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  • 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous  (30)
  • 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques  (27)
  • Mt. Etna  (22)
  • Elsevier Science Limited  (43)
  • Springer  (19)
  • Cabildo Insular de Tenerife Fundación Canaria ITER  (6)
  • Geological Society of America  (6)
  • Blackwell Publishing Ltd
  • Essen : Verl. Glückauf
  • Krefeld : Geologischer Dienst Nordhein-Westfalen
  • 2010-2014  (61)
  • 2005-2009  (13)
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  • 1
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    High time resolution fluctuations in volcanic carbon dioxide degassing from Mount Etna (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-12-17
    Beschreibung: We report here on thefirst record of carbon dioxide gas emission rates from a volcano, captured at≈1 Hz. These data were acquired with a novel technique, based on the integration of UV camera observations (to measure SO2 emission rates) and field portable gas analyser readings of plume CO2/SO2 ratios. Our measurements were performedat the North East crater of Mount Etna, southern Italy, and the data reveal strong variability in CO2 emissions over timescales of tens to hundreds of seconds, spanning two orders of magnitude. This carries importantimplications for attempts to constrain global volcanic CO2 release to the atmosphere, and will lead to an increased insight into short term CO2 degassing trends. A common oscillation in CO2 and SO2 emission rates in addition to the CO2/SO2 ratios was observed at periods of ≈89 s. Our results are furthermore suggestive of an intriguing temporal lag between oscillations in CO2 emissions and seismicity at periods of ≈300–400 s, with peaks and troughs in the former series leading those in the latter by ≈150 s. This work opens the way to the acquisition of further datasets with this methodology across a range of basaltic systems to better our understandingof deep magmatic processes and of degassing links to manifest geophysical signals
    Beschreibung: Published
    Beschreibung: 115–121
    Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Carbon dioxide ; Passive degassing ; Volcanic remote sensing ; Plume imaging ; Volcano seismology ; 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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  • 2
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    Spatial probability distribution of future volcanic eruptions at El Hierro Island (Canary Islands, Spain) (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: The 2011 submarine eruption that took place in the proximity of El Hierro Island (Canary Islands, Spain) has raised the need to identify the most likely future emission zones even on volcanoes characterized by low frequency activity. Here, we propose a probabilistic method to build the susceptibility map of El Hierro, i.e. the spatial distribution of vent opening for future eruptions, based on the probabilistic analysis of volcano-structural data of the Island collected through newfieldworkmeasurements, bathymetric information, as well as analysis of geological maps, orthophotos and aerial photographs. These data have been divided into different datasets and converted into separate and weighted probability density functions, which were included in a non-homogeneous Poisson process to produce the volcanic susceptibility map. The most likely area to host new eruptions in El Hierro is in the south-western part of the West rift. High probability locations are also found in the Northeast and South rifts, and along the submarine parts of the rifts. This map represents the first effort to deal with the volcanic hazard at El Hierro and can be a support tool for decision makers in land planning, emergency measures and civil defense actions.
    Beschreibung: This work has been partially funded by the Spanish Geological Survey (IGME) through the MODEX Project (directed by Luis Laín) and a Research Grant for LB, and the Research grant program “Innova Canarias 2020®” from the “Fundación Universitaria de Las Palmas”.
    Beschreibung: Published
    Beschreibung: 21-30
    Beschreibung: 1V. Storia e struttura dei sistemi vulcanici
    Beschreibung: 2V. Dinamiche di unrest e scenari pre-eruttivi
    Beschreibung: 3V. Dinamiche e scenari eruttivi
    Beschreibung: 4V. Vulcani e ambiente
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Susceptibility ; Volcanic hazard ; Eruptive vent ; Volcano-tectonics ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 3
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    Continental delamination and mantle dynamics drive topography extension and fl uid discharge in the Apennines (2014)
    Geological Society of America
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: The Apennines belt of Italy undergoes a northeast-trending extension at a rate of a few millimeters per year that generates moderate to large normal-faulting earthquakes. In this paper, we show that seismicity, large earthquakes, strong gas emission, and belt topography all correlate with a broad, low Vp anomaly in the uppermost mantle. We propose that a thermal/fl uid anomaly in the mantle, associated with sub-lithospheric mantle replacement after delamination of the Adria lithosphere, supports the topography of the belt and drives the extensional tectonics. The mantle anomaly is likely caused by deep fl uids coming from the dehydration of the material subducted during the Europe-Adria collision and the delamination of Adria. Beneath the belt, CO2-rich fl uids are accumulated and occasionally discharged during large normal faulting earthquakes. After the replacement of sub-lithospheric mantle, the temperature at the base of the crust increases causing crustal stretching, anatexis, and strong degassing.
    Beschreibung: Published
    Beschreibung: 715-718
    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): mantle anomaly ; Continental delamination ; the Apennines ; 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)
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  • 4
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    The 2011-2012 summit activity of Mount Etna: birth, growth and products of the new SE crater. (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Between January 2011 and April 2012, the Southeast Crater (SEC) on Mount Etna was the site of 25 episodes of lava fountaining, which led to the construction of a new pyroclastic cone on the eastern flank of the SEC. During these episodes lava overflows reached 4.3 km in length with an area of 3.19 km2 and a volume of 28 x 106 m3. The new cone, informally called New Southeast Crater (NSEC), grew over a pre-existing subsidence depression (pit crater), which had been formed in 2007-2009. The evolution of the NSEC cone was documented from its start by repeated GPS surveys carried out both from a distance and on the cone itself, and by the acquisition of comparison photographs. These surveys reveal that after the cessation of the lava fountains in April 2012, the highest point of the NSEC stood 190 m above the pre-cone surface, while the cone volume was about 19 x 106 m3, representing 38 % of the total (bulk) volume of the volcanic products including pyroclastic fallout erupted in 2011-2012, which is 50 x 106 m3 (about 33 x 106 m3 dense-rock equivalent). Growth of the new cone took place exclusively during the paroxysmal phases of the lava fountaining episodes, which were nearly always rather brief (on the average 2 hours). Overall, the paroxysmal phases of all 25 episodes represent 51 hours of lava fountaining activity – the time needed to build the cone. This is the fastest documented growth of a newborn volcanic cone both in terms of volume and height. Mean effusion rates during the lava fountaining episodes on 20 August 2011 (E11), as well as 12 and 24 April 2012 (E24 and E25) exceeded 500 m3/s (with maximum rates of 980 m3/s during E11) and thus they are among the highest effusion rates ever recorded at Etna. The composition of the erupted products varies in time, reflecting different rates of magma supply into the shallow feeding system, but without notable effects on the eruptive phenomenology. This implies that the dynamics leading to the episodic lava fountaining was largely, though not entirely, controlled by the repeated formation and collapse of a foam layer in the uppermost portion of the magmatic reservoir of the NSEC.
    Beschreibung: Published
    Beschreibung: 10-21
    Beschreibung: 1V. Storia e struttura dei sistemi vulcanici
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Etna, summit eruptions; scoria cone growth; lava and tephra volume; collapsing foam model ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 5
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    Evidence of active subsidence at Basiluzzo island (Aeolian islands, southern Italy) inferred from a Roman age wharf (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: The Aeolian Arc (Southern Tyrrhenian Sea, Italy) is one of the most active volcanic areas of the Mediterranean basin, affected by volcanic/hydrothermal and seismic activity. Ancient populations settled this region since historical times, building coastal installations which currently are valuable archaeological indicators of relative sea level changes and vertical land movements. In this study we show and discuss data on the relative sea level change estimated from a submerged wharf of Roman age dated between 50 B.C. and 50 A.D., located at Basiluzzo Island. This structure has been studied through marine surveys and archaeological interpretations and is presently located at a corrected depth of 4.10 0.2 m. We explain this submergence by a cumulative effect of the relative sea level change caused by the regional glaciohydro- isostatic signal, active since the end of the last glacial maximum, and the local volcano-tectonic land subsidence. Finally, a total subsidence rate of 2.05 0.1 mm/yr 1, with a volcano-tectonic contribution of 1.43 0.1 mm/yr 1 for the last 2 ka BP, is inferred from the comparison against the latest predicted sea level curve for the Southern Tyrrhenian Sea, suggesting new evaluations of the volcanotectonic hazard for this area of the Aeolian islands.
    Beschreibung: Published
    Beschreibung: 143-150
    Beschreibung: 4V. Vulcani e ambiente
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Aeolian islands, sea level, crustal deformations ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 6
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    Distinguishing contributions to diffuse CO2 emissions in volcanic areas from magmatic degassing and thermal decarbonation using soil gas 222Rn–δ13 C systematics: Applicationto Santorini volcano,Greece (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2022-06-10
    Beschreibung: Between January 2011 and April 2012, Santorini volcano (Greece) experienced a period of unrest characterised by the onset of detectable seismicity and caldera-wide uplift. This episode of inflation represented the first sizeable intrusion of magma beneath Santorini in the past 50 years. We employ a new approach using 222 Rn– δ 13 C systematics to identify and quantify the source of diffuse degassing at Santorini during the period of renewed activity. Soil CO 2 flux measurements were made across a network of sites on Nea Kameni between September 2010 and January 2012. Gas samples were collected in April and September 2011 for isotopic analysis of CO 2 ( δ 13 C), and radon detectors were deployed during September 2011 to measure ( 222 Rn). Our results reveal a change in the pattern of degassing from the summit of the volcano (Nea Kameni) and suggest an increase in diffuse CO 2 emissions between September 2010 and January 2012. High-CO 2 -flux soil gas samples have δ 13 C ∼ 0 .Using this value and other evidence from the literature we conclude that these CO 2 emissions from Santorini were a mixture between CO 2 sourced from magma, and CO 2 released by the thermal or metamorphic breakdown of crustal limestone. We suggest that this mixing of magmatic and crustal carbonate sources may account more broadly for the typical range of δ 13 CvaluesofCO 2 (from ∼− 4 to ∼+ 1 )in diffuse volcanic and fumarole gas emissions around the Mediterranean, without the need to invoke unusual mantle source compositions. At Santorini a mixing model involving magmatic CO 2 (with δ 13 C of − 3 ± 2 and elevated ( 222 Rn)/CO 2 ratios ∼ 10 5 –10 6 Bqkg − 1 )andCO 2 released from decarbonation of crustal limestone (with ( 222 Rn)/CO 2 ∼ 30–300 Bqkg − 1 ,and δ 13 Cof + 5 ) can account for the δ 13 C and ( 222 Rn)/CO 2 characteristics of the ‘high flux’ gas source. This model suggests ∼ 60% of the carbon in the high flux deep CO 2 end member is of magmatic origin. This combination of δ 13 Cand( 222 Rn) measurements has potential to quantify magmatic and crustal contributions to the diffuse outgassing of CO 2 in volcanic areas, especially those where breakdown of crustal limestone is likely to contribute significantly to the CO 2 flux
    Beschreibung: Published
    Beschreibung: 180-190
    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): volcanic unrest ; soil gas measurements ; carbon isotopic analysis ; magmatic degassing ; 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
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  • 7
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    Gas geochemistry of the magmatic-hydrothermal fluid reservoir in the Copahue–Caviahue Volcanic Complex (Argentina) (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2024-05-09
    Beschreibung: Copahue volcano is part of the Caviahue–Copahue Volcanic Complex (CCVC),which is located in the southwestern sector of the Caviahue volcano-tectonic depression (Argentina–Chile). This depression is a pull-apart basin accommodating stresses between the southern Liquiñe–Ofqui strike slip and the northern Copahue–Antiñir compressive fault systems, in a back-arc setting with respect to the Southern Andean Volcanic Zone. In this study, we present chemical (inorganic and organic) and isotope compositions (δ13C-CO2, δ15N, 3He/4He, 40Ar/36Ar, δ13C-CH4, δD-CH4, and δD-H2O and δ18O-H2O) of fumaroles and bubbling gases of thermal springs located at the foot of Copahue volcano sampled in 2006, 2007 and 2012. Helium isotope ratios, the highest observed for a Southern American volcano (R/Ra up to 7.94), indicate a non-classic arc-like setting, but rather an extensional regime subdued to asthenospheric thinning. δ13C-CO2 values (from −8.8‰ to −6.8‰ vs. V-PDB), δ15N values (+5.3‰ to +5.5‰ vs. Air) and CO2/3He ratios (from 1.4 to 8.8 × 109) suggest that the magmatic source is significantly affected by contamination of subducted sediments. Gases discharged from the northern sector of the CCVC show contribution of 3He-poor fluids likely permeating through local fault systems. Despite the clear mantle isotope signature in the CCVC gases, the acidic gas species have suffered scrubbing processes by a hydrothermal system mainly recharged by meteoric water. Gas geothermometry in the H2O-CO2-CH4-CO-H2 system suggests that CO and H2 re-equilibrate in a separated vapor phase at 200°–220 °C. On the contrary, rock–fluid interactions controlling CO2, CH4 production from Sabatier reaction and C3H8 dehydrogenation seem to occur within the hydrothermal reservoir at temperatures ranging from 250° to 300 °C. Fumarole gases sampled in 2006–2007 show relatively low N2/He and N2/Ar ratios and high R/Ra values with respect to those measured in 2012. Such compositional and isotope variations were likely related to injection of mafic magma that likely triggered the 2000 eruption. Therefore, changes affecting the magmatic systemhad a delayed effect on the chemistry of the CCVC gases due to the presence of the hydrothermal reservoir. However, geochemical monitoring activities mainly focused on the behavior of inert gas compounds (N2 and He), should be increased to investigate the mechanism at the origin of the unrest started in 2011.
    Beschreibung: Published
    Beschreibung: 44–56
    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): Fluid geochemistry ; Copahue volcano ; Fumarolic fluid ; Hydrothermal reservoir ; Volcanic unrest ; 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
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  • 8
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    Diffuse soil emission of hydrothermal gases (CO2, CH4, and C6H6) at Solfatara crater (Campi Flegrei, southern Italy) (2014)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2024-05-09
    Beschreibung: Measurements of soil fluxes of hydrothermal gases, with special emphasis on C6H6, as well as chemical composition of mono-aromatic compounds in fumaroles and air, were carried out in April 2012 at the Solfatara crater (Campi Flegrei, Southern Italy) to investigate the distribution and behavior of these species as they migrate through the soil from their deep source to the atmosphere. Soil fluxes of CO2, CH4 and C6H6 exhibit good spatial correlation, suggesting that diffuse degassing is mainly controlled by local fractures. The calculated total output of diffuse C6H6 from Solfatara is 0.10 kg day 1, whereas fluxes of CO2 and CH4 are 79 103 and 1.04 kg day 1, respectively. A comparison between soil gas fluxes and fumarole composition reveals that within the crater soil CH4 is significantly affected by oxidation processes, which are more efficient for low gas fluxes, being dependent on the residence time of the uprising hydrothermal gases at shallow depth. Benzene degradation, mainly proceeding through oxidation via benzoate, seems to be strongly controlled by the presence of a shallow SO2 4 -rich aquifer located in the central and southwestern sectors of the crater, suggesting that the process is particularly efficient when SO2 4 acts as terminal electron acceptor (SO4 reduction). Relatively high C6H6/C7H8 ratios, typical of hydrothermal fluids, were measured in air close to the main fumarolic field of Solfatara crater. Here, C6H6 concentrations, whose detection limit is 0.1 lgm 3, are more than one order of magnitude higher than the limit value for ambient air (5 lgm 3). This suggests that hydrothermal fluids have a strong impact on air quality in the immediate surroundings of the fumarolic vents. Significant concentrations of endogenous mono-aromatics were also detected in air samples collected from the northern and western sides of the crater, where these gas compounds are mostly fed by diffuse degassing through the crater bottom soil.
    Beschreibung: Published
    Beschreibung: 142–153
    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): hydrothermal gases ; Solfatara crater ; 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)
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  • 9
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    Human colonization and volcanic activity in the eastern Campania Plain (Italy) between the Eneolithic and Late Roman periods (2013)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Archaeological and volcanological studies conducted in the Naples area have revealed that numerous high-intensity explosive eruptions that occurred in the past 10 ka caused damage and victims in the human communities living in the plain surrounding the Neapolitan volcanoes. These catastrophic events were interspersed by hundred to thousand year long periods of quiescence, usually exceeding a human life-time. During the Early Bronze Age in particular, the Campania Plain was densely inhabited due to favourable climatic conditions and soil fertility. The archaeological and volcanological investigation of the sequences found in archaeological excavations has permitted the detailed reconstruction of the effects of eruptions and deposition mechanisms of their products on settlements. This paper discusses the example of Nola- Palma Campania during a most interesting, though poorly known, period of activity bracketed by the Vesuvian Pomici di Avellino (Early Bronze Age) and Pollena (AD 472) Plinian eruptions. Through this timespan the Plainwas variably inhabited, crossed by long-lived roads and subject to agricultural exploitation. Eruptions caused significant breaks in the occupation of the area, but also maintained the plain’s extraordinary fertility. During this period, at least eight other eruptions occurred: the Pomici di Pompei Plinian event (AD 79), two sub-Plinian to phreato-Plinian events, and five violent Strombolian to Vulcanian events. Thin and poorly developed to thicker and mature palaeosols or erosional unconformities separate the various pyroclastic deposits. Almost all the eruptions and related phenomena interacted with human settlements in the Campania Plain, and in their sequences many traces of the displacement of people during the eruptions may be seen, as well as land reclamation and re-utilization soon afterwards. Despite the various kinds of hazard posed by volcanic and related phenomena, humans nevertheless found good reasons for settlement in the Campania Plain and flourished there. A multidisciplinary approach has yielded detailed information regarding the evolution of the area and the effects of eruptions on settlements. These data are of paramount importance for an improved understanding of past events and in evaluating the hazard of eruptions and related phenomena.
    Beschreibung: Published
    Beschreibung: 132-141
    Beschreibung: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Beschreibung: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Beschreibung: 3.10. Storia ed archeologia applicate alle Scienze della Terra
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): stratigrafy ; volcanology ; archaeology ; volcanic hazard ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 10
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    An innovative method for continuous measurement of soil CO2 flux (2013)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Herein, we present a method for continuous measurement of soil CO2 flux that is completely new and distinct from existing instruments. The foremost difference is that instead of using an infrared gas analyser (IRGA), the new device measures soil CO2 flux by means of a simple pressure sensor, measuring pressure transients inside a closed polymeric tube inserted into the soil. This allows continuous measurements even in soil placed in environments that could potentially damage IRGA. In addition, due to the innovative operating principle, measurements of soil CO2 flux can be effortlessly performed also in strongly harsh weather conditions. Theoretical equations were derived for calculating soil CO2 flux solely using measured transient values. The reliability of the equations was rigorously tested with a variety of experiments. Continuous measurements over four months, acquired in a high-emission area on the Island of Vulcano, compared favourably with the data obtained using an established method.
    Beschreibung: Published
    Beschreibung: 102-109
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Soil CO2 flux measurements ; Continuous monitoring ; Methods of measurement ; Polymeric membranes ; 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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  • 11
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    Defining a 3D physical model for the hydrothermal circulation at Campi Flegrei caldera (Italy) (2013)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Our study is aimed to develop a 3D physical model of the Campi Flegrei geothermal system, in order to achieve a more accurate and comprehensive representation of the hydrothermal processes occurring in the caldera. The new model, developed by using the TOUGH2 code simulator, accounts for the caldera rocks' physical properties, bathymetry and water table topography. In particular, the computational domain is constrained by density values obtained by tomographic inversion of gravity data collected during several surveys at CF both onshore and offshore the caldera. Empirical relations between density and porosity and between porosity and permeability, derived by published data on samples cored in deep wells or collected in outcrops, allowed us to characterize the main rocks physical parameters controlling the dynamic of the CF geothermal system. We have performed and compared several simulations investigating the effects of the injection at depth, underneath Solfatara crater, of a hot gaseous mixture rich in CO2. We show that, with respect to the available literature on 2D axisymmetric models, the effects of the water table topography together with the bathymetry and the heterogeneous distribution of the rocks' physical properties, lead to important differences in the hydrothermal circulation of fluids at CF. These constraints allow the activation of convective cells with different behaviors, which produce variable patterns of temperature inside the hydrothermal system. As a consequence, the predominant effect is again represented by a central plume below the Solfatara crater, but with a non-axisymmetric structure and a wider extension. Additionally, high temperature zones are present near the coastline and in the middle part of the submerged area of the caldera with a SE–NW alignment. Moreover, our results indicate that, the submerged part of the CF caldera would deserve a more accurate study and survey, being affected by phenomenon of heating and degassing. This information could be very useful in terms of hazard assessment and volcanic risk mitigation in such an active and densely inhabited volcanic and geothermal area.
    Beschreibung: Published
    Beschreibung: 172-182
    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): Campi Flegrei ; Geothermal system ; 3D model ; Water table topography ; 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)
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  • 12
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    Seismic and Infrasound Signals at Mt. Etna: Modelling the North-East Crater Conduit and its Relation with the 2008-2009 Eruption Feeding System (2013)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: On 13 May 2008, an eruption began at Mt. Etna from an eruptive fissure that opened on the upper eastern flank of the volcano. During 12-13 May, 157 infrasonic events, together with the related seismic transients, were collected. We carried out several analyses to obtain dominant frequencies, pseudospectrograms, peak-to-peak amplitudes, source locations and time lags between infrasonic and seismic events. Spectra of the infrasonic events show two main spectral peaks in the frequency bands ~0.4-0.7 Hz and 1.5-2.0 Hz, respectively. Both infrasonic and seismic events were separately located below the North-East Crater, where no eruptive activity was observed. Moreover, significant changes in infrasound spectral content, as well as in the infrasonic-seismic lags, were found a few hours before the beginning of the eruption. On the basis of the collected information the infrasound source mechanism was modelled as a superposition of pipe and Helmholtz resonance, also leading to outline the geometry of the shallower portion of the North-East Crater plumbing system. The occurrence of these seismo-infrasonic events together with other geological and geophysical evidences, led us to inferring a direct link between North-East Crater activity and the eruptive fissure. Further, based on variations over time of both spectral features and seismicinfrasonic time lag, shallowing phenomena of the free magma column inside North-East Crater conduit were hypothesized. Such an uprise of magma was likely caused by a pressure increase inside the plumbing system occurring before the beginning of the 2008-2009 eruption.
    Beschreibung: Published
    Beschreibung: 53-68
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): infrasound ; Helmholtz resonator ; plumbing system geometry ; seismo-acoustic studies ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 13
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    A two-component mantle source feeding Mt. Etna magmatism: Insights from the geochemistry of primitive magmas (2013)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-10-06
    Beschreibung: Themajor elements, trace elements and Sr and Nd isotopes of selected Etnean primitive rocks (b15 ky BP) were studied in order to characterize their mantle source. The noble-gas geochemistry of fluid inclusions in minerals fromthe same lavaswas also investigated. Themajor element compositions ofwhole rocks and minerals showed that these products are among the most primitive atMt. Etna, comprising 6.3–17.5 wt.% MgO. The variable LREE (Light Rare Earth Elements) enrichment relative to MORB (Mid-Ocean Ridge Basalt) (Lan/Ybn = 11–26), togetherwith the patterns of certain trace-element ratios (i.e., Ce/Yb versus Zr/Nb and Th/Y versus La/Yb), can be attributed to varying degrees of melting of a common mantle source. Numerical simulations performed with the MELTS program allowed the melting percentages associated with each product to be estimated. This led us to recalculate the hypothetical parental trace-element content of the Etneanmantle source, whichwas common to all of the investigated rocks. The characteristics of the Sr, Nd and He isotopes confirmed the primitive nature of the rocks,with themost-depleted and primitive lava being that ofMt. Spagnolo (SPA; 143Nd/144Nd = 0.512908 87Sr/ 86Sr = 0.703317–0.703325 and 3He/4He = 7.6 Ra), and highlighted the similarity of the mantle sources feeding the volcanic activity of Mt. Etna and the Hyblean Plateau (a region to the south of Mt. Etna and characterized by oldermagmatismthan Mt. Etna). The coupling of noble gases and trace elements suggests an origin for the investigated Etnean lavas from melting of a Hyblean-like mantle, consisting of a two-component source where a peridotitic matrix is veined by 10% pyroxenite. A variable degree of mantle contamination by crustal-like fluids, probably related to subduction, is proposed to explain the higher Sr-isotope and lowerNd-isotope values in some rocks (143Nd/144Nd up to 0.512865 and 87Sr/86Sr up to 0.703707). This process probably occurred in the source prior tomagma generation, refertilizing some portions of themantle. Accordingly, the estimated degree of melting responsible for each magma appears to be related to its 87Sr/86Sr enrichment. In contrast, the decoupling between 3He/4He and 87Sr/86Sr ratios requires the occurrence in the crustal reservoirs of further processes capable of shifting the He isotope ratio towards slightly more radiogenic values, such as magma aging or a contribution of shallow fluid. Therefore, different residence times in the Etnean reservoir and/or various rates of magma ascent could be key parameters for preserving the original He isotope marker of the Etnean mantle source.
    Beschreibung: Published
    Beschreibung: 243-258
    Beschreibung: 5V. Sorveglianza vulcanica ed emergenze
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Mt. Etna ; Hyblean Plateaux ; Primitive magma ; Mantle metasomatism ; Peridotite ; Pyroxenite ; 04. Solid Earth::04.01. Earth Interior::04.01.03. Mantle and Core dynamics ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
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  • 14
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    Probabilistic seismic hazard at Mt. Etna (Italy): The contribution of local fault activity in mid-term assessment (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-03-01
    Beschreibung: In this work, we tackle the problem of seismic hazard at Etna deriving from the recurrent seismogenic activity of local faults, by adopting two independent methods based on probabilistic approaches. We assess the hazard in terms of macroseismic intensity and represent the occurrence probability calculated for different exposure times both on maps and at fault scale. Seismic hazard maps obtained by applying the “site approach” through the SASHA code and a new probabilistic attenuation model, indicate the eastern flank of the volcano as the most hazardous, with expected intensity (Iexp) in 50 years (i.e. the standard exposure time adopted in the seismic regulations) ranging from degrees IX to X EMS. In shorter exposure periods (20, 10, 5 years), values of Iexp up to IX are also reached in the same area, but they are clearly determined by the earthquakes generated by the Timpe fault system. In order to quantify the contribution of local seismogenic sources to the hazard of the region, we reconstruct the seismic history of each fault and calculate with SASHA the probability that earthquakes of a given intensity may be generated in different exposure times. Results confirm the high level of hazard due to the S. Tecla, Moscarello and Fiandaca faults especially for earthquakes of moderate intensity, i.e. VI≤I0≤VII, with probabilities respectively exceeding 50% and 20% in 10 years, and 30% and 10% in 5 years. Occurrence probability of major events (I0≥VIII) at the fault scale has also been investigated by statistics on intertimes. Under stationary assumptions we obtain a probability of 6.8% in 5 years for each structure; by introducing the time-dependency (time elapsed since the last event occurred on each fault) through a BPT model, we identify the Moscarello and S. Tecla faults as the most probable sources to be activated in the next 5 years (2013–2017). This result may represent a useful indication to establish priority criteria for actions aimed at reducing seismic risk at a local scale.
    Beschreibung: Published
    Beschreibung: 158-169
    Beschreibung: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Macroseismic intensity ; Seismic history ; Occurrence probability ; Time-dependent renewal process ; Individual sources ; Seismic hazard ; Mt. Etna ; 04. Solid Earth::04.06. Seismology::04.06.02. Earthquake interactions and probability ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 15
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    UV camera measurements of fumarole field degassing (La Fossa crater, Vulcano Island) (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-06-25
    Beschreibung: The UV camera is becoming an important new tool in the armory of volcano geochemists to derive high time resolution SO2 flux measurements. Furthermore, the high camera spatial resolution is particularly useful for exploring multiple-source SO2 gas emissions, for instance the composite fumarolic systems topping most quiescent volcanoes. Here, we report on the first SO2 flux measurements from individual fumaroles of the fumarolic field of La Fossa crater (Vulcano Island, Aeolian Island), which we performed using a UV camera in two field campaigns: in November 12, 2009 and February 4, 2010. We derived ~ 0.5 Hz SO2 flux time-series finding fluxes from individual fumaroles, ranging from 2 to 8.7 t d−1, with a total emission from the entire system of ~ 20 t d−1 and ~ 13 t d−1, in November 2009 and February 2010 respectively. These data were augmented with molar H2S/SO2, CO2/SO2 and H2O/SO2 ratios, measured using a portable MultiGAS analyzer, for the individual fumaroles. Using the SO2 flux data in tandem with the molar ratios, we calculated the flux of volcanic species from individual fumaroles, and the crater as a whole: CO2 (684 t d−1 and 293 t d−1), H2S (8 t d−1 and 7.5 t d−1) and H2O (580 t d−1 and 225 t d−1).
    Beschreibung: Published
    Beschreibung: 47-52
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): UV camera ; fumaroles ; 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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  • 16
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    Forecasting seismic scenarios on Etna volcano (Italy) through probabilistic intensity attenuation models: A Bayesian approach (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-03-01
    Beschreibung: In this paper, we apply a probabilistic procedure to model the attenuation of the macroseismic intensity in the Mt. Etna region, which allows estimating probabilistic seismic scenarios. Starting from the local earthquake catalogue, we select a dataset of 47 events having epicentral intensity I0 from VI to IX–X EMS, and update the model parameters previously achieved for Italy according to the Bayesian paradigm. For each class of epicentral intensity I0, we then estimate the probability distribution of the intensity at a site conditioned on the epicentre-site distance through a binomial-beta model, under the assumption of a point seismic source and isotropic decay (circular). The mode of the distribution is taken as the expected intensity Is at that site. Since the strongest earthquakes show a preferential propagation of shaking along the fault strike and a rapid decrease in the perpendicular direction, we also consider the anisotropic decay (elliptical) of the intensity due to a linear source (finite fault). We therefore transform the plane so that the ellipse has the length of the fault rupture as maximum axis and its strike as azimuth is changed into a circle with fixed diameter; then we apply the probabilistic model obtained for the isotropic case to the modified data. The entire calculation procedure is implemented in the software PROSCEN which, given the location and the epicentral intensity (and eventually the fault parameters) of the earthquake to be simulated, generates the probabilistic seismic scenario according to the isotropic and anisotropic models of attenuation. The results can be plotted on grid maps representing (1) the intensity that can be exceeded with a fixed probability, or (2) the probability of exceeding a fixed intensity value. The first representation may also find application in seismic monitoring at Etna volcano, in order to produce real-time intensity ShakeMaps based on the instrumental parameters calculated by the automatic earthquake processing system.
    Beschreibung: Published
    Beschreibung: 149-157
    Beschreibung: 4.2. TTC - Modelli per la stima della pericolosità sismica a scala nazionale
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Macroseismic intensity ; Attenuation Probability distribution ; Source models ; Seismic scenario ; Mt. Etna ; 04. Solid Earth::04.06. Seismology::04.06.05. Historical seismology ; 04. Solid Earth::04.06. Seismology::04.06.11. Seismic risk
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  • 17
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    The Alban Hills and Monti Sabatini volcanic products used in ancient Roman masonry (Italy): An integrated stratigraphic, archaeological, environmental and geochemical approach (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-06-22
    Beschreibung: The rocks of Alban Hills and Monti Sabatini volcanoes (Central Italy) and their associated epiclastic deposits have been extensively used as building material in ancient Rome from about VIIIth century BCE to IVth century CE. However, the identification of the source areas of these rocks is difficult due to the lack of an integrated stratigraphic and geochemical analysis of the relationships between the two volcanic districts, and to the alteration affecting the primary products as consequence of weathering and pedogenetic processes. Here, a comprehensive, upgraded stratigraphic and geochronological review of the two volcanic districts, corroborated by new geochronological data for several eruptive units and altered deposits is presented, coupled to a complete geochemical background, achieved by means of newly determined major and trace element analyses for all the main eruptive units. A study of the alteration processes of the primary products is also presented, and the age of the main weathering and pedogenetic phases, associated to Quaternary climatic changes, are also investigated. The results are integrated with those from literature in order to construct discriminant diagrams based on selected trace elements, and allow us to characterize the primary and altered volcanic deposits in the Rome area, distinguish products of different volcanic districts, discuss the effects of different weathering processes on the mobility of some elements, and provide a reference frame for the provenance of the volcanic materials employed in ancient Roman masonry. The interdisciplinary data set and results presented here provide groundwork for volcanological, climate, pedological and archaeological provenance studies.
    Beschreibung: Published
    Beschreibung: 115–136
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Quaternary volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 18
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    Generation of pyroclastic flows by explosive interaction of lava flows with ice/water-saturated substrate (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-01-27
    Beschreibung: We describe a new type of secondary rootless phreatomagmatic explosions observed at active lava flows at volcanoes Klyuchevskoy (Russia) and Etna (Italy). The explosions occurred at considerable (up to 5 km) distances from primary volcanic vents, generally at steep (15–35°) slopes, and in places where incandescent basaltic or basaltic-andesitic lava propagated over ice/water-saturated substrate. The explosions produced high (up to 7 km) vertical ash/steam-laden clouds as well as pyroclastic flows that traveled up to 2 km downslope. Individual lobes of the pyroclastic flow deposits were up to 2 m thick, had steep lateral margins, and were composed of angular to subrounded bomb-size clasts in a poorly sorted ash–lapilli matrix. Character of the juvenile rock clasts in the pyroclastic flows (poorly vesiculated with chilled and fractured cauliflower outer surfaces) indicated their origin by explosive fragmentation of lava due to contact with external water. Non-juvenile rocks derived from the substrate of the lava flows comprised up to 75% in some of the pyroclastic flow deposits. We suggest a model where gradual heating of a water-saturated substrate under the advancing lava flow elevates pore pressure and thus reduces basal friction (in the case of frozen substrate water is initially formed by thawing of the substrate along the contact with lava). On steep slope this leads to gravitational instability and sliding of a part of the active lava flow and water-saturated substrate. The sliding lava and substrate disintegrate and intermix, triggering explosive “fuel–coolant” type interaction that produces large volume of fine-grained clastic material. Relatively cold steam-laden cloud of the phreatomagmatic explosion has limited capacity to transport upward the produced clastic material, thus part of it descends downslope in the form of pyroclastic flow. Similar explosive events were described for active lava flows of Llaima (Chile), Pavlof (Alaska), and Hekla (Iceland) indicating that this type of explosions and related hazard is common at snow/ice-clad volcanoes and sometimes happens also on fluid-saturated hydrothermally altered slopes.
    Beschreibung: Published
    Beschreibung: 60–72
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): lava flow; pyroclastic flow; secondary explosion; phreatomagmatic explosion; Klyuchevskoy; Etna ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 19
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    A study on the reproducibility of counting vesicles in volcanic rocks (2012)
    Geological Society of America
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Vesicle size distributions in two and three dimensions of two samples were independently measured by three different researchers to investigate whether or not such measurements are reproducible. Additionally, two different software programs were used to measure the three-dimensional vesicle size distributions: the 3D Object Counter plugin for ImageJ and Blob3D. Manual thresholding by each of the authors produced similar results for both samples using both programs; however, use of the automatic, maximum entropy technique for thresholding produced measurably different results because it did not discriminate between vesicles and plagioclase crystals in one case and between vesicles and some cracks in another. Use of asymmetric erosion and dilation processes on the images is shown to affect the vesicle size distribution, but it does not have a significant effect on the power-law exponent that describes intermediate-sized vesicles or on the vesicle number density in these samples. However, such a technique is not recommended.
    Beschreibung: Published
    Beschreibung: 70-78
    Beschreibung: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcanic rocks ; vesicle counting ; reproducibility ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 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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  • 20
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    Quaternary still-stand landforms and relations with flank instability events of the Palinuro Bank (southeastern Tyrrhenian Sea) (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-03
    Beschreibung: A high-resolution morphological and geological inspection was carried out on the Palinuro Bank (39 300N, 14 480E), a volcanic complex made by several, coalescent volcanic features located on the Cam- panian continental slope (Eastern Tyrrhenian Sea, Italy). A shallow ( 84 m asl) volcanic edifice, char- acterized by a flat top modelled surface, is present on its central sector. The use of a very high-resolution Digital Terrain Model allowed recognition of the presence of relict morphologies (perhaps notches/inner margins) related to the past sea-level still-stands. Three depth levels of paleo-shorelines markers are located at 90 m, 100 m, and 123 m, respectively. In addiction, the truncated shape of the cone itself, located between 84 m and 130 m, could be interpreted as a tilted marine terrace. Breaks in slope produced by terrace landforms caused oversteepening that could have triggered lateral collapses both on the northern and southern flanks of the Bank, as suggested by the presence of steep slopes (25e40 ) and indicated by acoustic facies on chirp high-resolution mono-channel seismic profiles. The results allow further hypotheses on vertical displacement between the western sector of the Palinuro Bank, where caldera shapes are present, and the central sector, made by shallower volcanic cones. These two sectors also differ in terms of magnetic properties.
    Beschreibung: Published
    Beschreibung: 228-237
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Palinuro Bank ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 21
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    Triggering mechanisms of static stress on Mount Etna volcano. An application of the boundary element method (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: In the last thirty years, numerous eruptions and associated deformation episodes have occurred at Mt. Etna volcano. Datasets recorded by continuous monitoring of these episodes provide a unique opportunity to study the relationships between volcanism, flank instability and faulting activity. We have investigated the stress triggering mechanism between magmatic reservoir inflation, intrusive episodes and flank dynamics. Using three-dimensional numerical Boundary Elements Models we simulated volcano-tectonic events and calculated Coulomb stress changes. Using this modeling approach, we analyzed four realistic scenarios that are representative of recent kinematics occurring at Mt. Etna. The main results obtained highlight how (1) the inflation of a deep spherical magma source transfers elastic stress to a sliding plane and faults (2) the opening of the NE Rift and S Rift (to a less efficient extent) favor movements of the instable sector and may encourage seismicity on the eastern flank faults, and (3) flank instability may trigger the uprising of magma. Defining the effects of the elastic stress transfer and relationships among the main forces acting on volcano, may help to forecast possible eruption scenarios during future episodes of unrest at Mount Etna and provide an important tool for decision makers during volcanic emergencies involving the highly populated areas of the volcano.
    Beschreibung: Published
    Beschreibung: 149-158
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Coulomb Stress changes ; Mount Etna ; 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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  • 22
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    A pilot GIS database of active faults of Mt. Etna (Sicily): A tool for integrated hazard evaluation (2012)
    Elsevier Science Limited
    In:  Supplementary data associated with this article can be found in the online version, at http://dx.doi.org/10.1016/j.jvolgeores.2012.08. 013.
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: A pilot GIS-based system has been implemented for the assessment and analysis of hazard related to active faults affecting the eastern and southern flanks of Mt. Etna. The system structure was developed in ArcGis® environment and consists of different thematic datasets that include spatially-referenced arc-features and associated database. Arc-type features, georeferenced into WGS84 Ellipsoid UTM zone 33 Projection, represent the five main fault systems that develop in the analysed region. The backbone of the GIS-based system is constituted by the large amount of information which was collected from the literature and then stored and properly geocoded in a digital database. This consists of thirty five alpha-numeric fields which include all fault parameters available from literature such us location, kinematics, landform, slip rate, etc. Although the system has been implemented according to the most common procedures used by GIS developer, the architecture and content of the database represent a pilot backbone for digital storing of fault parameters, providing a powerful tool in modelling hazard related to the active tectonics of Mt. Etna. The database collects, organises and shares all scientific currently available information about the active faults of the volcano. Furthermore, thanks to the strong effort spent on defining the fields of the database, the structure proposed in this paper is open to the collection of further data coming from future improvements in the knowledge of the fault systems. By layering additional user-specific geographic information and managing the proposed database (topological querying) a great diversity of hazard and vulnerability maps can be produced by the user. This is a proposal of a backbone for a comprehensive geographical database of fault systems, universally applicable to other sites.
    Beschreibung: Published
    Beschreibung: 170-186
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: 5.5. TTC - Sistema Informativo Territoriale
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): GIS-based system ; Hazard assessment ; Volcano-tectonics ; Flank dynamics ; Georeferenced arc-features ; Active fault database ; 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::04.04.06. Rheology, friction, and structure of fault zones ; 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::04.07. 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 ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 23
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    Fluorine adsorption by volcanic soils at Mt. Etna, Italy (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-03
    Beschreibung: Fluorine adsorption experiments were performed on 28 samples of the first 5 cm of topsoil collected on the flanks of Mt. Etna. The soil samples were equilibrated with F-rich rainwater (3.25 mg/L) at a soil/water weight ratio of 1/25. Aliquots of the supernatant were collected after 1, 7, 72, 720 and 5640 h and analysed for F content. The soil samples could be subdivided into three groups based on their F-adsorption behaviours after 1 h and at the end of the experiment: (1) negative adsorption (F released from the soil to the solution) after 1 h and negative or moderately positive adsorption at the end, (2) from negative after 1 h to strongly positive adsorption at the end, and (3) always strong positive adsorption. The adsorption capacity of the soils was positively correlated with the soil pH, the contents of finer granulometric fractions (clay and silt) and the weathering stage (as quantified by the chemical alteration index). The most F adsorbing soils are found at the periphery of the volcano where aquifers are more vulnerable to contamination due to the shallower depth of the water table. This study further evidences the importance of the Etnean soils in protecting groundwater from an excessive magmatic F input.
    Beschreibung: Published
    Beschreibung: 1179–1188
    Beschreibung: 4.4. Scenari e mitigazione del rischio ambientale
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): volcanic soils ; fluoride adsorption ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 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)
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  • 24
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    Magma-ascent processes during 2005–2009 at Mt Etna inferred by soil CO2 emissions in peripheral areas of the volcano (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: In this paper, we report four years of soil CO2 emission data measured monthly at 130 sites in two peripheral areas of Mt Etna Volcano that are well known for their high discharge rates of volcanic gas. We remove the influence of atmospheric parameters, and by means of statistical analyses, we (i) demonstrate that variations in CO2 emissions are due mainly to CO2 of a deep origin and (ii) quantify the total amounts of CO2 derived from a deep magma source. Periods of anomalous deep degassing are identified in both areas. A comparison of the timing of these anomalies and geophysical data indicates that the periods of anomalous degassing can be mostly ascribed to intrusions of fresh magma into the Etna plumbing system, which is in agreement with many previous works. Based on the existing literature, we formulate an interpretative framework of magma migration within the plumbing system, consistent with temporal trends in the observed anomalies. Finally, we reconstruct the processes of recent magma ascent at Mt Etna based on our interpretative framework, published geophysical data, and records of volcanic activity.
    Beschreibung: Published
    Beschreibung: 218-227
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Soil CO2 flux ; Mt Etna ; Volcanic activity ; Magma transfer ; 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::04.08.06. Volcano monitoring
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  • 25
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    Unbekannt
    A forward test for interaction between remote earthquakes and volcanic eruptions: the case of Sumatra (June 2000) and Denali (November 2002) earthquakes (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: We propose a formal procedure to validate the hypothesis of a causal relationship between great tectonic earthquakes and volcanic eruptions through a forward statistical test. This approach allows such a hypothesis to be evaluated in an objective way, ruling out any possible unconscious overfitting of the past data. The procedure consists of two steps: (a) the computation of the stress perturbation in a volcanic area due to some selected seismic event, by means of a spherical, layered, viscoelastic and self- gravitating earth model; and (b) the application of a statistical test to check the differences in the spatio-temporal distribution of eruptions before and after the earthquake, weighting each eruption with the stress perturbation induced at the volcano at the time of the eruption. Finally, for the sake of example, we apply the method to the case of the recent Engano earthquake in Sumatra (June 2000) and the Denali earthquake in Alaska (November 2002).
    Beschreibung: Published
    Beschreibung: 383 – 395
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): earthquake–volcano interaction ; post-seismic stress perturbation ; forward test ; Engano earthquake ; Denali earthquake ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 26
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    Soil gases and SAR measurements reveal hidden faults on the sliding flank of Mt. Etna (Italy) (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: From October 2008 to November 2009, soil CO2, radon and structural field surveys were performed on Mt. Etna, in order to acquire insights into active tectonic structures in a densely populated sector of the south-eastern flank of the volcano, which is involved in the flank dynamics, as highlighted by satellite data (InSAR). The studied area extends about 150 km2, in a sector of the volcano where InSAR results detected several lineaments that were not well-defined from previous geological surveys. In order to validate and better constrain these features with ground data evidences, soil CO2 and soil radon measurements were performed along transects roughly orthogonal to the newly detected faults, with measurement points spaced about 100 m. In each transect, the highest CO2 values were found very close to the lineaments evidenced by InSAR observations. Anomalous soil CO2 and radon values were also measured at old eruptive fractures. In some portions of the investigated area soil gas anomalies were rather broad over transects, probably suggesting a complex structural framework consisting of several parallel volcano-tectonic structures, instead of a single one. Soil gas measurements proved particularly useful in areas at higher altitude on Mt. Etna (i.e. above 900 m asl), where InSAR results are not very informative/ are fairly limited, and allowed recognizing the prolongation of some tectonic lineaments towards the summit of the volcano. At a lower altitude on the volcanic edifice, soil gas anomalies define the active structures indicated by InSAR results prominently, down to almost the coastline and through the northern periphery of the city of Catania. Coupling InSARwith soil gas prospectingmethods has thus proved to be a powerful tool in detecting hidden active structures that do not show significant field evidences.
    Beschreibung: This work was funded by the DPC-INGV project “Flank”
    Beschreibung: Published
    Beschreibung: 27-40
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): CO2 ; Radon ; InSAR ; Faults ; Etna ; Volcano-tectonics ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 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)
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  • 27
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    New insights into volcanic processes at Stromboli from Cerberus, a remote-controlled open-path FTIR scanner system (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: The ordinary, low intensity, activity of Stromboli volcano is sporadically interrupted by more energetic events termed, depending on their intensity, “major explosions” and “paroxysms”. These short-lived energetic episodes represent a potential risk to visitors to the highly accessible summit of Stromboli. Observations made at Stromboli over the last decade have shown that the composition of gas emitted from the summit craters may change prior to such explosions, allowing the possibility that such changes may be used to forecast these potentially dangerous events. In 2008 we installed a novel, remote-controlled, open-path FTIR scanning system called Cerberus at the summit of Stromboli, with the objective of measuring gas compositions from individual vents within the summit crater terrace of the volcano with high temporal resolution and for extended periods. In this work we report the first results from the Cerberus system, collected in August-September 2009, November 2009 and May-June 2010. We find significant, fairly consistent, intra-crater variability for CO2/SO2 and H2O/CO2 ratios, and relatively homogeneous SO2/HCl ratios. In general, the southwest crater is richest in CO2, and the northeast crater poorest, while the central crater is richest in H2O. It thus appears that during the measurement period the southwest crater had a somewhat more direct connection to a primary, deep degassing system; whilst the central and northeast craters reflect a slightly more secondary degassing nature, with a supplementary, shallow H2O source for the central crater, probably related to puffing activity. Such water-rich emissions from the central crater can account for the lower crystal content of its eruption products, and emphasise the role of continual magma supply to the shallowest levels of Stromboli's plumbing system. Our observations of heterogeneous crater gas emissions and high H2O/CO2 ratios do not agree with models of CO2-flushing, and we show that simple depressurisation during magma ascent to the surface is a more likely model for H2O loss at Stromboli. We highlight that alternative explanations other than CO2 flushing are required to explain distributions of H2O and CO2 amounts dissolved in melt inclusions. We detected fairly systematic increases in CO2/SO2 ratio some weeks prior to major explosions, and some evidence of a decrease in this ratio in the days immediately preceding the explosions, with periods of low, stable CO2/SO2 ratios between explosions otherwise. Our measurements, therefore, confirm the medium term (~ weeks) precursory increases previously observed with MultiGas instruments, and, in addition, reveal new, short-term precursory decreases in CO2/SO2 ratios. immediately prior to the major explosions. Such patterns, if shown to be systematic, may be of great utility for hazard management at Stromboli's summit. Our results suggest that intra-crater CO2/SO2 variability may produce short-term peaks and troughs in CO2/SO2 time series measured with in-situ MultiGas instruments, due simply to variations in wind direction.
    Beschreibung: Published
    Beschreibung: 66-76
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): OP-FTIR scanning system ; Stromboli Volcano ; Explosive activity ; 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)
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  • 28
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    Brittle creep in basalt and its application to time-dependent volcano deformation (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: Time-dependent brittle deformation is a fundamental and pervasive process operating in the Earth's upper crust. Its characterization is a pre-requisite to understanding and unraveling the complexities of crustal evolution and dynamics. The preferential chemical interaction between pore fluids and strained atomic bonds at crack tips, a mechanism known as stress corrosion, allows rock to fail under a constant stress that is well below its short-term strength over an extended period of time; a process known as brittle creep. Here we present the first experimental measurements of brittle creep in a basic igneous rock (a basalt from Mt. Etna volcano) under triaxial stress conditions. Results from conventional creep experiments show that creep strain rates are highly dependent on the level of applied stress (and can be equally well fit by a power law or an exponential law); with a 20% increase in stress producing close to three orders of magnitude increase in creep strain rate. Results from stress-stepping creep experiments show that creep strain rates are also influenced by the imposed effective confining pressure. We show that only part of this change can be attributed to the purely mechanical influence of an increase in effective pressure, with the remainder interpreted as due to a reduction in stress corrosion reactions; the result of a reduction in crack aperture that restricts the rate of transport of reactive species to crack tips. Overall, our results also suggest that a critical level of crack damage is required before the deformation starts to accelerate to failure, regardless of the level of applied stress and the time taken to reach this point. The experimental results are discussed in terms of microstructural observations and fits to a macroscopic creep law, and compared with the observed deformation history at Mt. Etna volcano.
    Beschreibung: Published
    Beschreibung: 71–82
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): stress corrosion ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 29
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    An overview of experimental models to understand a complex volcanic instability: Application to Mount Etna, Italy (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Volcanic edifices are often unable to support their own load, triggering the instability of their flanks. Many analogue models have been aimed, especially in the last decade, at understanding the processes leading to volcano flank instability; general behaviors were defined and the experimental results were compared to nature. However, available data at well-studied unstable volcanoes may allow a deeper understanding of the specific processes leading to instability, providing insights also at the local scale. Etna (Italy) constitutes a suitable example for such a possibility, because of its well-monitored flank instability, for which different triggering factors have been proposed in the last two decades. Among these factors, recent InSAR data highlight the role played by magmatic intrusions and a weak basement, under a differential unbuttressing at the volcano base. This study considers original and recently published experimental data to test these factors possibly responsible for flank instability, with the final aim to better understand and summarize the conditions leading to flank instability at Etna. In particular, we simulate the following processes: a) the longterm activity of a lithospheric boundary, as the Malta Escarpment, separating the Ionian oceanic lithosphere from the continental Sicilian lithosphere, below the most unstable east flank of the volcano; b) spreading due to a weak basement, with different boundary conditions; c) the pressurization of a magmatic reservoir, as that active during the 1994–2001 inflation period; d) dike emplacement, as observed during the major 2001 and 2002–2003 eruptions. The experimental results suggest that: 1) the long-term activity of a lithospheric tectonic boundary may create a topographic slope which provides a differential buttressing at the volcano base, a preparing factor to drive longer-term (〉105 years) instability on the east flank of the volcano; 2) volcano spreading (b104 years) has limited effect on flank instability at Etna; 3) magmatic intrusions (b101 years), both in the form of Mogi-like sources or dikes, provide the most important conditions to trigger flank instability on the shorter-term.
    Beschreibung: Thisworkwas partially funded by INGV and the Italian DPC (DPC-INGV project V4 “Flank”).
    Beschreibung: Published
    Beschreibung: 98-111
    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: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): volcano instability ; analogue modeling ; Etna ; unbuttressing ; 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::04.04.06. 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::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 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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  • 30
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    Intrusive mechanism of the 2008–2009 Mt. Etna eruption: Constraints by tomographic images and stress tensor analysis (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Since January 2008, several geophysical parameters have evidenced a recharging phase at Mt. Etna volcano culminating with an effusive eruption that began on May 13, 2008. Seismic activity recorded at Mt. Etna from January 2007 to May 2008 was analyzed in order to provide seismological constraints to the volcano dynamics leading to the eruption. A total of 336 selected earthquakes, withML≥1.5, were used as data source for this study. Specifically, we calculated 3D velocity and attenuation tomography, including a 3D relocation of the events, and we computed 53 selected fault plane solutions (FPSs) that were used for stress tensor inversion. The most important result obtained from the joint analysis of VP, VP/VS and P-wave attenuation is an anomalous zone with normal to high VP (values between 3.5 and 4.5 km/s) and low VP/VS (values≤1.64), which partially overlaps with a low QP (values≤50) volume located along a NS trending channel beneath the central crater. This can be interpreted as a shallow volume characterized by high temperature where the magma is located with the presence of supercritical fluids. The analysis of seismic stress tensor evidenced an extensional regime in the depth range 3–13 km with a vertically oriented σ1. This finding may suggest an extensional stress regime, probably related to the kinematic response of the volcanic edifice to both a deep magmatic intrusion and a condition of decreased regional compressive stress facilitated by sliding processes of the eastern flank of the volcano.
    Beschreibung: Published
    Beschreibung: 50–63
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Mt. Etna ; Volcanic eruptions ; Stress Tensor ; Velocity tomography ; Attenuation tomography ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 31
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    Multiphase-flow numerical modeling of the 18 May 1980 lateral blast at Mount St. Helens, USA (2012)
    Geological Society of America
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Volcanic lateral blasts are among the most spectacular and devastating of natural phenomena, but their dynamics are still poorly understood. Here we investigate the best documented and most controversial blast at Mount St. Helens (Washington State, United States), on 18 May 1980. By means of three-dimensional multiphase numerical simulations we demonstrate that the blast front propagation, final runout, and damage can be explained by the emplacement of an unsteady, stratified pyroclastic density current, controlled by gravity and terrain morphology. Such an interpretation is quantitatively supported by large-scale observations at Mount St. Helens and will influence the definition and predictive mapping of hazards on blast-dangerous volcanoes worldwide.
    Beschreibung: Published
    Beschreibung: 535-538
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): volcanic blast ; multiphase model ; Mount St. Helens ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 32
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    Hazard assessment at Mount Etna using a hybrid lava flow inundation model and satellite-based land classification (2012)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Using a lava flow emplacement model and a satellite-based land cover classification, we produce a map to allow assessment of the type and quantity of natural, agricultural and urban land cover at risk from lava flow invasion. The first step is to produce lava effusion rate contours, i.e., lines linking distances down a volcano’s flank that a lava flow will likely extend if fed at a given effusion rate from a predetermined vent zone. This involves first identifying a vent mask and then running a downhill flow path model from the edge of every pixel around the vent mask perimeter to the edge of the DEM. To do this, we run a stochastic model whereby the flow path is projected 1,000 times from every pixel around the vent mask perimeter with random noise being added to the DEM with each run so that a slightly different flow path is generated with each run. The FLOWGO lava flow model is then run down each path, at a series of effusion rates, to determine likely run-out distance for channel-fed flow extending down each path. These results are used to plot effusion rate contours. Finally, effusion rate contours are projected onto a land classification map (produced from an ASTER image of Etna) to assess the type and amount of each land cover class falling within each contour. The resulting maps are designed to provide a quick look-up capability to assess the type of land at risk from lava extending from any location at a range of likely effusion rates. For our first (2,000 m) vent zone case used for Etna, we find a total of area of ~680 km2 is at risk from flows fed at 40 m3 s−1, of which ~6 km2 is urban, ~150 km2 is agriculture and ~270 km2 is grass/woodland. The model can also be run for specific cases, where we find that Etna’s 1669 vent location, if active today, would likely inundate almost 11 km2 of urban land, as well as 15.6 km2 of agricultural land, including 9.5 km2 of olive groves and 5.2 km2 of vineyards and fruit/nut orchards.
    Beschreibung: Published
    Beschreibung: 1001-1027
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Lava flow ; Risk ; FLOWGO ; ASTER image ; Land classification ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 33
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    Geochemical evidence for mixing between fluids exsolved at different depths in the magmatic system of Mt Etna (Italy) (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: A 4-year geochemical survey of some fumaroles at the Voragine summit crater of Mt Etna was performed in combination with synchronous monitoring of peripheral gas emissions at the base of the volcano. This was the first geochemical study at Mt Etna to have included the abundances of Ar, He, and C isotopes. Once the effects of postmagmatic shallow processes were identified and quantitatively removed, the He–Ar–CO2 systematics of the Voragine crater fumaroles and peripheral gas emissions described the same degassing path. Combining the carbon-isotope composition with information about noble gases provided evidence that the crater fumaroles are fed from a two-endmember mixture composed of a deep member coming from pressures between 200 and 400 MPa (depending on time), and a shallower one exsolved at 130 MPa. Similar mixing processes probably also occur in gases from peripheral vents. The simultaneous assessment of d13CCO2 and He/Ar values of crater fumaroles over time has identified simple changes in the mixing proportion between the two endmembers and, moreover, periods during which the exsolution pressure of the deep fluid increased. These periods seem to be linked to pre-eruptive phases of the volcano. The identified open-system degassing processes are indicative of efficient bubble–melt decoupling at depth, whereas the mixing process requires a convective transfer of the deeply exsolved fluids toward shallower levels of magma where further vapor is exsolved. In agreement with the most recent geophysical and petrological data from Mt Etna, these observations allow inferences about a deep portion of the plumbing system (5 to 12 km b.s.l.), comprising sill-like reservoirs connected by small vertical structures, and a main reservoir at 2–3 km b.s.l. that is probably fluxed by magmatic volatiles. 2012 Elsevier Ltd. All rights reserved.
    Beschreibung: Published
    Beschreibung: 380-394
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): gas geochemistry, isotopes, degassing, modelling ; 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
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 34
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    Evidence for a recent change in the shallow plumbing system of Mt. Etna (Italy): Gas geochemistry and structural data during 2001–2005 (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: We analyzed crater SO2 fluxes from Mt Etna, together with soil CO2 effluxes from the volcano's flanks, in the period from 2001 to 2005. Between the 2001 and 2002–2003 eruptions, persistently low values of both parameters suggest that no new gas-rich magma was accumulating at shallow depth (b5 km) within Etna's central conduit, whereas very high SO2 sin-eruptive fluxes during the two eruptions indicated sudden decompression of an un-degassed magma rising along newly-formed eccentric conduits. In November 2003, soil CO2 data indicate migration of gas-rich magma from deep (〉10 km) to shallow (b5 km) portions of the feeding conduits, preceded by an increase in crater SO2 fluxes. A similar behavior was observed also during and after the following 2004–2005 eruption. This degassing style matches a period of increased structural instability of the volcanic edifice caused by acceleration of spreading that affected both its eastern and southern flanks. Spreading could have triggered progressively deeper depressurization in the central conduit, inducing release of the more soluble gas (SO2) first, and then of CO2, contrary to what was observed before the 2001 eruption. This suggests that the edifice has depressurized, promoting ascent of fresh-magma and increasing permeability favouring release of CO2 flux. By integrating geochemical and structural data, previous degassing models developed at Mt. Etna have been updated to advance the understanding of eruptive events that occurred in recent years.
    Beschreibung: This work was funded by grants from the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and from the Dipartimento per la Protezione Civile (Italy).
    Beschreibung: Published
    Beschreibung: 90-97
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    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: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Geochemical modeling ; volcano monitoring ; volcanic gases ; Tectonics and magmatism ; flank collapse ; 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::04.04. 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::04.07.05. 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::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.04. Thermodynamics ; 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::05.08. Risk::05.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 35
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    Influence of volcanic gases on the epidermis of Pinus halepensis Mill. in Campi Flegrei, Southern Italy: A possible tool for detecting volcanism in present and past floras (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Cuticle micromorphology together with epidermal and epistomatal wax, in both current- and first-year-old needles of conifer Pinus halepensis (Aleppo pine) trees growing under volcanic gas fumigation was analysed in Pisciarelli area, Campi Flegrei, Southern Italy. As a control, current- and first-year-old needles growing far from volcanic gas emission were also sampled. Using a multidisciplinary approach with SEM, TEM and X-ray, volcanic gases were shown to cause degradation on epicuticular and epistomatal waxes. Significant statistical variations of ultrastructural components of the cuticle, with 30 measurements, including total thickness of the cuticle, and details and proportions of all different layers, and use of confidence interval, revealed a high degree of sensitivity of Aleppo pine to this extreme environment. In the present study, non-significant thickness variations of the cell wall plus cuticle among current- and first-year-old needles of both fumigated and non fumigated trees have been found. However, at the ultrastructural level, significant variations in cell wall and total cuticle thickness, especially within the three zones of B1 fibrillar layer, revealed different equilibria for each of the four types of material. Using energy dispersive X-ray microanalysis, no sulphur was found in either cuticle or epidermal cells, but the presence of H2S in the fumarole gas is suspected to cause indirect and/or direct cuticle alterations of wax structure. Ultrastructural characters of plant cuticles related to emission of volcanic gases during the geological past are also discussed. Among these considerations, an identification key enabling distinction between non fumigated and fumigated materials with 9 characters, provides a good tool detecting the influence of volcanism for extant and fossil plants.
    Beschreibung: Published
    Beschreibung: 1–17
    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): Campi Flegrei ; Volcanic gases ; Pinus halepensis ; Hydrogen sulphide (H2S) ; 04. Solid Earth::04.03. Geodesy::04.03.06. 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
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  • 36
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    Continental margin large-scale instability controlling the flank sliding of Etna volcano (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: Etna volcano is affected by a downward sliding of its eastern flank, as rapid as a few cm/year, whose nature is highly debated. Recently collected marine geological and geophysical data allows a detailed image of the morphostructural setting of the continental margin facing the volcano. Here, a large bulge offsets the margin that is deeply affected by widespread semicircular steps, interpreted as evidence of large-scale gravitational instability. Such features permeate the whole margin and extend inshore to the volcano sector where the larger ground deformations are measured. Both submarine instability and subaerial flank sliding are bounded by two regional tectonic lineaments interpreted as weakness lines. These cross the coastline to accommodate the basinward movement of this large sector of the continental margin topped by the Etna volcanic pile. The new data allows re-interpreting the tectonic setting of the coastal belt and proposing a novel structural model, highlighting the active role of the continental margin instability to drive the seaward sliding of the volcano's eastern flank. This model may suggest why a very active basaltic volcano has so unusually developed in front of an active thrust belt.
    Beschreibung: Published
    Beschreibung: 57–64
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): volcano sliding ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 37
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    Morphometry of scoria cones, and their relation to geodynamic setting: A DEM-based analysis (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: The morphometry of a great number of scoria cones, belonging to volcanic fields of various geodynamic settings, has been measured and analyzed, addressing the question whether there is a relation between the prevalent cone shape in a given field and the geodynamic setting of the field itself. Morphometric analysis was carried out on freely downloadable digital elevation models (DEMs). The accuracy of the used DEMs and the associated error in scoria cone morphometry were determined by cross-comparing high-resolution LIDAR-derived DEMs, USGS NED, TINITALY DEM and ASTER GDEM. The 10-m TINITALY/01 and USGS NED DEMs are proven to be suitable for scoria cone morphometry, whereas ASTER GDEM can be used reliably for cones with volume greater than 30 × 106 m3. According to a detailed morphometry of all scoria cones, we propose that the cones related to subductional setting show relatively higher values of Hco/Wco and lower values of Wcr/Wco than the cones related to extensional setting. The detected differences can be imputable to peculiar eruption dynamics resulting in slight but systematic changes in shape, and differences in lithological and sedimentological characteristics that govern post-eruptive erosion. To constrain the pathway of scoria cone erosion, the detected morphometric changes were also interpreted using a simple linear degradation model. Utilizing the obtained simulation results, the inferred initial cone base, and the age of scoria cones, we calculated a diffusion coefficient (K) for several dated cones, which are related to the prevalent climate. Our results, despite the high error associated, allow to assess the median K for all volcanic fields. Due to the complexity of the factors behind, it is not easy to understand if the prevalent shape characterizing a certain volcanic field is due mainly to sin-eruptive or post-eruptive mechanisms; however, our distinction between the two main geodynamic settings may be the first step to decipher these factors.
    Beschreibung: Published
    Beschreibung: 56-72
    Beschreibung: 1.10. TTC - Telerilevamento
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Scoria cone ; Digital elevation models (DEMs) ; Morphometry ; Volcanic field ; Cone degradation simulation ; Geodynamic setting ; 04. Solid Earth::04.04. Geology::04.04.03. Geomorphology ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 38
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    Electrical conductivity, ground displacement, gravity changes, and gas flow at Solfatara crater (Campi Flegrei caldera, Italy): Results from numerical modeling (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: Hydrothermal fluid circulation may cause measurable gravity changes and ground deformation. We extend our previous studies and increase the number of observable parameters to include gas temperature, the rate of diffuse degassing, the extent of the degassing area, and electrical conductivity. We have carried out simulations using TOUGH2/EOS2 of a large scale hydrothermal system, then we have calculated observables arising from changes in hydrothermal fluid circulation. Our results show that fluids affect many observable parameters generating detectable signals. However, a more detailed description of the shallow subsurface is necessary to properly calculate electrical conductivity. Studies at Solfatara volcano (Campi Flegrei caldera, Italy) highlight the presence of an unsaturated layer at depth and allow to determine the position of the water table. Then, we present results from a new, small scale simulation, focused on the crater, and carried out with a new, refined meshgrid taking into account the real topography. Aim of the work is to calculate a detailed electrical conductivity map and reproduce the main features of the Solfatara crater.
    Beschreibung: Published
    Beschreibung: 93–105
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Electrical conductivity ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 39
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    Evidence for Late Pleistocene uplift at the Somma-Vesuvius apron near Pompeii (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: Detailed stratigraphic and micropalaeontological analyses of samples from boreholes at the Somma-Vesuvius apron, between Pompeii and the sea, allowed reconstruction of Late Quaternary palaeoenvironmental evolution of the Sarno coastal plain. In all, 116 samples were recovered from seven boreholes drilled from 2–10 m a.s.l. to 16.5–26 m b.s.l. Microfossil assemblages, with special regard to benthic foraminifers and ostracods, were used to reconstruct the depositional palaeoenvironment. Fossil remains show that all the pre-79 AD fossiliferous sediments from 2 to − 24 m a.s.l. were deposited in shallow marine waters for a long time despite an appreciable sea level rise. The data indicate alternation of both shallow marine and subaerial conditions during the last ~ 15 kyr, evidencing ground uplift of the area of about 75 m at a rate of ~ 5 mm/year. Marine sediment accumulation (~ 6 m/kyr) and tectonic uplift long offset the sea level rise, and as a consequence, submerged areas remained the same as well.
    Beschreibung: Published
    Beschreibung: 211–227
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): ground uplift; Somma-Vesuvius; Pleistocene; Palaeoecology; benthic foraminifers; ostracods ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 40
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    Multitemporal laser scanner-based observation of the Mt. Vesuvius crater: Characterization of overall geometry and recognition of landslide events (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: Results of observations of the Mt. Vesuvius caldera, carried out by means of terrestrial laser scanning (TLS) in May 2005, October 2006 and June 2009, are reported here. In each survey the whole crater was acquired with 17/20 scans from 6 different viewpoints and the corresponding digital surface models were generated and registered into the UTM-WGS84 reference frame. In this way, a comparison between the multitemporal models leads to an evaluation of the occurred changes. The deformation maps, i.e. the contouring plots of the differences between the models along the direction of maximum variations, showed a progressive mass loss due to rock-falls from the NE vertical crater wall whose area was about View the MathML source. The TLS data also showed the accumulation at the bottom. The volume loss which occurred from 2005 to 2009, was computed by subtraction of volumes defined with respect to reference planes parallel to the caldera walls and was estimated to be View the MathML source. The volume uncertainties due to registration errors, subsampling noise effects, and effects due to choice of the reference plane, were also estimated. Some results were also interpreted on the basis of micro-seismic and meteorological data in order to plan a monitoring technique where seismic signals related to rock-fall and/or signals of intense rainfalls are used as alarms for fast TLS surveys able to characterize the corresponding changes of the caldera walls. The proposed methodology, in particular the simple but effective approach used in the estimation of volume uncertainties, can be applied to each rock slope instability phenomenon, regardless of the particular environment.
    Beschreibung: Published
    Beschreibung: 327–336
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Terrestrial laser scanning ; 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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  • 41
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    Influence of thermal and mechanical cracks on permeability and elastic wave velocities in a basalt from Mt. Etna volcano subjected to elevated pressure (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2020-02-24
    Beschreibung: We report simultaneous laboratory measurements of seismic velocities and fluid permeability on lava flow basalt from Etna (Italy). Results were obtained for dry and saturated samples deformed under triaxial compression. During each test, the effective pressure was first increased up to 190 MPa to investigate the effect of pre-existing crack closure on seismic properties. Then, the effective pressure was unloaded down to 20 MPa, a pressure which mirrors the stress field acting under a lava pile of approximately 1.5–2 km thick, and deviatoric stress was increased until failure of the specimens. Using an effective medium model, the measured elastic wave velocities were inverted in terms of two crack densities: ρi the crack density of the pre-existing thermal cracks and ρv the crack density of the stress-induced cracks. In addition a link was established between elastic properties (elastic wave velocities Vp and Vs) and permeability using a statistical permeability model. Our results show that the velocities increase with increasing hydrostatic pressure up to 190 MPa, due to the closure of the pre-existing thermal cracks. This is interpreted by a decrease of the crack density ρi from ~ 1 to 0.2. The effect of pre-existing cracks closure is also highlighted by the permeability evolution which decreases of more than two orders of magnitude. Under deviatoric loading, the velocities signature is interpreted, in the first stage of the loading, by the closure of the pre-existing thermal cracks. However, with increasing deviatoric loading newly-formed vertical cracks nucleate and propagate. This is clearly seen from the velocity signature and its interpretation in term of crack density, from the location of the acoustic emission sources, and from microstructural observations. This competition between pre-existing cracks closure and propagation of vertical cracks is also seen from the permeability evolution, and our study shows that mechanically-induced cracks has lesser influence on permeability change than pre-existing thermal cracks.
    Beschreibung: Published
    Beschreibung: 60–74
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Elastic wave velocity ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 42
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    Source and mobility of minor and trace elements in a volcanic aquifer system: Mt. Vulture (southern Italy) (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2022-03-02
    Beschreibung: In this paper we provide a geochemical investigation on 34 groundwater samples in the Mt. Vulture volcanic aquifer representing one of the most important groundwater resources of the southern Italy pumped for drinking and irrigation supply. The present study includes the first data on the abundance and mobility of minor and trace elements and the thermodynamic considerations on water–rock interaction processes in order to evaluate the conditions of alkali basalt weathering by waters enriched in magma-derived CO2. The results highlight the occurrence of two hydrofacies: bicarbonate alkaline-earth and alkaline waters deriving from low-temperature leaching of volcanic rocks of Mt. Vulture, and bicarbonate-sulfate-alkaline waters (high-salinity waters) related to prolonged water circulation in alkali and feldspathoids-rich pyroclastic layers interbedded with clay deposits. The Al-normalized relative mobility (RM) of metals in Vulture's aquifer varies over a wide range (10− 1 〈 RM 〈 104), confirming that the basalt weathering is not a congruent and isochemical process. Chemical equilibrium studies show that the bicarbonate alkaline-earth and alkaline waters, having a short interaction with silicate minerals, plot very close to the kaolinite–smectite stability boundary, whereas the high-salinity waters fall in the stability field of smectite and muscovite because of prolonged interaction with alkali and feldspathoids-rich pyroclastic layers. Overall, for the bicarbonate alkaline-earth and alkaline waters, the release of toxic metals in solutions is related to the spatial variation of host-rock geochemistry, the high-salinity waters, collected near urban areas, show values higher than legal limits for Ni and As, likely as a consequence of anthropogenic contribution.
    Beschreibung: Published
    Beschreibung: 233-244
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): volcanic aquifer system ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 43
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    Hazardous gas emissions from the flanks of the quiescent Colli Albani volcano (Rome, Italy) (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-09-03
    Beschreibung: Gas hazard was evaluated in the three most important cold gas emission zones on the flanks of the quiescent Colli Albani volcano. These zones are located above structural highs of the buried carbonate basement which represents the main regional aquifer and the main reservoir for gas rising from depth. All extensional faults affecting the limestone reservoir represent leaking pathways along which gas rises to the surface and locally accumulates in shallow permeable horizons forming pressurized pockets that may produce gas blowout when reached by wells. The gas, mainly composed by CO2 (〉90 vol.%), contains appreciable quantities of H2S (0.35-6 vol.%), and both represent a potentially high local hazard. Both gases are denser than air and accumulate near ground where they may reach hazardous concentrations, and actually lethal accidents frequently occur to animals watering at local ponds. In order to evaluate the rate of degassing and the related hazard, CO2 and H2S diffuse soil flux surveys have been repeatedly carried out by accumulation chamber. The viscous gas flux of some important discrete emissions has been also evaluated and the CO2 and H2S air concentration measured by portable devises and by Tunable Diode Laser profiles. The minimum potential lethal concentration of the two gases (250 ppm for H2S and 8 vol.% for CO2) is 320 times higher for CO2, whereas the CO2/H2S concentration ratio in the emitted natural gas is significantly lower (15-159). This explains why H2S reaches hazardous, even lethal, concentrations more frequently than CO2. A relevant hazard exists for both gases in the depressed zones (channels, excavations) particularly in the non-windy early hours of the day.
    Beschreibung: Published
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Beschreibung: JCR Journal
    Beschreibung: partially_open
    Schlagwort(e): gas hazard ; hydrogen sulfide ; carbon dioxide ; Colli Albani volcano ; 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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  • 44
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    Tephrostratigraphy and glass compositions of post-15 kyr Campi Flegrei eruptions: implications for eruption history and chronostratigraphic markers (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-12-06
    Beschreibung: Volcanic ash (tephra) erupted from the frequently active Campi Flegrei volcano forms layers in many palaeoenvironmental archives across Italy and the Mediterranean. Proximal deposits of 50 of the post-15 ka eruptions have been thoroughly sampled and analysed to produce a complete database of glass compositions (〉1900 analyses) to aid identification of these units. The deposits of individual eruptions are compositionally diverse and this variability is often greater than that observed between different units. Many of the tephra units do not have a unique glass chemistry, with compositionally similar tephra often erupted over long periods of time (1000s years). Thus, glass chemistry alone is not enough to robustly correlate most of the tephra from Campi Flegrei, especially in the last 10 kyrs. In order to reliably correlate the eruption units it is important to take into account the stratigraphy, chronology, magnitude, and dispersal of the eruptions, which has been collated to aid identification. An updated chronology is also presented, which was constrained using Bayesian analysis (OxCal) of published radiocarbon dates and 40Ar/39Ar ages. All the data presented can be employed to help correlate post-15 ka tephra units preserved in archaeological and Holocene palaeoenvironmental archives. The new database of proximal glass compositions has been used to correlate proximal volcanic deposits through to distal tephra layers in the Lago di Monticchio record ( [Wulf et al., 2004] and [Wulf et al., 2008]) and these correlations provide information on eruption stratigraphy and the tempo of volcanism at Campi Flegrei.
    Beschreibung: Published
    Beschreibung: 3638–3660
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Tephrochronology ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
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  • 45
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    Ultra-distal tephra deposits from super-eruptions: Examples from Toba, Indonesia and Taupo Volcanic Zone, New Zealand (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2021-12-06
    Beschreibung: Voluminous rhyolitic eruptions from Toba, Indonesia, and Taupo Volcanic Zone (TVZ), New Zealand have dispersed volcanic ash over vast areas in the late Quaternary. The w74 ka Youngest Toba Tuff (YTT) eruption deposited ash over the Bay of Bengal and the Indian subcontinent to the west. The w340 ka Whakamaru eruption (TVZ) deposited the widespread Rangitawa Tephra, dominantly to the southeast (in addition to occurrences northwest of vent), extending across the landmass of New Zealand, and the South Pacific Ocean and Tasman Sea with distal terrestrial exposures on the Chatham Islands. These super-eruptions involved w2500 km3 and w1500 km3 of magma (dense-rock equivalent; DRE), respectively. Ultra-distal terrestrial exposures of YTT at two localities in India, Middle Son Valley, Madhya Pradesh, and Jurreru River Valley, Andhra Pradesh, at distances of 〉2000 km from the source caldera, show a basal ‘primary’ ashfall unit w4 cm thick, although deposits containing reworked ash are up to w3 m in total thickness. Exposures of Rangitawa Tephra on the Chatham Islands, 〉900 km from the source caldera, are w15e30 cm thick. At more proximal localities (w200 km from source), Rangitawa Tephra is w55e70 cm thick and characterized by a crystal-rich basal layer and normal grading. Both distal tephra deposits are characterized by very-fine ash (with high PM10 fractions) and are crystal-poor. Glass chemistry, stratigraphy and grain-size data for these distal tephra deposits are presented with comparisons of their correlation, dispersal and preservation. Using field observations, ash transport and deposition were modeled for both eruptions using a semi-analytical model (HAZMAP), with assumptions concerning average wind direction and strength during eruption, column shape and vent size. Model outputs provide new insights into eruption dynamics and better estimates of eruption volumes associated with tephra fallout. Modeling based on observed YTT distal tephra thicknesses indicate a relatively low (〈40 km high), very turbulent eruption column, consistent with deposition from a co-ignimbrite cloud extending over a broad region. Similarly, the Whakamaru eruption was modeled as producing a predominantly Plinian column (w45 km high), with dispersal to the southeast by strong prevailing winds. Significant ash fallout of the main dispersal direction, to the northwest of source, cannot be replicated in this modeling. The widespread dispersal of large volumes of fine ash from both eruptions may have had global environmental consequences, acutely affecting areas up to thousands of kilometers from vent.
    Beschreibung: Published
    Beschreibung: 54–79
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Toba eruption ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 46
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    The MU-RAY project: Volcano radiography with cosmic-ray muons (2012)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2023-01-25
    Beschreibung: Cosmic-ray muon radiography is a technique for imaging the variation of density inside the top few 100m of a volcanic cone. With resolutions up to 10s of meters in optimal detection conditions, muon radiography can provide images of the top region of a volcano edifice with a resolution that is considerably better than that typically achieved with conventional methods. Such precise measurements are expected to provide us with information on anomalies in the rock density distribution, like those expected from dense lava conduits, low density magma supply paths or the compression with depth of the overlying soil. The MU-RAY project aims at the construction of muon telescopes and the development of new analysis tools for muon radiography. The telescopes are required to be able to work in harsh environment and to have low power consumption, good angular and time resolutions, large active area and modularity. The telescope consists of two X–Y planes of 2x2 square meters area made by plastic scintillator strips of triangular shape. Each strip is read by a fast WLS fiber coupled to a silicon photomultiplier. The readout electronics is based on the SPIROC chip.
    Beschreibung: Published
    Beschreibung: 120-123
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: restricted
    Schlagwort(e): Muon radiography ; Volcano structure ; Silicon photomultiplier ; 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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  • 47
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    Quantitative analysis of X-ray microtomography images of geomaterials: Application to volcanic rocks (2011)
    Geological Society of America
    Details
    Publikationsdatum: 2021-01-27
    Beschreibung: X-ray computed microtomography is an excellent tool for the three-dimensional analysis of rock microstructure. Digital images are acquired, visualized, and processed to identify and measure several discrete features and constituents of rock samples, by means of mathematical algorithms and computational methods. In this paper, we present digital images of volcanic rocks collected with X-ray computed microtomography techniques and studied by means of a software library, called Pore3D, custom-implemented at the Elettra Synchrotron Light Laboratory of Trieste (Italy). Using the Pore3D software, we analyzed the fabrics and we quantified the characteristics of the main constituents (vesicles, crystals, and glassy matrix) of four different types of pyroclasts: frothy pumice, tube pumice, scoria, and “crystalline” scoria. We identified the distinctive features of these different types of volcanic rocks. The frothy pumices show vesicles that coalesce in isotropic aggregates, especially toward the sample interior, while the scoriae have a low porosity and an abundance of isolated vesicles. In the “crystalline” scoria sample most of the vesicle separation is due to the presence of crystals of different types, while the tube pumice shows an anisotropic distribution of vesicles and crystals at the microscale, as also observed at the scale of the hand sample. Quantitative analysis and textural information may supply an additional tool to investigate the eruptive processes and the origin of volcanic rocks.
    Beschreibung: Published
    Beschreibung: 793-804
    Beschreibung: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): X-ray tomography ; 3D imaging ; volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 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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  • 48
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    Geochemical evidence of the renewal of volcanic activity inferred from CO2 soil and SO2 plume fluxes: the 2007 Stromboli eruption (Italy) (2011)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: On 27 February 2007, a new eruption occurred on Stromboli which lasted until 2 April. It was characterized by effusive activity on the Sciara del Fuoco and by a paroxysmal event (15 March). This crisis represented an opportunity for us to refine the model that had been developed previously (2002–2003 eruption) and to improve our understanding of the relationship between the magmatic dynamics of the volcano and the geochemical variations in the fluids. In particular, the evaluation of the dynamic equilibrium between the volatiles (CO2 and SO2) released from the magma and the corresponding fluids discharged from the summit area allowed us to evaluate the level of criticality of the volcanic activity. One of the major accomplishments of this study is a 4-year database of summit soil CO2 flux on the basis of which we define the thresholds (low–medium–high) for this parameter that are empirically based on the natural volcanological evolution of Stromboli. The SO2 fluxes of the degassing plume and the CO2 fluxes emitted from the soil at Pizzo Sopra la Fossa are also presented. It is noteworthy that geochemical signals of volcanic unrest have been clearly identified before, during and after the effusive activity. These signals were found almost simultaneously in the degassing plume (SO2 flux) and in soil degassing (CO2 flux) at the summit, although the two degassing processes are shown to be clearly different. The interpretation of the results will be useful for future volcanic surveillance at Stromboli.
    Beschreibung: Published
    Beschreibung: 443-456
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 2.4. TTC - Laboratori di geochimica dei fluidi
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Stromboli volcano ; CO2 soil flux ; Geochemical monitoring ; 2007 eruption ; 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 ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 49
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    Large-eddy simulation of pyroclastic density currents (2011)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: We investigate the dynamics of turbulent pyroclastic density currents (PDCs) by adopting a 3D, Eulerian-Eulerian multiphase flow model, in which solid particles are treated as a continuum and the grain-size distribution is simplified by assuming two particulate phases. The turbulent sub-grid stress of the gas phase is modelled within the framework of Large-Eddy Simulation (LES) by means of a eddy-viscosity model together with a wall closure. Despite the significant numerical diffusion associated to the upwind method adopted for the Finite-Volume discretization, numerical simulations demonstrate the need of adopting a Sub-Grid Scale (SGS) model, while revealing the complex interplay between the grid and the SGS filter sizes. We also analyse the relationship between the averaged flow dynamic pressure and the action exerted by the PDC on a cubic obstacle, to evaluate the impact of a PDC on a building. Numerical results suggest that the average flow dynamic pressure can be used as a proxy for the force per unit surface acting on the building envelope (Fig. 5), even for such steeply stratified flows. However, it is not possible to express such proportionality as a constant coefficient such as the drag coefficient in a steady-state current. The present results indeed indicate that the large epistemic and aleatory uncertainty on initial and boundary conditions has an impact on the numerical predictions which is comparable to that of grid resolution.
    Beschreibung: Published
    Beschreibung: 161-170
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: open
    Schlagwort(e): Large-Eddy Simulation ; pyroclastic density currents ; numerical simulation ; multiphase flows ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
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  • 50
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    Rapid terrain-based mapping of some volcaniclastic flow hazard using Gis-based automated methods: a case study from southern Campania, Italy (2011)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Destructive volcaniclastic flows are among the most recurrent and dangerous natural phenomena in volcanic areas. They can originate not only during or shortly after an eruption (syn-eruptive) but also during a period of volcanic quiescence (inter-eruptive), when heavy and/or persistent rains remobilize loose pyroclastic deposits. The area in Italy most prone to such flows is that of the Apennine Mountains bordering the southern Campania Plain. These steep slopes are covered by pyroclastic material of variable thickness (a few cm to several m) derived from the explosive activity of the Somma-Vesuvius and Campi Flegrei volcanoes a few tens of kilometers to the west. The largest and most recent devastating event occurred on May 5, 1998, causing the death of more than 150 people and considerable damage to villages at the foot of the Apennine Mountains. This tragic event was only the most recent of a number of volcaniclastic flows affecting the area in both historical and prehistoric times. Historical accounts report that more than 500 events have occurred in the last five centuries and that more than half of these occurred in the last 100 years, causing hundreds of deaths. In order to improve volcaniclastic flow hazard zonation and risk mitigation in the study area, we produced a zonation map that identifies the drainage basins potentially prone to disruption. This map was obtained by combining morphological characteristics (concavity and basin shape factor) and the mean slope distribution of drainage basins derived from a digital elevation model with a 10-m resolution. These parameters allowed for the classification of 1,069 drainage basins, which have been grouped into four different classes of proneness to disruption: low, moderate, high and very high. The map compiled in a GIS environment, as well as the linked database, can be rapidly queried.
    Beschreibung: Published
    Beschreibung: 371-387
    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): Volcaniclastic flow hazard ; GIS ; Vesuvian area ; Southern Campania Plain ; Slope instability ; 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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  • 51
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    First 13C/12C isotopic characterisation of volcanic plume CO2 (2011)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: We describe analytical details and uncertainty evaluation of a simple technique for the measurement of the carbon isotopic composition of CO2 in volcanic plumes. Data collected at Solfatara and Vulcano, where plumes are fed by fumaroles which are accessible for direct sampling, were first used to validate the technique. For both volcanoes, the plume-derived carbon isotopic compositions are in good agreement with the fumarolic compositions, thus providing confidence on the method, and allowing its application at volcanoes where the volcanic component is inaccessible to direct sampling. As a notable example, we applied the same method to Mount Etna where we derived a δ13C of volcanic CO2 between −0.9 ± 0.27‰ and −1.41 ± 0.27‰ (Bocca Nuova and Voragine craters). The comparison of our measurements to data reported in previous work highlights a temporal trend of systematic increase of δ13C values of Etna CO2 from ~ −4‰, in the 1970’s and the 1980’s, to ~ −1‰ at the present time (2009). This shift toward more positive δ13C values matches a concurrent change in magma composition and an increase in the eruption frequency and energy. We discuss such variations in terms of two possible processes: magma carbonate assimilation and carbon isotopic fractionation due to magma degassing along the Etna plumbing system. Finally, our results highlight potential of systematic measurements of the carbon isotopic composition of the CO2 emitted by volcanic plumes for a better understanding of volcanic processes and for improved surveillance of volcanic activity.
    Beschreibung: In press
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: 2.4. TTC - Laboratori di geochimica dei fluidi
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Volcanic plume ; Carbon isotope ; Etna ; Magmatic degassing ; 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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  • 52
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    The distal segment of Etna’s 2001 basaltic lava flow (2011)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Etna’s 2001 basaltic lava flow provided a good example of the distal flow segment between the flow front and stable channel, across which the flow evolves from channel-contained to dispersed. This zone was mapped with meter precision using LIDAR data collected during 2004 and 2005. These data, supported by field mapping, show that the flow front comprised eight lobes each 10 to 20 m high. The flow front appears to have advanced not as a single unit, but as a series of lobes moving forward one lobe at a time. Primary lobes were centered on the channel axis and marginal lobes were off-axis. The lobes advanced as breakouts of low-yield-strength lava from the flow core of the stalled flow front. Marginal lobes were abandoned and contributed to marginal levees flanking the transitional channel. For Etna’s 2001 flow, the transitional channel is 140 m wide, 700 m long and fed a 240-m-long zone of dispersed flow; the change from stable to transitional channel occurred at a major reduction in slope. Above this, the stable channel is 5.2 km long, 55 to 105 m wide and bounded by 15- to 25-m-high levees, and the stable channel is located over a previous channel. In a final stage of activity, lava ponding at the break-in-slope that marks the terminus of the stable channel put pressure on the eastern levee, causing it to fail. Liberated lava then fed a final break-out to the east. Similar flow front-features occur at other volcanoes, indicating that similar processes are characteristic of dispersed flow zones.
    Beschreibung: Published
    Beschreibung: 119-127
    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): Basalt lava ; Channelised lava flow ; Flow front ; Zone of dispersed flow ; Flow dynamics ; 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)
    Materialart: article
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  • 53
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    Towards an automatic monitoring system of infrasonic events at Mt. Etna: strategies for source location and modelling (2010)
    Springer
    Details
    Publikationsdatum: 2020-11-16
    Beschreibung: Active volcanoes characterized by open conduit conditions generate sonic and infrasonic signals, whose investigation provides useful information for both monitoring purposes and studying the dynamics of explosive processes. In this work, we discuss the automatic procedures implemented for a real-time application to the data acquired by a permanent network of five infrasound stations running at Mt. Etna volcano. The infrasound signals at Mt. Etna consist in amplitude transients, called infrasound events. The adopted procedure uses a multi-algorithm approach for event detection, counting, characterization and location. It is designed for an efficient and accurate processing of infrasound records provided by single-site and array stations. Moreover, the source mechanism of these events can be investigated off-line or in near real-time by using three different models: i) Strombolian bubble; ii) resonating conduit and iii) Helmholtz resonator. The infrasound waveforms allow us to choose the most suitable model, to get quantitative information about the source and to follow the time evolution of the source parameters.
    Beschreibung: Published
    Beschreibung: 1215–1231
    Beschreibung: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): infrasound ; monitoring system ; Mt. Etna ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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  • 54
    facet.materialart.
    Unbekannt
    Large-eddy simulation of pyroclastic density currents (2010)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: We investigate the dynamics of turbulent pyroclastic density currents (PDCs) by adopting a 3D, Eulerian-Eulerian multiphase flow model, in which solid particles are treated as a continuum and the grain-size distribution is simplified by assuming two particulate phases. The turbulent sub-grid stress of the gas phase is modelled within the framework of Large-Eddy Simulation (LES) by means of a eddy-viscosity model together with a wall closure. Despite the significant numerical diffusion associated to the upwind method adopted for the Finite-Volume discretization, numerical simulations demonstrate the need of adopting a Sub-Grid Scale (SGS) model, while revealing the complex interplay between the grid and the SGS filter sizes. We also analyse the relationship between the averaged flow dynamic pressure and the action exerted by the PDC on a cubic obstacle, to evaluate the impact of a PDC on a building. Numerical results suggest that the average flow dynamic pressure can be used as a proxy for the force per unit surface acting on the building envelope (Fig. 5), even for such steeply stratified flows. However, it is not possible to express such roportionality as a constant coefficient such as the drag coefficient in a steady-state current. The present results indeed indicate that the large epistemic and aleatory uncertainty on initial and boundary conditions has an impact on the numerical redictions which is comparable to that of grid resolution.
    Beschreibung: Unpublished
    Beschreibung: (10)
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: open
    Schlagwort(e): Large-Eddy Simulation ; pyroclastic density currents ; numerical simulation ; multiphase flows ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: book chapter
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  • 55
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    Unbekannt
    Towards an Automatic Monitoring System of Infrasonic Events at Mt. Etna: Strategies for Source Location and Modeling (2010)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Active volcanoes characterized by open conduit conditions generate sonic and infrasonic signals, whose investigation provides useful information for both monitoring purposes and studying the dynamics of explosive processes. In this work, we discuss the automatic procedures implemented for a real-time application to the data acquired by a permanent network of five infrasound stations running at Mt. Etna volcano. The infrasound signals at Mt. Etna consist in amplitude transients, called infrasound events. The adopted procedure uses a multi-algorithm approach for event detection, counting, characterization and location. It is designed for an efficient and accurate processing of infrasound records provided by single-site and array stations. Moreover, the source mechanism of these events can be investigated off-line or in near real-time by using three different models: (1) Strombolian bubble; (2) resonating conduit and (3) Helmholtz resonator. The infrasound waveforms allow us to choose the most suitable model, to get quantitative information about the source and to follow the time evolution of the source parameters.
    Beschreibung: Published
    Beschreibung: 1215–1231
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Infrasound ; monitoring system ; Mt. Etna volcano ; 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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  • 56
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    A New Cycle of Activity At Mt. Etna (Sicily, Italy) During 2009, Revealed from Diffuse CO2 Degassing and Crater Emissions of SO2 and Halogens (2010)
    Cabildo Insular de Tenerife Fundación Canaria ITER
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: In 2009, Mt. Etna (Italy) activity was characterised by the end of a long-lasting flank eruption started on 13 May 2008 and by the opening of a new summit degassing vent on the E flank of the South-East crater on 6 November. This was preceded by a sequence of significant anomalies in volcanic degassing, detected by periodic measurements of soil CO2 efflux on the east flank of the volcano, continuous measurements of SO2 flux from five fixed monitoring stations, and periodic FTIR measurements of the SO2/HCl and SO2/HF molar ratios in the volcanic plume. Since April 2009, soil and crater emissions showed a progressive increase marked at least by two major steps, in April-May and September-October. Increases were not observed simultaneously; in fact, they were detected first in soil CO2 emissions and then, a few days/weeks later, in crater SO2 flux. Only minor increases of HCl and HF crater fluxes were observed between November and December. The highest SO2 and halogens fluxes were recorded in coincidence with the opening of the November 6 vent. The degassing behaviour of the volcano in 2009 is consistent with the differential release of magmatic gas species, according to their different solubilities, from a magma body rising from ~5 km depth to the surface. Our results suggest the start of a new phase in Etna’s activity, in which the new vent might reflect improved efficiency in the release of magmatic gas through the main feeding system, supplied by a magma body stored at depths between 4 and 2 km. If degassing at the new vent will remain steadystate, thus forming a stable feeding system, then its opening might represent the eastward migration of the South-East crater activity with the likely formation of a new stable summit cone.
    Beschreibung: Published
    Beschreibung: Puerto de la Cruz, Tenerife, Canary Islands, Spain
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; crater degassing ; soil gases ; volcanic activity ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Oral presentation
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  • 57
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    Hidden Tectonic Framework Of The Summit Of Mt.Etna (Sicily, Italy) Revealed From Soil CO2 Efflux And Soil Temperature Surveying. (2010)
    Cabildo Insular de Tenerife Fundación Canaria ITER
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Mount Etna in Sicily (973 km2), the most active European volcano, is known as one of the largest contributors of magmatic CO2 released to the atmosphere. A significant part of this gas is released in diffuse form through the volcano’s flanks, along faults and fractured zones, particularly around its summit (about 3350 m). Etna is also characterized by significant and often dramatic slope failure of its eastern flank, which is thought to trigger summit collapses and some lateral eruptions. In order to map the faulted areas near Etna’s summit and to study possible weak zones, a diffuse CO2 efflux survey was carried out at Mt. Etna in October, 2008. A total of 1442 sites were surveyed for soil CO2 efflux and soil temperature over an area of about 9 km2 that included most of the summit part of Mt. Etna above 2600 m a.s.l. The results show the presence of several degassing faults in all of the surveyed area except its west part, which seems to be structurally stable. Most of the degassing faults start from the summit craters and run parallel to the borders of the eastward collapsing sector of the volcano. Many of them are related to the development of the South-East Crater, but others seem to be related to a large buried crater rim, probably a remnant of the 1669 collapse crater formed during the largest eruption in the last 2000 years. Some degassing faults are not accompanied by thermal anomalies, thus suggesting that the gas source is too deep and/or the ground permeability is too low to allow high-enthalpy fluids to reach the surface before their condensation. These “cold” faults bound the anomalous degassing areas to the west, therefore they would be relatively new and shallow, suggesting a progressive westward shift of slope failure.
    Beschreibung: Published
    Beschreibung: Puerto de la Cruz, Tenerife, Canary Islands, Spain
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; soil CO2 effluxes ; hidden faults ; soil temperature ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Oral presentation
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  • 58
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    Continuous Monitoring Of Soil Radon Activity And Soil Temperature Near The Summit Of Mt. Etna (Sicily, Italy) During 2007-2009: Correlations With Stress Field And Volcanic Activity (2010)
    Cabildo Insular de Tenerife Fundación Canaria ITER
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: During the period 2007-2009, the volcanic activity of Mt. Etna (Italy) was characterized by a series of paroxysmal events in 2007 that preceded a long-lasting (419 days) flank eruption. Four months after the end of that eruption, the opening of a new summit degassing vent marked the beginning of a new phase of activity, so far characterized only by degassing phenomena. Soil radon activity and soil temperature were monitored every 15 minutes at a low-temperature fumarole near the summit craters of Etna starting from late May 2007. The temporal pattern of these parameters showed in general their significant cross-correlation, thus pointing to a common gas transport mechanism. Magmatic/ hydrothermal fluids in the sub-surface ground are convectively transported towards the surface along a major fault that runs from Etna’s summit towards SSE and partly marks the boundary of an eastward sliding sector of the volcano that is involved into phenomena of flank collapse. Both of the monitored parameters indicate the occurrence of three long-term cycles of soil degassing during the period investigated, each one characterized by high average values of temperature and radon. The first cycle started in June 2007 and lasted until early April 2008, thus accompanying the recharge of the volcano. The second cycle lasted from late April 2008 to mid-May 2009, thus preceding and accompanying the first phase of the 13 May 2008 – 5 July 2009 flank eruption. The third cycle started in mid-July 2009 and it’s still ongoing. It marked a new recharge of the volcano that culminated in the opening of the new summit degassing vent in early November 2009. Therefore, continuous monitoring of soil radon and soil temperature near the summit of Mt. Etna has proven helpful in determining states of volcanic unrest related to recharge and/or pre-eruptive magma ascent.
    Beschreibung: Published
    Beschreibung: Puerto de la Cruz, Tenerife, Canary Islands, Spain
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; soil radon ; active faults ; volcanic activity
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Poster session
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  • 59
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    Monitoring Volcanic Eruptions Using Trace Metals In Tree-Rings: Preliminary Results From Mt. Etna (2010)
    Cabildo Insular de Tenerife Fundación Canaria ITER
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Active volcanoes can influence surrounding vegetation both through passive degassing during quiescent periods and through eruptive degassing, by introducing into the atmosphere several metals as gases and particles. The chemical composition of tree-rings has been generally used to investigate the effects of anthropogenic gas emissions and dendrochemical methods have successfully recorded variations in the pollution levels. The use of tree-rings analysis in active volcanic areas has shown that vascular plants could be used as archives of volcanogenic metals deposition. Tree cores of Pinus Nigra and Populus tremula were collected in sites located both on the downwind (Citelli and Mt. Fontane sites) and on the upwind (Mt. Intraleo site) sectors of Mt. Etna in June 2008. Individual and composited tree-rings were analyzed by inductively-coupled-plasma mass-spectrometry for the determination of several trace elements (As, Cd, Li, Mn, Mo, Ni, Se, Sr, Pb, V). Tree cores were dated dendrochronologically before analysis, and their ages date back to 1915. The preliminary results show that some elements have significant differences in concentration between the two tree species analyzed, and in general metals are more concentrated in the samples from the downwind sites, hence more exposed to crater gas emissions. Furthermore, the temporal patterns of metal contents show some evident peaks likely related to some of the major flank eruptions of the volcano, particularly those occurred after 1945. This method can be used in many active volcanoes to reconstruct their past degassing rate and recognize possible eruptive cycles, thus helping forecast their future behaviour.
    Beschreibung: Published
    Beschreibung: Puerto de la Cruz, Tenerife, Canary Islands, Spain
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; tree rings ; trace metals ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 60
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    Unbekannt
    Diffuse and Visible Emission of CO2 from Etna Volcano, Italy (2010)
    Cabildo Insular de Tenerife Fundación Canaria ITER
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: This work reports the first estimation of total CO2 emission to the atmosphere (visible and non-visible) from Etna volcano, Sicily, by means of direct methods. Until present, only direct measurements of the CO2 emitted by the volcanic plume of Etna had been performed, and not data of direct soil CO2 efflux from surface environment of this volcano were available. To estimate the total CO2 emission, 4075 soil CO2 efflux measurements were performed by means of the accumulation chamber method in October-November 2008. Most of the study area showed background levels of soil CO2 efflux (0.53 g·m-2·d-1), while peak values (〉1725 g·m-2·d-1) were mainly identified inside the summit craters and at Torre del Filosofo area. Other zones with relatively high CO2 efflux values were identified at Paternó, Zafferana Etnea and Trecastagni-Viagrande. The total output of CO2 diffuse emission from the study area (973 km2) was computed in 20320 t·d-1, where 1671 t·d-1, about 8.3% of CO2 diffuse emission, was emitted by an area of 87 km2 which includes the summit craters and Torre del Filosofo. To evaluate the visible/diffuse CO2 emission ratio, plume CO2 emission rate was estimated by multiplying SO2 emission rate times observed CO2/SO2 plume ratio following the methodology described by Shinohara (2005). Total CO2 visible emission was estimated about 31.5 kt·d-1, value is in the range reported for Etna volcano (0.9-67.5 kt·d-1; Aiuppa et al., 2006). The total output of CO2 diffuse emission represents 39% of the total CO2 emission from Etna volcano to the atmosphere. These results agree with the observations of Allard et al. (1991), who reported that diffuse and visible CO2 emissions were in the same order of magnitude. This study demonstrates the importance of measuring diffuse CO2 emissions from active volcanoes like Mt. Etna in order to have a better approach on the global estimate of CO2 emission to the atmosphere from subaerial volcanoes
    Beschreibung: Published
    Beschreibung: Puerto de la Cruz, Tenerife, Canary Islands, Spain
    Beschreibung: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; soil CO2 effluxes ; CO2 budget ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Poster session
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  • 61
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    The Southern Boundary Of The Seaward-Sliding Eastern Flank Of Mt. Etna: Evidences On Active Faults In Urban Areas From Soil Gases And Satellite Data (2010)
    Cabildo Insular de Tenerife Fundación Canaria ITER
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: From October 2008 to November 2009, soil CO2 and Rn surveys have been performed, in order to get insights upon active tectonic structures in a densely populated sector of the South-Eastern flank of Mt Etna, which seems to be involved in the flank dynamics, as highlighted by satellite data (INSAR). The investigated area extends about 150 km2, in an area, where INSAR data detected several lineaments not known from geological surveys. The method adopted to perform the 345 soil CO2 measurements is the “dynamic concentration” method (Gurrieri and Valenza, 1988; Camarda et al., 2006), which provides a proxy for soil CO2 fluxes. The gas measurements have been performed along transects roughly orthogonal to the lineaments, with measurement points spaced about 100m. The method appeared more efficient than a regular grid, which would have requested much more measurements and a time-consuming field work. CO2 data show the highest values, along each transect, very close to the lineaments evidenced by INSAR observations. Anomalous values also occur in correspondence of eruptive fractures. In some portions of the investigated area, rather broad anomalies are observed, and this would imply that, instead of a single well-defined lineament, a wider fault zone probably exists. A set of both CO2 and Rn measurements, performed at about 900m of altitude, are worth of note, because they allow identifying the lengthening of detected lineaments at higher elevation, where the INSAR data are poorly informative. Finally, at the base of the volcanic edifice, the soil gas anomalies strikingly define the active structures until almost the coastline through the northern periphery of Catania town. The coupling of the two methods thus revealed as a powerful tool to detect buried active structures, which conversely do not show significant field evidences.
    Beschreibung: Published
    Beschreibung: Puerto de la Cruz, Tenerife, Canary Islands, Spain
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; soil gases ; gravitational spreading ; INSAR ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: Poster session
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  • 62
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    Relationship between soil CO2 flux and volcanic tremor at Mt. Etna: Implications for magma dynamics (2009)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Large variations of the CO2 flux through the soil were observed between November 2002 and January 2006 at Mt. Etna volcano. In many cases, the CO2 flux was strongly influenced by changes in air temperature and atmospheric pressure. A new filtering method was then developed to remove the atmospheric influences on soil CO2 flux and, at the same time, to highlight the variations strictly related to volcanic activity. Successively, the CO2 corrected data were quantitatively compared with the spectral amplitude of the volcanic tremor by cross correlation function, cross-wavelet spectrum and wavelet coherence. These analyses suggested that the soil CO2 flux variations preceded those of volcanic tremor by about 50 days. Given that volcanic tremor is linked to the shallow (a few kilometer) magma dynamics and soil CO2 flux related to the deeper (*12 km b.s.l.) magma dynamics, the “delayed similarity” between the CO2 flux and the volcanic tremor amplitude was used to assess the average speed in the magma uprising into the crust, as about 170–260 m per day. Finally, the large amount of CO2 released before the onset of the 2004–2005 eruption indicated a deep ingression of new magma, which might have triggered such an eruption.
    Beschreibung: In press
    Beschreibung: N/A or not JCR
    Beschreibung: reserved
    Schlagwort(e): Mt. Etna ; Soil CO2 flux ; Volcanic tremor ; Cross-wavelet spectrum ; Wavelet coherence ; Cross correlation function ; 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::05.02.02. Seismological data
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  • 63
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    Petrology of lavas from the 2004–2005 flank eruption of Mt. Etna, Italy: inferences on the dynamics of magma in the shallow plumbing system (2009)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Following the 2001 and 2002–2003 flank eruptions, activity resumed at Mt. Etna on 7 September 2004 and lasted for about 6 months. This paper presents new petrographic, major and trace element, and Sr–Nd isotope data from sequential samples collected during the entire 2004–2005 eruption. The progressive change of lava composition allowed defining three phases that correspond to different processes controlling magma dynamics inside the central volcano conduits. The compositional variability of products erupted up to 24 September is well reproduced by a fractional crystallization model that involves magma already stored at shallow depth since the 2002–2003 eruption. The progressive mixing of this magma with a distinct new one rising within the central conduits is clearly revealed by the composition of the products erupted from 24 September to 15 October. After 15 October, the contribution from the new magma gradually becomes predominant, and the efficiency of the mixing process ensures the emission of homogeneous products up to the end of the eruption. Our results give insights into the complex conditions of magma storage and evolution in the shallow plumbing system of Mt. Etna during a flank eruption. Furthermore, they confirm that the 2004–2005 activity at Etna was triggered by regional movements of the eastern flank of the volcano. They caused the opening of a complex fracture zone extending ESE which drained a magma stored at shallow depth since the 2002–2003 eruption. This process favored the ascent of a different magma in the central conduits, which began to be erupted on 24 September without any significant change in eruptive style, deformation, and seismicity until the end of eruption.
    Beschreibung: Published
    Beschreibung: 781–793
    Beschreibung: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Geochemistry ; Isotopic compositions ; Magma feeding system ; Magma mixing ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 64
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    Effusive Activity at Mount Etna Volcano (Italy) During the 20th Century: A Contribution to Volcanic Hazard Assessment (2008)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Mount Etna is an open conduit volcano, characterised by persistent activity, consisting of degassing and explosive phenomena at summit craters, frequent flank eruptions, and more rarely, eccentric eruptions. All eruption typologies can give rise to lava flows, which represent the greatest hazard by the volcano to the inhabited areas. Historical documents and scientific papers related to the 20th century effusive activity have been examined in detail, and volcanological parameters have been compiled in a database. The cumulative curve of emitted lava volume highlights the presence of two main eruptive periods: (a) the 1900–1971 interval, characterised by a moderate slope of the curve, amounting to 436 · 106 m3 of lava with average effusion rate of 0.2 m3/s and (b) the 1971–1999 period, in which a significant increase in eruption frequency is associated with a large issued lava volume (767 · 106 m3) and a higher effusion rate (0.8 m3/s). The collected data have been plotted to highlight different eruptive behaviour as a function of eruptive periods and summit vs. flank eruptions. The latter have been further subdivided into two categories: eruptions characterised by high effusion rates and short duration, and eruptions dominated by low effusion rate, long duration and larger volume of erupted lava. Circular zones around the summit area have been drawn for summit eruptions based on the maximum lava flow length; flank eruptions have been considered by taking into account the eruptive fracture elevation and combining them with lava flow lengths of 4 and 6 km. This work highlights that the greatest lava flow hazard at Etna is on the south and east sectors of the volcano. This should be properly considered in future land-use planning by local authorities.
    Beschreibung: Published
    Beschreibung: 407–443
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Mt. Etna ; effusive activity ; database ; lava flow length ; eruptive fractures ; vent elevation ; hazard zonation ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 65
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    Simultaneous magma and gas eruptions at three volcanoes in southern Italy: an earthquake trigger? (2008)
    Geological Society of America
    Details
    Publikationsdatum: 2017-04-03
    Beschreibung: In September 2002, a series of tectonic earthquakes occurred north of Sicily, Italy, followed by three events of volcanic unrest within 150 km. On October 28, 2002, Mt. Etna erupted; on November 3, 2002, submarine degassing occurred near Panarea Island; and on December 28, 2002, Stromboli Island erupted. All of these events were considered unusual: the Mt. Etna NE-rift eruption was the largest in 55 yr, the Panarea degassing was one of the strongest ever detected there, and the Stromboli eruption, which produced a landslide and tsunami, was the largest effusive eruption in 17 yr. Here, we investigate the synchronous occurrence of these clustered unrest events, and develop a possible explanatory model. We compute short-term earthquake-induced dynamic strain changes and compare them to long-term tectonic effects. Results suggest that the earthquake-induced strain changes exceeded annual tectonic strains by at least an order of magnitude. This agitation occurred in seconds, and may have induced fluid and gas pressure migration within the already active hydrothermal and magmatic systems.
    Beschreibung: In press
    Beschreibung: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: 3.1. Fisica dei terremoti
    Beschreibung: 3.2. Tettonica attiva
    Beschreibung: 3.5. Geologia e storia dei sistemi vulcanici
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: 4.2. TTC - Scenari e mappe di pericolosità sismica
    Beschreibung: 4.3. TTC - Scenari di pericolosità vulcanica
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): earthquake trigger ; magma and gas eruptions ; 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::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 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::04.06.04. Ground motion ; 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::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.04. Plate boundaries, motion, and tectonics ; 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
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 66
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    Volcanological inferences from seismic-strain tensor computations at Mt. Etna Volcano, Sicily (2008)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Kostrov's (1974) algorithm for seismic-strain tensor computations, in the version implemented by Wyss et al. (1992a) for error estimates, has been applied to shear-type earthquakes occurring beneath the Etna volcano during 1990-1996. Space-time variations of strain orientations and amplitudes have been examined jointly with ground-deformation and gravimetric data collected in the same period and reported in the literature. Taking also into account the information available from volcanological observations and structural geology, we propose a model assuming that hydraulic pressure by magma emplaced in nearly north-south vertical structures produces the E-W orientation of the maximum compressive strain found in the upper 10 km beneath the crater area. In contrast, regional tectonics deriving from the slow, north-south convergence between the African and European plates appear to play a dominant role in the generation of stress and strain fields at crustal depths deeper than 10 km below the volcano. According to our interpretation, the progressive ascent of magma through the upper crust prior to eruption produces the observed gravity changes, cone inflation and unusual seismic strain rate in the upper 10 km associated with a more sharply defined seismic deformation regime (i.e. very small confidence limits of the epsilon 1 orientation). In agreement with this model, deflation revealed by ground-deformation data during the course of the major 1991-1993 eruption was accompanied by a practically nil level of shallow seismicity.
    Beschreibung: Published
    Beschreibung: 318-330
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): Mt. Etna ; Italy ; Earthquakes ; Seismic strain ; Stress inversion ; Volcanic processes ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 67
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    Observations of Mt. Etna volcanic ash plumes in 2006: an integrated approach from ground-based and polar satellite NOAA-AVHRR monitoring system (2008)
    Elsevier Science Limited
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Mt. Etna, in Sicily (Italy), is one of the world’s most frequent emitters of volcanic plumes. During the last ten years, Etna has produced copious tephra emission and fallout that have damaged the inhabited and cultivated areas on its slopes and created serious hazards to air traffic. Recurrent closures of the Catania International airport have often been necessary, causing great losses to the local economy. Recently, frequent episodes of ash emission, lasting from a few hours to days, occurred from July to December 2006, necessitating a look at additional monitoring techniques, such as remote sensing. The combination of a ground monitoring system, with polar satellite data represents a novel approach to monitor Etna’s eruptive activity and makes Etna one of the few volcanoes for which this surveillance combination is routinely available. In this work, ash emission information derived from an integrated approach, based on comparing ground and NOAA-AVHRR polar satellite observations, is presented. This approach permits us to define the utility of real time satellite monitoring systems for both sporadic and continuous ash emissions. Using field data (visible observations, collection of tephra samples and accounts by local inhabitants), the duration and intensity of most of the tephra fallout events were evaluated in detail and, in some cases, the order of magnitude of the erupted volume was estimated. The ground data vs. satellite data comparison allowed us to define five different categories of Etna volcanic plumes according to their extension and length, while taking into account plume height and wind intensity. Using frequent and good quality satellite data in real time, this classification scheme could prove helpful for investigations into a possible correlation between eruptive intensity and the presence and concentration of ash in the volcanic plume. The development and improvement of this approach may constitute a powerful warning system for Civil Protection, thus preventing unnecessary airport closures.
    Beschreibung: FIRB B5 Italian project “Sviluppo Nuove Tecnologie per la Protezione e Difesa del Territorio dai Rischi Naturali” funded by MIUR
    Beschreibung: Published
    Beschreibung: 135–147
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): volcanic ash ; Mt. Etna ; ground monitoring ; NOAA–AVHRR ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 68
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    Lava effusion rate definition and measurement: a review (2007)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Measurement of effusion rate is a primary objective for studies that model lava flow and magma system dynamics, as well as for monitoring efforts during on-going eruptions. However, its exact definition remains a source of confusion, and problems occur when comparing volume flux values that are averaged over different time periods or spatial scales, or measured using different approaches. Thus our aims are to: (1) define effusion rate terminology; and (2) assess the various measurement methods and their results. We first distinguish between instantaneous effusion rate, and time-averaged discharge rate. Eruption rate is next defined as the total volume of lava emplaced since the beginning of the eruption divided by the time since the eruption began. The ultimate extension of this is mean output rate, this being the final volume of erupted lava divided by total eruption duration. Whether these values are total values, i.e. the flux feeding all flow units across the entire flow field, or local, i.e. the flux feeding a single active unit within a flow field across which many units are active, also needs to be specified. No approach is without its problems, and all can have large error (up to ∼50%). However, good agreement between diverse approaches shows that reliable estimates can be made if each approach is applied carefully and takes into account the caveats we detail here. There are three important factors to consider and state when measuring, giving or using an effusion rate. First, the time-period over which the value was averaged; second, whether the measurement applies to the entire active flow field, or a single lava flow within that field; and third, the measurement technique and its accompanying assumptions.
    Beschreibung: Published
    Beschreibung: 1-22
    Beschreibung: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Lava ; Instantaneous effusion rate ; Time-averaged discharge rate ; Eruption rate ; Monitoring ; 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
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  • 69
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    Review of Microgravity Observations at Mt. Etna: A Powerful Tool to Monitor and Study Active Volcanoes. (2007)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Microgravity observations at Mt. Etna have been routinely performed as both discrete (since 1986) and continuous (since 1998) measurements. In addition to describing the methodology for acquiring and reducing gravity data from Mt. Etna, this paper provides a collection of case studies aimed at demonstrating the potential of microgravity to investigate the plumbing system of an active volcano and detect forerunners to paroxysmal volcanic events. For discrete gravity measurements, results from 1994– 1996 and 2001 are reported. During the first period, the observed gravity changes are interpreted within the framework of the Strombolian activity which occurred from the summit craters. Gravity changes observed during the first nine months of 2001 are directly related to subsurface mass redistributions which preceded, accompanied and followed the July-August 2001 flank eruption of Mt. Etna. Two continuous gravity records are discussed: a 16-month (October 1998 to February 2000) sequence and a 48-hour (26–28 October, 2002) sequence, both from a station within a few kilometers of the volcano’s summit. The 16-month record may be the longest continuous gravity sequence ever acquired at a station very close to the summit zone of an active volcano. By cross analyzing it with contemporaneous discrete observations along a summit profile of stations, both the geometry of a buried source and its time evolution can be investigated. The shorter continuous sequence encompasses the onset of an eruption from a location only 1.5 km from the gravity station. This gravity record is useful for establishing constraints on the characteristics of the intrusive mechanism leading to the eruption. In particular, the observed gravity anomaly indicates that the magma intrusion occurred ‘‘passively’’ within a fracture system opened by external forces.
    Beschreibung: Published
    Beschreibung: 769-790
    Beschreibung: 2.6. TTC - Laboratorio di gravimetria, magnetismo ed elettromagnetismo in aree attive
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Mt. Etna ; microgravity ; 04. Solid Earth::04.03. Geodesy::04.03.05. Gravity variations
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  • 70
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    Coupled textural and compositional characterization of basaltic scoria: insights into the transition from Strombolian to fire fountain activity at Mount Etna (2007)
    Geological Society of America
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Strombolian and fire fountain activities represent a common expression of explosive basaltic eruptions. However, the transition between these two eruptive styles and their source mechanisms are still debated. We use textural and compositional studies to characterize pyroclastic material from both the Strombolian and Hawaiian-style fire fountain phases of the January–June 2000 Etna activity. We find that basaltic scoria presents distinctive textural and compositional features that reflect different modes of magma vesiculation and crystallization in the two eruptive regimes. Overall, magma that forms Strombolian scoria is far more crystallized, less vesicular, and more evolved, indicating strong volatile depletion and longer residence time before being erupted. Fire fountain scoria indicates a fast-rising magma with evidence of moderate syneruptive volatile exsolution. The new textural and compositional data set is integrated with previous volcanological and geophysical investigations to provide further insights into the dynamics of fire fountains, and to frame the transition from Strombolian explosions to fire fountain activity into a model that may apply to future eruptions at Mount Etna as well as other active basaltic volcanoes.
    Beschreibung: Published
    Beschreibung: 201-204
    Beschreibung: reserved
    Schlagwort(e): Mt. Etna ; explosive activity ; scoria ; textures ; glass compositions ; eruption dynamics ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
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  • 71
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    Reply to: comments to: “Volcanic geomorphology and tectonics of the Aeolian Archipelago (Southern Italy) based on integrated DEMdata” by Favalli et al. (2007)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: No abstract
    Beschreibung: Published
    Beschreibung: 117-118
    Beschreibung: 3.6. Fisica del vulcanismo
    Beschreibung: JCR Journal
    Beschreibung: open
    Schlagwort(e): geomorphology ; tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 72
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    High precision locations of LP events on Mt. Etna: reconstruction of the fluid-filled volume (2007)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: During 1991−93 at Mount Etna, long-period (LP) events occurring in swarms characterized the evolution of the eruption. The presence of multiplets i.e. groups of events with similar waveform signatures, has been recognized within this activity. Traditional techniques for locating LP events do not allow obtaining reliable hypocenters, which have only succeeded in placing earthquakes in a roughly 1 km2 area slightly east of the Mt. Etna Northeast Crater. Hypocenters have been relocated in two steps: the absolute location has been improved using Thurber’s code and a complex 3D velocity model; a highly precise relative location has been applied on multiplets to define the source geometry. 3D locations and high precision analysis suggest that during the 1991−93 eruption the resonator producing LP events was a part of the uppermost Northeast Crater conduit, measuring 210 meters in height and 45−50 meters in diameter.
    Beschreibung: Published
    Beschreibung: 663-674
    Beschreibung: reserved
    Schlagwort(e): waveform correlation ; stacked events ; 1991−93 eruption ; conduct geometry ; Mt. Etna Northeast Crater ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
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  • 73
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    The morphology and evolution of the Stromboli 2002–2003 lava flow field: an example of a basaltic flow field emplaced on a steep slope (2007)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: The use of a hand-held thermal camera during the 2002–2003 Stromboli effusive eruption proved essential in tracking the development of flow field structures and in measuring related eruption parameters, such as the number of active vents and flow lengths. The steep underlying slope on which the flow field was emplaced resulted in a characteristic flow field morphology. This comprised a proximal shield, where flow stacking and inflation caused piling up of lava on the relatively flat ground of the vent zone, that fed a medial–distal lava flow field. This zone was characterized by the formation of lava tubes and tumuli forming a complex network of tumuli and flows linked by tubes. Most of the flow field was emplaced on extremely steep slopes and this had two effects. It caused flows to slide, as well as flow, and flow fronts to fail frequently, persistent flow front crumbling resulted in the production of an extensive debris field. Channel-fed flows were also characterized by development of excavated debris levees in this zone (Calvari et al. 2005). Collapse of lava flow fronts and inflation of the upper proximal lava shield made volume calculation very difficult. Comparison of the final field volume with that expecta by integrating the lava effusion rates through time suggests a loss of ~70% erupted lava by flow front crumbling and accumulation as debris flows below sea level. Derived relationships between effusion rate, flow length, and number of active vents showed systematic and correlated variations with time where spreading of volume between numerous flows caused an otherwise good correlation between effusion rate, flow length to break down. Observations collected during this eruption are useful in helping to understand lava flow processes on steep slopes, as well as in interpreting old lava–debris sequences found in other steep-sided volcanoes subject to effusive activity.
    Beschreibung: Published
    Beschreibung: JCR Journal
    Beschreibung: reserved
    Schlagwort(e): Lava flow field ; Morphology ; Tumuli ; Lava tubes ; Effusion rate ; Rheology ; Stromboli volcano ; 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)
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    The role of the Pernicana Fault System in the spreading of Mt. Etna (Italy) during the 2002-2003 eruption (2005)
    Springer
    Details
    Publikationsdatum: 2017-04-04
    Beschreibung: Flank instability and collapse are observed at many volcanoes. Among these, Mt. Etna is characterized by the spreading of its eastern and southern flanks. The eastern spreading area is bordered to the north by the EW-trending Pernicana Fault System (PFS). During the 20022003 Etna eruption, ground fracturing along the PFS migrated eastward from the NE Rift, to as far as the 18 km distant coastline. The deformation consisted of dextral en-echelon segments, with sinistral and normal kinematics. Both of these components of displacement were one order of magnitude larger (~1 m) in the western, previously known, portion of the PFS with respect to the newly surveyed (~9 km long) eastern section (~0.1 m). This eastern section is located along a pre-existing, but previously unknown, fault, where displaced man-made structures give overall slip rates (11.9 cm/year), only slightly lower than those calculated for the western portion (1.42.3 cm/year). After an initial rapid motion during the first days of the 20022003 eruption, movement of the western portion of the PFS decreased dramatically, while parts of the eastern portion continued to move. These data suggest a model of spreading of the eastern flank of Etna along the PFS, characterized by eruptions along the NE Rift, instantaneous, short-lived, meter-scale displacements along the western PFS and more long-lived centimeter-scale displacements along the eastern PFS. The surface deformation then migrated southwards, reactivating, one after the other, the NNWSSE-trending Timpe and Trecastagni faults, with displacements of ~0.1 and ~0.04 m, respectively. These structures, along with the PFS, mark the boundaries of two adjacent blocks, moving at different times and rates. The new extent of the PFS and previous activity over its full length indicate that the sliding eastern flank extends well below the Ionian Sea. The clustering of seismic activity above 4 km b.s.l. during the eruption suggests a deep décollement for the moving mass. The collected data thus suggests a significant movement (volume 〉1,100 km3) of the eastern flank of Etna, both on-shore and off-shore.
    Beschreibung: Published
    Beschreibung: 417-430
    Beschreibung: partially_open
    Schlagwort(e): Volcano spreading ; Fracturing ; Mt. Etna ; Pernicana Fault System ; NE Rift ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 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
    Repository-Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Materialart: article
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