Maggio 2023

PubAIV Visite: 352
PubAIV 2023
(aggiornamento di Maggio 2023)
TEMATICHE GENERALI:

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

Tematica 1: Magmi e sistemi di alimentazione
Tematica 2: Dinamiche eruttive e di messa in posto
Tematica 3: Geologia e struttura dei vulcani
Tematica 4: Monitoraggio, pericolosità e rischio vulcanico
Costa G., Mereu L., Prestifilippo M., Scollo S., Viccaro M. (2023)
Modeling the Trajectories of Ballistics in the Summit Area of Mt. Etna (Italy) during the 2020–2022 Sequence of Lava Fountains.
Geosciences 13, 145
https://doi.org/10.3390/geosciences13050145
Data di pubblicazione: 12/05/2023
PubAIV-ID-00109 - Articolo in Rivista (open access)
Abstract
Between 2020 and 2022, more than sixty lava fountains occurred at Mt. Etna (Italy), which formed high eruption columns rising up to 15 km above sea level (a.s.l.). During those events, several ballistics fell around the summit craters, sometimes reaching touristic areas. The rather frequent activity poses questions on how the impact associated with the fallout of those particles, can be estimated. In this work, we present field data collected soon after the lava fountain on 21 February 2022. This event produced a volcanic plume of about 10 km a.s.l. which was directed toward the southeast. Several ballistics fell in the area of the Barbagallo Craters (just southeast of the summit area at around 2900 m a.s.l.), which is one of the most popular touristic areas on Etna. Hence, we collected several samples and performed laboratory analyses in order to retrieve their size, shape and density. Those values together with a quantitative analysis of the lava fountain were compared with results obtained by a free-available calculator of ballistic trajectories named the ‘Eject!’. A similar approach was hence applied to other lava fountains of the 2020–2022 sequence for which the fallout of large clasts was reported. This work is a first step to identifying in near real-time the area affected by the fallout of ballistics during Etna lava fountains and quantifying their hazard.
Galetto F., Reale D., Sansosti E., Acocella V. (2023)
Implications for Shallow Magma Transfer During the 2017 and 2018 Eruptions at Fernandina (Galápagos) Inferred From InSAR Data.
Journal of Geophysical Research: Solid Earth, e2022JB026174
https://doi.org/10.1029/2022JB026174
Data di pubblicazione: 27/05/2023
PubAIV-ID-00110 - Articolo in Rivista (non-open access)
Abstract
Previous work at Fernandina, the most active volcano of the Western Galápagos (Ecuador),
revealed evidence for both a shallow and a deep magma reservoir, but the relative contribution of the two
reservoirs to eruptions remains unclear. Here we investigate the September 2017 circumferential eruption and
the June 2018 radial eruption using interferometric synthetic aperture radar data and geodetic modeling. Our
results show that during the 2017 eruption magma was simultaneously withdrawn from the deep reservoir,
injected upwards through the shallow reservoir, and then fed the circumferential feeder dike to the SW of the
caldera. Two episodes of inflow of new magma occurred in both the deep and shallow magma reservoirs in
the inter-eruptive period from December 2017 to May 2018. During the 2018 eruption, both reservoirs fed
two radial feeder dikes below the north flank, probably interacting with an underlying peripheral melt pocket,
and an inclined sheet below the NW sector of the caldera. Our results highlight the primary role of the deeper
reservoir which accumulates most of the magma before eruptions. Both eruptions were characterized by rapid
magma transfer from the deeper to the shallower reservoir. This is similar to what is observed at the nearby
Wolf volcano, but unlike nearby Sierra Negra, where a shallower reservoir accumulates higher volumes of
magma before eruptions. These differences in the pre-eruptive role of the deeper and shallower reservoirs might
be related to the different evolutionary stages of Fernandina and Wolf with regard to the more mature Sierra
Negra.
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Pensa A., Giordano G., Corrado S., Petrone P.P. (2023)
A new hazard scenario at Vesuvius: deadly thermal impact of detached ash cloud surges in 79CE at Herculaneum.
Scientific Reports 13, 5622
https://doi.org/10.1038/s41598-023-32623-3
Data di pubblicazione: 06/04/2023
PubAIV-ID-00108 - Articolo in Rivista (open access)
Abstract
Diluted pyroclastic density currents are capable to cause huge devastation and mortality around volcanoes, and temperature is a crucial parameter in assessing their lethal power. Reflectance analysis on carbonized wood from ancient Herculaneum allowed a new reconstruction of the thermal events that affected buildings and humans during the 79CE Vesuvius eruption. Here we show that the first PDC entered the town was a short-lived, ash cloud surge, with temperatures of 555–495 °C, capable of causing instant death of people, while leaving only a few decimeters of ash on ground, which we interpret as detached from high concentration currents. The subsequent pyroclastic currents that progressively buried the town were mostly higher concentration PDCs at lower temperatures, between 465 and 390 and 350–315 °C. Charcoal proved to be the only proxy capable of recording multiple, ephemeral extreme thermal events, thus revealing for the first time the real thermal impact of the 79CE eruption. The lethal impact documented for diluted PDC produced during ancient and recent volcanic eruptions suggests that such hazard deserves greater consideration at Vesuvius and elsewhere, especially the underestimated hazard associated with hot detached ash cloud surges, which, though short lived, may expose buildings to severe heat damages and people to death.
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Tematica 5: Vulcani e società
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