Search results for "PANA"
showing 10 items of 193 documents
Regional Saharan dust modelling during the SAMUM 2006 campaign
2011
The regional dust model system LM-MUSCAT-DES was developed in the framework of the SAMUM project. Using the unique comprehensive data set of near-source dust properties during the 2006 SAMUM field campaign, the performance of the model system is evaluated for two time periods in May and June 2006. Dust optical thicknesses, number size distributions and the position of the maximum dust extinction in the vertical profiles agree well with the observations. However, the spatio-temporal evolution of the dust plumes is not always reproduced due to inaccuracies in the dust source placement by the model. While simulated winds and dust distributions are well matched for dust events caused by dry syn…
Rates of carbon dioxide plume degassing from Mount Etna volcano,
2006
We report here on the real-time measurement of CO2 and SO2 concentrations in the near-vent volcanic gas plume of Mount Etna, acquired by the use of a field portable gas analyzer during a series of periodic field surveys on the volcano's summit. During the investigated period (September 2004 to September 2005), the plume CO2/SO2 ratio ranged from 1.9 to 10.8, with contrasting composition for Northeast and Voragine crater plumes. Scaling the above CO2/SO2 ratios by UV spectroscopy determined SO2 emission rates, we estimate CO2 emission rates from the volcano in the range 0.9-67.5 kt d-1 (average, 9 kt d-1). About 2 kt of CO2 were emitted daily on average during quiescent passive degassing, wh…
Reactive halogen chemistry in volcanic plumes
2007
[1] Bromine monoxide (BrO) and sulphur dioxide (SO2) abundances as a function of the distance from the source were measured by ground-based scattered light Multiaxis Differential Optical Absorption Spectroscopy (MAX-DOAS) in the volcanic plumes of Mt. Etna on Sicily, Italy, in August–October 2004 and May 2005 and Villarica in Chile in November 2004. BrO and SO2 spatial distributions in a cross section of Mt. Etna's plume were also determined by Imaging DOAS. We observed an increase in the BrO/SO2 ratio in the plume from below the detection limit near the vent to about 4.5 × 10−4 at 19 km (Mt. Etna) and to about 1.3 × 10−4 at 3 km (Villarica) distance, respectively. Additional attempts were …
Volcanic plume monitoring at Mount Etna by diffusive (passive) sampling
2004
[1] This paper reports the use of diffusive tubes in determining HF, HCl, and SO2 in the volcanic plume of Mount Etna in an attempt to highlight the potential of this method in studying volcanoes. In a first application a network of 18 diffusive tubes was installed on Etna's flanks, aimed at evaluating the atmospheric dispersion of the volcanic plume on a local scale. Results showed a monotonic decrease in volatile air concentrations with distance from the craters (HF from 0.15 to <0.003 μmol m−3, HCl from 2 to <0.01 μmol m−3, and SO2 from 11 to 0.04 μmol m−3), revealing the prevalently volcanic contribution. Matching of SO2/HCl and HCl/HF volatile ratios with contemporaneous measurements a…
Sources, size distribution, and downwind grounding of aerosols from Mount Etna
2006
The number concentrations and size distributions of aerosol particles >0.3 mm diameter were measured at the summit of Mount Etna and up to 10 km downwind from the degassing vents during July and August 2004. Aerosol number concentrations reached in excess of 9 106 L1 at summit vents, compared to 4–8 104 L1 in background air. Number concentrations of intermediate size particles were higher in emissions from the Northeast crater compared to other summit crater vents, and chemical composition measurements showed that Northeast crater aerosols contained a higher mineral cation content compared to those from Voragine or Bocca Nuova, attributed to Strombolian or gas puffing activity within the ve…
Magmatic gas leakage at Mount Etna (Sicily, Italy): Relationships with the volcano-tectonic structures, the hydrological pattern and the eruptive act…
2004
In this paper we provide a review of chemical and isotopic data gathered over the last three decades on Etna volcano's fluid emissions and we present a synthetic framework of their spatial and temporal relationships with the volcano-tectonic structures, groundwater circulation and eruptive activity. We show that the chemistry, intensity and spatial distribution of gas exhalations are strongly controlled by the main volcano-tectonic fault systems. The emission of mantle-derived magmatic volatiles, supplied by deep to shallow degassing of alkali-hawaiitic basalts, persistently occurs through the central conduits, producing a huge volcanic plume. The magmatic derivation of the hot gases is ver…
S, Cl and F degassing as an indicator of volcanic dynamics: The 2001 eruption of Mount Etna
2002
[1] The recent eruption of Mount Etna (July 2001) offered the opportunity to analyze magma-derived volatiles emitted during pre- and syn-eruptive phases, and to verify whether their composition is affected by changes in volcanic dynamics. This paper presents the results of analyses of F, Cl and S in the volcanic plume collected by filter-packs, and interprets variations in the composition based on contrasting solubility in magmas. A Rayleigh-type degassing mechanism was used to fit the acquired data and to estimate Henry's solubility constant ratios in Etnean basalt. This model provided insights into the dynamics of the volcano. Abundances of sulfur and halogens in eruptive plumes may help …
Mercury content and speciation in the Phlegrean Fields volcanic complex: evidence from hydrothermal system and fumaroles
2009
Abstract Mercury is outstanding among the global environmental pollutants of continuing concern. Although degassing of active volcanic areas represents an important natural source of mercury into the atmosphere, still little is known about the amount and behaviour of Hg in volcanic aquifers, especially regarding its chemical speciation. In order to assess the importance of mercury emissions from active volcanoes, thermal waters were sampled in the area surrounding La Solfatara, Pozzuoli bay. This is the most active zone of the Phlegrean Fields complex (coastal area north–west of Naples), with intense hydrothermal activity at present day. Studied groundwaters show total Hg (THg) concentratio…
L’antica tradizione produttiva, il restauro e la manutenzione delle campane della Fonderia Virgadamo a Burgio, in Sicilia
2015
La percezione della città storica è sempre stata segnata dalla presenza dei campanili, uno dei segni architettonici più rilevanti nell’identificazione di un edificio sacro. Oltre a segnare il paesaggio, il campanile, attraverso il suono delle campane, scandisce lo scorrere del tempo, annuncia gli accadimenti e richiama le comunità di fedeli alla preghiera. La campane fanno parte del patrimonio culturale locale ed il loro suono è un bene che appartiene alla collettività. A Burgio, in Sicilia, l’antica tradizione produttiva delle campane di bronzo sopravvive da oltre cinque secoli, preservata e tramandata da generazione in generazione nella fonderia della famiglia Virgadamo. Le realizzazioni …
Chemical Composition of the Essential Oils of Three Species of the Apiaceae Family Growing Wild in Sicily: Bonannia graeca, Eryngium maritimum and Op…
2013
n the present study the chemical composition of the essential oils from aerial parts of Bonannia graeca (L.) Halácsy and Opopanax chironium (L.) Kock, and from aerial parts and roots of Eryngium maritimum L. was evaluated by GC and GC-MS. α-Pinene (15.2%) and β-pinene were recognized as the main constituents of B. graeca, whereas the aerial parts of O. chironium contained mainly the diterpene cembrene and the coumarin angelicin. In both aerial parts and roots of E. maritimum germacrene D (10.4% and 15.9%, respectively) and 2,4,5-trimethylbenzaldehyde (8.3% and 6.7%) were the most abundant components