ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Elsevier  (214,365)
  • American Meteorological Society
  • 2005-2009  (217,873)
  • 1980-1984
  • 1970-1974
  • 1925-1929
  • 2009  (112,935)
  • 2006  (104,940)
Collection
Keywords
Publisher
Years
Year
  • 1
    facet.materialart.
    Unknown
    The Afragola settlement near Vesuvius, Italy: The destruction and abandonment of a Bronze Age village revealed by archaeology, volcanology and rock-magnetism (2009)
    Elsevier
    Details
    Publication Date: 2021-06-15
    Description: Public works in progress in the Campanian plain north of Somma-Vesuvius recently encountered the remains of a prehistoric settlement close to the town of Afragola. Rescue excavations brought to light a Bronze Age village partially destroyed and buried by pyroclastic density currents (PDCs) of the Vesuvian Pomici di Avellino eruption (3.8 14C ka BP) and subsequently sealed by alluvial deposits. Volcanological and rockmagnetic investigations supplemented the excavations. Careful comparison between volcanological and archaeological stratigraphies led to an understanding of the timing of the damage the buildings suffered when they were struck by a series of PDCs. The first engulfed the village, located some 14 km to the north of the inferred vent, and penetrated into the dwellings without causing major damage. The buildings were able to withstand the weak dynamic pressure of the currents and deviate their path, as shown by the magnetic fabric analyses. Some later collapsed under the load of the deposits piled up by successive currents. Stepwise demagnetization of the thermal remanent magnetization (TRM) carried by potsherds embedded in the deposits yields deposition temperatures in the order of 260– 320 °C, fully consistent with those derived from pottery and lithic fragments from other distal and proximal sites. The fairly uniform temperature of the deposits is here ascribed to the lack of pervasive air entrainment into the currents. This, in turn, resulted from the lack of major topographical obstacles along the flat plain. The coupling of structural damage and sedimentological analyses indicates that the currents were not destructive in the Afragola area, but TRM data indicate they were still hot enough to cause death or severe injury to humans and animals. The successful escape of the entire population is apparent from the lack of human remains and from thousands of human footprints on the surface of the deposits left by the first PDCs. People were thus able to walk barefoot across the already emplaced deposits and escape the subsequent PDCs. The rapid cooling of the deposits was probably due to both their thinness and heat dissipation due to condensation of water vapour released in the mixture by magma–water interaction.
    Description: Published
    Description: 408–421
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: pyroclastic density current ; Bronze Age ; magnetic fabric ; deposition temperature ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.05. Geomagnetism::04.05.07. Rock magnetism ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Helium isotopes in hydrothermal volcanic fluids of the Azores Archipelago (2009)
    Elsevier
    Details
    Publication Date: 2021-06-25
    Description: We present the first helium isotope data for thermal waters and gas emissions on the islands of Terceira, Graciosa, Faial, Pico and Flores, as well as new data for Sao Miguel. The results allow us to track current mantle degassing associated with the Azores hot spot, to delineate its spatial distribution and to discuss its possible origin. As a general rule, we find that free gases tend to display somewhat higher 3He/4He ratio than groundwaters.We argue that this difference is likely due to radiogenic helium inputs to aquifers duringwater– rock interactions and, therefore, that gas phases are the fluid carriers with the most representative of mantle source signature. The measured 3He/4He ratios (normalized to the air ratio, Ra) range from lower-than-MORB values (5.23–6.07 Ra) on central Sao Miguel, to MORB values on Faial (8.53 Ra) and Flores (8.04 Ra) – located on either side of the Mid-Atlantic Ridge – and to plume-type values on Graciosa (11.2 Ra) and Terceira (13.5 Ra) where free gases also display ten times higher-than-MORB CO2/3He ratios (1.8–2.6×1010). Such a wide He isotopic range and its spatial distribution corroborate with available data for volcanic rocks, indicating that plume's head presently underlies the central part of the archipelago. The plume-type 3He/4He ratios on Terceira and Graciosa agree with geochemical and seismic evidence of a deep-rooted mantle plume feeding the Azores hot spot. Our finding that high 3He/4He ratios correspond to low 3He concentrations and high (arctype) CO2/3He values exclude a simple plume supply of 3He-rich primitive mantle. Instead, the simultaneity of both elevated CO2/3He and 3He/4He ratios is best explained by a 3He-rich contribution from the lower mantle diluted in a CO2-rich feeding plume that contains a recycled altered oceanic plate component. The alternative possibility of an enhanced time-integrated 3He/(U+Th) ratio in the Azores plume due to a greater compatibility of helium relative to U and Th during melting events is difficult to reconcile with the enriched pattern of volcanic rocks from the central islands. In any case, the Azores plume should derive from a mantle reservoir that could escape convective homogenization for a very long period of time, in agreement with subchondritic osmium isotopic ratios in volcanic rocks from the central islands of the archipelago.
    Description: Published
    Description: 70−80
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: hydrothemal fluids ; helium isotopes ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    Integrated stratigraphic reconstruction for the last 80 kyr in a deep sector of the Sardinia Channel (Western Mediterranean) (2009)
    Elsevier
    Details
    Publication Date: 2021-07-14
    Description: A quantitative analysis of planktonic foraminifera, coupled with petrophysical and paleomagnetic measurements and 14C AMS calibrations, was carried out on a deep core recovered in the Sardinia Channel (Western Mediterranean Sea), during the CIESM Sub2 survey, providing an integrated stratigraphic time-framework over the last 80 kyr. Significant changes in the quantitative distribution of planktonic foraminifera allowed the identification of several eco-bioevents useful to accurately mark the boundaries of the eco-biozones widely recognised in the Western Mediterranean records and used for large scale correlations. Namely, 10 eco-biozones were identified based on the relative abundance of selected climate sensitive planktonic foraminiferal species. Sixteen codified eco-bioevents were correlated with the Alboran Sea planktonic foraminiferal data and four climatic global events (Sapropel S1, Younger Dryas, Greenland Isotope Interstadial 1, Greenland Isotope Stadial 2, Heinrich event H1-H6) were recognized. The eco-bioevents together with the 14C AMS calibrations allowed us to define an accurate age model, spanning between 2 and 83 kyr. The reliability of the age model was confirmed by comparing the colour reflectance (550 nm%) data of the studied record with the astronomically tuned record from the Ionian sea (ODP-Site 964). A mean sedimentation rate of about 7 cm/kyr included three turbidite event beds that were chronologically constrained within the relative low stand and lowering sea level phases of the MIS 4 and 3. The deep-sea sedimentary record includes a distinct tephra occurring at the base of the core which dates 78 ka cal. BP. The paleomagnetic data provide a well-defined record of the characteristic remanent magnetization that may be used to reconstruct the geomagnetic paleosecular variation for the Mediterranean back to 83 kyr.
    Description: Published
    Description: 725 - 737
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Integrated stratigraphy ; Late Neogene marine record ; Eco-bio-events ; Reflectance 550 nm % ; Sardinia Channel ; Western Mediterranean ; 04. Solid Earth::04.04. Geology::04.04.04. Marine geology ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Monte Carlo technique in modeling ground motion coherence in sedimentary filled valleys (2009)
    Elsevier
    Details
    Publication Date: 2020-11-16
    Description: Using a Monte Carlo method based on a random walk in ad hoc N-dimensional phase space, we construct N random time series having prescribed coherence spatial decay. We apply the method in seismology by designing a numerical experiment to investigate how the coherence of the bedrock motion relates to the coherence of the surface ground motion in a sedimentary valley. The main features of the coherence behavior in the valley are found to tie in with data analysis and field observations.
    Description: Part of the research activities have been carried out by A. Caserta, for his PhD study, in cooperation with the Charles University in Prague (Czech Republic) and in the frame of the projects GACR 205/07/0502 and MSM 0021620860.
    Description: Published
    Description: 133-138
    Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica
    Description: JCR Journal
    Description: reserved
    Keywords: Coherence of seismic waves ; Monte Carlo numerical simulations ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Present-day stress-field modelling of southern Italy constrained by stress and GPS data (2009)
    Elsevier
    Details
    Publication Date: 2020-11-16
    Description: The present-day tectonic setting of the Italian peninsula is very complex and involves competing geodynamic processes. In this context, southern peninsular Italy is characterised by extension along the Apenninic belt and in the Tyrrhenian margin and by transpression in the Apulia-Gargano region. The extension is well defined by means of geological, seismological, and contemporary stress data. For the latter only few data are available in the Apulia-Gargano region, leaving the state of stress in that area unresolved. Here we develop a finite-element model of the southern Italian region in order to predict the contemporary stress field. Our model predictions are constrained by model-independent observations of the orientation of maximum horizontal stress (SHmax), the tectonic regime, and the horizontal velocities derived from GPS observations. We performed a blind test with 31 newly acquired SHmax orientations in the Southern Apennines. These new data come from the analysis of borehole breakouts performed in 46 deep oil exploration wells ranging in depth from 1300 to 5500 m. The model results agree with the stress data that define a prevailing NW-SE SHmax orientation along the Apenninic belt and foredeep and thus are capable to predict the stress field where no stress information is available. We first analyse how much model predictions, based on older data, deviate from present-day stress data and then recalibrate the models based on our new stress data, giving insight into the resolution of both models and data. In the studied region, which is affected by low deformation rates, we find that geodetic data alone cannot resolve such low levels of deformation due to the high relative measurement errors. We conclude that both GPS and stress data are required to constrain model results.
    Description: This research was supported by the Italian Presidenza del Consiglio dei Ministri - Dipartimento della Protezione Civile (DPC) through the INGV-DPC project S1.
    Description: Published
    Description: 193-204
    Description: 2T. Deformazione crostale attiva
    Description: JCR Journal
    Description: open
    Keywords: Neotectonics ; Borehole-breakouts ; Southern Apennines ; Finite-element models ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations ; 04. Solid Earth::04.03. Geodesy::04.03.08. Theory and Models ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. Stress ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    Cosmogenic 26Al in the atmosphere and the prospect of a 26Al/10Be chronometer to date old ice (2009)
    Elsevier
    In:  EPIC3Earth and Planetary Science Letters, Elsevier, 287, pp. 453-462
    Details
    Publication Date: 2017-10-09
    Description: Cosmogenic radionuclides in the one-million-year half-life range offer unique possibilities for age determinations in geophysics. In measurements where the radioactive decay is being utilized as a clock, uncertainties in age determinations may be reduced if the ratio of two radioisotopes with different half-lives can be used as a chronometer. In this work we investigate the atomic ratio of atmospheric 26Al (t1/2= 0.717 Ma) to 10Be (t1/2=1.386 Ma) measured with accelerator mass spectrometry (AMS), and its potential as a chronometer for dating old ice. The 26Al/10Be ratio decreases with an effective half-life of t1/2(26Al/10Be)= 1.49 Ma. For its application as a chronometer, the atmospheric 26Al/10Be ratio has to be well characterized. However, the properties of atmospheric 26Al have been understood only poorly so far. At the VERA AMS facility of the University of Vienna, a first systematic study of the global variations of the 26Al/10Be ratio in the atmosphere and in surface firn has been carried out, and pilot measurements of the 26Al/10Be ratio in deep Antarctic ice have been performed. Our results indicate that this ratio is globally constant to within 5% in the atmosphere and in surface firn with a mean value of 1.89×10−3. The data also suggest that non-atmospheric sources of 26Al, such as extraterrestrial, in situ produced or re-suspended 26Al, do not contribute significantly to the observed 26Al/10Beratio. In addition, atmospheric mixing seems to exert only aminor influence. In a first application of the method,26Al/10Be ratios were measured in chips collected in connection with the drilling of the lowest part of an ice core (2250 to 2760 m) in Dronning Maud Land,Antarctica. Surprisingly, variable 26Al/10Be ratios ranging between0.5 and up to 2 times the atmospheric ratio were found at different locations in this deep ice core. While the cause for the ratios higher than atmospheric remains unexplained so far, the ratios lower than atmospheric may be caused by radioactive decay, allowing a first dating attempt using the 26Al/10Be ratio. Thus, at an ice depthof 2760 m an approximate date of (6.7±2.6)×105years was established.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 7
    facet.materialart.
    Unknown
    Numerical simulation of pyroclastic density currents on Campi Flegrei topography: a tool for statistical hazard estimation. (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We describe a numerical simulation of both concentrated and dilute gravity-driven pyroclastic flows on a digital topographic model of the Campi Flegrei volcanic field. Families of numerical flows are generated by sampling a multi-dimensional matrix of vent coordinates, flow properties and dynamical parameters within a wide range of values. Hazard maps are constructed from the data base of simulated flows, using a mixed deterministic^statistical approach. The set of probable vents covers the area of recent eruptions. Results show the key role of topography in controlling the flow dispersion. The maximum hazard appears to be the NE sector of the caldera. Flows in the eastern sector, including the city of Naples, are shown to be efficiently hindered by the Posillipo and Camaldoli hills at the caldera borders, thus reducing the hazard. The results represent the first physically based estimate of hazard from pyroclastic flows in this densely populated area, and can be used for civil defence purposes.
    Description: Published
    Description: 1-14
    Description: partially_open
    Keywords: Campi flegrei ; calderas ; pyroclastic flows ; hazard maps ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis ; 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)
    Type: article
    Format: 497 bytes
    Format: 966713 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Microbial communities near the oxic/anoxic interface in the hydrothermal system of Vulcano Island, Italy (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Hydrothermal fluids and sediments from subaerial and shallow submarine sites at Vulcano Island, Italy were investigated for relations between the thermophilic microbial communities, as analysed by fluorescence in situ hybridization, and their geochemical environment, as assessed by photometry, chromatography, and in situ microsensor measurements. Mixing between hydrothermal fluids and seawater in the sediment pore space was reflected in the chemical composition of the emitted fluids, in depth profiles of pore water oxygen and sulfide concentrations, and in the structure of the benthic microbial community. Organic compounds did not accumulate in the vent fluids (b10 AM fatty acids) or in the sediments (b0.1% Corg), suggesting that efficient utilization supported microbial populations on the order of 104 cells per ml fluid and 108 cells per cm3 sediment. Groups of thermophiles that typically gain metabolic energy from the fermentation of organic matter (Thermococcales, Thermotoga/Thermosipho spp., and Bacillus sp.)were detected in significant abundances at all study sites. Also abundant were thermophiles capable of oxidizing organic acids with oxygen, nitrate, or sulfate. Aerobic thermophiles (Aquificales and Thermus sp.) were more abundant at oxic sites than at anoxic sites. Increasingly oxygenated habitats were associated with decreasing abundance of anaerobic (hyper)thermophiles belonging to the order Archaeoglobales.
    Description: Published
    Description: 169– 182
    Description: partially_open
    Keywords: Biogeochemistry ; Hydrothermal system ; Marine sediment ; Microbial ecology ; Microsensor ; Thermophiles ; 03. Hydrosphere::03.04. Chemical and biological::03.04.04. Ecosystems ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 539 bytes
    Format: 315050 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    European-Mediterranean regional centroid-moment tensor catalog: solutions for years 2001 and 2002 (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We present regional centroid-moment tensor (RCMT) solutions for 168 moderate-magnitude earthquakes that occurred in the European-Mediterranean region during 2001 and 2002. Events with moment magnitudes as low as 4.0 were successfully analyzed, although this low threshold is only achievable in regions with the best azimuthal coverage and with stations at a few hundred kilometers distance. Earthquakes with focal depths from 10 to more than 200 km were analyzed. Comparison with standard Harvard CMTs, when available, shows good agreement. The solutions shown in this paper represent an addition to the European-Mediterranean RCMT catalog that we are maintaining. The RCMT catalog now spans 6 years, from 1997 to 2002, and contains 420 solutions. We also outline the main seismic sequences that occurred in the European-Mediterranean region during 2001–2002.
    Description: MedNet Data Centre ORFEUS-MEREDIAN GEOFON IRIS
    Description: Published
    Description: 127-147
    Description: reserved
    Keywords: Seismicity ; Seismic moment tensors ; European-Mediterranean region ; 05. General::05.02. Data dissemination::05.02.02. Seismological data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1128414 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Evidence of active tectonics on a Roman aqueduct system (II–III century A.D.) near Rome, Italy (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: In this paper we describe evidence of strong tectonic deformation affecting two aqueducts of Roman age (II–III century A.D.). The channels are located approximately 20 km northeast of Rome along the ancient Via Tiburtina. Brittle and ductile deformation affects these two structures, including extensional joint systems, NE-oriented faults, and horizontal distortion. This deformation is consistent with rightlateral movement on major N-striking faults, and represents the first evidence that tectonic deformation took place in historical times in the vicinity of Rome, with local strike–slip movement superimposed on a regional extensional fault system.
    Description: Published
    Description: 679–690
    Description: reserved
    Keywords: Strike–slip tectonics ; Active tectonics ; Geo-archaeology ; Rome ; Italy ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 3290147 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 11
    facet.materialart.
    Unknown
    Solubility and speciation of sulfur in silicate melts: The Conjugated Toop-Samis-Flood-Grjotheim (CTSFG) model (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: A Conjugated Toop-Samis-Flood-Grjotheim (CTSFG) model is developed by combining the framework of the Toop-Samis polymeric approach with the Flood-Grjotheim theoretical treatment of silicate melts and slags. Electrically equivalent ion fractions are computed over the appropriate matrixes (anionic and cationic) in a Temkin notation for fused salts, and are used to weigh the contribution of the various disproportionation reactions of type: M2/pO(melt)+ 1/2S(gas)+M2/pS(melt)+1/2O2(gas) M2/po(melt)+1/2S2(gas)+3/2O2(gas)-M2/pSO4(melt)v being the charge of the generic Mp-1 cation. The extension of the anionic matrix is calculated in the framework of a previously developed polymeric model (Ottonello et al., 2001), based on a parameterization of Lux-Flood acid-base properties of melt components. Model activities follow the Raoultian behavior implicit in the Temkin notation, without the needs of introducing adjustable parameters. The CTSFG model is based on a large amount of data available in literature and exhibits a satisfactory heuristic capability, with virtually no compositional limits, as long as the structural role given to each oxide holds. The model may be employed to compute gas-melt equilibria involving sulfur and allows computing sulfide and sulfate contents of silicate melts whenever the fugacity of a gaseous sulfur species and oxygen are known. Alternatively, the model calculates the oxidation state of the system (i.e., oxygen fugacity), whenever an analytical determination of either sulfide/sulfate or ferrous/ferric ratios in the melt is provided. Calculated sulfide and sulfate capacities allow the estimates of sulfur abundance in various melts of geological interest, both under anhydrous and hydrous conditions or, alternatively, of fS2, given fO2 and the bulk sulfur content. In this case, fSO2 and fH2S may be eventually computed along the water-sulfur-melt boundary provided fH2O is known.
    Description: Published
    Description: 801-823
    Description: partially_open
    Keywords: sulfur ; silicate melts ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 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
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 568 bytes
    Format: 1278538 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 12
    facet.materialart.
    Unknown
    Three-dimensional strain tensor estimation by GPS observations: methodological aspects and geophysical applications (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The aim of this paper is to describe the theoretical fundamentals, the main features and some geophysical applications of a software (STRAINGPS) suitably implemented to estimate the strain tensor from repeated GPS surveys of deformation control networks. Current softwares developed for geophysical applications generally estimate or compute bi-dimensional strain, since this is the most requested use. On the contrary, this software allows for a three-dimensional (3D) estimate of the strain tensor and does not need a subdivision of the network in triangles. It accounts for all the significant coordinate differences (or velocities) coming from repeated surveys and estimates the strain tensor components by the least squares method, starting from the hypothesis of one homogeneous strain field. Moreover, some tests to control both model adequacy and detecting outliers are performed, allowing a subdivision of the field into sub-domains with homogeneous strain field. We applied this software to three real geophysical situations. The first concerns the geodynamic (long term) induced deformation at regional scale, by estimating extensional strain rate ((0.22 ± 0.06) × 10−7) per year in central-southern Italy across the Apennines chain; the second is co-seismic strain by the assessment of the strike slip style of the Molise (central-southern Italy) earthquakes (31 October and 1 November 2002); the last regards the subsidence induced strain in the Travale-Radicondoli (central Italy) exploitation area. © 2004 Elsevier Ltd. All rights reserved.
    Description: Published
    Description: 1-18
    Description: reserved
    Keywords: GPS observations ; 04. Solid Earth::04.02. Exploration geophysics::04.02.05. Downhole, radioactivity, remote sensing, and other methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 348274 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 13
    facet.materialart.
    Unknown
    Carbon dioxide of Pu`u`O`o volcanic plume at Kilauea retrieved by AVIRIS hyperspectral data (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: A remote sensing approach permits for the first time the derivation of a map of the carbon dioxide concentration in a volcanic plume. The airborne imaging remote sensing overcomes the typical difficulties associated with the ground measurements and permits rapid and large views of the volcanic processes together with the measurements of volatile components exolving from craters. Hyperspectral images in the infrared range (1900–2100 nm), where carbon dioxide absorption lines are present, have been used. These images were acquired during an airborne campaign by the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) over the Pu`u` O`o Vent situated at the Kilauea East Rift zone, Hawaii. Using a radiative transfer model to simulate the measured up-welling spectral radiance and by applying the newly developed mapping technique, the carbon dioxide concentration map of the Pu`u` O`o Vent plume were obtained. The carbon dioxide integrated flux rate were calculated and a mean value of 396±138 t d−1 was obtained. This result is in agreement, within the measurements errors, with those of the ground measurements taken during the airborne campaign.
    Description: Published
    Description: 3192–3199
    Description: 1.10. TTC - Telerilevamento
    Description: JCR Journal
    Description: partially_open
    Keywords: Hyperspectral data ; Volcanic plume ; Carbon dioxide ; AVIRIS ; Kilauea ; 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)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 14
    facet.materialart.
    Unknown
    Comparison between the 1994–2006 seismic and gravity data from Mt. Etna: New insight into the long-term behavior of a complex volcano (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We investigate the relationship between changes of the gravity field and the release of the seismic energy at Mt. Etna over a 12-year period (1994-2006), during which the volcano exhibited different eruptive patterns. Over the two sub-periods when intense gravity decreases occur, centered on the upper southeastern sector of the volcano (late-1996 to mid-1999 and late-2000 to mid-2001), the strain release curve displays neat long-term accelerations, with many hypocenters clustered in the volume containing the gravity source. Various evidences suggest that, since 1994 and until the breakout of the 2001 eruption, the eastern flank of Etna remained peripheral to the lines of rise of the magma from the deep storage to the surface. Accordingly, we hypothesize that, rather than being directly associated to the migration of the magma, the joint anomalies we found image phases of higher tensile stress on the upper southeastern sector, associated to increase in the rate of microfracturing along the NNW-SSE fracture zone. Such an increase implies a local density (gravity) decrease, and an increase in the release of seismic energy, thus explaining the correlation we observe. The second period of gravity decrease/strain release increase culminated in the breakout of the 2001 flank eruption, as a pressurized deeper magma accumulation used the inferred zone of increasing microfracturing as a path to the surface. This eruption marks an important modification in the structure of Etna’s plumbing system, as also testified by the absence of post-2001 long-term gravity changes and accelerations in the strain release curve and the neat modification of the seismicity and ground deformation patterns. Thus we prove that joint microgravity and seismic studies can allow zones of the medium experiencing an increase in the rate of microfracturing to be identified months to years before a magma batch is conveyed through them to the surface, setting off a lateral eruption.
    Description: Published
    Description: 282–292
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: microgravity changes ; seismic strain release ; 04. Solid Earth::04.03. Geodesy::04.03.05. Gravity variations ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 15
    facet.materialart.
    Unknown
    A model for Ischia hydrothermal system: Evidences from the chemistry of thermal groundwaters (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Ischia volcano, in Central Italy, has long been known for its copious surface hydrothermal manifestations, signs of a pervasive circulation of hot fluids in the subsurface. Because of the significant chemical heterogeneity of fumarolic gas discharges and hot spring discharges, evidences of a complex hydrothermal setting, a definite model of fluid circulation at depth is currently unavailable, in spite of the several previous efforts. Here, we report on the chemical and isotopic composition of 120 groundwater samples, collected during several sampling surveys from 2002 to 2007. The acquired data suggest that the composition of surface manifestations reflect contributions from meteoric water, sea water, and thermal fluids rising from two distinct hydrothermal reservoir, with equilibrium temperatures of respectively ~150 °C and ~270 °C, and depths of 150–300 m and N300 m (but possibly N1000 m). We also make use of an isotopic characterization of the dissolved gas phase in thermal waters to demonstrate that the Ischia hydrothermal system is currently supplied by a deep-rising gas component (DGC), characterized by CO2 ~97.7±1.2 vol.% (on a water-free basis), δ13CCO2=−3.51±0.9‰, and helium isotopic ratio of about 3.5 Ra (3He/4He ratio normalized to the air ratio, Ra), likely magmatic in origin. An assessment of the thermal budget for Ischia hydrothermal system is also presented, in the attempt to derive a first estimate of the size and rate of degassing of the magmatic reservoir feeding the gas emissions. We calculate that a heat flow of about 153–222 MW presently drives hydrothermal circulation on the island, which we suggest is supplied in convective form (e.g., by the ascent of a high-T magmatic vapour phase) by complete degassing of 2.2–3.3 107 m3 yr−1 of trachytic magma (with ~2.1 wt.% dissolved H2O content). If extrapolated to entire period of quiescence lasting since the Arso eruption in 1302 A.D., this volume corresponds to 1.6–2.3 1010 m3 of magma degassed in about 700 years of quiescent activity.
    Description: Published
    Description: 133–159
    Description: JCR Journal
    Description: reserved
    Keywords: Ischia ; hydrothermal systems ; thermal groudwaters ; thermal and volatile budget ; 03. Hydrosphere::03.02. Hydrology::03.02.02. Hydrological processes: interaction, transport, dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 16
    facet.materialart.
    Unknown
    Mercury concentration, speciation and budget in volcanic aquifers: Italy and Guadeloupe (Lesser Antilles) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Quantifying the contribution of volcanism to global mercury (Hg) emissions is important to understand the pathways and the mechanisms of Hg cycling through the Earth's geochemical reservoirs and to assess its environmental impacts. While previous studies have suggested that degassing volcanoes might contribute importantly to the atmospheric budget of mercury, little is known about the amount and behaviour of Hg in volcanic aquifers. Here we report on detailed investigations of both the content and the speciation of mercury in aquifers of active volcanoes in Italy and Guadeloupe Island (Lesser Antilles). In the studied groundwaters, total Hg (THg) concentrations range from 10 to 500 ng/l and are lower than the 1000 ng/l threshold value for human health protection fixed by the World Health Organization [WHO (1993): WHO Guidelines for Drinking Water Quality- http://www.who.int/water_sanitation_health/GDWQ/index.htlm]. Positive co-variations of (THg) with sulphate indicate that Hg-SO4-rich acid groundwaters receive a direct input of magmatic/hydrothermal gases carrying mercury as Hg0 (gas). Increasing THg in a volcanic aquifer could thus be a sensitive tracer of magmatic gas input prior to an eruption. Since the complex behaviour and toxicity of mercury in waters depend on its chemical speciation, we carefully determined the different aqueous forms of this element in our samples.We find that dissolved elemental Hg0 (aq) and particulate-bound Hg (HgP) widely prevail in volcanic aquifers, in proportions that highlight the efficiency of Hg adsorption onto colloidal particles. Moreover, we observe that dissolved Hg0 aq and Hg(II) forms coexist in comparable amount in most of the waters, in stark contrast to the results of thermodynamic equilibrium modelling. Therefore, chemical equilibrium between dissolved mercury species in volcanic waters is either prevented by natural kinetic effects or not preserved in collected waters due to sampling/storage artefacts. Finally, we provide a first quantitative comparison of the relative intensity of aqueous transport and atmospheric emissions of mercury at Mount Etna, a very active basaltic volcano.
    Description: Published
    Description: 96-106
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: JCR Journal
    Description: reserved
    Keywords: speciation ; volcanic aquifers ; total and dissolved mercury ; mercury cycling ; volatile budget ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 17
    facet.materialart.
    Unknown
    Helium and carbon isotopes in the dissolved gases of Friuli Region (NE Italy): Geochemical evidence of CO2 production and degassing over a seismically active area (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The first geochemical data showing the existence of an active degassing activity over a large seismically active sector of the Southern Alps (Friuli Region, NE Italy) are presented. The dissolved gases, helium and carbon isotopic systematics of 46 water samples taken from 13 sites running along E–W and NE–SW faults besides the natural degassing of a 5000 km2 wide area are investigated. The chemical composition of the dissolved gases revealed that a CO2-rich gas phase feeds the local groundwaters. 3He/4He ratios (R) normalized to the atmospheric 3He/4He ratio (Ra=1.39×10−6) and corrected for the atmospheric contamination (R/Rac), range from 0.29 to 1 as a result of a two component (radiogenic and atmospheric) mixing. The δ13C values of total dissolved inorganic carbon (TDIC) ranging from −15.28 to −0.75‰ vs. PDB, show the occurrence of multiple gas–water interactions. The mixing between the atmospheric air and a crustal source and the gas–water interactions occurring at various extents appears to be the main control on the observed He–C systematics. The natural CO2 degassing was evaluated by a soil gas survey carried out by a grid of about 100 measuring sites located over the area that generated destructive seismic sequences (e.g. the Gemona sequence of 1976; main shocks M6.4 of 6th May and M6.1 of 11th and 15th September). The results obtained show that a significant amount of crustal-originated gases are released over the continental area of Eastern Southern Alps. The evidence that carbon dioxide is associated with radiogenic-type helium denotes the lack of the mantle as primary energy and degassing source, highlighting the possibility that CO2 is produced by thermo-mechanical processes occurring at seismogenic depth. The information provided here may be used to start up a long-term geochemical monitoring of this seismically active area and could be able to detect the modifications occurring to the circulating fluids to gain a better insight on the relationships between the fluids' geochemistry and the activity of the local seismogenic faults.
    Description: Published
    Description: 76–85
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: Fluids ; Faults ; geochemistry ; isotopes ; 04. Solid Earth::04.02. Exploration geophysics::04.02.01. Geochemical exploration
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 18
    facet.materialart.
    Unknown
    Pleistocene magnetochronology of early hominin sites at Ceprano and Fontana Ranuccio, Italy (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Paleomagnetic analyses were conducted on two cores drilled at Ceprano in central Italy where an incomplete hominin cranium was discovered in1994, as well as on two additional cores from the nearby site of Fontana Ranuccio that yielded hominin remains associated with an Acheulean industry. No evidence for the 0.78 Ma Brunhes–Matuyama boundary was found at Ceprano down to 45 m below the level that yielded the hominin cranium. The Ceprano lithostratigraphy and the paleomagnetic age constraints are broadly consistent with the stratigraphy of the Liri lacustrine sequence of the Latina Valley, constrained by published K–Ar ages between ~0.6 and ~0.35Ma, and according to an age model with magnetic susceptibility supported by pollen facies data, suggest that the level that yielded the hominin cranium has an age of ~0.45 (+0.05, −0.10) Ma. Evidence for the Brunhes–Matuyama boundary was found at Fontana Ranuccio about 40 m below the hominin level, consistent with a K–Ar age of ~0.46 Ma reported for this level. Hence the Ceprano and Fontana Ranuccio hominin occurrences may be of very similar mid-Brunhes age.
    Description: Published
    Description: 255-268
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: Pleistocene ; Ceprano ; Fontana Ranuccio ; magnetostratigraphy ; hominins ; Italy ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 19
    facet.materialart.
    Unknown
    Mercury gas emissions from La Soufrière Volcano, Guadeloupe Island (Lesser Antilles) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Quantifying mercury (Hg) emissions from active volcanoes is of particular interest for better constraining the global cycle and environmental impact of this highly toxic element. Here we report on the abundance of total gaseous (TGM=Hg0 (g)+HgII (g)) and particulate (Hg(p)) mercury in the summit gas emissions of La Soufrière andesitic volcano (Guadeloupe island, Lesser Antilles), where enhanced degassing of mixed hydrothermalmagmatic volatiles has been occurring since 1992 from the Southern summit crater.We demonstrate that Hg in volcanic plume occurs predominantly as gaseous mercury, with a mean TGM/Hg(p) mass ratio of ~63. Combining the mean TGM/H2S mass ratio of the volcanic plume (~3.2×10−6), measured close to the source vent, with the H2S plume flux (~0.7 t d−1), determined simultaneously, allows us to estimate a gaseous mercury emission rate of 0.8 kg yr−1 from La Soufrière summit dome. Somewhat lower TGM/Stot mass ratio in fumarolic gases from the source vent (4.4×10−7) suggests that plume chemical composition is not well represented by the emission source (fumaroles) due to chemical processes prior to (or upon) discharge. Current mercury emission from La Soufrìere volcano represents a very small contribution to the estimated global volcanic budget for this element.
    Description: Published
    Description: 276-282
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Mercury ; Fumaroles ; Volcanic plume ; Trace metals ; Gaseous and particulate mercury ; Emission rate ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 20
    facet.materialart.
    Unknown
    Pre-existing cross-structures and active fault segmentation in the northern-central Apennines (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The multideformed axial zone of the Apennines provides a great opportunity to explore the influence of preexisting cross-structures (inherited from pre-Quaternary tectonic phases) on the segmentation of Quaternary/active seismogenic extensional faults. Detailed geological and structural data and their comparison with seismological data show that although the attitudes (strike and dip) of oblique preexisting faults are certainly an important factor in determining a segment boundary, the size of the inherited oblique structures seems to be more crucial. Pre-existing cross-structures with lengths ranging from several kilometers to a few tens of kilometers show a twofold behavior. They can act as segment barriers during the rupture of a single fault segment or they can be reactivated as transfer zones inducing the activation of two adjacent segments that belong to the same fault system. Regional basement/crustal oblique pre-existing cross-structures, with lengths ranging from several tens of kilometers to hundreds of kilometers (commonly NNE-striking), may act as “persistent structural barriers” that halt both fault segment and fault system propagation, thus determining their terminations and maximum sizes. In the northern-central Apennines, the NNE-striking Ancona–Anzio, Valnerina, and Ortona–Roccamonfina tectonic lineaments, although having been repeatedly reactivated since the Mesozoic, represent the most important examples of these structures. Moreover, probably due to their misorientation with respect to the present extensional stress field, regional NNE-striking pre-existing structures appear to be less likely to produce strong magnitude events (no surface evidence for Quaternary faulting has been found thus far and historical and instrumental seismicity shows only Mb6 events). M ~7 event, on the other hand, is more likely to occur along the (N)NW–(S)SE trending normal fault systems. Lastly, we propose a model that can explain the different sizes of fault segments and fault systems on the basis of their location with respect to the “persistent structural barriers” and their spacing. In this view, our results may contribute to a more reasonable assessment of the nature and size of future surface ruptures in the northern-central Apennines, which are of critical importance to estimating seismic hazard.
    Description: Published
    Description: 304-319
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: open
    Keywords: Active faults ; Segmentation ; Pre-existing cross-structure ; Structural barrier ; Northern/central Apennines ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 21
    facet.materialart.
    Unknown
    Insight on recent Stromboli eruption inferred from terrestrial and satellite ground deformation measurements (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The multi-parametric permanent system (tilt and GPS networks, robotized geodetic station) for monitoring ground deformation at Stromboli volcano was set up in the 1990s and later greatly improved during the effusive event of 2002–2003. Unlike other volcanoes, e.g. Mt. Etna, the magnitude of ground deformation signals of Stromboli is very small and through the entire period of operation of the monitoring system, only two major episodes of deformation, in 1994–1995 and 2000, which did not lead to an eruption but rather pure intrusion, were measured. Similarly to the 2002–2003 eruption, no important deformations were detected in the months before the 2007 eruption. However, unlike the 2002–2003 eruption, GPS and tilt stations recorded a continuous deflation during the entire 2007 eruption, which allowed us to infer a vertical elongated prolate ellipsoidal source, centered below the summit craters at depth of about 2.8 km b.s.l. Due to its geometry and position, this source simulates an elongated plumbing system connecting the deeper LP magma storage (depth from 5 to 10 km) with the HP shallower storage (0.8–3 km), both previously identified by petrologic and geochemical studies. This result represents the first contribution of geophysics to the definition of the plumbing system of Stromboli at intermediate depth. Finally, no deformation due to the plumbing system was measured for a long time after the end of the eruption. Meanwhile, the new terrestrial geodetic monitoring system installed within the Sciara del Fuoco, on the lava fan formed during the eruption, indicated that during the first months after the end of the eruption the ground velocity progressively decreased in time, suggesting that part of the deformation was due to the thermal contraction of the lava flow.
    Description: Published
    Description: 172-181
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli ; Ground Deformation ; source modelling ; flank instability ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.03. Geodesy::04.03.09. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 22
    facet.materialart.
    Unknown
    Halogens in volcanic systems (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The transport, degassing and atmospheric release of halogens from active volcanism on Earth have been the focus of increasing interest over the last few decades, and have recently been the subject of the 1st workshop on “Halogens in volcanic systems and their environmental impacts” that was held in December of 2007 at Yosemite Lodge in Yosemite National Park, California. As an introduction to this Chemical Geology special issue, collecting contributions from many of the participants at the workshop, we review here recent advances in this field, including experimental and theoretical investigations of halogen behaviour in volcanic and related magmatic systems. We discuss previous research on several aspects of halogen geochemistry, including halogen abundances in the mantle and magmas on Earth; the effects of halogens on phase equilibria and melt viscosities; their partitioning between melt and fluid phase(s) upon decompression, cooling and crystallisation of magmas in the Earth's crust; and their final atmospheric release as volcanic gases. The role of halogens in the genesis of hydrothermal systems and in the transport of ore-forming metals is also reviewed, and we discuss our current understanding of atmospheric processing of volcanic halogens in both the troposphere and stratosphere, and their consequent impacts. In spite of these recent advancements, our current understanding of halogen geochemistry at active volcanoes is still far too fragmentary, and the key questions that require answers from future research are summarised in our conclusions.
    Description: Published
    Description: 1-18
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Halogens ; Magmatic fluids ; Ore deposits ; Volcanic degassing ; Volcanic gas ; Atmospheric effects ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 23
    facet.materialart.
    Unknown
    Degassing of halogens from basaltic volcanism: Insights from volcanic gas observations (2009)
    Elsevier
    Details
    Publication Date: 2017-04-03
    Description: The currently available data set of S–Cl–F abundances in volcanic gas plumes and high-temperature fumarolic gas samples from basaltic volcanism is reviewed here in the attempt to derive constraints on the modes of halogen degassing from mafic silicate melts. Apart from large volcano-to-volcano variations, reflecting remarkable differences in volatile abundances in the source magmas, each of the explored volcanoes displays large changes of SO2/HCl and SO2/HF ratios with the style of volcanic activity, with HCl/HF staying fairly constant. Halogen abundances are low and SO2/HCl and SO2/HF are high when fresh (volatile-rich) magmas sustain degassing, as during explosive eruptions, at the onset of eruptive cycles, or shortly before paroxysmal events. Low SO2/HCl and SO2/HF ratios are instead characteristic of late stages of volcanic degassing, typically being observed in the concluding stages of basaltic eruptions, or during periods of reduced magma supply at persistently degassing volcanoes. These observations are taken as evidence of halogens being less keen to enter the gas phase (relative to S) during degassing of basaltic magmas; and quantitatively interpreted in light of a Rayleigh-type open-system degassing model. The model, though simple, quantitatively reproduces the range of volcanic gas compositions observed at basaltic volcanoes worldwide, and allows prediction of vapour/melt partitioning contrasts of factors ~9 and ~36 for the volatile couples S–Cl and S–F, respectively. These predictions require validation from appropriately designed experiments of halogen partitioning between magmatic vapours and silicate melts over a range of P–T–X conditions.
    Description: Published
    Description: 99-109
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Volcanic degassing ; Halogens ; Volcanic gases ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 24
    facet.materialart.
    Unknown
    Fault plane orientation of microearthquakes at Mt. etna from the inversion of P-wave rise times (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: crucial point in the analysis of tectonic earthquakes occurring in a volcanic area is the inference of the orientation of the structures along which the ruptures occur. These structures represent zones of weakness which could favor the migration of melt toward the surface and the assessment of their geometry is a fundamental step toward efficient evaluation of volcanic risk. We analyzed a high-quality dataset of 171 low-magnitude, tectonic earthquakes occurred at Mt. Etna during the 2002-2003 eruption. We applied a recently developed technique aimed at inferring the source parameters (source size, dip and strike fault) and the intrinsic quality factor Qp of P waves from the inversion of rise times. The technique is based on numerically calibrated relationships among the rise time of first P waves and the source parameters for a circular crack rupturing at a constant velocity. For the most of the events the directivity source effect did not allow us to constrain the fault plane orientation. For a subset of 45 events with well constrained focal mechanisms we were able to constrain the “true” fault plane orientation. The level of resolution of the fault planes was assessed through a non linear analysis based on the random deviates technique. The significance of the retrieved fault plane solutions and the fit of the assumed source model to data was assessed through a χ-square test. Most of the retrieved fault plane solutions agree with the geometrical trend of known surface faults. The inferred source parameters and Qp are in agreement with the results of previous studies.
    Description: In press
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: open
    Keywords: rise time ; Mt. Etna ; 04. Solid Earth::04.02. Exploration geophysics::04.02.06. Seismic methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 25
    facet.materialart.
    Unknown
    The effects of volcanic eruptions on atmospheric chemistry (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Volcanoes are very strong sources of sulphur, acids and other gases, as well as particles, that are of atmospheric relevance. Some gases only behave as passive tracers, others affect the formation, growth or chemical characteristics of aerosol particles and many lead to adverse effects on vegetation and human health when deposited in the vicinity of volcanoes. In this article the main effects of volcanic emissions on atmospheric chemistry are discussed, with a focus on sulphur and halogen compounds, and to a smaller extent on climate. We primarily focus on quiescent degassing but the main effects of explosive eruptions on the troposphere and stratosphere are covered as well. The key distinction between chemistry in magmatic and hydrothermal settings and the atmosphere is that the atmosphere is oxidising whereas the chemistry is typically reducing in the former cases due to very low oxygen concentrations. Rapid catalytic cycles involving radicals are a further characteristic of atmospheric chemistry. Most reaction cycles involve the photolysis of molecules as a key part of the reaction chains. Recent measurements of halogen radicals in volcanic plumes showed that volcanic plumes are chemically very active. We explain the formation mechanism of halogen oxides in plumes as well as their relevance for the atmosphere.
    Description: Published
    Description: 131-142
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Quiescent degassing ; Troposphere ; Halogens ; Atmospheric chemistry ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 26
    facet.materialart.
    Unknown
    The evolution of the Sciara del Fuoco subaerial slope during the 2007 Stromboli eruption: Relation between deformation processes and effusive activity (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Focusing on the Island of Stromboli, this research investigates whether airborne remote sensing systems, such as those based on digital photogrammetry and laser scanner sensors, can be adopted to monitor slope deformation and lava emplacement processes in active volcanic areas. Thanks to the capability of extracting accurate topographic data and working on flexible time schedules, these methods can be used to constrain the regular and more frequent measurements derived from satellite observations. This work is dedicated to the monitoring of Stromboli's volcanic edifice which is beneficial when obtaining quantitative data on the geometry of deformation features and the displaced (failures and landslides) and emplaced (lava flows) volumes. In particular, we focus on the capability of extracting average effusion rates from volume measurements that can be used to validate or integrate satellite-derived estimates. Since 2001, a number of airborne remote sensing surveys, namely Digital Photogrammetry (DP) and Airborne Laser Scanning (ALS), have been carried out on Stromboli's volcano to obtain high resolution Digital Elevation Models (DEM) and orthophotos with sub-meter spatial resolution and a time schedule suitable for monitoring the morphological evolution of the surface during the quiescent phases. During the last two effusive eruptions (2002–2003 and 2007) the surface modifications, created on the Sciara del Fuoco slope and on the crater area as a consequence of effusive activity, were quantified and monitored using the same methodologies. This work, which is based on the results obtained from the multi-temporal quantitative analysis of the data collected from 2001 to 2007, mainly focuses on the 2007 eruption but also accounts for analogies and differences regarding the 2002–2003 event. The 2007 eruption on the Sciara del Fuoco slope from 27 February until 2 April, produced a compound lava field including a lava delta on the shoreline, discharging most of the lava into the sea. The comparison of the 2007 DEMs with a pre-eruption surface (2006 LIDAR survey) allowed for the evaluation of the total lava volume that accumulated on the subaerial slope while two syn-eruption DEMs were used to calculate the average effusion rates during the eruption. Since the evolution of a lava field produced during an eruption can be seen as a proxy for the magma intrusion mechanism, hypotheses are formulated on the connection between the lava discharge and the instabilities suffered by the slope.
    Description: Published
    Description: 201-213
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: Slope deformation ; Effusive activity ; Aerial surveys ; Digital elevation model ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 27
    facet.materialart.
    Unknown
    Hazards from pyroclastic density currents at Mt. Etna (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-03
    Description: Despite the recent recognition of Mount Etna as a periodically violently explosive volcano, the hazards from various types of pyroclastic density currents (PDCs) have until now received virtually no attention at this volcano. Large-scale pyroclastic flows last occurred during the caldera-forming Ellittico eruptions, 15–16 ka ago, and the risk of them occurring in the near future is negligible. However, minor PDCs can affect much of the summit area and portions of the upper flanks of the volcano. During the past ~ 20 years, small pyroclastic flows or base-surge-like vapor and ash clouds have occurred in at least 8 cases during summit eruptions of Etna. Four different mechanisms of PDC generation have been identified during these events: (1) collapse of pyroclastic fountains (as in 2000 and possibly in 1986); (2) phreatomagmatic explosions resulting from mixing of lava with wet rock (2006); (3) phreatomagmatic explosions resulting from mixing of lava with thick snow (2007); (4) disintegration of the unstable flanks of a lava dome-like structure growing over the rim of one of the summit craters (1999). All of these recent PDCs were of a rather minor extent (maximum runout lengths were about 1.5 km in November 2006 and March 2007) and thus they represented no threat for populated areas and human property around the volcano. Yet, events of this type pose a significant threat to the lives of people visiting the summit area of Etna, and areas in a radius of 2 km from the summit craters should be off-limits anytime an event capable of producing similar PDCs occurs. The most likely source of further PDCs in the near future is the Southeast Crater, the youngest, most active and most unstable of the four summit craters of Etna, where 6 of the 8 documented recent PDCs originated. It is likely that similar hazards exist in a number of volcanic settings elsewhere, especially at snow- or glacier-covered volcanoes and on volcano slopes strongly affected by hydrothermal alteration.
    Description: Published
    Description: 148-160
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: reserved
    Keywords: Pyroclastic density currents ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 28
    facet.materialart.
    Unknown
    Chronology of the 2007 eruption of Stromboli and the activity of the Scientific Synthesis Group (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: On 27 February 2007, at 12.49 GMT, a new eruption of Stromboli took place with the effusion of a lava flow from a fracture cutting the flank of the NE cone, which rapidly reached the sea. The eruption had been heralded by an increase in the amplitude of tremor and flank movement since at least the 14th of February. Short-term precursors were an increase in the rate of occurrence of small landslides within the “Sciara del Fuoco” scar on the North-western flank of the volcano. A new effusive vent opened at 18.30 GMT on the Sciara del Fuoco at an height of 400 m asl. The new lava emission caused the sudden termination of the summit flow and initiated a period of non-stationary lava outpouring which ended on 2 April, 2007. The eruption has been characterized by a rapid decrease in the eruption rate after the first days and subsequently by episodic pulse increases. On the 15th of March, the increase in lava outpouring, monitored by a thermal camera, heralded by 9 min the occurrence of a violent paroxysmal explosion with the formation of an impulsive eruption column and the emission of small pumices mingled with black scoriae. The pumice had a bulk composition similar to that of the lava and of the black scoriae, but with a distinct lower content of phenocrysts. A similar feature has been repeatedly observed during the major explosive paroxysms of Stromboli. Short term precursors of the paroxysm were recorded by strainmeter and tiltmeter stations. The volcano monitoring activity has been made by a joint team of researchers from the INGV sections of Catania, Napoli, Palermo and Rome, along with researchers from the Universities of Florence, Pisa, Roma Tre, and Palermo. The scientific activity was coordinated by a Synthesis Group made up by scientists responsible for the different monitoring techniques of INGV and Universities and by the volcanic experts of Commissione Nazionale Grandi Rischi of the Prime Minister Office (Civil Protection Department). The group made a daily evaluation of the state of the volcano and transmitted its recommendations to the Civil Protection Department (DPC). Several prevention measures were adopted by DPC, the main of which were the evacuation of the coast zone when strong acceleration of the Sciara del Fuoco slope motion (occurred twice) could led to a dangerous tsunami by flank collapse (as last occurred on 30 December 2002) and four days before the 15 March paroxysm when access was prohibited to the part of the volcano above 290 m asl.
    Description: Published
    Description: 123–130
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli volcano ; 2007 eruption ; scientific emergency management ; 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)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 29
    facet.materialart.
    Unknown
    Regional gravity anomaly map and crustal model of the Central-Southern Apennines (Italy) (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The deep structures of the Central–Southern Apennines are analysed on the basis of the regional component of gravity anomalies, obtained applying a stripping technique. This procedure allows the accurate removal of the gravimetric effect of the three-dimensional shallow (within the first 10 km) geological bodies from the observed Bouguer anomaly. The resulting anomaly map differs quite significantly from the Bouguer anomaly map, providing new constraints on the nature of the deeper part of the crust and on the upper mantle. The stripping reveals that the regional gravity lows are shifted westward in comparison with Bouguer anomaly lows. Moreover, the gravimetric pattern indicates a lack of cylindrism for the deep structures of the Apennine Chain, which in the study area can be roughly divided into three main segments. The observed differences between the gravity anomalies pattern of the Central Apennines and that of the Southern Apennines are marked. The integration of gravimetric results with other geophysical data suggests that: (i) a ramp-dominated style for the buried Apulia (Adria) units and part of the underlying basement is compatible with gravimetric data and (ii) most of the regional gravity anomalies in the Central Apennines seem to originate within the lower crust.
    Description: Published
    Description: 73-91
    Description: open
    Keywords: Bouguer anomalies ; Rock density ; Stripping technique ; Deep crust ; Southern Italy ; 04. Solid Earth::04.02. Exploration geophysics::04.02.02. Gravity methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1098583 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 30
    facet.materialart.
    Unknown
    Detection of invisible and crucial events: from seismic fluctuations to the war against terrorism (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We argue that the recent discovery of the non-Poissonian statistics of the seismic main-shocks is a special case of a more general approach to the detection of the distribution of the time increments between one crucial but invisible event and the next. We make the conjecture that the proposed approach can be applied to the analysis of terrorist network with significant benefits for the Intelligence Community.
    Description: Published
    Description: 77-85
    Description: partially_open
    Keywords: crucial events ; against terrorism ; 05. General::05.01. Computational geophysics::05.01.02. Cellular automata, fuzzy logic, genetic alghoritms, neural networks ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 457 bytes
    Format: 137058 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 31
    facet.materialart.
    Unknown
    The 2002 Molise earthquake sequence: What can we learn about the tectonics of southern Italy? (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: On October 31, 2002 a ML=5.4 earthquake occurred in southern Italy, at the margin between the Apenninic thrust belt (to the west) and the Adriatic plate (to the east). In this area, neither historical event nor seismogenic fault is reported in the literature. In spite of its moderate magnitude, the earthquake caused severe damage in cities close to the epicenter and 27 people, out of a total of 29 casualties, were killed by the collapse of a primary school in S. Giuliano di Puglia. By inverting broadband regional waveforms, we computed moment tensor solutions for 15 events, as small as ML=3.5 (Mw=3.7). The obtained focal mechanisms show pure strike-slip geometry, mainly with focal planes oriented to NS (sinistral) and EW (dextral). In several solutions focal planes are rotated counterclockwise, in particular for later events, occurring west of the mainshock. From the relocated aftershock distribution, we found that the mainshock ruptured along an EW plane, and the fault mechanisms of some aftershocks were not consistent with the mainshock fault plane. The observed stress field, resulting from the stress tensor inversion, shows a maximum principal stress axis with an east–west trend (N83°W), whereas the minimum stress direction is almost N–S. Considering both the aftershock distribution and moment tensor solutions, it appears that several pre-existing faults were activated rather than a single planar fault associated with the mainshock. The finite fault analysis shows a very simple slip distribution with a slow rupture velocity of 1.1 km/s, that could explain the occurrence of a second mainshock about 30 h after. Finally, we attempt to interpret how the Molise sequence is related to the normal faulting system to the west (along the Apennines) and the dextral strike-slip Mattinata fault to the east.
    Description: Published
    Description: 141-154
    Description: reserved
    Keywords: waveform modeling ; source parameters ; stress field ; southern Apennines ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 937391 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 32
    facet.materialart.
    Unknown
    Magma dynamics at mid-ocean ridges by noble gas kinetic fractionation: Assessment of magmatic ascent rates (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Despite its impact in understanding oceanic crust formation and eruptive styles of related volcanism, magma dynamics at midocean ridges are poorly known. Here, we propose a new method to assess ascent rates of mid-ocean ridge basalt (MORB) magmas,as well as their pre- and sin-eruptive dynamics. It is based on the idea that a rising magma can reach a variable degree of both CO2 supersaturation in melt and kinetic fractionation among noble gases in vesicles in relation to its ascent rate through the crust. To quantify the relationship, we have used a model of multicomponent bubble growth in MORB melts, developed by extending the single-component model of Proussevitch and Sahagian [A.A. Proussevitch, D.L. Sahagian, Dynamics and energetics of bubble growth in magmas: analytical formulation and numerical modeling, J. Geophys. Res. 103 (1998), 18223–18251.] to CO2–He–Ar gas mixtures. After proper parameterization, we have applied it to published suites of data having the required features (glasses from Pito Seamount and mid-Atlantic ridges). Our results highlight that the investigated MORB magmas display very different ranges of ascent rates: slow rises of popping rock forming-magmas that cross the crust (0.01–0.5 m/s), slightly faster rates of energetic effusions (0.1–1 m/s), up to rates of 1–10 m/s which fall on the edge between lava effusion and Hawaiian activity. Inside a single plumbing system, very dissimilar magma dynamics highlight the large differences in compressive stress of the oceanic crust on a small scale. Constraints on how the systems of ridges work, as well as the characteristics of the magmatic source, can also be obtained. Our model shows how measurements of both the dissolved gas concentration in melt and the volatile composition of vesicles in the same sample are crucial in recognizing the kinetic effects and definitively assessing magma dynamics. An effort should be made to correctly set the studied samples in the sequence of volcanic submarine deposits where they are collected. Enhanced knowledge of a number of physical properties of gas-bearing MOR magmas is also required, mainly noble gas diffusivities, to describe multicomponent bubble growth at a higher confidence level.
    Description: Published
    Description: 138-158
    Description: partially_open
    Keywords: Bubble growth ; MORB ; Noble gas ; Kinetic fractionation ; Modeling ; 04. Solid Earth::04.04. Geology::04.04.07. Rock geochemistry ; 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::04.08.03. Magmas ; 04. Solid Earth::04.08. Volcanology::04.08.04. Thermodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 539 bytes
    Format: 695380 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 33
    facet.materialart.
    Unknown
    The 1980 pressure response and flank failure of Mount St. Helens (USA) inferred from seismic scaling exponents (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The cataclysmic 18 May 1980 eruption at Mount St. Helens was preceded by intense seismic activity marking the mechanical response of the volcanic edifice to interior pressurisation. This seismicity is analysed to yield the temporal change in the seismic scaling exponent, D, inferred from the seismic b-value, that in-turn is related to the seismic moment of an earthquake. Time evolution of D preceding the eruption onset reveals: (1) a major decrease in D occurring over only a few days at the end of March; (2) a steady but stepped decrease in D (steps ~5–10 days) occurring from the end of March to early May; (3) a sharp decrease in D in early May; and (4) steady low values of D occurring 2–3 days before the eruption onset. This response is interpreted as major ruptures, formed at the end of March, arresting and participating in, but not triggering the ultimate failure of the flank. Rather, the rate of interior fracturing slowed in the 2 months preceding the 18 May 1980 major blast, and the triggering of failure is consistent with interior gas overpressurisation. The occurrence of two swarms of low frequency seismic events and the high values of the harmonic tremor indicate the action of interior pressurisation on a cycle of 20–25 days. Solutions are applied to represent the harmonic interior pressurisation of the edifice by gas exsolving from the volcano core. The transient radial migration of overpressured gas may reduce the apparent strength of the edifice, and ultimately trigger failure of the flank. Importantly, this mechanism is capable of triggering flank failure both after multiple core pressurisation cycles have been sustained, and as core pressures are low and diminishing—and may be a minimum. These twin attributes are both apparent in the seismic record for Mount St. Helens, used as a proxy for the unrecorded timing and magnitude of gas pressurisation at the volcano core.
    Description: Published
    Description: 155-168
    Description: partially_open
    Keywords: seismicity ; scaling exponents ; haronic inflation ; pressurisation mechanics ; 04. Solid Earth::04.01. Earth Interior::04.01.04. Mineral physics and properties of rocks ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 497 bytes
    Format: 338420 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 34
    facet.materialart.
    Unknown
    Geochemical monitoring of thermal waters in Slovenia: relationships to seismic activity (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Thermally anomalous fluids released in seismic areas in Slovenia were the subjects of geochemical monitoring. Thermal waters were surveyed from the seismically active area of Poso$cje (Bled and Zatolmin; NW Slovenia) and from Rogaska Slatina in eastern Slovenia. Continuous monitoring of geochemical parameters (radon concentration, electrical conductivity, and water temperature) was performed with discrete gas sampling for their 3He/4He ratio. The observed values were correlated with meteorological parameters (rainfall, barometric pressure and air temperature) and with seismic activity. Only a few earthquakes occurred in the vicinity of the measuring sites during the monitoring period. Nevertheless, changes in radon concentration, water temperature, electrical conductivity and helium isotopic ratio were detected at the three thermal springs in the periods preceding the earthquakes. A close correlation was also observed of both water temperature and electrical conductivity with the Earth tide, making the observations in the selected sites a promising tool for addressing the widely debated question of earthquake prediction.
    Description: Ministry of Education,Science and Sport of Slovenia
    Description: Published
    Description: 919–930
    Description: partially_open
    Keywords: Seismicity ; Thermal waters ; Geochemistry ; 03. Hydrosphere::03.02. Hydrology::03.02.02. Hydrological processes: interaction, transport, dynamics ; 03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 539 bytes
    Format: 482322 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 35
    facet.materialart.
    Unknown
    Rainwater-induced leaching of selenium, arsenic and vanadium from Etnean volcanic soils (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Active volcanoes emit considerable amounts of contaminants such as As, Se and V. Mount Etna is the biggest volcano of Europe and an excellent geochemical site to study water-soil processes. Due to its volcanic activity, the rainwater has a strong compositional gradient, both in time and space. At present, the behaviour of trace elements in the soils around Mt Etna is poorly understood. To determine the influence of the rainwater pH on the potential mobilization of geogenic pollutants, batch experiments have been performed with synthetic rainwater for 25 soils collected along the flanks of the volcano. Our results show that: i) The maximum concentrations in the leaching solutions are higher for acid rain than for neutral rain (e.g. 7.7 vs 1.3 mg/L for Se). ii) With neutral rain conditions the soils upwind from the volcano have higher concentrations of Se than those downwind (up to 1.3 mg/L compared to ≤0.3 mg/L for the other samples). This trend is less clear for As and V. iii) For soils collected from 2 to 10 km downwind of the craters, Se concentrations in acid rain leachates decrease one order of magnitude with increasing distance. A similar pattern is also observed upwind from the volcano. For As and V no clear relationship between concentrations and location with respect to the volcanic craters is observed. Both i) and ii) result in a low pH dependence for samples upwind from the volcano. The biggest difference between acid and neutral leaching for As and V is observed for a sample 2 km downwind from the craters. The observed patterns are influenced by potential controlling factors, such as organic matter content, total concentrations, mineralogy, influence of the volcanic plume, etc. Our results have implications for the chemical composition of the Etnean aquifer, the only water resource to the one million inhabitants around Mt Etna, as well as for the bioavailability and potential toxicity through agricultural activities, essential to the local economy.
    Description: Published
    Description: Davos, Switzerland
    Description: 4.4. Scenari e mitigazione del rischio ambientale
    Description: open
    Keywords: volcanic soils ; selenium ; arsenic ; vanadium ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 03. Hydrosphere::03.03. Physical::03.03.01. Air/water/earth interactions ; 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)
    Type: Oral presentation
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 36
    facet.materialart.
    Unknown
    A seismic sequence from Northern Apennines (Italy) provides new insight on the role of fluids in the active tectonics of accretionary wedges (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We analyze a seismic sequence which occurred in 2000 along the Northern Apennines accretionary wedge (Italy). The sequence developed within the Cretaceous–Triassic limestones of the tectonic wedge, where methane-rich and oil reservoirs are stored. Ruptures mainly developed on WNW–ESE striking thrusts. The compressive stress field is consistent with that acting at regional scale in Northern Apennines. Seismic parameters indicate that fluids are involved in the seismogenic process. The amplitudes of the P and S phases and data from some stations evidence a P to S conversion within Vp/Vs=2.1 layer. The attenuation properties of crust show a higher attenuation zone located west of the epicentral cloud. Eight hundred aftershocks delineate a sub-vertical cloud of events between 7 and 14 km depth. The space–time evolution of the aftershocks is consistent with a diffusive spreading (diffusivity=1.9 m2/s) along vertically superimposed thrusts. Diffusion also controls the time evolution of the sequence. Fluid pressure is estimated to be roughly equal to the vertical, lithostatic stress. The overpressure within reservoirs develops by tectonic compaction processes. The fluids upraise along sub-vertical fractures related to the shortening of the wedge. The 2000 sequence occurred in an area that separates a thermal and deeper petroleum system from a shallower biogenic system. The divider of these systems controls the attenuation properties of the crust. The fluid–rock interaction at seismogenetic depth is related to hydrothermal processes more than to compaction. In accretionary wedges, seismicity activating superimposed thrusts may drive methane and oil upraising from the upper crust.
    Description: Published
    Description: 99-109
    Description: 3.1. Fisica dei terremoti
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: partially_open
    Keywords: seismicity ; fluids ; accretionary wedge ; thrust ; geodynamics ; Northern Apennines ; 04. Solid Earth::04.04. Geology::04.04.01. Earthquake geology and paleoseismology ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 37
    facet.materialart.
    Unknown
    Effects of soil gas permeability and recirculation flux on soil CO2 flux measurements performed using a closed dynamic accumulation chamber (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Dynamic accumulation chamber methods have been extensively used to estimate the total output of CO2 released from active volcanic area. In order to asses the performance and reliability of a closed dynamic system several tests were carried out with different soil permeabilities and soil CO2 fluxes. A special device was used to create a constant one-dimensional CO2 flux through a soil column with a known permeability. Three permeabilities were investigated, ranging between 3.6 × 10− 2 and 3.5 × 10 μm2, as were several CO2 fluxes (ranging between 1.1 × 10− 6 and 6.3 × 10− 5 kg m− 2 s− 1). The results highlight that the accuracy of soil CO2 flux measurements strictly depends on the soil gas permeability and the soil CO2 flux regimen. Generally chamber measurements underestimate CO2 fluxes at low soil permeability and low soil CO2 fluxes, whereas appreciable overestimations occur for high permeability soil, especially for high soil CO2 fluxes. Other tests carried out with different settings for the measurement device, such as the chamber volume and the flux of the pump used to recirculate air through the chamber and the gas analyzer (recirculation flux), revealed a strong dependence of the closed dynamic chamber measurements on the recirculation flux. Low recirculation fluxes (0.2–0.4 l min− 1) decreased the performance of the measurement system, causing underestimations of the actual soil CO2 flux, whereas higher values (0.6–1.0 l min− 1) resulted in overestimations, especially for elevated soil CO2 fluxes. An empirical equation was deduced to allow accumulation chamber fluxes to be calculated very accurately based on soil gas permeabilities measured in the field.
    Description: Published
    Description: 387-393
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: JCR Journal
    Description: reserved
    Keywords: Soil CO2 flux measuraments ; Closed dynamic chamber ; soil gas permeability ; 04. Solid Earth::04.02. Exploration geophysics::04.02.01. Geochemical exploration ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. 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)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 38
    facet.materialart.
    Unknown
    Time-dependent deformation of the eastern flank of Mt. Etna: after-slip or viscoelastic relaxation? (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Major results of post-intrusive GPS monitoring of the five months encompassing and following the onset of 2002-03 Mt. Etna eruption are presented and discussed here. The overall ground deformation pattern is characterized by a time-dependent relaxation function. We evaluated two different parameterizations of relaxation functions, each one linked to a different relaxation process: i) viscoelastic relaxation and ii) after-slip mechanism. The former indicated that the process occurred within a weak layer characterized by viscosity values ranging between 7.1 • 1014 Pa s and 1.3 • 1015 Pa s. The latter evidenced that frictional processes occurred beneath a layer of velocity-strengthening having a thickness with values ranging between 0.4 km and 1.7 km. Either model may explain the observed time-dependent deformation, both from the statistical point of view and the comparison with geologic and seismic information. Although we are unable to favour one model rather than the other, these results indicate that the mechanism, responsible for the observed post-intrusive deformation, occurs within a sliding “zone” located inside the clayey sedimentary basement.
    Description: This study was undertaken with financial support from the FLANK project (DPC-INGV 2008 - 2010 contract)
    Description: Published
    Description: 300-311
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: 2002-03 Mt. Etna eruption ; Post-intrusive relaxation ; Viscoelastic ; After-slip ; Rheology ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 39
    facet.materialart.
    Unknown
    Magma dynamics during the 2007 Stromboli eruption (Aeolian Islands. Italy): mineralogical, geochemical and isotopic data (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: After the 6 month-long effusive event of 2002-2003, a new lava effusion occurred at Stromboli between 27 February and 2 April 2007. Despite the different durations, approximately the same volume of magma was emitted in both eruptions, in the order of 107 m3 . A paroxysmal eruption occurred at the summit craters in both the 2002–2003 and 2007 episodes, during which a significant amount of low porphyritic (LP), volatile- rich magma was erupted. In both cases, the paroxysm did not interrupt the lava emission. Here, we present compositional data, including texture, mineralogy, chemistry and Sr and Nd isotope ratios of bulk-rock, groundmass and separated minerals of lavas erupted in 2007, together with chemistry and Sr and Nd isotope composition of the pumices emitted during the 15 March paroxysm. As a whole, the lavas have the same texture and chemistry that characterize the highly porphyritic (HP) products usually erupted at Stromboli during normal Strombolian activity and effusive events. Compared to the previous HP products, the 2007 lavas show minor but systematic mineralogical and isotopic variations which are consistent with a modest increase of the magma supply rate of the volcano. Compositional variations during the entire duration of the event are very modest. Glass chemistry changes in lavas erupted in the second half of March can be explained by theminormixing between the volatile-rich LPmagma rising through the shallowmagmatic systemduring the 15 March paroxysm and the degassed residing HP magma. A first conclusion of this study is that there is no compositional evidence supporting major changes in the magma dynamics of the volcano accompanying the effusive activity, as also suggested for the 2002–2003 event. The activity of Stromboli is controlled by a steady state feeding system in which refilling, mixing, degassing and crystallization at shallow level continuously operate,withmodest oscillations in themagma supply rate. Switching between normal Strombolian and effusive activity is related to periods of relatively more vigorous refilling of the shallow system, leading to progressive pressure increase in the upper conduits associated with only minor compositional variations in the erupted products.
    Description: Published
    Description: 255–268
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli volcano ; petrological monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 40
    facet.materialart.
    Unknown
    Effects of wall-rock elasticity on magma flow in dykes during explosive eruptions (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Magma flow during explosive volcanic eruptions has been described assuming rigid conduits with simple cylindrical or planar geometries. Here we study the dynamics of explosive volcanic flows to take account of the role of elastic deformation of the conduit influenced by local magmatic pressure. Three cases are investigated: a dyke with elliptical cross-section, a cylindrical conduit and a deep dyke connected to a shallow cylinder. The model CPIUC (Macedonio et al., 2005) was used for simulations and generalized to account for elastic deformations of the conduit cross-section area due to magmatic overpressure. Fragmentation level is typically deeper in a dyke than in a cylinder. For flows in wide dykes pressure at the fragmentation depth can be lower than the surrounding lithostatic pressure by several tens of MPa, indicating that the wall-rocks of the dyke will be unstable, constraining the dyke width and eventually blocking the eruption. On the other hand, when the fragmentation level is shallow the corresponding lithostatic pressure is not large enough to close the dyke and eruptions from wide dykes are possible. The behaviour changes drastically when we assume the conduit is a dyke at depth that evolves to a cylinder near the surface. In this case even very wide dykes can be stable because the fragmentation level moves into the cylindrical region where deformation is negligible.
    Description: Published
    Description: 455–462
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: conduit geometry ; explosive eruption ; elastic effect ; dyke deformation ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.06. Rheology, friction, and structure of fault zones ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 41
    facet.materialart.
    Unknown
    Geochemistry of fluids from submarine hot springs at Punta de Mita, Nayarit, Mexico (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Thermal springs with a maximum measured temperature of 89°C discharge hot water and gas from a depth of 11 m, 400 m offshore of Punta Pantoque, located in the northern part of Bahìa de Banderas, near Puerto Vallarta, Mexico. The composition of all water samples collected from the sea bottom is close to that of sea water. Nevertheless, it was possible to estimate the thermal endmember composition by extrapolating the sulfate concentration to zero. This endmember is similar in chemical composition both to waters of the Rio Purificacion and La Tuna thermal springs, located to the South along the Pacific coast of the Jalisco Block, and to pore waters from the deep-sea drilling cores from some accretionary complexes. Gas composition as well as isotopic composition of He and carbon from CO2, CH4 and C2H6 suggests an essentially thermo-biogenic origin for the gas and the presence of a high proportion of radiogenic, crustal helium. Isotopic composition of He in the Punta de Mita gas (0.4 Ra) is the lowest ever measured in Mexican hydrothermal gases. These findings do not support the idea that there exists a direct connection between the Punta de Mita springs and the last volcanic events which occurred in this area at V3 Ma. Rather, this hydrothermal activity is related to deep active faulting and the existence of a deep regional aquifer or local aquifers of connate waters underlying the granites of the Jalisco Block.
    Description: Published
    Description: 329-338
    Description: partially_open
    Keywords: submarine springs ; hydrothermal systems ; geothermometry ; He-isotopes ; formation waters ; Jalisco Block ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 539 bytes
    Format: 269561 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 42
    facet.materialart.
    Unknown
    The Gubbio normal fault (Central Italy): geometry, displacement distribution and tectonic evolution (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Normal faults within orogenic belts can be pre-, syn- or post-orogenic features. We studied the Gubbio normal fault (central Italy), which is an example of a pre-orogenic fault reactivated in a post-orogenic stage. The Gubbio Fault is a 22-km-long fault bordering a Quaternary basin and part of an active faults system in the Umbria–Marche region (Central Italy). The interpretation of a set of seismic profiles enables us to reconstruct the fault geometry in detail and to measure displacement and throw distributions along the fault strike. Seismic data indicate that the Gubbio Fault represents an example of multiple reactivation: at least a portion of the fault was active in the Miocene and only a part of the total displacement was achieved in the Quaternary. The reconstruction of the fault geometry at depth shows that the fault is characterised by listric geometry. The fault is also characterised by a bend along strike and structure contours show that this geometry is maintained at depth. As the fault is commonly addressed as presently active, the maximum fault dimensions are correlated to the maximum expected earthquake, and the presence of the fault bend is discussed as a possible barrier to seismic ruptures propagation.
    Description: Published
    Description: (2233–2249)
    Description: reserved
    Keywords: Listric normal faults ; Fault reactivation ; Seismic profiles ; Displacement distribution ; Earthquakes ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 2540699 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 43
    facet.materialart.
    Unknown
    Integrated stratigraphic reconstruction for the last 80 kyr in a deep sector of the Sardinia Channel (Western Mediterranean) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: A quantitative analysis of planktonic foraminifera, coupled with petrophysical and paleomagnetic measurements and 14C AMS calibrations, was carried out on a deep core recovered in the Sardinia Channel (Western Mediterranean Sea), during the CIESM Sub2 survey, providing an integrated stratigraphic time-framework over the last 80 kyr. Significant changes in the quantitative distribution of planktonic foraminifera allowed the identification of several eco-bioevents useful to accurately mark the boundaries of the eco-biozones widely recognised in the Western Mediterranean records and used for large scale correlations. Namely, 10 eco-biozones were identified based on the relative abundance of selected climate sensitive planktonic foraminiferal species. Sixteen codified eco-bioevents were correlated with the Alboran Sea planktonic foraminiferal data and four climatic global events (Sapropel S1, Younger Dryas, Greenland Isotope Interstadial 1, Greenland Isotope Stadial 2, Heinrich event H1-H6) were recognized. The eco-bioevents together with the 14C AMS calibrations concurred to define an accurate age model, spanning between 2 and 83 kyr cal. BP. The reliability of the age model was confirmed by comparing the colour reflectance (550 nm%) data of the studied record with the astronomically tuned one of the Ionian sea (ODP-Site 964). A mean sedimentation rate of about 7 cm/kyr was evaluated including three turbidite event beds that were chronologically constrained within the relative low stand and lowering sea level phases of the MIS 4 and MIS 3. The deep sea sedimentary record includes a distinct tephra occurring at the base of the core which dates 79 ka. The paleomagnetic data provide a well-defined record of the characteristic remanent magnetization that may be used to reconstruct the geomagnetic paleosecular variation for the Mediterranean back to 83 kyr cal. BP.
    Description: In press
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: open
    Keywords: integrated stratigraphy, late Neogene marine record, eco-bio-events, reflectance 550 nm %, Sardinia ; 04. Solid Earth::04.04. Geology::04.04.04. Marine geology ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 44
    facet.materialart.
    Unknown
    Statistical analysis of the Central-Europe Seismicity (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The aim of this paper is to characterize the spatio-temporal distribution of Central-Europe seismicity. Specifically, by using a non-parametric statistical approach, the proportional hazard model, leading to an empirical estimation of the hazard function, we provide some constrains on the time behavior of earthquake generation mechanisms. The results indicate that the most conspic- uous characteristics of MW 4.0+ earthquakes is a temporal clustering lasting a couple of years. This suggests that the probability of occurrence increases immediately after a previous event. After a few years, the process becomes almost time independent. Furthermore, we investigate the cluster properties of the seismicity of Central-Europe, by comparing the obtained result with the one of synthetic catalogs generated by the epidemic type aftershock sequences (ETAS) model, which previously have been successfully applied for short term clustering. Our results indicate that the ETAS is not well suited to describe the seismicity as a whole, while it is able to capture the features of the short- term behaviour. Remarkably, similar results have been previously found for Italy using a higher magnitude threshold.
    Description: In press
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: open
    Keywords: Earthquake Distribution ; Earthquake Forecast ; Spatio-temporal statistical analysis ; Cluester ; Central Europe ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 45
    facet.materialart.
    Unknown
    Methane fluxes from the soils in active volcanic areas: the case of Pantelleria Island (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Methane, the most abundant hydrocarbon in the atmosphere, plays an important role in the Earth’s atmospheric chemistry and radiative balance being the second most important greenhouse gas after CO2. Methane is released to the atmosphere by a wide number of sources, both natural and anthropogenic, with the latter being twice as large as the former (Kvenvolden and Rogers, 2005). It has recently been established that significant amounts of geological methane, produced within the Earth’s crust, are currently released naturally into the atmosphere (Etiope, 2004). Among natural sources the volcanic/geothermal emissions are probably the least constrained. Recent estimations for volcanic and geothermal systems in Europe (Etiope et al. 2007) gave a rather large provisional range (4-16 kt/a) that claims for much more field measurements in order to widen the current database and decrease the present uncertainties. Pantelleria is an active volcanic complex, at present in quiescent status, hosting a high enthalpy geothermal system. Explorative geothermal wells tapped an exploitable water-dominated reservoir at 600-800 m depth with maximum measured temperatures of 250 °C. While some data are available on diffuse CO2 fluxes, data on CH4 are available only for fumarolic fluids. In the present study we measured CH4 fluxes in the area of Favara Grande characterized by intense diffuse degassing and widespread signs of geothermal activity (fumaroles, steaming grounds and large zones devoid of vegetation). Values range from negative (-43 to 0 mgCH4 m2 day), typical of soils with methanotrophic activity, up to 3500 mgCH4 m2 day in the most thermalized area. The preliminary estimate of the methane release from the area of Favara Grande is about 2.5 t/a. Extrapolation to the whole volcanic/geothermal system of Pantelleria gives about 10 t/a.
    Description: Published
    Description: Davos, Switzerland
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: open
    Keywords: soil gases ; methane output ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 46
    facet.materialart.
    Unknown
    Miocene–Quaternary structural evolution of the Uyuni–Atacama region, Andes of Chile and Bolivia (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We describe the Miocene–Quaternary geological–structural evolution of the region between the Salar de Uyuni and de Atacama, Andes of Chile and Bolivia. We recognized four main tectonic events based on fold geometry, fault kinematics and stratigraphic data. The oldest event, of Miocene age, is characterized by folding and reverse faulting of the sedimentary successions with an E–W direction of shortening in the northern part of the studied area and a WNW–ESE shortening in the southern part. The following two events, of Pliocene age, are characterized by lower shortening amounts; they occurred first by reverse faulting with a NW–SE-trending greatest principal stress (ó1, computed with striated fault planes) and a vertical least principal stress (ó3), followed by pervasive strike-slip faulting with the same NW–SE-trending ó1 and a horizontal NE–SW ó3. The fourth event, dating to the late Pliocene–Quaternary is characterized by normal faulting: the ó3 still trends NE–SW, whereas the intermediate principal stress ó2 exchanged with ó1. Volcanism accompanied both the contractional, transcurrent and extensional tectonic phases. The Mio–Pliocene compression appears directly linked to a rapid convergence and an apparently important coupling between the continental and oceanic plates. The E–W to WNW–ESE direction of shortening of the Miocene structures and the NW–SE ó1 of the Pliocene structures seem to be more linked to an intra-Andean reorientation of structures following the WNW-directed absolute motion of the South-American Plate. The extensional deformations can be interpreted as related to gravity forces affecting the highest parts of the volcanic belt in a sort of asymmetrical (SW-ward) collapse of the belt.
    Description: Published
    Description: 114-135
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: Chile ; Bolivia ; Andes ; Fault ; Fold ; Tectonic phases ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 47
    facet.materialart.
    Unknown
    The evolution of a dynamic geological system: the support of a GIS for geochemicd measurements at the fumarole field of Vulcano, Italy (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The island of Vulcano (Aeolian arc, Southern Italy) has displayed several periods of volcanic unrest since the end of the last eruption (1890). We report here results obtained from a long-term survey concerning variations of both the steam output and the exhaling surface area at the sun~mit crater fumarolic field of La Fossa. The field measurements analysed in a Geographiciil Information System (GIS: show a highly dynamic volcanic system in which deep variations in the geochemishy and the temperature of the released fluids were accompanied by fluctuations in the mass output of steam and the topography of the crater field. The use of a GIS facilitated digitized reconstructions of maps of the crater field in addition to analysis (of the steam flux data. The furnarolic field expanded its surface area from 50 m2 in 1983 to more than 2400 m* in 1995, accompanied by an increase in steam output from 152 to about 1400 tonnes per day. The possibility that the observed phenomena are related to volcano-tectonic activity and to magma uprising is taken into consideration.
    Description: Published
    Description: 253-263
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: volcanic surveillance ; Steam output ; tectonic lines ; flux ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 48
    facet.materialart.
    Unknown
    Geochemical evaluation of observed changes in volcanic activity during the 2007 eruption at Stromboli (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: On February 27, 2007 a new eruption started at Stromboli that lasted until April 2 and included a paroxysmal explosion on March 15. Geochemical monitoring carried out over several years revealed some appreciable variations that preceded both the eruption onset and the explosion. The carbon dioxide (CO2) flux from the soil at Pizzo Sopra La Fossa markedly increased a few days before the eruption onset, and continued during lava effusion to reach its maximum value (at 90,000 g m−2 d−1) a few days before the paroxysm. Almost contemporarily, the δ13CCO2 of the SC5 fumarole located in the summit area increased markedly, peaking just before the explosion (δ13CCO2~−1.8‰). Following the paroxysm, helium (He) isotopes measured in the gases dissolved in the basal thermal aquifer sharply increased. Almost contemporarily, the automatic station of CO2 flux recorded an anomalous degassing rate. Also temperatures and the vertical thermal gradient, which had been measured since November 2006 in the soil at Pizzo Sopra La Fossa, showed appreciable variabilities that lasted until the end of the eruption. The geochemical variations indicated the degassing of a new batch of volatile-rich magma that preceded and probably fed the paroxysm. The anomalous 3He/4He ratio suggested that the ascent of a second batch of volatile-rich magma toward the surface was probably responsible of the resumption of the ordinary activity. A comparison with the geochemical variations observed during the 2002–2003 eruption indicated that the 2007 eruption was less energetic.
    Description: Published
    Description: 246-254
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: geochemistry ; eruption ; dissolved gases ; Stromboli ; volcanic activity ; 03. Hydrosphere::03.02. Hydrology::03.02.03. Groundwater processes ; 03. Hydrosphere::03.04. Chemical and biological::03.04.03. Chemistry of waters ; 03. Hydrosphere::03.04. Chemical and biological::03.04.05. Gases ; 03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems ; 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 ; 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)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 49
    facet.materialart.
    Unknown
    Dike propagation in volcanic edifices: Overview and possible developments (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Eruptions are fed by dikes; therefore, better knowledge of dike propagation is necessary to improve our understanding of how magma is transferred and extruded at volcanoes. This study presents an overview of dike patterns and the factors controlling dike propagation within volcanic edifices. Largely based on published data, three main types of dikes (regional, circumferential and radial) are illustrated and discussed. Dike pattern data from 25 volcanic edifices in different settings are compared to derive semi-quantitative relationships between the topography (relief, shape, height, and presence of sector collapses) of the volcano, tectonic setting (presence of a regional stress field), and mean composition (SiO2 content). The overview demonstrates how dike propagation in a volcano is not a random process; rather, it depends from the following factors (listed in order of importance): the presence of relief, the shape of the edifice and regional tectonic control. We find that taller volcanoes develop longer radial dikes, whose (mainly lateral) propagation is independent of the composition of magma or the aspect ratio of the edifice. Future research, starting from these preliminary evaluations, should be devoted to identifying dike propagation paths and likely locations of vent formation at specific volcanoes, to better aid hazards assessment.
    Description: Partly fundedwith DPC-INGVfunds (LAVAProject).
    Description: Published
    Description: 67–77
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 3.2. Tettonica attiva
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: dikes ; volcanoes ; topography ; tectonic setting ; eruptions ; 03. Hydrosphere::03.04. Chemical and biological::03.04.02. Carbon cycling ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. Tectonophysics::04.07.05. 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::05.02.99. General or miscellaneous ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions ; 05. General::05.08. Risk::05.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 50
    facet.materialart.
    Unknown
    Intrusion of eccentric dikes: The case of the 2001 eruption and its role in the dynamics of Mt. Etna volcano (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The 2001 eruption represents one of the most studied events both from volcanological and geophysical point of view on Mt. Etna. This eruption was a crucial event in the recent dynamics of the volcano, marking the passage from a period (March 1993–June 2001) of moderate stability with slow, continuous flank sliding and contemporaneous summit eruptions, to a period (July 2001 to present) of dramatically increased flank deformations and flank eruptions. We show new GPS data and high precision relocation of seismicity in order to demonstrate the role of the 2001 intrusive phase in this change of the dynamic regime of the volcano. GPS data consist of two kinematic surveys carried out on 12 July, a few hours before the beginning of the seismic swarm, and on 17 July, just after the onset of eruptive activity. A picture of the spatial distribution of the sin-eruptive seismicity has been obtained using the HypoDD relocation algorithm based on the double-difference (DD) technique. Modeling of GPS measurements reveals a southward motion of the upper southern part of the volcano, driven by a NNW–SSE structure showing mainly left-lateral kinematics. Precise hypocenter location evidences an aseismic zone at about sea level, where the magma upraise was characterized by a much higher velocity and an abrupt westward shift, revealing the existence of a weakened or ductile zone. These results reveal how an intrusion of a dike can severely modify the shallow stress field, triggering significant flank failure. In 2001, the intrusion was driven by a weakened surface, which might correspond to a decollement plane of the portion of the volcano affected by flank instability, inducing an additional stress testified by GPS measurements and seismic data, which led to an acceleration of the sliding flanks.
    Description: This work was funded by the Istituto Nazionale di Geofisica e Vulcanologia and by the Dipartimento per la Protezione Civile (Italy).
    Description: Published
    Description: 78–86
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: 1.4. TTC - Sorveglianza sismologica delle aree vulcaniche attive
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: 3.2. Tettonica attiva
    Description: 3.6. Fisica del vulcanismo
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: reserved
    Keywords: stress release ; dike ; volcano-tectonics ; flank instability ; Mt. Etna ; instrumental monitoring ; 04. Solid Earth::04.01. Earth Interior::04.01.99. General or miscellaneous ; 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes ; 04. Solid Earth::04.02. Exploration geophysics::04.02.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.99. General or miscellaneous ; 04. Solid Earth::04.03. Geodesy::04.03.07. Satellite geodesy ; 04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous ; 04. Solid Earth::04.04. Geology::04.04.09. Structural geology ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology ; 04. Solid Earth::04.07. Tectonophysics::04.07.99. General or miscellaneous ; 04. Solid Earth::04.07. 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::05.02.99. General or miscellaneous ; 05. General::05.02. Data dissemination::05.02.02. Seismological data ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 51
    facet.materialart.
    Unknown
    Attenuation of body waves in Southeastern Sicily (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The attenuation of P- and S-waves in Southeastern Sicily was estimated by applying two different methods in time and frequency domains. We analyzed waveforms from about 290 local events (0.6 ≤ ML ≤ 4.6) recorded at a three-component digital network. By applying the pulse broadeningmethod to the first P-wave pulse,we found an averageQp value of ca. 140. The application of the frequency decay method provided a Qp value of ca. 120, in the low-frequency band (3–9Hz). Conversely, in the high frequency range (16–27Hz) the average Qp is significantly larger (ca. 640). The frequency decay method was also applied to S-waves spectra. In the low frequency range (2–5Hz) the estimated average Qs is ca. 190. As for Qp, also Qs, in the high frequency range (16–27Hz), is larger (ca. 700). These results evidenced a frequency dependence of both the quality factors Qp and Qs, as commonly observed in tectonically active zones characterized by high degree of heterogeneity
    Description: Published
    Description: 267-279
    Description: JCR Journal
    Description: reserved
    Keywords: attenuation ; body waves ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 52
    facet.materialart.
    Unknown
    New geological insights and structural control on fluid circulation in La Fossa cone (Vulcano, Aeolian Islands, Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Electric resistivity tomography (ERT), self-potential (SP), soil CO2 flux, and temperature are used to study the inner structure of La Fossa cone (Vulcano, Aeolian Islands). Nine profiles were performed across the cone with a measurement spacing of 20 m. The crater rims of La Fossa cone are underlined by sharp horizontal resistivity contrasts. SP, CO2 flux, and temperature anomalies underline these boundaries which we interpret as structural limits associated to preferential circulation of fluids. The Pietre Cotte crater and Gran Cratere crater enclose the main hydrothermal system, identified at the centre of the edifice on the base of low electrical resistivity values (b20 Ω m) and strong CO2 degassing, SP, and temperature anomalies. In the periphery, the hydrothermal activity is also visible along structural boundaries such as the Punte Nere, Forgia Vecchia, and Palizzi crater rims and at the base of the cone, on the southern side of the edifice, along a fault attributed to the NW main tectonic trend of the island. Inside the Punte Nere crater, the ERT sections show an electrical resistive body that we interpret as an intrusion or a dome. This magmatic body is reconstructed in 3D using the available ERT profiles. Its shape and position, with respect to the Pietre Cotte crater fault, allows replacing this structure in the chronology of the development of the volcano. It corresponds to a late phase of activity of the Punte Nere edifice. Considering the position of the SP, soil CO2 flux, and temperature maxima and the repartition of conductive zones related to hydrothermal circulation with respect to the main structural features, La Fossa cone could be considered as a relevant example of the strong influence of preexisting structures on hydrothermal fluid circulation at the scale of a volcanic edifice.
    Description: Published
    Description: 231-245
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: partially_open
    Keywords: electrical resistivity ; self-potential ; soil CO2 degassing ; temperature ; fluid circulation ; hydrothermal system ; structural boundary ; Vulcano ; La Fossa cone ; 03. Hydrosphere::03.02. Hydrology::03.02.04. Measurements and monitoring ; 03. Hydrosphere::03.03. Physical::03.03.02. General circulation ; 04. Solid Earth::04.01. Earth Interior::04.01.01. Composition and state ; 04. Solid Earth::04.02. Exploration geophysics::04.02.07. Instruments and techniques ; 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)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 53
    facet.materialart.
    Unknown
    Seismicity, seismotectonics and crustal velocity structure of the Messina Strait (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Messina Strait is the most important structural element interrupting the southernmost part of the Alpine-Apenninic orogenic belt, known as the Calabro-Peloritan Arc. It is being a narrow fan-shaped basin linking the Ionian Sea to the Tyrrhenian Sea. This region is affected by considerable seismic activity which mirrors the geodynamic processes due to the convergence between the African and the Eurasian plates. In the last four centuries, a significant number of disastrous earthquakes originated along the Arc. Among these, the most noteworthy event occurred on December 28, 1908 (known as the Reggio Calabria-Messina earthquake), in the Messina Strait area and caused a large tsunami and more than 100,000 casualties. In this research we focus on the relationships between the general tectonic setting, which characterize the Messina Strait and adjacent areas, seismicity patterns and the crustal structure. We analyzed a data set consisting of more than 300 events occurring in the years from 1999 to 2007, having a magnitude range from 1.0 to 3.8. This data set was exploited in a local earthquake tomography, by carrying out a simultaneous inversion of both the three-dimensional velocity structure and the distribution of seismic foci. We applied the “tomoADD” algorithm, which uses a combination of absolute and differential arrival times and a concept of self-adapting grid geometry, accounting for ray density encountered across the volume. With this method the accuracy of event locations is improved and velocity structure near the source region is resolved in more detail than standard tomography. Fault plane solutions were obtained for the major and best-recorded earthquakes. The obtained velocity images highlight vertical and lateral heterogeneities that can be associated with structural features striking from NNE-SSW to NE-SW. These results are consistent with important tectonic elements visible at the surface and the pattern delineated by earthquake locations and focal mechanisms.
    Description: Published
    Description: 65-78
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: open
    Keywords: Crustal structure ; Focal mechanism ; Seismicity ; Seismotectonics ; Tomography ; 04. Solid Earth::04.06. Seismology::04.06.03. Earthquake source and dynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 54
    facet.materialart.
    Unknown
    Sweet chestnut (Castanea sativa) leaves as a bio-indicator of volcanic gas, aerosol, and ash deposition onto the flanks of Mt. Etna in 2005-2007 (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Sweet chestnut leaves (Castanea sativa) collected from the flanks of Mt Etna volcano in 2005–2007 were analysed by inductively-coupled plasma mass spectrometry to investigate the spatial and temporal variability of element concentrations. The aim of this work was to determine whether these leaves are a bio-indicator for volcanic gas, aerosol and ash deposition and to gain new insights into the environmental effects of quiescent and eruptive volcanic plumes. Results show a positive correlation between sample variability in the concentration of elements in Castanea sativa and enrichment factors of elements in the plume. The spatial and temporal variability of chalcophilic elements (As, Cd, Cu, Mo, Tl, Zn) is consistent with prevailing winds transporting eruptive plumes to the south-east of the summit, resulting in enhanced plume deposition onto the flanks of the volcano. Similar spatial and temporal variability was found for the halideforming elements (Cs, K, Rb) and intermediate elements (Al, Co, Mn). The spatial variability of chalcophilic, intermediate and halide-forming elements during quiescent periods was diminished (relative to eruptive periods) and could not be explained by plume deposition. In contrast, the concentrations of lithophilic elements (Ba, Ca, Mg, Sr) did not show any clear spatial variability even during eruptive periods. Comparisons between enrichment factors for elements in Castanea sativa and literature values for enrichment factors of the volcanic plume, groundwater and lichen were made. Whilst Castanea sativa offers insights into the spatial and temporal variability of deposition, the species may not be a bio-indicator for plume composition due to biological fractionation.
    Description: Published
    Description: 107-119
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Mt Etna ; vegetation ; Castanea sativa ; bio-indicator ; emission ; dispersion ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 55
    facet.materialart.
    Unknown
    Reply to comments on “Separation of Qi and Qs from passive data at Mt. Vesuvius: A reappraisal of the seismic attenuation estimates” by Ugalde, A. and Carcolé, E. (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The paper by Del Pezzo et al. (2006), hereafter named DPBZ, deals with the estimate of the seismic attenuation in the high frequency range for the volcanic area of Mt. Vesuvius. In particular DPBZ use a method based on the fit of the observed local earthquake coda envelopes to the radiative transfer classical equation (see Sato and Fehler, 1998 for a wide and exhaustive review on this argument) in terms of the intrinsic attenuation and the scattering attenuation coefficients. Ugalde and Carcolé in their comment (hereafter named UC) discuss two points of DPBZ that we summarize here in their essence: (a) Two approximations of the exact solution of the 3-D radiative transfer model have been calculated, that discussed by Zeng (1991) – hereafter Z91 – expressed by Formula (5) of UC, and that by Paasschens (1997) – hereafter P97 – expressed by Formula (6) of UC. UC show that P97 is more accurate than Z91, which is instead used in DPBZ. (b) DPBZ obtain the separated estimates of intrinsic- and scattering-attenuation coefficients, respectively !i and !s, first stacking the normalized energy envelopes (starting at 2Ts lapse time) and then fitting the experimental data with the normalized (in the same way) theoretical curve. UC disagree with this procedure. Their opinion is that DPBZ should have inverted the single energy envelopes and then have averaged the results obtained. In the following we reply to points (a) and (b) in two separate sections.
    Description: Published
    Description: 195–196
    Description: 3.1. Fisica dei terremoti
    Description: JCR Journal
    Description: reserved
    Keywords: Seismic scattering ; Elastic attenuation ; 04. Solid Earth::04.06. Seismology::04.06.99. General or miscellaneous ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 56
    facet.materialart.
    Unknown
    Radioactivity in waters of Mt. Etna (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Radioactivity in underground waters from Mt. Etna was investigated on the basis of 13 samples. The samples were collected from springs, wells and galleries around the volcano. Water from nine out of thirteen intakes is used for consumption. Activity concentration of uranium isotopes 234,238U, radium isotopes 226,228Ra and radon 222Rn were determined with the use different nuclear spectrometry techniques. The measurements of radium and radon activity concentration were performed with the use of a liquid scintillation counter. The determination of uranium isotopes was carried out with the use of alpha spectrometry. All samples show uranium concentration above Minimum Detectable Activity (MDA), with the highest total uranium (234U þ 238U) activity concentration equal to 130 mBq/l. For radium isotopes, all samples except one showed the activity concentration below MDA. Radon activity concentration was within the range from 1 to 13 Bq/l, hence these waters can be classified as low-radon waters.
    Description: Published
    Description: 384-389
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: JCR Journal
    Description: reserved
    Keywords: Ra-226 ; Ra-228 ; U-238 ; U-234 ; Rn-222 ; Drinking water ; Activity concentration ; Effective dose ; 03. Hydrosphere::03.04. Chemical and biological::03.04.07. Radioactivity and isotopes
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 57
    facet.materialart.
    Unknown
    Late Matuyama climate forcing on sedimentation at the margin of the southern Alps (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Pleistocene history of climate control on sedimentation in the Southern Alps-Po Plain system, northern Italy, was reconstructed using an integrated magnetostratigraphic, palynological, and petrographical approach on a 47-m-deep core. The core mainly consists of lacustrine sediments pertaining to the Bagaggera sequence, deposited at the foothills of the Southern Alps during the late Matuyama subchron (0.99–0.78 Ma). At that time, climate worsened globally and locally it caused the progradation of an alluvial fan unit onto the nearby Po Plain, triggering lake formation by damming of a tributary valley. These new data are used in conjunction with data from the literature to highlight and track the effects of climate forcing on sedimentation during the late Matuyama subchron in different orographic and geodynamic settings of the Southern Alps-Po Plain system as part of the greater Alpine area. We found that the episodes of alluvial fan and braidplain progradation observed in the southern foreland of the Alps during the late Matuyama global cooling seem broadly synchronous with the deposition of most of the so-called Günz and Älterer Deckenschotter deposits in the northern forelands of the Alps as well as with the first major waxing of the Alpine valley glaciers, possibly around the Marine Isotope Stage 22 (~0.87 Ma).
    Description: In press
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: Pleistocene ; magnetostratigraphy ; pollen analysis ; sand petrography ; Alps ; Po Plain ; lacustrine sequence ; alluvial fan ; 02. Cryosphere::02.03. Ice cores::02.03.05. Paleoclimate ; 04. Solid Earth::04.04. Geology::04.04.02. Geochronology ; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 58
    facet.materialart.
    Unknown
    Long-term forecast of eruption style and size at Campi Flegrei caldera (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Campi Flegrei caldera is an active and restless volcano in the densely inhabited Neapolitan area of southern Italy. Because of the very high value (lives, properties, infrastructures, etc.) exposed to potential volcanic hazards, it is one of the areas at highest volcanic risk on Earth. In such a situation we have made an attempt to contribute to assessment of its volcanic hazards by providing a quantitative probabilistic longterm forecast of style and size of the next eruption. We have evaluated the most relevant physical parameters of the 22 explosive eruptions of the Campi Flegrei caldera over the past 5 ka. This time span has been taken as the reference period for volcanic hazards assessment on the basis of the volcanic and deformation history of the caldera. The evaluated parameters include dispersal, volume and density of the pyroclastic deposits, volume of erupted magma, total erupted mass, and eruption magnitude. The obtained results permit a size classification of the explosive eruptions, which are grouped into three sizes: small, medium, and large. On the basis of the reconstructed eruption dynamics, we have considered a type event(s) representative of each size class and hypothesized the style of the next event. An effusive eruption will likely generate a dome or very small lava flows, while an explosive event of any size very probably will produce particles fallout and flowage of pyroclastic density currents. Using a Bayesian inference procedure, we have assigned a conditional probability of occurrence to each of the eruption size classes. A small-size explosive eruption is the most likely event with a probability of about 60%; a large-size explosive eruption is the least likely event with a probability of about 4%; a medium-size explosive eruption has a probability of occurrence of about 25%; an effusive eruption has about 11% probability of occurrence.
    Description: Published
    Description: 265–276
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: 4.3. TTC - Scenari di pericolosità vulcanica
    Description: JCR Journal
    Description: reserved
    Keywords: volcanic hazards assessment ; eruption size ; eruption style ; Campi Flegrei caldera ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 59
    facet.materialart.
    Unknown
    Modelling ground deformation caused by oscillating overpressure in a dyke conduit at Soufrière Hills Volcano, Montserrat (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: A dyke conduit has been shown to be a realistic model for the shallow magmatic feeder system for the dome forming eruption at Soufrière Hills Volcano, Montserrat. Here we use a three-dimensional Finite Element model to examine the ground deformation that can be expected due to the pressurization of a dyke conduit. We find that the generated deformation has a bilateral symmetry with nearly no displacement in the direction of dyke strike, and a maximal ground deformation about 1 km away from the vent in the perpendicular direction. Resultant surface deformation is mainly triggered by the upper part of the feeder system, where the dyke opens into a cylindrical conduit. We apply our deformation model to investigate tilt data collected in 1997 in order to infer the orientation of the dyke. We obtain a best-fit for a NNW–SSE trending dyke, which matches observations of the ground displacement field obtained by differential GPS and the alignment of main structural geologic features of southern Montserrat.
    Description: Published
    Description: 87–95
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: Soufrière Hills Volcano ; Dyke conduit ; Finite Element Model ; Ground deformation ; 04. Solid Earth::04.07. Tectonophysics::04.07.08. Volcanic arcs ; 04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk ; 05. General::05.01. Computational geophysics::05.01.03. Inverse methods
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 60
    facet.materialart.
    Unknown
    Modeling hydrothermal fluid circulation and gravity signals at the Phlegraean Fields caldera (2006)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Phlegraean Fields caldera is an active volcanic system where episodes of ground deformation are accompanied by significant changes in geochemical and geophysical parameters monitored at the surface. These changes derive from a complex interaction between magmatic system and hydrothermal fluid circulation. We calculate the gravity changes associated with the variable density of hydrothermal fluids. We simulate the multi-phase and multi-component fluid circulation triggered by a pulsating magma degassing, periodically increasing the discharge of CO2-enriched fluids into the shallow hydrothermal system. The simulated evolution of the hydrothermal system successfully reproduces the observed composition of gas discharged at the surface. At the same time, results indicate that changes in average fluid density generate a detectable gravity signal that is of the same order of magnitude of the observed changes. This contribution to gravity changes can explain the peculiar behavior of gravity data collected at Solfatara, where surface hydrothermal phenomena are present. Simultaneous fitting of two independent sets of monitoring data (gas composition and gravity changes) confirms the conceptual model proposed for the hydrothermal system at Solfatara, and it provides new insights for the interpretation of gravity data.
    Description: Published
    Description: 328–338
    Description: partially_open
    Keywords: Phlegraean Fields ; Models ; Gas composition ; Gravity ; Hydrothermal circulation ; Monitoring ; 04. Solid Earth::04.03. Geodesy::04.03.05. Gravity variations ; 04. Solid Earth::04.03. Geodesy::04.03.06. Measurements and monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 477 bytes
    Format: 673441 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 61
    facet.materialart.
    Unknown
    Reply to the comment by R.M. Prol-Ledesma on ‘‘Geochemistry of fluids from submarine thermal springs at Punta de Mita, Nayarit, Mexico’’ (2006)
    Elsevier
    In:  Taran Y. A., Inguaggiato S., Marin M., and Yurova L. M. (2002) Geochemistry of fluids from submarine hot springs at Punta de Mita, Nayarit, Mexico. J. Volcanol. Geoth. Res. 115, 329-338.
    Details
    Publication Date: 2017-04-04
    Description: We thank R.M. Prol-Ledesma for her comment on the paper by Taran et al. (2002a) and the new data presented on the water composition of the Punta de Mita (PM) submarine springs. Prol-Ledesma (2003) comments refer to a supposedly wrong citation, superficial description of the geological background, incorrect method of water sampling, wrong approach for the estimation of the end-member composition, irrelevant discussion on the origin of fluids and, lastly, the using of someone else’s ideas and conclusions. In addition, she claims that our data on the fluid chemistry of the springs are not the first (original)ones. The Comment is supported by numerous references to publications by Prol-Ledesma et al. The text below follows the rubrics in the Comment.
    Description: Published
    Description: 319-322
    Description: partially_open
    Keywords: submarine springs ; hydrothermal systems ; geothermometry ; He-isotopes ; formation waters ; Jalisco Block ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 539 bytes
    Format: 164856 bytes
    Format: text/html
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 62
    facet.materialart.
    Unknown
    Remote detection of fumarolic gas chemistry at Vulcano, Italy, using an FT-IR spectral radiometer (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: An infrared absorption spectroscopy remote sensing technique was used to determine the S02/HCl ratio in fumarolic plumes at Vulcano, Italy. The measurements were made from the southern crater rim of Fossa Grande Crater, about 400 m from the fumarolic area in the crater. Infrared absorption spectra of HCl and SO, were observed for four fumaroles a few tens of metres apart using the hot fumarolic surface as an infrared light source. The measured S02/HCl ratios in the FA, F47, FW and lower parti of the F21 fumaroles were 4.5-5.4, 3.5, 9.5-11.2 and 5.8 respectively. The S02/HCl ratio of the FA fumarole was higher than that of the gas collected directly in the fumarolic vent (S02/HCl ratio = 2.9), and was closer to the S~,,,,,,/HCl ratio (= 4.6) of the collected gas. Our results show that the SO,/HCl ratios of two fumaroles only a few tens of metres apart exhibits differences of about twofold. This suggests that this remote monitoring technique is capable of detecting spatial distribution in the S02/HCl ratios of volcanic plumes. Because temporal variations in S/Cl ratios can provide precursory signals for volcanic eruptions [l-31, this remote sensing technique can used efficiently for evaluation of volcanic activity.
    Description: Published
    Description: 219-224
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: open
    Keywords: Gas chemistry ; FTIR ; Volcano ; fumaroles ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 63
    facet.materialart.
    Unknown
    Sourcing hydrocarbons in CO2-rich in hydrothermal systems (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Methane (CH4) emanating from a continental volcanichydrothermal system in Nisyros, Greece, is processed through the abiogenic reduction of mantle- and marine limestonederived CO2 [1]. Evidence for the occurrence of abiogenic hydrothermal reduction of CO2 is from the chemical and carbon isotopic equilibrium patterns. We have further characterized this abiogenic methane (C1) source for the concentrations of ethane (C2) and propane (C3), as well as for the hydrogen isotopic composition of CH4, H2O, H2 and H2S. C1/C2+ ratios are significantly higher than those typically observed for purely thermogenic sources. Hydrocarbon distribution ratios for other continental-hydrothermal sources rich in CO2 are comparable to those of the Nisyros fumaroles implying that abiogenic methane might be significantly more widespread than previously assumed [2]. Relative concentrations of hydrocarbons in continental-hydrothermal discharges are even indistinguishable from those measured in ultramafic hydrothermal emissions. The fact that redox conditions do not seem to exert any control on the relative concentrations of hydrocarbons in hydrothermal emissions in general, implies that the same two sources account for hydrocarbon production in continental and ultramafic environments. One source generates methane exclusively through the selective abiogenic reduction of CO2 (Sabatierreaction). The other source produces minor amounts of methane, ethane and propane by a random process and represents either the thermal cracking of organic matter or the polymerization starting from methane. Hydrogen isotope partitioning between H2O, H2S, H2 and CH4 in Nisyros fumaroles reveals that isotopic exchange rates are highest for H2O-H2S followed by H2O-H2. In contrast to H2 and H2S, the hydrogen isotopic composition of methane exhibits almost no local variations. This is in agreement with its predominantly abiogenic hydrothermal origin and with the low temperature sensitivity of the hydrogen isotope fractionation factor between water vapor and methane.
    Description: Published
    Description: Davos, Switzerland
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: open
    Keywords: hydrothermal gases ; methane ; ethane ; propane ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Oral presentation
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 64
    facet.materialart.
    Unknown
    From mantle to crust: Stretching the Mediterranean (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The origin of forces driving the deformation of the continental crust near subduction zones and especially in backarc regions is debated. Thiswork is based on a compilation of SKS fast splitting directions that give an image of flowlines in themantle around theMediterranean subduction zones and a comparisonwith stretching and shear directions in metamorphic core complexes that show the pattern of deformation at the scale of the middle and lower crusts.We find that : (1) the two sets of directions are parallel in the three main backarc regions, namely the Alboran Sea, the Tyrrhenian Sea and the Aegean Sea showing that the lithosphere deformswith the samedirection of stretching in the crust and themantle, suggesting that (2) crustal deformation ismainly driven frombelowby slab retreat, and (3) the lithospheric fabric is reset within a few millions of years in backarc environments.
    Description: Published
    Description: 198–209
    Description: 3.3. Geodinamica e struttura dell'interno della Terra
    Description: JCR Journal
    Description: reserved
    Keywords: subduction ; seismic anisotropy ; backarc extension ; slab retreat ; stretching lineation ; metamorphic core complexes ; Mediterranean ; Aegean ; Tyrrhenian ; Alboran ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 65
    facet.materialart.
    Unknown
    Pressure dependence of viscosity of rhyolitic melts (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Viscosity of silicate melts is a critical property for understanding volcanic and igneous processes in the Earth. We investigate the pressure effect on the viscosity of rhyolitic melts using two methods: indirect viscosity inference from hydrous species reaction in melts using a piston cylinder at pressures up to 2.8 GPa and direct viscosity measurement by parallel-plate creep viscometer in an internally-heated pressure vessel at pressures up to 0.4 GPa. Comparison of viscosities of a rhyolitic melt with 0.8 wt% water at 0.4 GPa shows that both methods give consistent results. In the indirect method, viscosities of hydrous rhyolitic melts were inferred based on the kinetics of hydrous species reaction in the melt upon cooling (i.e., the equivalence of rheologically defined glass transition temperature and chemically defined apparent equilibrium temperature). The cooling experiments were carried out in a piston-cylinder apparatus using hydrous rhyolitic samples with 0.8–4 wt% water. Cooling rates of the kinetic experiments varied from 0.1 K/s to 100 K/s; hence the range of viscosity inferred from this method covers 3 orders of magnitude. The data from this method show that viscosity increases with increasing pressure from 1 GPa to 3 GPa for hydrous rhyolitic melts with water content 0.8 wt% in the high viscosity range. We also measured viscosity of rhyolitic melt with 0.13 wt% water using the parallel-plate viscometer at pressures 0.2 and 0.4 GPa in an internally-heated pressure vessel. The data show that viscosity of rhyolitic melt with 0.13 wt% water decreases with increasing pressure. Combining our new data with literature data, we develop a viscosity model of rhyolitic melts as a function of temperature, pressure and water content.
    Description: NSF Grants EAR-0537598 and EAR-0711050
    Description: Published
    Description: 3680-3693
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: reserved
    Keywords: viscosity ; rhyolite ; water species ; pressure ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 66
    facet.materialart.
    Unknown
    Filling the North European Early/Middle Eocene (Ypresian/Lutetian) boundary gap: Insights from the Pyrenean continental to deep-marine record (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Early/Middle Eocene (Ypresian/Lutetian) transition is represented by a hiatus in many North European sections, including those in which the classic stratotypes were originally defined. However, the Global Stratotype Section and Point of the Lutetian Stage, which is still pending definition, should be placed at a globally correlatable event included within that unrepresented interval. The Pyrenean Eocene outcrops display sedimentary successions that offer the rare opportunity to analyse the Ypresian/Lutetian boundary interval in almost continuous sections and in very different settings. Seven reference stratigraphic sections were selected on the basis of their quality and correlated by means of biomagnetostratigraphic data. This correlation framework casts light on the sequence of chronostratigraphic events that characterize the Ypresian/Lutetian boundary interval, which may prove useful in defining the main correlation criterion of the base of the Lutetian. All of the Pyrenean sections show a similar sedimentary evolution, despite being up to 350 km apart from each other, containing deposits of different origins (intrabasinal carbonate sediments, siliciclastic sediments sourced from the Iberian plate, and terrigenous sediments sourced from the uplifting Pyrenees) and despite having been accumulated in different sedimentary environments (from continental to deep marine) and in different geodynamic settings (piggy-back basin, foreland basin and cratonic margin). This common evolution can be readily interpreted in terms of a sea-level driven depositional sequence whose lowstand and transgressive systems tracts are included within the Ypresian/Lutetian boundary interval. The Pyrenean Ypresian/Lutetian depositional sequence can reasonably be correlated with depositional sequences from classic North European areas, shedding light on the palaeoenvironmental history which in those areas has not been recorded. Furthermore, these depositional sequences may possibly correlate with others from the Antarctic Ocean and from New Jersey, as well as with oceanic temperature variations, suggesting that they might be the result of climatically-driven glacioeustatic sea-level changes. Should this hypothesis prove correct, it would confirm previous suggestions that the onset of Antarctic glaciations needs to be backshifted to the late Ypresian at least.
    Description: Published
    Description: 313-332
    Description: 2.2. Laboratorio di paleomagnetismo
    Description: JCR Journal
    Description: reserved
    Keywords: Eocene ; Lutetian ; Chronostratigraphy ; Sequence stratigraphy ; Climate ; Pyrenees ; 03. Hydrosphere::03.01. General::03.01.06. Paleoceanography and paleoclimatology ; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy ; 04. Solid Earth::04.05. Geomagnetism::04.05.02. Geomagnetic field variations and reversals ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 67
    facet.materialart.
    Unknown
    Nitrogen Isotopes in Volcanic Fluids of Different Geodynamic Settings (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Nitrogen isotopes , N2/36Ar and 3He/4He were measured in volcanic fluids within different geodynamic settings. Subduction zones are represented by Aeolian archipelago, Mexican volcanic belt and Hellenic arc, spreading zones – by Socorro island in Mexico and Iceland and hot spots by Iceland and Islands of Cabo Verde. The δ15N values, corrected for air contamination of volcanic fluids, discharged from Vulcano Island (Italy), highlighted the presence of heavy nitrogen (around +4.3 ±0.5‰). Similar 15N values (around +5‰), have been measured for the fluids collected in the Jalisco Block, that is a geologically and tectonically complex forearc zone of the northwestern Mexico [1]. Positive values (15N around +3‰) have been also measured in the volcanic fluids discharged from Nysiros island located in the Ellenic Arc characterized by subduction processes. All uncorrected data for the Socorro island are in the range of -1 to -2‰. The results of raw nitrogen isotope data of Iceland samples reveal more negative isotope composition (about -4.4‰). On the basis of the non-atmospheric N2 fraction (around 50%) the corrected data of 15N for Iceland are around -16‰, very close to the values proposed by [2]. In a volcanic gas sample from Fogo volcano (Cabo Verde islands) we found a very negative value: -9.9‰ and -15‰ for raw and corrected values, respectively.
    Description: Geochimica et Cosmochimica Acta
    Description: Published
    Description: Davos, Switzerland
    Description: 2.4. TTC - Laboratori di geochimica dei fluidi
    Description: open
    Keywords: Nitrogen Isotopes ; Helium Isotopes ; Volcanic fluids ; 04. Solid Earth::04.07. Tectonophysics::04.07.02. Geodynamics ; 04. Solid Earth::04.07. Tectonophysics::04.07.07. Tectonics ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.01. Geochemical data
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 68
    facet.materialart.
    Unknown
    Hydrothermal methane fluxes from the soil at Pantelleria island (Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Chemical and isotopic analyses of the main gas manifestations of the island of Pantelleria (Italy) were used to gain insight on the origin of the released methane. Results indicate that the most probable origin is through abiogenic reactions within the hydrothermal system. Methane and CO2 flux measurements from the soils were made with the accumulation chamber method in an area of about 0.015 km2 within the main fumarolic area of the island (Favara Grande). The 23 measurements range from –34 to 3550 mg m-2 d-1 for CH4 and from 0.6 to 379 g m-2 d-1 for CO2. The relationships between CH4 and CO2 fluxes and the CH4/CO2 ratios in the gases collected between 25 and 100 cm depth provide evidence for methanotrophic processes within the soils. Methane output for the surveyed area was calculated in 2.5 t a-1 and extrapolated to about 5-10 t a-1 for the entire volcanic/hydrothermal system of the island. Previous higher estimates of the CH4 output at Pantelleria (Etiope et al., 2007 - J. Volcanol. Geotherm. Res., 165, 76 – 86) were based on soil CO2 output and CH4/CO2 ratios in fumarolic gases; the present work provides the first direct CH4 flux data and it suggests that methanotrophic activity in the soil could be substantial in reducing the CH4 emission to the atmosphere.
    Description: Published
    Description: 147-157
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: 4.5. Studi sul degassamento naturale e sui gas petroliferi
    Description: JCR Journal
    Description: reserved
    Keywords: hydrothermal systems ; gas geochemistry ; isotope composition ; methane output ; methanotrophic consumption ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 04. Solid Earth::04.04. Geology::04.04.12. Fluid Geochemistry ; 04. Solid Earth::04.08. Volcanology::04.08.01. Gases
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 69
    facet.materialart.
    Unknown
    Volcanic signature of volatile trace elements on atmospheric deposition at Mt. Etna, Italy (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Volcanic volatiles and aerosol emitted into the atmosphere ultimately fall on the Earth’s surface as wet or dry deposition, and they can influence the environment and the ecosystems at local and regional scales. Therefore, atmospheric deposition plays a key-role in the geochemical cycles, redistributing volcanogenic elements to the ground. For this reason, estimating the volcanogenic trace element fluxes from the atmosphere to the surface is necessary for a better knowledge of the environmental impact of the volcanic emissions. Nevertheless, from a literature review, we have recognized the scarcity of investigation on trace element deposition in the surroundings of active volcanoes. Here, we present a chemical characterization of bulk deposition around Mt. Etna, Italy, including both major and many trace elements. Bulk depositions were collected approximately fortnightly, from April 2006 to December 2007, using a network of five rain gauges, located at various altitudes on the upper flanks around the summit craters of the volcano. For most elements highest concentrations have been found close to the emission vent, confirming the prevailing volcanic contribution to rainwater composition close to the summit craters. Comparison with contemporaneously collected plume emissions shows that deposition processes produce no evident element-to-element fractionation. By contrast, comparison with whole rock composition indicates a contrasting behaviour between volatile elements, which are highly-enriched in rainwater, and refractory elements, which have low rainwater/whole rock concentration ratios. Chemical concentrations in bulk deposition were used to estimate the deposition rates of a large suite of elements. Deposition rates for volatile trace elements like Se, As, and Cd range from 1.7, 1.2 and 0.9 µg m-2 day-1 nearby to the summit vents, to 0.5, 0.3, and 0.1 µg m-2 day-1 at the local background site on the upwind western sector.
    Description: Published
    Description: Davos, Switzerland
    Description: 4.4. Scenari e mitigazione del rischio ambientale
    Description: open
    Keywords: trace metals ; atmospheric deposition ; 01. Atmosphere::01.01. Atmosphere::01.01.07. Volcanic effects ; 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)
    Type: Poster session
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 70
    facet.materialart.
    Unknown
    Volcanic unrest of the Colli Albani (central Italy) detected by GPS monitoring test (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Colli Albani volcanic complex, located in central Italy about 15km SE of Rome, has been dominated by periodic eruptive histories started about 561 ka and ending with the most recent and voluminous activity of the Albano maar (〈70 ka) phase. Earthquakes of moderate intensity, gas emissions and significant ground deformations are the recent evidences of a residual activity. We decided to start a monitoring test by installing as first step three GPS permanent stations on the volcanic structure, in sites easily accessible. The analysis of about 2 years of GPS observations has evidenced a peculiar velocity pattern of the Colli Albani stations with respect to those located nearby, but outside the volcano edifice. With respect to Eurasia, the horizontal velocities are NE directed with magnitudes of 2.2±1.4mm/year (RDPI), 3.0±0.8mm/year (RMPO) and 3.3±1.2mm/year (NEMI). The uplift rates are determined with minor accuracy and range from 3.3 and 6.0mm/year. We used a non-linear inversion algorithm to determine the best-fit parameters for a Mogi spherical source based on the Levenberg–Marquardt least squares approach. The best-fit is obtained with a source at 4.6km depth beneath thewestern flank of the volcano and a volume variation of 3.6×10−4 km3/year. This result is in agreement with the volume rate retrieved by PS-InSAR technique and rather different from the rate inferred from leveling surveys. Consequently, non-linear trends of the hydrothermal system charge cannot be excluded apriori and the continuous GPS monitoring should be considered a priority in assessing the hazard of the Colli Albani.
    Description: This work has been partially supported by the Dept. of Civil Protection, Project DPC115 V3 Colli Albani.
    Description: Published
    Description: 79-87
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Colli Albani ; GPS ; Volcano monitoring ; Mogi source ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 71
    facet.materialart.
    Unknown
    Inferences on active faults at the Southern Alps–Liguria basin junction from accurate analysis of low energy seismicity (2009)
    Elsevier
    Details
    Publication Date: 2017-04-03
    Description: Seismotectonic studies concern themselves with understanding the distribution of earthquakes in space, time, size and style. Therefore, the better these parameters are known, the most correct the association of any seismic event with the faulting structure that caused it will result. The use of accurate location methods is especially required when dealing with very complex areas, where several faulting systems or relatively small seismogenic structures exist. In fact, even though routinely determined epicentres are capable of revealing the rough picture of the seismicity, they are not suitable for studies of the fine structure of the causative fault, as their location uncertainties are often larger than the source dimension itself. In this work the probabilistic approach of the “Non Linear Localization” has been used to compute precise locations for earthquakes occurred in the last twenty years nearby the Saorge–Taggia line, a complex fault system situated in Western Liguria, close to the border between Italy and France. Together with the Breil– Sospel–Monaco and the Peille–Laghet faults, this line is responsible for the seismic activity of the area. The seismotectonic study is completed through a local tomographic study and the analysis of the focal mechanisms computed for an enlarged area. The results show that the seismicity associated with this fault system is confined within the first 10 km depth. Many clusters of seismic events are identified along the Saorge–Taggia line. The existence of a not previously mapped branch perpendicular to the Saorge–Taggia line is also recognized. Although its position may suggest it to be the continuation of the Breil–Sospel–Monaco fault system towards NE, our finding would rather suggest no association with the fault. The overall results confirm the complexity of the area; in particular the hypothesis that the Saorge–Taggia system may represent the eastward limit of a subalpine crustal block comprised within the Nice Arc, the named fault and a thrust front which is supposed to be located 20 km offshore find a confirm in the shallow depth of the seismic events. In addition we propose that the western limit of the block, located along the Nice arc, could be instead shifted where the Peille–Laghet fault lays.
    Description: Published
    Description: 470-479
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: High precision locations ; Focal mechanisms ; Fault geometry ; Western Liguria ; 04. Solid Earth::04.06. Seismology::04.06.01. Earthquake faults: properties and evolution
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 72
    facet.materialart.
    Unknown
    Converted phases analysis of the Campi Flegrei caldera using active seismic data (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: We applied a type of depth migration for converted seismic phases to active and passive seismic data sets from the Campi Flegrei volcanic region in southern Italy. The migration method is based on the diffraction summation migration technique. Travel times to grid points in a volume were calculated in smooth P and S-velocity models and trace energy near the calculated converted phase time was stacked over multiple sources at one receiver. Weighting factors based on Snell's Law at an arbitrarily oriented local interface were applied to better focus trace energy. PP reflection images from the active data set provide increased detail to images of the caldera rim from other studies. The migrated images also show features near 2–3 km in depth beneath Pozzuoli City, which may be associated with an over-pressured gas volume, as suggested by other geophysical investigations. Possible deeper features near 4 km depth may be related to the presence of the carbonate basement or may image a previously undetected feature, such as a small body of strongly thermometamorphosed volcanic rock. The current passive earthquake data set from the 1984 ground uplift episode was not well suited to the converted phases analysis due to narrow P–S windows and high noise levels in the traces. However, two stations provide confirmation and extension of imaged features in the active data.
    Description: Published
    Description: 243-256
    Description: 3.2. Tettonica attiva
    Description: JCR Journal
    Description: reserved
    Keywords: converted phases ; migration ; seismic imaging ; Caampi Flegrei ; 04. Solid Earth::04.06. Seismology::04.06.09. Waves and wave analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 73
    facet.materialart.
    Unknown
    Modeling unusual eruptive behavior of Mt. Etna, Italy, by means of event bush (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: One of the best-studied volcanoes of the world, Mt. previous termEtnanext term in Sicily, repeatedly exhibits eruptive scenarios that depart from the behavior commonly considered typical for this volcano. Episodes of intense explosive activity, pyroclastic flows, dome growth and cone collapse pose a variety of previously underestimated threats to human lives in the summit area of the volcano. However, retrospective analysis of these events shows that they were likely caused by the same very sets of premises and starting conditions as “normal” eruptions, yet combined in an unexpected, probably unique, way. To cope with such unexpected consequences, we involve an approach of artificial intelligence developed specially for needs of the geosciences, the event bush. Scenarios inferred from the event bush fit the observed ones and allow to foresee other low-probability events that may occur at the volcano. Application of the event bush provides a more impartial vision of volcanic phenomena and may serve as an intermediary between expert knowledge and numerical assessment, e.g., by means of Bayesian Belief Networks.
    Description: Published
    Description: 157-171
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: Etna ; Event bush method ; artificial intelligence ; 05. General::05.01. Computational geophysics::05.01.05. Algorithms and implementation
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 74
    facet.materialart.
    Unknown
    Three-years of SO2 flux measurements of Mt. Etna using an automated UV scanner array: Comparison with conventional traverses and uncertainties in flux retrieval (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: Routine measurements of SO2 flux using the traverse method on Mt. Etna (Italy) were augmented in late 2004 when an array of automatic scanning ultraviolet spectrometers was installed. Each instrument allows one SO2 scan to be recorded every ~6 min. Here we report the methods that we developed to automatically and robustly transform SO2 profiles into SO2 flux data. Radian geometry and Fast Fourier Transform algorithm were used for reducing plume cross-sections and for discriminating between volcanic plumes from those produced by water vapour clouds. Uncertainty in flux measurements depends on the accuracy of plume height estimation, on assumptions concerning plume-geometry, and on the quality of the retrieved SO2 amounts. We compare 3 years of flux measurements made using both the automated network and “conventional” traverse methods beneath the plume.We found a good agreement between the datasets, both in terms of magnitude and in temporal variations. These results validate the Etna SO2 flux monitoring system. Emission rates are available to the 24-hour manned operations room via intranet, providing real-time information on degassing rates and plume location.
    Description: (1)Sviluppo di sistemi di monitoraggio Dipartimento di Protezione Civile della Regione Sicilia, (2)INGV (Istituto Nazionale di Geofisica e Vulcanologia, sezione di Catania — Italy), (3)NOVAC (Network for Observation of Volcanic and Atmospheric Change)EU-funded Sixth Framework Programme project 18354. ()4 UK NERC National Centre for Earth Observation via the “Dynamic Earth and geo-hazards”.
    Description: Published
    Description: 76-83
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: sulphur dioxide, scanning spectrometer, car-based traverse, DOAS, Mt. Etna, volcano surveillance ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 75
    facet.materialart.
    Unknown
    Novel retirval of volcanic SO2 abundance form ultraviolet spectra (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The recent development of fixed networks of scanning ultraviolet spectrometers for automatic determination of volcanic SO2 fluxes has created tremendous opportunities for monitoring volcanoes but has brought new challenges in processing (and interpreting) the copious data flow they produce. A particular difficulty in standard implantation of differential optical absorption (DOAS) methods is the requirement for a clear-sky (plume-free) background spectrum. Our experience after four years of measurements with two UV scanner networks on Etna and Stromboli shows that wide plumes are frequently observed, precluding simple selection of clear-sky spectra. We have therefore developed a retrieval approach based on simulation of the background spectrum. We describe the method here and tune it empirically by collecting clear, zenith sky spectra using calibration cells containing known amounts of SO2. We then test the performance of this optimised retrieval using clear-sky spectra collected with the same calibration cells but for variable scan angles, time of day, and season (through the course of 1 year), finding acceptable results (~12% error) for SO2 column amounts. We further illustrate the analytical approach using spectra recorded at Mt. Etna during its July 2006 eruption. We demonstrate the reliability of the method for tracking volcano dynamics on different time scales, and suggest it is widely suited to automated SO2-plume monitoring
    Description: (1)FIRB-MIUR “Simulazione dei flussi lavici con gli automi cellulari” N. RBAU01RMZ4_002 and “Sviluppo di sistemi di monitoraggio' Dipartimento di Protezione Civile della Regione Sicilia, INGV(Istituto Nazionale di Geofisica e Vulcanologia, sezione di Catania – Italy). (2) EU-funded Sixth Framework Programme project 18354 “NOVAC” (Network forObservation of Volcanic and Atmospheric Change). (3) Leverhulme Trust fellowship
    Description: Published
    Description: 141-153
    Description: 1.2. TTC - Sorveglianza geochimica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Volcanic Gas Monitoring, Scanning spectrometer network, DOAS, Ultraviolet Spectroscopy, Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 76
    facet.materialart.
    Unknown
    Geochemical and B–Sr–Nd isotopic evidence for mingling and mixing processes in the magmatic system that fed the Astroni volcano (4.1–3.8 ka) within the Campi Flegrei caldera (southern Italy) (2009)
    Elsevier
    Details
    Publication Date: 2017-04-04
    Description: The Astroni volcano was built through seven eruptions that generated pyroclastic deposits and lava domes within the Campi Flegrei caldera (southern Italy) 4.1–3.8 ka BP. Whole-rock geochemical and B–Sr–Nd isotopic investigations were carried out on representative samples of all seven eruptions. The products vary from tephriphonolites to phonolites, and from latites to trachytes. They show textural, mineralogical and isotopic evidence of disequilibrium, including distinct clinopyroxene populations, rounded and/or resorbed plagioclase and alkali-feldspar, and reverse-zoned phenocrysts of all these mineral phases. The Sr, Nd and B isotopic composition of whole rocks is variable and correlated with the degree of chemical evolution, suggesting open-system processes in addition to fractional crystallisation. Moreover, significant Sr-isotopic disequilibrium between the phenocrysts and glass has been documented for one sample. The chemostratigraphy of the products indicates that Astroni eruptions 1 through 5 were fed by magmas of trachytic to phonolitic composition that were less enriched in radiogenic Sr and 11B up-section. This variability has been interpreted as the result of mingling between at least two distinct magmatic endmembers, one more evolved and the other less evolved. Another heterogeneous batch of magma, resulting from almost complete mixing between the same two end-members, was drained during eruptions 6 and 7. The more evolved end-member, characterised by 87Sr/86Sr≥0.7075, 143Nd/144Nd≤0.51247 and δ11B≥−8‰, was very similar to the magma that fed the final phases of the Agnano–Monte Spina eruption, which occurred a few centuries earlier in the Astroni vent area. The less evolved end-member had 87Sr/ 86Sr≤0.70726, 143Nd/144Nd≥0.51251 and δ11B≤10‰, and was likely derived by fractional crystallisation of a mantle-derived magma. An abrupt decrease in both the Sr isotope ratio and the Th content, detected at the transition between Unit 4 and 5, suggests that another magma with a 87Sr/86Sr ratio intermediate between those of the two identified end-members may have been involved in Astroni activity. The more evolved endmember is interpreted as a residue of the Agnano–Monte Spina eruption that was invaded by either the intermediate or the less evolved magmatic end-member, promoting mingling and triggering Astroni activity. This study of Astroni provides insights for both short- and long-term volcanic hazard assessment, as the Astroni volcano is the best example of a very close sequence of eruptions from the same vent area in the Campi Flegrei caldera.
    Description: Published
    Description: 135–151
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: 3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
    Description: JCR Journal
    Description: reserved
    Keywords: Campi Flegrei caldera ; B–Sr–Nd isotope geochemistry ; Magma mingling/mixing ; Chemostratigraphy ; 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)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 77
    facet.materialart.
    Unknown
    "Explosive Energy" during volcanic eruptions from fractal analysis of pyroclasts (2006)
    Elsevier
    Details
    Publication Date: 2020-01-08
    Description: Despite recent advances by means of experiments and high-resolution surveys and the growing understanding of the physical processes before and during volcanic eruptions, duration and type of eruptive activity still remain highly unpredictable. This uncertainty hinders appropriate hazard and associated risk assessment tremendously. In an effort to counter this problem, experimentally generated pyroclasts have been studied by fractal statistics with the aim of evaluating possible relationships between eruption energy and fragmentation efficiency. Rapid decompression experiments have been performed on three differently porous sample sets of the 1990–1995 eruption of Unzen volcano (Japan) at 850 °C and at initial pressure values above the respective fragmentation threshold [U. Kueppers, B. Scheu, O. Spieler, D. B. Dingwell, Fragmentation efficiency of explosive volcanic eruptions: a study of experimentally generated pyroclasts. J. Volcanol. Geotherm. Res. 153 (2006) 125–135.,O. Spieler, B. Kennedy, U. Kueppers, D.B. Dingwell, B. Scheu, J. Taddeucci, The fragmentation threshold of pyroclastic rocks. EPSL 226 (2004) 139–148.]. The size distribution of generated pyroclasts has been studied by fractal fragmentation theory and the fractal dimension of fragmentation (Df), a value quantifying the intensity of fragmentation, has been measured for each sample. Results showthat size distribution of pyroclastic fragments follows a fractal law(i.e. power-law) in the investigated range of fragment sizes, indicating that fragmentation of experimental samples reflects a scale-invariant mechanism. In addition, Df is correlated positively with the potential energy for fragmentation (PEF) while showing a strong influence of the open porosity of the samples. Results obtained in this work indicate that fractal fragmentation theory may allow for quantifying fragmentation processes during explosive volcanic eruptions by calculating the fractal dimension of the size distribution of pyroclasts. It emerges fromthis study that fractal dimension may be utilised as a proxy for estimating the explosivity of volcanic eruptions by analysing their natural pyroclastic deposits.
    Description: Published
    Description: 800-807
    Description: open
    Keywords: volcanic fragmentation ; simulation of eruptions ; explosive energy ; pyroclasts ; fragment size distribution ; fractal fragmentation theory ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 279718 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 78
    facet.materialart.
    Unknown
    Fragmentation efficiency of explosive volcanic eruptions: A study of experimentally generated pyroclasts (2006)
    Elsevier
    Details
    Publication Date: 2020-01-08
    Description: Products of magma fragmentation can pose a severe threat to health, infrastructure, environment, and aviation. Systematic evaluation of the mechanisms and the consequences of volcanic fragmentation is very difficult as the adjacent processes cannot be observed directly and their deposits undergo transport-related sorting. However, enhanced knowledge is required for hazard assessment and risk mitigation. Laboratory experiments on natural samples allow the precise characterization of the generated pyroclasts and open the possibility for substantial advances in the quantification of fragmentation processes. They hold the promise of precise characterization and quantification of fragmentation efficiency and its dependence on changing material properties and the physical conditions at fragmentation. We performed a series of rapid decompression experiments on three sets of natural samples from Unzen volcano, Japan. The analysis comprised grain-size analysis and surface area measurements. The grain-size analysis is performed by dry sieving for particles larger than 250 Am and wet laser refraction for smaller particles. For all three sets of samples, the grain-size of the most abundant fraction decreases and the weight fraction of newly generated ash particles (up to 40 wt.%) increases with experimental pressure/potential energy for fragmentation. This energy can be estimated from the volume of the gas fraction and the applied pressure. The surface area was determined through Argon adsorption. The fragmentation efficiency is described by the degree of fineparticle generation. Results show that the fragmentation efficiency and the generated surface correlate positively with the applied energy.
    Description: Published
    Description: 125-135
    Description: partially_open
    Keywords: experimental volcanology ; fragmentation efficiency ; particle analysis ; ash ; magma ; porosity ; Unzen volcano ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 504138 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 79
    facet.materialart.
    Unknown
    Field-based density measurements as tool to identify preeruption dome structure: set-up and first results from Unzen volcano, Japan (2006)
    Elsevier
    Details
    Publication Date: 2020-01-08
    Description: For an improvement in the quality of conduit flow and dome-related explosive eruption models, knowledge of the preeruption or precollapse density of the rocks involved is necessary. As close investigation is impossible during eruption, the best substitute comes from quantitative investigation of the eruption deposits. The porosity of volcanic rocks is of primary importance for the eruptive behaviour and, accordingly, a key-parameter for realistic models of dome stability and conduit flow. Fortunately, this physical property may be accurately determined via density measurements. We developed a robust, battery-powered device for rapid and reliable density measurements of dry rock samples in the field. The density of the samples (sealed in plastic bags at 250 mbar) is determined using the Archimedean principle. We have tested the device on the deposits of the 1990–1995 eruption of Unzen volcano, Japan. Short setup and operation times allow up to 60 measurements per day under fieldwork conditions. The rapid accumulation of correspondingly large data sets has allowed us to acquire the first statistically significant data set of clast density distribution in block-and-ash flow deposits. More than 1100 samples with a total weight of 2.2 tons were measured. The data set demonstrates that the deposits of the last eruptive episode at Unzen display a bimodal density distribution, with peaks at 2.0F0.1 and 2.3F0.1 g/cm3, corresponding to open porosity values of 20 and 8 vol.%, respectively. We use this data set to link the results of laboratory-based fragmentation experiments to field studies at recently active lava domes.
    Description: Published
    Description: 65-75
    Description: partially_open
    Keywords: field-based density measurements ; dome ; Unzen volcano ; explosive eruption ; block-and-ash flow ; fragmentation behaviour ; volcanology ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 710471 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 80
    facet.materialart.
    Unknown
    The fragmentation threshold of pyroclastic rocks (2006)
    Elsevier
    Details
    Publication Date: 2020-01-08
    Description: In response to rapid decompression, porous magma may fragment explosively. This occurs when the melt can no longer withstand forces exerted upon it due to the overpressure in included bubbles. This occurs at a critical pressure difference between the bubbles and the surrounding magma. In this study we have investigated this pressure threshold necessary for the fragmentation of magma. Here we present the first comprehensive, high temperature experimental quantification of the fragmentation threshold of volcanic rocks varying widely in porosity, permeability, crystallinity, and chemical composition. We exposed samples to increasing pressure differentials in a high temperature shock tube apparatus until fragmentation was initiated. Experimentally, we define the fragmentation threshold as the minimum pressure differential that leads to complete fragmentation of the pressurized porous rock sample. Our results show that the fragmentation threshold is strongly dependent on porosity; high porosity samples fragment at lower pressure differentials than low porosity samples. The fragmentation threshold is inversely proportional to the porosity. Of the other factors, permeability likely affects the fragmentation threshold at high porosity values, whereas chemical composition, crystallinity and bubble size distribution appear to have minor effects. The relationship for fragmentation threshold presented here can be used to predict the minimum pressure differential necessary for the initiation or cessation of the explosive fragmentation of porous magma.
    Description: Published
    Description: 139-148
    Description: partially_open
    Keywords: fragmentation ; threshold ; experimental ; volcanology ; magma ; eruption ; porosity ; decompression ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 411365 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 81
    facet.materialart.
    Unknown
    Special Issue: The sixth international workshop on unstructured mesh numerical modelling of coastal, shelf and ocean flows. Imperial College London, September 19-21, 2007 (2009)
    Elsevier
    In:  EPIC3Ocean Modelling, Elsevier, 28(1-3), pp. 1-1, ISSN: 1463-5003
    Details
    Publication Date: 2019-07-16
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 82
    facet.materialart.
    Unknown
    Influence of topography on ground deformation at Mt.Vesuvius (Italy) by finite element modelling (2009)
    Elsevier
    Details
    Publication Date: 2022-04-22
    Description: Ground deformations are observed in connection with volcanic activity, and therefore, geodetic monitoring can provide significant indication of changes of equilibrium conditions. The aim of this paper is to study the deformation of Mount Vesuvius (Italy) caused by overpressure sources at various depths, using a commercial (Ansys) 3D finite element code, in the framework of linear elastic isotropic material behavior. Both homogenous and heterogeneous media with carbonate basement were analyzed to understand the influence of topography on the ground deformations. The topography of the Somma-Vesuvius was taken into account, using a digital terrain model, and the carbonate basement was schematically modelled by assuming two horizontal layers with different Young moduli. The presence of a strong deviation from axially symmetric pattern of the displacement field, and of small subsidence areas, was found. These characteristics are completely unknown from the simple Mogi model and by simplified topography model, as verified by ad hoc simulations. These preliminary results, showing areas of the volcanic edifice experiencing high deformation, can improve the determination of the sources of deformations, i.e. the most relevant problem in the volcano monitoring. Moreover, the knowledge of the deformation pattern, including the topography effects, can provide significant indications to optimize the location of sensors and the characteristics needed to design an efficient and reliable geodetic monitoring network able to detect shallow intrusion events.
    Description: Istituto Nazionale di Geofisica e Vulcanologia and Dipartimento della Protezione Civile
    Description: Published
    Description: 178-186
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Ground deformations ; Geodetic monitoring ; Topography ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 83
    facet.materialart.
    Unknown
    Corrigendum to "Climatological mean and decadal change in surface ocean pCO2, and net sea-air CO2 flux over the global oceans" [Deep Sea Res. II 56 (2009) 554-577] (2009)
    Elsevier
    In:  EPIC3Deep-Sea Research I, Elsevier, 56(11), pp. 2075-2076, ISSN: 0967-0637
    Details
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 84
    facet.materialart.
    Unknown
    Evidence for Holocenic uplift at Somma-Vesuvius (2009)
    Elsevier
    Details
    Publication Date: 2022-02-16
    Description: Detailed stratigraphical, archaeological, micropalaeontological, archaeometrical and petrochemical analyses of samples from trenches and boreholes at insula of Casti Amanti, in Pompeii, allowed a faithful reconstruction of the recent environmental evolution of the site. The present data clearly indicate the alternation of both subaerial and shallow marine conditions during Holocene times. Taking into account the relative local sea level variations, a ~30 m ground uplift event in the last 6 kyr (with an average vertical uplift rate of ~5 mm/yr) was inferred for the first time.
    Description: Published
    Description: 451–461
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: ground uplift ; Somma-Vesuvius ; Pompeii ; Holocene ; 04. Solid Earth::04.03. Geodesy::04.03.01. Crustal deformations
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 85
    facet.materialart.
    Unknown
    Sub-surface dynamics and eruptive styles of maars in the Colli Albani Volcanic District, Central Italy (2009)
    Elsevier
    Details
    Publication Date: 2021-12-15
    Description: Eruptive scenarios associated with the possible reactivation of maar-forming events in the Quaternary, ultrapotassic Colli Albani Volcanic District (CAVD) provides implications for volcanic hazard assessment in the densely populated area near Rome. Based on detailed stratigraphy, grain size, componentry, ash morphoscopy and petro-chemical analyses of maar eruption products, along with textural analysis of cored juvenile clasts, we attempt to reconstruct the eruptive dynamics of the Prata Porci and Albano maars, as related to pre- and syn-eruptive interactions between trachybasaltic to K-foiditic feeder magmas and carbonate–silicoclastic and subvolcanic country rocks. Magma volumes in the order of 0.5–3.1×108 m3 were erupted during the monogenetic Prata Porci maar activity and the three eruptive cycles of the Albano multiple maar, originating loose to strongly lithified, wet and dry pyroclastic surge deposits, Strombolian scoria fall horizons and lithic-rich explosion breccias. These deposits contain a wide range of accessory and accidental lithic clasts, with significant vertical stratigraphic variations in the lithic types and abundances. The two maar study cases hold a record of repeated transitions between magmatic (i.e, Strombolian fallout) and hydromagmatic (wet and dry pyroclastic surges) activity styles. Evidence of phreatic explosions, a common precursor of explosive volcanic activity, is only found at the base of the Prata Porci eruptive succession. The quantitative evaluation of the proportions of the different eruptive styles in the stratigraphic record of the two maars, based on magma vs. lithic volume estimates, reveals a prevailing magmatic character in terms of erupted magma volumes despite the hydromagmatic footprint. Different degrees of explosive magma–water interaction were apparently controlled by the different hydrogeological and geological–structural settings. In the Prata Porci case, shifts in the depth of magma fragmentation are proposed to have accompanied eruption style changes. In the Albano case, a deeply dissected geothermal aquifer in peri-caldera setting and variable mass eruption rates were the main controlling factors of repeated shifts in the eruptive style. Finally, textural evidence from cored juvenile clasts and analytical modeling of melt–solid heat transfer indicate that the interacting substrate in the Prata Porci case was at low, uniform temperature (~ 100 °C) as compared to the highly variable temperatures (up to 700–800 °C) inferred for the geothermal system beneath Albano.
    Description: Protezione Civile, Italy 2004–2006 Agreement with Istituto Nazionale di Geofisica e Vulcanologia— INGV, project V3_1
    Description: Published
    Description: 189-202
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: maar ; hydromagmatic eruption ; 04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 86
    facet.materialart.
    Unknown
    Geotechnical characterization of the upper Pleistocene-Holocene alluvial deposits of Roma (Italy) by means of multivariate geostatistics: Cross-validation results (2009)
    Elsevier
    Details
    Publication Date: 2023-06-05
    Description: We are presenting an attempt to evaluate the spatial variability of geotechnical parameters in the upper Pleistocene–Holocene alluvial deposits of Roma (Italy) by means of multivariate geostatistics. The upper Pleistocene–Holocene alluvial deposits of Roma are sensitive to high levels of geohazard. They occupy a sizable and significant part of the city, being the foundation for many monuments, historical neighborhoods, and archaeological areas, and the main host of the present and future subway lines. We have stored information from more than 2000 geotechnical boreholes crossing the alluvial deposits into a relational database. For the present study, only the boreholes with lithologic/textural interpretation and geotechnical information were selected. The set includes 283 boreholes and 719 samples, which have a set of geotechnical information comprising physical properties and mechanical parameters. Techniques of multivariate statistics and geostatistics were combined and compared to evaluate the estimation methods of the mechanical parameters, with special reference to the drained friction angle from direct shear test (φ′). Principal Component Analysis was applied to the dataset to highlight the relationships between the geotechnical parameters. Through cross-validation analysis, multiple linear regression, kriging, and cokriging were tested as estimators of φ′. Cross-validation demonstrates that the cokriging with granulometries as auxiliary variables is the most suitable method to estimate φ′. In addition to proving that cokriging is a good estimator of φ′, cross-validation demonstrates that input data are coherent and this allows us to use them for estimation of geotechnical parameters, although they come from different laboratories and different vintages. Nevertheless, to get the same good results of cross-validation in estimation, it is necessary for granulometries to be available at grid points. Since this information being not available at all grid points, it is expected that, in the future, textural information can be derived in an indirect way, i.e., from lithologic/textural spatial reconstructions.
    Description: Published
    Description: 251-268
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: open
    Keywords: Alluvial deposits ; Geotechnical properties ; Principal Component Analysis ; Multivariate geostatistics ; Roma ; 05. General::05.01. Computational geophysics::05.01.04. Statistical analysis
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 87
    Electronic Resource
    Electronic Resource
    A measurement of τ polarization in Z^0 decays (1992-8977)
    Amsterdam : Elsevier
    Physics Letters B 294 (1992), S. 466-478 
    Details
    ISSN: 0370-2693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0370-2693(92)91549-O
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Measurement of the average lifetime of b hadrons (1993-4325)
    Amsterdam : Elsevier
    Physics Letters B 317 (1993), S. 474-484 
    Details
    ISSN: 0370-2693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0370-2693(93)91027-K
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    facet.materialart.
    Unknown
    An integrated systems engineering approach to aircraft design (2006)
    Elsevier
    Details
    Publication Date: 2006-06-01
    Print ISSN: 0376-0421
    Electronic ISSN: 1873-1724
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 90
    facet.materialart.
    Unknown
    Differential regulation of IL-6 and TNF-α via calcineurin in human skeletal muscle cells (2006)
    Elsevier
    Details
    Publication Date: 2006-11-01
    Print ISSN: 1043-4666
    Electronic ISSN: 1096-0023
    Topics: Biology , Medicine
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 91
    facet.materialart.
    Unknown
    Time-dependent onset of Interferon-α2b-induced apoptosis in isolated hepatocytes from preneoplastic rat livers (2006)
    Elsevier
    Details
    Publication Date: 2006-12-01
    Print ISSN: 1043-4666
    Electronic ISSN: 1096-0023
    Topics: Biology , Medicine
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 92
    facet.materialart.
    Unknown
    An Application of the Infinite Matrix Theory to Mathieu Equation (2006)
    Elsevier
    Details
    Publication Date: 2006-11-01
    Print ISSN: 0898-1221
    Electronic ISSN: 1873-7668
    Topics: Mathematics
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 93
    facet.materialart.
    Unknown
    Comparative Analysis of Eubacterial DNA Polymerase III Alpha Subunits (2006)
    Elsevier
    Details
    Publication Date: 2006-01-01
    Print ISSN: 1672-0229
    Electronic ISSN: 2210-3244
    Topics: Biology
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 94
    facet.materialart.
    Unknown
    Effect of IL-1 on the hydrolysis of the tumor antigen epitope gp100280–288 by fibroblast-expressed enzymes (2006)
    Elsevier
    Details
    Publication Date: 2006-11-01
    Print ISSN: 1043-4666
    Electronic ISSN: 1096-0023
    Topics: Biology , Medicine
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 95
    facet.materialart.
    Unknown
    Divisible Load Scheduling and Markov Chain Models (2006)
    Elsevier
    Details
    Publication Date: 2006-11-01
    Print ISSN: 0898-1221
    Electronic ISSN: 1873-7668
    Topics: Mathematics
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 96
    facet.materialart.
    Unknown
    Synthesis, resolution, and absolute configuration of two novel and selective cyclooxygenase-2 inhibitors based on the 1,5-diarylpyrrole structure (2006)
    Elsevier
    Details
    Publication Date: 2006-12-01
    Print ISSN: 0957-4166
    Electronic ISSN: 1362-511X
    Topics: Chemistry and Pharmacology
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 97
    facet.materialart.
    Unknown
    Enantiomeric synthesis of carbocyclic d-4′-C-methylribonucleosides as potential antiviral agents (2006)
    Elsevier
    Details
    Publication Date: 2006-12-01
    Print ISSN: 0957-4166
    Electronic ISSN: 1362-511X
    Topics: Chemistry and Pharmacology
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 98
    facet.materialart.
    Unknown
    Using expected values to simplify decision making under uncertainty (2009)
    Elsevier
    Details
    Publication Date: 2009-04-01
    Print ISSN: 0305-0483
    Electronic ISSN: 1873-5274
    Topics: Economics
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 99
    facet.materialart.
    Unknown
    Combined MMF and insulin therapy prevents renal injury in experimental diabetic rats (2006)
    Elsevier
    Details
    Publication Date: 2006-12-01
    Print ISSN: 1043-4666
    Electronic ISSN: 1096-0023
    Topics: Biology , Medicine
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 100
    facet.materialart.
    Unknown
    STAT1 and STAT3 phosphorylation by porins are independent of JAKs but are dependent on MAPK pathway and plays a role in U937 cells production of interleukin-6 (2006)
    Elsevier
    Details
    Publication Date: 2006-12-01
    Print ISSN: 1043-4666
    Electronic ISSN: 1096-0023
    Topics: Biology , Medicine
    Published by Elsevier
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...