sonar seismic reflection profiles we selected three areas with different tectonic features associated to the NAF system, where we performed visual and instrumental seafloor inspections, including in-situ measurements of dissolved CH4, and sampling of the bottom water. Starting from background values of 2-10 nM, methane concentration in the bottom seawater increases abruptly up to 20 nM over the main NAF trace. CH4 concentration peaks up to ~120 nM were detected above mounds related probably to gas and fluids expulsion. Methane is microbial (δ13CCH4: -67.3 and -76 ‰ vs. VPDB), and was found mainly associated with pre- Holocene deposits topped by a 10-20 m thick draping of marine mud. The correlation between tectonic structures and gas-seepages at the seafloor suggests that the NAF in the Gulf of İzmit could represent a key site for long-term combined monitoring of fluid exhalations and seismicity to assess their potential as earthquake precursors.
    Beschreibung: Published
    Beschreibung: Q10018
    Beschreibung: 1.8. Osservazioni di geofisica ambientale
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): submarine ; gas seepage ; active fault ; Marmara sea ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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  • 79
    Publikationsdatum: 2024-05-09
    Beschreibung: Lake Albano (Alban Hills volcanic complex, Central Italy) is located in a densely populated area near Rome. The deep lake waters have significant dissolved CO2 concentrations, probably related to sub-lacustrine fluid discharges fed by a pressurized CO2-rich reservoir. The analytical results of geochemical surveys carried out in 1989 2010 highlight the episodes of CO2 removal from the lake. The total mass of dissolved CO2 decreased from ∼5.8× 107 kg in 1989 to ∼0.5×107 kg in 2010, following an exponential decreasing trend. Calculated values of both dissolved inorganic carbon and CO2 concentrations along the vertical profile of the lake indicate that this decrease is caused by CO2 release from the epilimnion, at depth 〈9 m, combined with (1) water circulation at depth 〈95 m and (2) CO2 diffusion from the deeper lake layers. According to this model, Lake Albano was affected by a large CO2 input that coincided with the last important seismic swarm at Alban Hills in 1989, suggesting an intimate relationship between the addition of deep-originated CO2 to the lake and seismic activity. In the case of a CO2 degassing event of an order of magnitude larger than the one that occurred in 1989, the deepest part of Lake Albano would become CO2-saturated, resulting in conditions compatible with the occurrence of a gas outburst. These results reinforce the idea that a sudden CO2 input into the lake may cause the release of a dense gas cloud, presently representing the major volcanic threat for this densely populated area
    Beschreibung: Published
    Beschreibung: 861-871
    Beschreibung: 2.4. TTC - Laboratori di geochimica dei fluidi
    Beschreibung: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Crater lakes ; Limnic eruption ; CO2 outburst ; Lake Albano ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 04. Solid Earth::04.02. Exploration geophysics::04.02.01. Geochemical exploration ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
    Standort Signatur Erwartet Verfügbarkeit
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