Marzo 2023

PubAIV 2023
(aggiornamento di Marzo 2023)

1) Magmi e sistemi di alimentazione (1 articolo) 
2) Dinamiche eruttive e di messa in posto (3 articoli)
3) Geologia e struttura dei vulcani (1 articolo)
4) Monitoraggio, pericolosità e rischio vulcanico (0 articoli)
5) Vulcani e società (0 articoli)

Tematica 1: Magmi e sistemi di alimentazione
Longo A., Garg D., Papale P., Montagna C.P. (2023)
Dynamics of Magma Chamber Replenishment Under Buoyancy and Pressure Forces.
Journal of Geophysical Research: Solid Earth, 128, e2022JB025316
Data di pubblicazione: 10/01/2023
PubAIV-ID-00101 - Articolo in Rivista (open access)

Active magma chambers are periodically replenished upon a combination of buoyancy and pressure forces driving upward motion of initially deep magma. Such periodic replenishments concur to determine the chemical evolution of shallow magmas, they are often associated to volcanic unrests, and they are nearly ubiquitously found to shortly precede a volcanic eruption. Here, we numerically simulate the dynamics of shallow magma chamber replenishment by systematically investigating the roles of buoyancy and pressure forces, from pure buoyancy to pure pressure conditions and across combinations of them. Our numerical results refer to volcanic systems that are not frequently erupting, for which magma at shallow level is isolated from the surface (“closed conduit” volcanoes). The results depict a variety of dynamic evolutions, with the pure buoyant end-member associated with effective convection and mixing and generation of no or negative overpressure in the shallow chamber, and the pure pressure end-member translating into effective shallow pressure increase without any dynamics of magma convection associated. Mixed conditions with variable extents of buoyancy and pressure forces illustrate dynamics initially dominated by overpressure, then, over the longer term, by buoyancy forces. Results globally suggest that many shallow magmatic systems may evolve during their lifetime under the control of buoyancy forces, likely triggered by shallow magma degassing. That naturally leads to long-term stable dynamic conditions characterized by periodic replenishments of shallow partially degassed, heavier magma by volatile-rich fresh deep magma, similar to those reconstructed from petrology of many shallow-emplaced magmatic bodies.
Tematica 2: Dinamiche eruttive e di messa in posto
Di Roberto, A., Re, G., Scateni, B., Petrelli, M., Tesi, T., Capotondi, L., Morigi C., Galli G., Colizza E., Melis R., Torricella F., Giordano G., Giglio F., Gallerani A., Gariboldi K. (2023)
Cryptotephras in the marine sediment record of the Edisto Inlet, Ross Sea: Implications for the volcanology and tephrochronology of northern Victoria Land, Antarctica.
Quaternary Science Advances, 100079.
Data di pubblicazione: 18/02/2023
PubAIV-ID-00102 - Articolo in Rivista (open access)

We present the results of the tephrochronology study of a 14.49 m long marine sediment core (TR 17–08) collected in the Edisto Inlet, Ross Sea (Antarctica). The core contains four cryptotephra layers at 55–56, 512–513, 517–518, and 524–525 cm of depth, which have been characterised by a detailed description of the texture, mineral assemblage, and single glass shards major and trace element geochemistry. The age model of the investigated sedimentary sequence, based on radiocarbon dating, indicates that the topmost cryptotephra correlates with the widespread 1254 CE tephra erupted by a historical eruption (696 ± 2 cal yrs BP) of Mount Rittmann, in northern Victoria Land. Deeper cryptotephra layers were derived from previously unknown explosive eruptions of Mount Melbourne volcano and were emplaced between 1615 cal yrs BP and 1677 cal yrs BP, e.g. between the 3rd and 4th centuries CE. This discovery demonstrates that the Mount Melbourne volcanic complex has been highly active in historical times allowing significant progress in the current understanding of regional eruptive history. Moreover, from a tephrochronological point of view, the detected cryptotephra provide new regional isochron markers to facilitate high-precision correlations and help stratigraphically constrain changes in environmental and climatic conditions that are identified by multidisciplinary studies.
Di Traglia F., Calvari C., Borselli L., Cassanego L., Giudicepietro F., Macedonio G., Nolesini T., Casagli N. (2023)
Assessing flank instability of Stromboli volcano (Italy) by reappraising the 30 December 2002 tsunamigenic landslides.
Data di pubblicazione: 13/03/2023
PubAIV-ID-00105 - Articolo in Rivista (open access)

Bearing in mind the destructive potential of tsunamis induced by volcanic landslides, the tsunamigenic event occurring at Stromboli volcano in Italy on 30 December 2002 has been re-examined here, by means of visible images and slope stability analysis. This was one of the few examples in the world of a flank collapse occurring at a volcano that was directly observed. We present the results of stability analyses, together with a sequence of photos collected from a helicopter a few minutes before the collapse. The result of this study is that the sequence of landslides triggering the 2002 Stromboli tsunami can be defined as the final stage of a lateral magma intrusion that exerted a high thrust at high altitude, destabilizing the entire slope. This study allows a more complete understanding of the event that took place on Stromboli on 30 December 2002. Furthermore, the approach used here, if appropriately modified, can be used in other contexts, contributing to the understanding of the condition that leads to tsunamigenic landslides.
Visalli R., Giuffrida M., Viccaro M. (2023)
Unraveling textural and chemical features in volcanic rocks through advanced image processing: a case study from the 2019 paroxysmal eruptions of Stromboli.
Geochemistry, Geophysics, Geosystems, 24, e2022GC010774.
Data di pubblicazione: 28/02/2023
PubAIV-ID-00103 - Articolo in Rivista (open access)

The Quantitative X-Ray Map Analyzer software, a new tool for image processing, has been tested on intertwined pumices and scoriae emitted during the two paroxysmal eruptions of Stromboli of 2019, whose textural and compositional heterogeneities reflect the coexistence of low porphyritic shoshonitic-basalts and high porphyritic shoshonites. The procedure applied was designed to quantitatively document the complex variations in texture and composition of these products, allowing substantial time reduction of analytical and data processing. The procedure utilizes Principal Components Analysis and supervised Maximum Likelihood Classification for multivariate statistical data handling of an array of X-ray elemental maps acquired at the millimeter scale in thin-sections. This technique permits the production of high-contrast colored images, which allow the classification of rock constituents, extrapolating the associated modal abundances and imaging chemical variations within the glass. Results highlight the close interconnection at the microscale of two types of magma in the erupted products, manifested in each processed image by the presence of contiguous areas preserving textural bulk properties typical of the pumice or scoria. The proportion of the two magmas feeding the eruptions is not simply represented by the proportions of scoria and pumice in individual clasts, as both scoria and pumice contain glass with the composition of shoshonitic-basalts and shoshonites. This method also allows the recognition of important discordances between the textural and chemical features of the two fractions involved, as well as discernment of the compositions of the two interacting magmas at the microscopic scale, even in those micro-domains showing evidence of intense interaction processes.
Tematica 3: Geologia e struttura dei vulcani
Galetto F., Pritchard M. E., Hornby A. J., Gazel E., Mahowald N. M. (2023)
Spatial and Temporal Quantification of Subaerial Volcanism From 1980 to 2019: Solid Products, Masses, and Average Eruptive Rates.
Reviews of Geophysics, e2022RG000783.
Data di pubblicazione: 02/03/2023
PubAIV-ID-00104 - Articolo in Rivista (non-open access)

Volcanism is one of the main mechanisms transferring mass and energy between the interior of the Earth and the Earth's surface. However, the global mass flux of lava, volcanic ash and explosive pyroclastic deposits is not well constrained. Here we review published estimates of the mass of the erupted products from 1980 to 2019 by a global compilation. We identified 1,064 magmatic eruptions that occurred between 1980 and 2019 from the Smithsonian Global Volcanism Program database. For each eruption, we reported both the total erupted mass and its partitioning into the different volcanic products. Using this data set, we quantified the temporal and spatial evolution of subaerial volcanism and its products from 1980 to 2019 at a global and regional scale. The mass of magma erupted in each analyzed decade ranged from 1.1–4.9 × 10^13 kg. Lava is the main subaerial erupted product representing ∼57% of the total erupted mass of magma. The products related to the biggest eruptions (Magnitude ≥6), with long recurrence times, can temporarily make explosive products more abundant than lava (e.g., decade 1990–1999). Twenty-three volcanoes produced ∼72% of the total mass, while two different sets of 15 volcanoes erupted >70% of the total mass of either effusive or explosive products. At a global scale, the 10 and 40-year average eruptive rates calculated from 1980 to 2019 have the same magnitude as the long-term average eruptive rates (from thousand to millions of years), because in both cases rates are scaled for times comparable to the recurrence time of the biggest eruptions occurred.
Tematica 4: Monitoraggio, pericolosità e rischio vulcanico
Tematica 5: Vulcani e società
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