ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Publication Date: 2021-02-03
    Description: In the presented work, the spectral emissivity of basaltic melts at magmatic temperatures was retrieved in a laboratory-controlled experiment by measuring their spectral radiance. Granulated bombs of Etnean basalts were melted and the radiant energy from the melting surface was recorded by a portable spectroradiometer in the short wavelength infrared (SWIR) spectral range between 1500 and 2500 nm. The Draping algorithm, an improved algorithm for temperature and emissivity separation, was applied for the first time to SWIR hyperspectral data in order to take into account the non-uniform temperature distribution of the melt surface and, at the same time, solving the two temperatures and the spectral emissivity. The results have been validated by comparing our results with the emissivity measured at a "lava simulator". Basalt spectral emissivity does not vary significantly at magmatic temperature, but shows an absorption feature in the range 2180–2290 nm, an atmospheric window pivotal for the IR remote sensing of active volcanoes
    Description: Published
    Description: 2046
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Keywords: temperature–emissivity separation ; Draping ; thermal remote sensing ; Lab experiment ; 04.08. Volcanology ; solid Earth
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2021-01-19
    Description: Multiparametric observations integrate signals from different techniques into a unified time and space frame, and are key in understanding and monitoring the evolution of volcanic systems and eruptive activity. Mafic explosive eruptions, with a relatively high frequency of occurrence and low intensity, allow for detailed multiparametric observations at a relatively close distance. Typically, pyroclast ejection in these eruptions is not steady, but is characterized by the occurrence of ejection pulses, linked to pressure release events and featuring a characteristic nonlinear decay of pyroclasts exit velocity. Pulse frequency, duration, and exit velocity define the dominant eruptive style, function of the volume and pressure of the released gas, conduit size, and magma rheological-mechanical properties. No important differences in pressure and velocity divide eruptions with different magnitude and style. Ejection pulses influence the geophysical signature, plume development, and the emplacement of ballistic volcanic projectiles at eruptions from Strombolian to Vulcanian styles.
    Description: Published
    Description: 379-411
    Description: 4V. Processi pre-eruttivi
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Keywords: Mafic eruption, Multiparametric monitoring, Eruption imaging, Volcano acoustic, Strombolian, Plume, Vent, Ballistic ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: book chapter
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2021-06-21
    Description: An unmanned aerial vehicle provided the high-resolution data that allowed scientists to construct their first detailed map of erupting vents at Stromboli, one of the world’s most active volcanoes.
    Description: This study was supported by funding from the National Science Foundation (NSF EAR14-27357) and the VERTIGO Marie Curie ITN, funded through the European Seventh Framework Programme (FP7 2007-2013) under grant agreement 607905.
    Description: Published
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: N/A or not JCR
    Keywords: UAV ; drone ; Stromboli ; eruptive dynamics ; DEM ; 04.08. Volcanology
    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: 2021-06-25
    Description: In a Strombolian volcanic eruption, bursting of a pressurized gas pocket produces and accelerates a mixture of gas and pyroclasts along a conduit and out of a vent. While mixture ejection at the vent is the subject of direct geophysical measurements, and a key to eruption understanding, the dynamics of how the mixture moves in the conduit are not observable and only partly understood. Here, we use analog, transparent shock tube experiments to study the dynamics of gas and particles under fast gas decompression in a vertical tube. Maximum particle exit velocity increases linearly with increasing energy (pressure times volume) of the pressurized gas, and, subordinately, with decreasing particle size and depth in the tube. Particles, initially at rest, are at first accelerated and dispersed in the conduit by the expanding gas. When the gas decelerates or even reverts its motion due to pressure changes in the tube, the particles, moving under their inertia, are then decelerated by the gas drag. Deceleration lasts longer for lower initial gas energy and for deeper particle starting position. Experiments and eruptions share two key vent ejection dynamics: 1) particles exit the vent already decelerating, and 2) the exit velocity of the particles decays over time following the same non-linear law. Friction with slower, or even back-flowing gas likely causes pyroclast deceleration in volcanic conduits during Strombolian explosions. Pyroclast deceleration, in turn, affects their exit velocity at the vent, as well as current estimates of the source depth of the explosions.
    Description: Published
    Description: e2019JB019182
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Keywords: Strombolian explosion ; volcanic conduit ; shock tube ; pyroclast ejection ; 04.08. Volcanology
    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: 2020-02-18
    Description: Explosive volcanic eruptions eject a mixture of rock/magma fragments and gases. Ground-based eruption imaging, combining thermal infrared, high-speed visible, and ultraviolet videos, can parameterize ejection dynamics and gas/fragment ratios at the seconds and centimeter
    Description: Published
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: N/A or not JCR
    Keywords: High speed photography; Laser velocimetry; Metrological instrumentation; Multispectral imaging; Optical flow; Thermal infrared imaging ; 04.08. Volcanology
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2019-03-27
    Description: Ash deposited during volcanic eruptions can be resuspended by wind and become hazardous for health and infrastructure hours to decades after an eruption. Accurate resuspension forecasting requires accurate modelling of the threshold friction velocity of the volcanic particles (Uth*), which is the key parameter controlling volcanic ash detachment by wind. Using an environmental wind tunnel facility this study provides much needed experimental data on volcanic particle resuspension, with the first systematic parameterization of Uth* for ash from the regions Campi Flegrei in Italy and also Eyjafjallajökull in Iceland. In this study atmospheric relative humidity (and related ash moisture content) was systematically varied, from 〈10% to 〉90%, which in the case of the Eyjafjallajökull fine ash (〈63 μm) produced a twofold increase in Uth*. Using the Campi Flegrei fine ash (〈63 μm) an increase in Uth* of only around a factor of 1.5 was observed. Reasonable agreement with force balance resuspension models was seen, which implied an increase in interparticle adhesion force of up to a factor of six due to high humidity. Our results imply that, contrary to dry conditions, one single modelling scheme may not satisfy the resuspension of volcanic ash from different eruptions under wet conditions.
    Description: Funded by Europlanet 2020 RI under the European Union’s Horizon 2020 research and innovation programme and grant agreement No 654208, Conv. INGV-DPC B2 2016 - Centro di Pericolosità Vulcanica, and by the Marie Curie Initial Training Network ‘VERTIGO’, funded through the European Seventh Framework Programme (FP7 2007–2013) under Grant Agreement number 607905. Optical granunlometry, SEM and Helium Pycnometer analyses are from HP-HT Laboratories of Experimental Volcanology and Geophysics at INGV- Roma.
    Description: Published
    Description: 14509
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Keywords: detachment thresold ; volcanic ash ; wind friction velocity ; wind tunnel ; 04.08. Volcanology ; 01.01. Atmosphere
    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: 2020-02-06
    Description: Basaltic volcanism is the most widespread volcanic activity on Earth and planetary bodies. On Earth, eruptions can impact global and regional climate, and threaten populations living in their shadow, through a combination of ash, gas and lava. Ash emissions are a very typical manifestation of basaltic activity; however, despite their frequency of occurrence, a systematic investigation of basaltic ash sources is currently incomplete. Here, we revise four cases of ash emissions at Mount Etna linked with the most common style of eruptive activity at this volcano: lava fountains (4–5 September 2007), continuous Strombolian activity transitioning to pulsing lava fountaining (24 November 2006), isolated Strombolian explosions (8 April 2010), and continuous to pulsing ash explosions (last phase of 2001 eruption). By combining observations on the eruptive style, deposit features and ash characteristics, we propose three mechanisms of ash generation based on variations in the magma mass flow rate. We then present an analysis of magma residence time within the conduit for both cylindrical and dike geometry, and find that the proportion of tachylite magma residing in the conduit is very small compared to sideromelane, in agreement with observations of ash componentry for lava fountain episodes at Mount Etna. The results of this study are relevant to classify ash emission sources and improve hazard mitigation strategies at basaltic volcanoes where the explosive activity is similar to Mount Etna.
    Description: Published
    Description: Article 193
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: JCR Journal
    Keywords: 04.08. Volcanology
    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: 2022-02-11
    Description: The resuspension of volcanic ash by wind is a significant source of hazard during and after volcanic eruptions. Parameterizing and modeling ash resuspension requires direct measurement of the minimum wind shear stress required to move particles, usually expressed as the threshold friction velocity U*th, a parameter that, for volcanic ash, has been measured only scarcely and always in the laboratory. Here, we report the first field measurements of U*th for volcanic ash, with a portable wind tunnel specifically developed, calibrated, and tested. Field measurements, performed on natural reworked ash deposits from Sakurajima (Japan) and Cordón Caulle (Chile) volcanoes, agree well with our laboratory determinations on ash from the same deposits, with values of U*th ranging from 0.13 to 0.38 m/s. Our results show that the median grain size of the deposit and particle shape have a stronger control on U*th than the local substratum nature and deposit texture.
    Description: Published
    Description: 116684
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Keywords: wind resuspension ; wind tunnel ; detachment threshold ; volcanic ash ; Sakurajima volcano ; Cordon Caulle volcano ; 04.08. Volcanology
    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...