Maggio 2022

PubAIV Visite: 276
PubAIV 2022
(aggiornamento di Maggio 2022)
TEMATICHE GENERALI:

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

Tematica 1: Magmi e sistemi di alimentazione
Frontoni A., Costa A., Vona A., Romano C. (2022)
A comprehensive database of crystal-bearing magmas for the calibration of a rheological model.
Scientific Data 9, 247
https://doi.org/10.1038/s41597-022-01363-w
Data di pubblicazione: 30/05/2022
PubAIV-ID-00064 - Articolo in Rivista (open access)

Abstract
In this work, we present a comprehensive rheological database including most of the existing data relevant for crystal-bearing magmas collected from the scientific literature, covering the entire range of natural volcanic conditions, in terms of crystal content (1–80%), crystal shape (aspect ratio R from 1 to 13), and strain rate (between 10^−7 and 10^2 s^−1). Datasets were collected and discerned as a function of the information which we considered necessary for building a general systematic model describing relative viscosity of crystal-bearing magmas, such as the apparent and melt viscosity, the crystal concentration, crystal shape, and the strain rate. The selected dataset was then used for modelling the relative viscosity of a liquid-solid mixture having different concentrations of particles with different R, subjected to different strain rates. The proposed model allows us to quantitatively describe the rheological behaviour of crystal-bearing magmatic systems.
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Del Carlo P., Di Roberto A., Di Vincenzo G., Re G., Albert P.G., Nazzari M., Smith V.C., Cannata A. (2022)
Tephrostratigraphy of proximal pyroclastic sequences at Mount Melbourne (northern Victoria Land, Antarctica): Insights into the volcanic activity since the last glacial period.
Journal of Volcanology and Geothermal Research, 422, 107457
https://doi.org/10.1016/j.jvolgeores.2021.107457
Data di pubblicazione: 21/12/2021
PubAIV-ID-00067 - Articolo in Rivista (non-open access)

Abstract
We report on the characterization of a thick sequence of pyroclastic deposits exposed on the summit area and flanks of Mount Melbourne volcano, in northern Victoria Land, Antarctica related to eruptions during the Late Glacial period. We provide a complete characterization of tephra deposits including mineralogy, single shard major- and trace-element glass compositions, and an 40Ar-39Ar age of feldspar crystals extracted from the deposit. The pyroclastic deposits are trachybasaltic to trachytic in composition and are interpreted to have resulted from four Strombolian/Vulcanian to sub-Plinian/Plinian eruptions. The younger and more intense sub-Plinian/Plinian eruption (our eruption 2) yielded an 40Ar-39Ar age of 13.5±4.3 ka (±2σ). The study ofMountMelbourne
proximal deposits provides significant new data for the reconstruction of the volcano eruptive history and a better assessment of the volcanic risk connected to a possible future eruption. We also explore geochemical correlations between MountMelbourne proximal deposits and distal tephra layers recognized in ice cores and blue ice fields of East Antarctica. A good geochemical match exists between the composition
of products from the trachytic sub-Plinian/Plinian eruption 2 and some tephra layers from Talos Dome and shards in Siple Dome which is also compatible in age (c. 9.3 ka) with our 40Ar-39Ar age determination. Our new insights into the volcanic history of Mount Melbourne and the new high-quality electron microprobe and trace element composition data on its proximal productswill help improve future correlations and synchronization of tephra archives in the region.
Tematica 2: Dinamiche eruttive e di messa in posto
Knuever M., Sulpizio R., Mele D., Costa A. (2022)
Magma–rock interactions: a review of their influence on magma rising processes with emphasis on short-timescale assimilation of carbonate rocks.
Di Capua, A., De Rosa, R., Kereszturi, G., Le Pera, E., Rosi, M. and Watt, S. F. L. (eds) Volcanic Processes in the Sedimentary Record: When Volcanoes Meet the Environment. Geological Society, London, Special Publications, 520
https://doi.org/10.1144/SP520-2021-177
Data di pubblicazione: 01/06/2022
PubAIV-ID-00065 - Capitolo di un Libro (non-open access)

Abstract
The interaction of magma and wall-rocks is inevitable when magma is moving through Earth's crust. These interactions happen on different timescales and especially the short-term interactions (seconds to days) during the final ascent of the magma can induce changes in eruption dynamics. However, information on this matter is scarce and scattered in different scientific fields. We conducted this review in order to present a full picture of the state of the art for short-timescale magma–wall-rock interactions. According to the three existing studies on short-term magma–carbonate interactions, magma viscosity is the most important controlling factor for carbonate assimilation. Lower viscosity magmas enhance CO2-bubble migration away from the reaction site, resulting in a higher carbonate assimilation rate. The released CO2 plays an important role regarding eruption dynamics since a higher CO2 release rate would result in accelerated magma ascent and may increase eruption intensity. Despite the importance for hazard assessment, important factors (pressure, magma composition, vapour phase solubilities, carbonate clast properties) for carbonate assimilation in general and CO2 release rate in particular are not or only poorly constrained. This review presents the present-day knowledge of short-term magma–carbonate interaction that is relevant to establish the basis for future work concerning magma–wall-rock interactions.
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Tematica 3: Geologia e struttura dei vulcani
Tematica 4: Monitoraggio, pericolosità e rischio vulcanico
Sciotto M., Cannata A., Di Grazia G., Montalto P. (2022)
Volcanic tremor and long period events at Mt. Etna: Same mechanism at different rates or not?
Physics of the Earth and Planetary Interiors, 324, 106850
https://doi.org/10.1016/j.pepi.2022.106850
Data di pubblicazione: 01/03/2022
PubAIV-ID-00066 - Articolo in Rivista (non-open access)

Abstract
Volcanic tremor and long period (LP) events are typical seismic signals recorded on active volcanoes and are characterized by different durations, longer than minutes and a few seconds - tens of seconds for the former and latter, respectively. As they share the same frequency content, they are often grouped together in the literature and referred to by the unique name of LP seismicity. The common spectral features, together with observations in some volcanoes of individual LP events merging to form volcanic tremor, led to hypotheses that LP events and volcanic tremor share the same source mechanism. However, it is still open to debate whether volcanic tremor can be considered a simple coalescence of LP events or not. In this work, to help answer such a question, we analysed volcanic tremor and LP events recorded at Mt. Etna during the period February 2019–June 2020, characterized by minor eruptive activity, varying from weak ash emission to explosive and effusive eruptions at all the summit craters. Results from spectral, amplitude and location analyses, as well as the different scaling laws explaining the distributions of the duration/number of events versus size, led us to infer that LP events and volcanic tremor at Mt. Etna are not due to a common source mechanism.
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