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Randazzo, Loredana
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- PublicationRestrictedImpact of hydrothermal alteration processes on element mobility and potential environmental implications at the Sousaki solfataric field (Corinthia - Greece)(2020-12)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Samples of efflorescences and encrustations of hydrothermal origin were collected at Sousaki (Greece) and analysed for their mineralogical (XRD) and chemical composition. Solutions obtained both from mineralization with HNO3 and from leaching with deionised water were analysed for major (ICP-OES), minor and trace metals (ICP-MS) and sulfate contents (IC). Results evidence the dependence of the chemical and mineralogical composition on micro-environmental conditions i.e. humidity, oxygen-rich or -poor environment, exposed or sheltered from meteoric agents. In fact, the presence of highly soluble sulfate minerals with elevated contents of many metals (e.g. Mg, Al, Fe, Mn, Cr, Ni, etc.) further underscores the important influence of hydrothermal activity on elements' mobility, whilst the sometimes very high concentrations in toxic elements like Al, Cr, Ni suggest also possible environmental impacts.524 17 - PublicationRestrictedDifferent methods for soluble salt removal tested on late-Roman cooking ware from a submarine excavation at the island of Pantelleria (Sicily, Italy)(2014-07)
; ; ; ; ; ; ;Montana, G. ;Randazzo, L. ;Castiglia, A. ;La Russa, M. F. ;La Rocca, R. ;Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ; ; ; ; ;tThis paper deals with the comparative evaluation of different procedures of salt extraction designed forarchaeological ceramics from submarine burial environments. The experimental work was carried outon a particular type of late-Roman cooking ware finds (Pantellerian ware) found in a shipwreck near theshoreline of the Island of Pantelleria (Sicily). The studied ceramic test-pieces were first recognised in termsof bulk characteristics (mineralogy, petrography and chemistry). SEM-EDS observation allowed verifica-tion of the presence of various secondary minerals at the surface and in the pore spaces formed after theprolonged permanence in seawater under oxidising or reducing conditions. Pore-size distribution wasalso determined in the same fragments that had been subjected to the salt extraction routines. Threesalt extraction methods were tested: two methods based on diffusion processes (water immersion understationary conditions and under mechanical stirring conditions) and one method based on both diffusiveand advective processes (multiple packages of sepiolite). The obtained experimental data allowed us toidentify strengths and weaknesses of the tested procedures with practical spin-off for archaeologists andrestorers (efficiency, kinetics, compatibility with the ceramic substrate, costs and simplicity of use). Saltextraction under mechanical stirring was the most effective method and, for this reason, is suitable forlaboratory fieldwork during or immediately after submarine archaeological excavations. Similar advan-tages are also intended for the preliminary treatments of the most precious findings prior to museumstorage.319 51 - PublicationRestrictedPossible impacts of volcanic ash emissions of Mount Etna on the primary productivity in the oligotrophic Mediterranean Sea: Results from nutrient-release experiments in seawater(2013)
; ; ; ; ; ; ; ; ;Olgun, N.; Dynamics of the Ocean Floor Division, Helmholtz-Center for Ocean Research, GEOMAR, Kiel, Germany ;Duggen, S.; Dynamics of the Ocean Floor Division, Helmholtz-Center for Ocean Research, GEOMAR, Kiel, Germany ;Andronico, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Kutterolf, S.; Dynamics of the Ocean Floor Division, Helmholtz-Center for Ocean Research, GEOMAR, Kiel, Germany ;Croot, P. L.; Marine Biogeochemistry Division, Helmholtz-Center for Ocean Research, GEOMAR, Kiel, Germany ;Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Censi, P.; Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università di Palermo, Via Archirafi, 36 90123 Palermo, Italy ;Randazzo, L.; Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università di Palermo, Via Archirafi, 36 90123 Palermo, Italy; ; ; ; ; ; ; Atmospheric deposition of volcanic ash has recently been recognized as an important nutrient source into the surface ocean. Mount Etna (Italy), one of the world's most active volcanoes, is located in the oligotrophic Mediterranean Sea (MedSea). Despite the active volcanismonMount Etna, the biogeochemical impacts of volcanic ash fallouts on the marine primary productivity (MPP) remain largely unknown. Here we present the results of seawater nutrient release experiments with volcanic ash samples fromMount Etna that have been collected during different eruptive episodes between 2001 and 2007. Our results show that volcanic ash fromMount Etna releases significant amounts of fixed-N (35–855 nmol/g), P (7–970 nmol/g), Si (3–2060 nmol/g), Fe (10–130 nmol/g) and Zn (b21 nmol/g). We further estimated an example representative of ash-fall from Etna based on the case-study focusing on 4–5 November 2002 activity, by using the general relation between the thicknesses of the ash deposits and the ash depositional areas. Etna explosive eruptions can transport volcanic ash as far as 800 km,with ashemissions exceeding the particle flux during dust stormevents (of 10 g/m2 input) as far as 400 km downwind fromthe volcano. Our results emphasize that Etna ash can provide a significant supply of nutrients, which can favor theMPP in the central MedSea.302 69 - PublicationOpen AccessVolcanogenic particulates and gases from Etna volcano (Italy)(ProScience, 2014-06-01)
; ; ; ; ; ; ; ;Calabrese, S.; Università di Palermo, Dip. DiSTeM, Italy ;Randazzo, L.; Università di Palermo, Dip. DiSTeM ;Scaglione, S.; Università di Palermo, Dip. DiSTeM, Italy ;Milazzo, S.; Università di Palermo, Dip. DiSTeM ;D'Alessandro, W.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Montana, G.; Università di Palermo, Dip. DiSTeM, Italy ;Parello, F.; Università di Palermo, Dip. DiSTeM, Italy; ; ; ; ; ; ;; ;Fiore, S.; University of Bari, ItalyVolcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity they may have important environmental impacts from the local to the global scale and they can severely affect the atmospheric and terrestrial environment also at timescales ranging from a few to million years. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2, and halogens) and particulate matter, including some toxic trace elements. The aim of this study was to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Nine samples were collected by using the filtration technique at different sites on summer 2010 and 2011. Chemical and mineralogical analyses allowed to discriminate two main constituents: the first is mainly referable to the silicate component in the volcanic plume, like lithic and juvenile fragments, crystals (e.g., plagioclases, pyroxenes, oxides) and shards of volcanic glass; the second one is linked to the soluble components like sulfosalts or halide minerals (sulfates, chlorides and fluorides). These investigations are especially important in the study area because the summit of Mt. Etna is yearly visited by nearly one hundred thousand tourists that are exposed to potentially harmful compounds.256 222 - PublicationRestrictedMount Etna volcano (Italy) as a major “dust” point source in the Mediterranean area(2016)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Calabrese, S.; università di palermo ;Randazzo, L.; università di palermo ;Daskalopoulou, K.; università di palermo ;Milazzo, S.; università di palermo ;Scaglione, S.; università di palermo ;Vizzini, S.; università di palermo ;Tramati, C. D.; università di palermo ;D'alessandro, W.; università di palermo ;Brusca, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Bellomo, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Giuffrida, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Pecoraino, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia ;Montana, G.; università di palermo ;Salerno, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Caltabiano, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia ;Parello, F.; università di palermo; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; Volcanic emissions represent one of the most relevant natural sources of trace elements to the troposphere. Due to their potential toxicity, they may have important environmental impacts from local to global scale. They can also severely affect the atmospheric and terrestrial environment at timescales ranging from a few to millions of years. Mt. Etna volcano is known as one of the largest global contributors of magmatic gases (CO2, SO2, and halogens) and particulate matter, including some toxic trace elements. Aim of this study is to characterize the chemical composition and the mineralogical features of the volcanogenic aerosol passively emitted from Mt. Etna. Twenty-five samples were collected by filtration technique from different sites between 2008 and 2014. Chemical and mineralogical analyses allowed to discriminate two main constituents: the first is mainly referable to the silicate component in the volcanic plume, like lithic, juvenile fragments or glass shards and crystals (e.g. plagioclases, pyroxenes, oxides); the second constituent consists of soluble compounds like sulfosalts or halide minerals (sulfates, chlorides and fluorides). Fluxes of major and trace metals emitted in the atmosphere have been estimated. By comparing the Etnean trace elements with those from European anthropic emissions, we conclude that Mt. Etna is the main persistent point source of major and trace metals in the Mediterranean region. Results gathered from this investigation is a fundamental importance due to the exposure and potential impact harmful chemical compounds for hundred thousand tourists visit each year the summit of Mt. Etna.720 43