Search results for "etna"

Environmental impact of magmatic fluorine emission in the Mt. Etna area

2007

The sustained and uninterrupted plume degassing at Mount Etna volcano, Southern Italy, represents the troposphere's most prominent natural source of fluorine. Of the ∼ 200 Mg of fluorine (as HFg) emitted daily by the volcano, 1.6 ± 2.7 Mg are deposited by wet and dry deposition. Fluorine-deposition via volcanic ash, here characterised for the first time, can be quite significant during volcanic eruptions (i.e. 60 Mg of fluorine were deposited during the 2001 eruption through volcanic ash, corresponding to ∼ 85% of the total fluorine deposition). Despite the fact that these depositions are huge, the fate of the deposited fluorine and its impact on the environment are poorly understood. We he…

Determinazione in continuo di CO2, CH4 e H2Ov in ambiente atmosferico attraverso tecnica ad assorbimento laser (UGGA)

2015

Molti dei composti chimici presenti nell’atmosfera terrestre prendono il nome di “gas serra”. Queste specie gassose consentono alla radiazione solare di entrare liberamente nell’atmosfera e di trattenere parte della radiazione solare riflessa dalla superficie terrestre come energia termica. Nel corso del tempo si instaura un complesso equilibrio termico tra la quantità di energia inviata dal sole e quella irradiata dalla superficie. L’alterazione di questo equilibrio, con l’aumento di uno o più gas serra in atmosfera, porta a degli squilibri termici e un conseguente innalzamento delle temperature. Questo fenomeno è definito come “effetto serra”. I principali gas serra in natura che prendono…

The impact of Mt. Etna's ash plume on the chemical composition of meteoric deposition

2019

Mt. Etna, in eastern coast of Sicily (Italy), is one of the most active and most intensely monitored volcanoes of the planet. It is the biggest volcanic point source of volcanic gases and particles to the troposphere in the Mediterranean basin. On the morning of December 24th 2018, a new lateral eruption of the Mount Etna started. This eruption was related to an intrusion of a magmatic dike on the high eastern flank of the volcano, which a two kilometers long fracture in the NNW - SSE direction. At the same time, the summit craters also produced a continuous strombolian activity generating a very dense dark ash plume, dispersed by the wind into the southeastern direction. This volcanic even…

The flight of Arcadia: spatial CO2/SO2 variations in a cross section above the Nord East crater of Etna volcano

2015

The CO2/SO2 ratio in volcanic plumes of open conduit volcanoes can provide useful information about the magma depth inside a conduit and the possible occurrence of an eruptive event. Moreover, the same CO2 measurement when combined with a SO2 flux measurement, commonly carried out at many volcanoes nowadays, is used to contribute to an improved estimate of global volcanic CO2 budget. Today worldwide at 13 volcanoes automated in-situ instruments (known as Multi-GAS stations) are applied to continuously determine CO2/SO2 ratios and to use this signal as additional parameter for volcanic monitoring. Usually these instruments carry out measurements of half an hour 4 – 6 times/day and thus provi…

Biomonitoring of volcanogenic trace elements using two endemic species (Senecio aethnensis and Rumex aethnensis) on Mt. Etna.

2009

A biomonitoring survey, above treeline level, using two endemic species (Senecio aethnensis and Rumex aethnensis) was performed on Mt. Etna, in order to evaluate the dispersion and the impact of volcanic emissions. Samples of leaves were collected in summer 2008 from 30 sites in the upper part of the volcano (1500-3000 m a.s.l). Acid digestion of samples was carried out with a microwave oven, and 44 elements were analysed by using plasma spectrometry (ICP-MS and ICP-OES). The highest concentrations of all investigated elements were found in the samples collected closest to the degassing craters, and in the downwind sector, confirming that the eastern flank of Mt. Etna is the most impacted b…

Volcano seismicity and ground deformation unveil the gravity-driven magma discharge dynamics of a volcanic eruption.

2015

Effusive eruptions are explained as the mechanism by which volcanoes restore the equilibrium perturbed by magma rising in a chamber deep in the crust. Seismic, ground deformation and topographic measurements are compared with effusion rate during the 2007 Stromboli eruption, drawing an eruptive scenario that shifts our attention from the interior of the crust to the surface. The eruption is modelled as a gravity-driven drainage of magma stored in the volcanic edifice with a minor contribution of magma supplied at a steady rate from a deep reservoir. Here we show that the discharge rate can be predicted by the contraction of the volcano edifice and that the very-long-period seismicity migrat…

Molecular and isotopic composition of free hydrocarbon gases from Sicily, Italy

2004

Chemical and isotopic data have been used as geochemical tracers for a genetic characterization of hydrocarbon gases from a total of eleven manifestations located in Eastern and Central-Southern Sicily (Italy). The molecular analysis shows that almost all the samples are enriched in methane (up to 93.2% Vol.), with the exception of four gas samples collected around Mt. Etna showing high mantle-derived CO2 content. Methane isotope signatures suggest that these are thermogenic gases or a mixture between thermogenic gases and microbial gases. Although samples from some mud volcanoes in Southern Sicily (Macalube di Aragona) show isotope signatures consistent with a mixing model between thermoge…

Noble gases investigation in fluid inclusions of olivines and pyroxenes from Etnean products erupted in the 2001-2004 period.

2008

Elemental and isotope covariation of noble gases in olivines and pyroxenes from Etnean volcanics erupted during 2001-2005, and genetic relation with …

2009

Alocucion de ... Pio ... VI tenida en el Consistorio secreto dia 13 de Noviembre 1775 de la preciosa muerte de Jacinto Castañeda español i Vicente …

1775

Corren exemplars sense port., que comencen amb una carta introductòria de Fr. Francisco Ruiz, Provincial de la Província d'Aragó i que inclouen, al verso de la p. 11, una oració del dit Provincial Escut xil. de Pius VI en les dues port. enfrentades Sign.: [ ]8 Notes a peu de pàg Reclams Doble port., en llatí i en castellà, i text bilingüe a dues col.: llatí i castellà