ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions  (7)
  • Viscosity  (5)
  • Elsevier  (12)
  • 2020-2024
  • 2005-2009  (12)
  • 2000-2004
  • 1990-1994
  • 1985-1989
  • 1980-1984
  • 2007  (12)
  • 1983
  • 1980
Collection
Years
  • 2020-2024
  • 2005-2009  (12)
  • 2000-2004
  • 1990-1994
  • 1985-1989
  • +
Year
  • 1
    Publication Date: 2020-10-29
    Description: We present new viscosity measurements for melts spanning a wide range of anhydrous compositions including: rhyolite, trachyte, moldavite, andesite, latite, pantellerite, basalt and basanite. Micropenetration and concentric cylinder viscometry measurements cover a viscosity range of 10−1 to 1012 Pas and a temperature range from 700 to 1650 °C. These new measurements, combined with other published data, provide a high-quality database comprising ∼800 experimental data on 44 well-characterized melt compositions. This database is used to recalibrate the model proposed by Giordano and Dingwell [Giordano, D., Dingwell, D. B., 2003a. Non-Arrhenian multicomponent melt viscosity: a model. Earth Planet. Sci. Lett. 208, 337–349] for predicting the viscosity of natural silicate melts. The present contribution clearly shows that: (1) the viscosity (η)–temperature relationship of natural silicate liquids is very well represented by the VFT equation [log η=A+B/ (T−C)] over the full range of viscosity considered here, (2) the use of a constant high-T limiting value of melt viscosity (e.g., A) is fully consistent with the experimental data, (3) there are 3 different compositional suites (peralkaline, metaluminous and peraluminous) that exhibit different patterns in viscosity, (4) the viscosity of metaluminous liquids is well described by a simple mathematical expression involving the compositional parameter (SM) but the compositional dependence of viscosity for peralkaline and peraluminous melts is not fully controlled by SM. For these extreme compositions we refitted the model using a temperature-dependent parameter based on the excess of alkalies relative to alumina (e.g., AE/SM). The recalibrated model reproduces the entire database to within 5% relative error (e.g., RMSE of 0.45 logunits).
    Description: Published
    Description: 42–56
    Description: reserved
    Keywords: Viscosity ; Model ; Silicate melts ; Metaluminous ; Peraluminous ; Peralkaline ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology ; 04. Solid Earth::04.04. Geology::04.04.05. Mineralogy and petrology ; 04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 717294 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2020-10-29
    Description: Viscosity of hydrous trachytes from the Agnano Monte Spina eruption (Phlegrean Fields, Italy) has been determined at 1.0 GPa and temperatures between 1200 and 1400 °C using the falling sphere method in a piston cylinder apparatus. The H2O content in the melts ranged from 0.18 to 5.81 wt.%. These high-temperature hydrous viscosities, along with previous ones determined at low-temperature (anhydrous and hydrous) and at high-temperature (anhydrous), at 1 atm on the same melt composition, represent the only complete viscosity data set available for K-trachyticmelts, frommagmatic to volcanic conditions.Viscosity decreases with increasing temperature andwater content in the melt.At constant temperature, viscosity appears to significantly decreasewhen the first wt.% ofH2Ois added.At H2O content higher than 3 wt.% the effect of temperature on viscosity is slight. Moreover, the deviation from Arrhenian behaviour towards greater “fragility” occurs with increasing water content. We combined low- and high-temperature viscosities (also from literature) and parameterized themby the use of a modified Vogel–Fulcher–Tamman equation, which accommodates the non-Arrhenian temperature dependence ofmelt viscosity.Moreover, in order to explore the extent to which the improved knowledge of Agnano Monte Spina trachyte viscosity may affect simulation of volcanic eruption at Phlegrean Fields, we included our viscosity models in numerical simulations of magma flow and fragmentation along volcanic conduits. These simulations show that the new parameterizations (and hence the new equations) give stronger predictions in the temperature interval relevant for magmatic and eruptive processes.
    Description: Published
    Description: 124-137
    Description: JCR Journal
    Description: reserved
    Keywords: Viscosity ; Trachyte ; Falling sphere method ; Vogel–Fulcher–Tamman equation ; 04. Solid Earth::04.08. Volcanology::04.08.02. Experimental volcanism ; 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 ...
  • 3
    Publication Date: 2020-10-29
    Description: In-situ falling-sphere viscometry using shadow radiography in a multianvil apparatus was conducted on a series of samples along the NaAlSi3O8–H2O join up to 2.8 wt.% H2O at the Spring-8 synchrotron radiation facility (Hyogo, Japan). This allowed us to determine viscosities normally too low to be measured at ambient pressure for hydrous silicate melts at high temperatures due to rapid devolatilization. Pressure was fixed at 2.5 GPa for all experiments allowing us to gauge the effect of chemical composition on viscosity. In particular, the series of samples allowed us to vary the melt's degree of polymerization while maintaining a constant Al to Si ratio. Our results show that, for all samples, viscosity decreases as a function of pressure between 1 atm and 2.5 GPa at 1550 °C, indicating that the pressure anomaly can still be observed as depolymerization of the melt increases from nominally 0 (dry albite liquid) to NBO/T=0.8 (assuming water speciation entirely as hydroxyl groups at experimental conditions). We also find that the magnitude of the decrease in viscosity over this pressure interval does not appear to be dependent on the amount of water in the melt (i.e., NBO/T). An explanation for this behavior might be that the molar volume, at least over this limited compositional range, is nearly constant and the effects of compression of these melts, though different in degree of polymerization, are similar.
    Description: Published
    Description: 2-9
    Description: JCR Journal
    Description: reserved
    Keywords: Viscosity ; Silicate melts ; High pressure ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology ; 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 ...
  • 4
    Publication Date: 2021-01-25
    Description: The Late Pleistocene Albano Maar hosted the most recent volcanic activity of the Colli Albani Volcanic District, represented at nearvent sections by a thick pyroclastic succession of seven units clustered in two main eruptive cycles dated at around 70–68 and 41–36 ka B.P., respectively. Recent stratigraphic investigations allowed us to recognise a pyroclastic succession comprising four eruptive units widely spread in the northeastern sectors of the Colli Albani volcano, up to 15km eastward from the Albano Maar. Integrated tephrostratigraphic, morpho-pedostratigraphic, archaeological, petrological and geochemical analyses enable us to recognise them as distal deposits of the first, third, fifth and seventh Albano Maar eruptions, enlarging significantly their previously supposed dispersion area. Further tephrostratigraphic studies in central Apennine area, allowed us to identify the Albano Maar products in Late Pleistocene deposits of several intermountain basins, extending still further the dispersion area of distal ash fallout as far as 100–120km from the vent. On the basis of the identification and the study of these previously unrecognised mid-distal Albano Maar deposits, a reappraisal of the eruptive scenarios and related energetic parameters is proposed.
    Description: Published
    Description: 160–178
    Description: 1.5. TTC - Sorveglianza dell'attività eruttiva dei vulcani
    Description: JCR Journal
    Description: reserved
    Keywords: Colli Albani ; Albano ; 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 ...
  • 5
    Publication Date: 2017-04-04
    Description: Video surveillance systems are consolidated techniques for monitoring eruptive phenomena in volcanic areas. Along with these systems, which use standard video cameras, people working in this field sometimes make use of infrared cameras providing useful information about the thermal evolution of eruptions. Real-time analysis of the acquired frames is required, along with image storing, to analyze and classify the activity of volcanoes. Human effort and large storing capabilities are hence required to perform monitoring tasks. In this paper we present a new strategy aimed at improving the performance of video surveillance systems in terms of human-independent image processing and storing optimization. The proposed methodology is based on real-time thermo-graphic analysis of the area considered. The analysis is performed by processing images acquired with an IR camera and extracting information about meaningful volcanic events. Two software tools were developed. The first provides information about the activity being monitored and automatically adapts the image storing rate. The second tool automatically produces useful information about the eruptive activity encompassed by a selected frame sequence. The software developed includes a suitable user interface allowing for convenient management of the acquired images and easy access to information about the volcanic activity monitored.
    Description: Published
    Description: 85-91
    Description: reserved
    Keywords: Volcano monitoring ; Image processing ; Smart storing rate ; Eruption data ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 483034 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2017-04-04
    Description: Viscosity of water-bearing float glass (0.03–4.87 wt% H2O) was measured in the temperature range of 573–1523 K and pressure range of 50–500 MPa using a parallel plate viscometer in the high viscosity range and the falling sphere method in the low viscosity range. Melt viscosity depends strongly on temperature and water content, but pressure up to 500 MPa has only minor influence. Consistent with previous studies on aluminosilicate compositions we found that the effect of dissolved water is most pronounced at low water content, but it is still noticeable at high water content. A new model for the calculation of the viscosities as a function of temperature and water content is proposed which describes the experimental data with a standard deviation of 0.22 log units. The depression of the glass tran- sition temperature Tg by dissolved water agrees reasonably well with the prediction by the model of Deubener [J. Deubener, R. Mu¨ ller, H. Behrens, G. Heide, J. Non-Cryst. Solids 330 (2003) 268]. Using water speciation measured by near-infrared spectroscopy we infer that although the effect of OH groups in reducing Tg is larger than that of H2O molecules, the difference in the contribution of both species is smaller than predicted by Deubener et al. (2003). Compared to alkalis and alkaline earth elements the effect of protons on glass fragility is small, mainly because of the relatively low concentration of OH groups (max. 1.5 wt% water dissolved as OH) in the glasses.
    Description: Published
    Description: JCR Journal
    Description: open
    Keywords: Glass transition ; Pressure effects ; FTIR measurements ; Alkali silicates ; Silicates ; Soda-lime-silica ; Fragility ; Viscosity ; Water in glass ; 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 ...
  • 7
    Publication Date: 2017-04-04
    Description: Stromboli is a composite volcano, rising about 2.5 km above the sea floor, whose top lies about 1 km above the sea level forming the northernmost island of the Aeolian Archipelago volcanic arc (Tyrrhenian Sea). On December 28th, 2002, lava flows outpoured from the northern wall of NE crater and come down in the Sciara del Fuoco (SdF), a deep depression that marks the NW flank of the volcano edifice. On December 30th, 2002, two landslides occurred on the northern part of the SdF; it moved a mass in the order of tens of millions of cubic meters both above and below the sea level. The landslide produced a tsunami that causes significant damage on the eastern cost of the island, reaching the others Aeolian Islands and the Sicilian and south Italian coasts. This event lead to the upgrade of the ground deformation monitoring system, already existing on the island; the new requirement was the real-time detection of the deformations related to potential slope failures of the SdF. To this aim, a remotely controlled monitoring system, based both on GPS and topographic techniques was planned and set up in few months. The new monitoring system allowed to continuously measure the ground deformations occurring on the SdF, by integrating both terrestrial topographic and satellite geodetic techniques. Despite this system was severely damaged during the 7-months lasting eruption, it allowed to monitor important eruptive phases. For the first time, an accurate data set about the actual mass movements of the SdF and the crater area was available. It provided data that significantly supported the Civil Protection Authorities in making decisions and constrain the hypothesis about the landslide movements and volcanic activity. After the end of the eruption, the system was reinstated in order to optimize the instruments and to set up a monitoring system aimed at measuring deformations forecasting other flank collapses.
    Description: Dipartimento Nazionale della Protezione Civile
    Description: Published
    Description: 13–31
    Description: 1.3. TTC - Sorveglianza geodetica delle aree vulcaniche attive
    Description: JCR Journal
    Description: reserved
    Keywords: Stromboli ; Ground deformation ; Real-time monitoring ; Eruption forecasting ; Landslide forecasting ; 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 ; 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 ...
  • 8
    Publication Date: 2017-04-04
    Description: Viscosity of water-bearing float glass (0.03–4.87 wt% H2O) was measured in the temperature range of 573–1523 K and pressure range of 50–500 MPa using a parallel plate viscometer in the high viscosity range and the falling sphere method in the low viscosity range. Melt viscosity depends strongly on temperature and water content, but pressure up to 500 MPa has only minor influence. Consistent with previous studies on aluminosilicate compositions we found that the effect of dissolved water is most pronounced at low water content, but it is still noticeable at high water content. A new model for the calculation of the viscosities as a function of temperature and water content is proposed which describes the experimental data with a standard deviation of 0.22 log units. The depression of the glass transition temperature Tg by dissolved water agrees reasonably well with the prediction by the model of Deubener [J. Deubener, R. Müller, H. Behrens, G. Heide, J. Non-Cryst. Solids 330 (2003) 268]. Using water speciation measured by near-infrared spectroscopy we infer that although the effect of OH groups in reducing Tg is larger than that of H2O molecules, the difference in the contribution of both species is smaller than predicted by Deubener et al. (2003). Compared to alkalis and alkaline earth elements the effect of protons on glass fragility is small, mainly because of the relatively low concentration of OH groups (max. 1.5 wt% water dissolved as OH) in the glasses.
    Description: Published
    Description: 223-236
    Description: 2.3. TTC - Laboratori di chimica e fisica delle rocce
    Description: JCR Journal
    Description: open
    Keywords: Glass transition ; Pressure effect ; FTIR measurements ; Alkali silicates ; Soda-lime-silica ; Fragility ; Viscosity ; Water in glass ; 04. Solid Earth::04.01. Earth Interior::04.01.05. Rheology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2017-04-04
    Description: Tephra fallout represented a major source of hazard for eastern Sicily during the 2001 eruption of Mt. Etna (Italy) between 19 July and 6 August. Long-lasting explosive activity was generated from the 2570 m vent, producing a volcanic plume up to 5 km high above sea level. The eruption caused copious lapilli and ash fallout over the volcano flanks for several days. Flight operations were cancelled at the Catania and Reggio Calabria airports; health risk and economic damage put communities living close to this active volcano on the alert. The explosive activity at the 2570 m vent had three main phases characterized by phreatomagmatic, magmatic and vulcanian explosions. In this paper, we analyze the first explosive phase between 19 and 24 July that formed a tephra deposit on the volcano's south-east flanks. Immediately after the first phase of the eruption, numerous tephra samples were collected in order to draw an isomass map, calculate physical parameters for the eruption and analyze the plume dispersion on the basis of deposit geometry. The tephra deposit shows a bilobate shape due to the change with time of both the vigour of the eruption and the wind direction and velocity that caused a higher rate of particle accumulation along two dispersal axes (SE and SSE). The total mass of tephra erupted was calculated with two different fitting methods: exponential line segments and a power law fit on the semi-logarithmic plot of mass per unit area versus , resulting in values of 1.02 109 kg and 2.31 109 kg, respectively. The whole deposit grain-size was calculated applying the Voronoi tessellation method, it shows a mode of 2 and thus indicates a high degree of magma fragmentation during the first phase of the eruption. Plume dispersal was investigated by an advection–diffusion model to reconstruct the tephra deposit. In the modelling, we took into account the variations of wind direction and velocity, and eruption intensity by dividing the explosive phase into sixteen sub-eruptions and considering the final deposit as the sum of the mass computed for each sub-eruption. Using best fit procedures, we find that the optimal agreement between computed values and field data is obtained by using the total mass calculated with the power law fit and a terminal settling velocity distribution with a particle aggregation model. The computed tephra dispersal was able to reproduce the bilobate shape of the real deposit. This work proves that advection–diffusion models can describe sedimentation processes of weak, i.e., bent-over, long-lasting plumes if the variations of wind direction and velocity, and eruptive intensity are included.
    Description: Published
    Description: 147-164
    Description: 3.6. Fisica del vulcanismo
    Description: JCR Journal
    Description: reserved
    Keywords: Mt. Etna ; basaltic explosive activity ; violent strombolian eruption ; tephra deposit ; dispersal modelling ; 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 ...
  • 10
    Publication Date: 2017-04-04
    Description: We investigated the relationships between modelled strain produced by explosive activity through a volcanic conduit, observed paroxystic episodes on Mt. Etna, and high-precision continuous tilt signals recorded during such events from the tilt monitoring network. The tilt changes detected during two different explosive episodes were compared with those calculated from analytical models of ground deformation in order to constrain source properties. The July 22, 1998 subplinian explosion from Voragine crater produced small tilt changes (order of 0.5–1.5 μrad) recorded over the entire volcano edifice, implying a small storage at nearly 2.5 km below sea level. The 1998–2000 period was characterized by tens of spectacular lava fountains from the South-East crater. Very small tilt change (∼ 0.1 μrad) was recorded by a single station on the high north-eastern flank of Mt. Etna and indicated the action of a limited and shallow conduit with 1.5–1.9 km depth. These results provide a contribution to better infer the shallow plumbing system beneath Mt. Etna.
    Description: Published
    Description: 221–234
    Description: reserved
    Keywords: explosive activity ; tilt data ; volcano source modeling ; Mt. Etna ; 04. Solid Earth::04.08. Volcanology::04.08.06. Volcano monitoring ; 05. General::05.02. Data dissemination::05.02.03. Volcanic eruptions
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Format: 1124063 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2017-04-04
    Description: Tropospheric volcanic plume features have been derived from airborne multispectral images collected during field measurement campaigns at the Mt. Etna volcano in June 1997, during a quiescent period, and in July 2001 during an eruptive period. Results have been obtained in terms of mapping the volcanic aerosol optical thickness (AOT), the A ˚ ngstro¨ m parameters and the water vapor content using different bands from visible to infrared. The AOT values show average values of 0.1 and 1, for quiescent and eruptive plumes, respectively, demonstrating that this geophysical parameter well indicates a major contribution of particulates in the explosive plume with respect to the quiescent one. The mapping of A ˚ ngstro¨ m parameters, in the explosive case, indicates the presence of larger particles and their distribution along the plume, while in the quiescent case indicates the particle size is dominated by small particles with an effective radius about 1 mm. Further in the quiescent case, the map of water vapor shows low values indicating that water vapor emitted condenses mainly in aerosols.
    Description: Published
    Description: 981-994
    Description: 1.10. TTC - Telerilevamento
    Description: JCR Journal
    Description: reserved
    Keywords: Mt. Etna; Volcanic aerosol; Mivis; Radiative transfer model ; 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 ...
  • 12
    Publication Date: 2023-01-16
    Description: On April 5, 2003, Stromboli volcano (Italy) produced the most violent explosion of the past 50 years. The event was exceptionally well documented thanks to the presence on the island of several scientists and a large number of instruments deployed over the preceding months to monitor the effusive eruption that began in December 2002. Integration of visual documentation, deposit features and geophysical data allowed an accurate reconstruction of the explosive event and its dynamics. The eruption consisted of a 8-min long explosive event which evolved through four phases whose timing was precisely recorded by an infrared thermometer located about 450 m from the summit crater. Phases 2 and 3 lasted 39 and 42 s, respectively. Both had an impulsive character, were responsible for ejecting almost the entire mass of the pyroclastic products. Phases 1 and 4 represented, respectively, a short-lived precursory event and a waning tale. During Phase 2, meter-sized ballistic blocks were launched with velocities of 170 m/s to altitudes of up to 1400 m above the craters. These fell on the volcano flanks and on the village of Ginostra, about 2 km distant from the vent. A vertical jet rose above the craters which developed to feed a convective plume that reached a height of up to 4 km. The calculated mass of the Phase 2 fallout deposit and mass discharge rate were 1.1–1.4×108 kg and 2.8– 3.6×106 kg/s, respectively. During Phase 3 a scoria flow deposit, with an estimated volume of 0.9–1.1×104 m3, was erupted from the same vent that fed the ongoing sustained lava flow. The average mass discharge rate for this phase was 2.5–3.1×105 kg/s. Products emitted during Phases 2 and 3 consisted of lithic and fresh magmatic material in similar proportions. The juvenile fraction consisted of a deep-originated, almost aphyric, highly vesicular pumice mingled with a shallow-derived, crystal-rich, moderately vesicular scoria. Similarities with the eruption dynamics of other historical paroxysms at Stromboli makes the April 5, 2003 explosion representative of these highly energetic events that constitute the most hazardous volcanic phenomena at Stromboli volcano.
    Description: Published
    Description: 594-606
    Description: JCR Journal
    Description: reserved
    Keywords: stromboli ; Thermal monitoring; paroxysm ; explosive dynamics ; ballistic ejecta ; 04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks ; 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 ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...