Genesis of chlorine and sulphur in fumarolic emissions at Vulcano Island (Italy): assessment of pH and redox conditions in the hydrothermal system     

V. Di Liberto  P. M. Nuccio  A. Paonita   《Journal of Volcanology and Geothermal Research》2002,116(1-2)

Chlorine- and sulphur-bearing compounds in fumarole discharges of the La Fossa crater at Vulcano Island (Italy) can be modelled by a mixing process between magmatic gases and vapour from a boiling hydrothermal system. This allows estimating the compounds in both endmembers. Magma degassing cannot explain the time variation of sulphur and HCl concentrations in the deep endmember, which are more probably linked to reactions of solid phases at depth, before mixing with the hydrothermal vapours. Based on the P–T conditions and speciation of the boiling hydrothermal system below La Fossa, the HCl and S_tot contents in the hydrothermal vapours were used to compute the redox conditions and pH of the aqueous solution. The results suggest that the haematite–magnetite buffer controls the hydrothermal fO₂ values, while the pH has increased since the end of the 1970s. The main processes affecting pH values may be linked to Na–Ca exchanges between evolved seawater, feeding the boiling hydrothermal system, and local rocks. While Na is removed from water, calcium enters the solution, undergoes hydrolysis and produces HCl, lowering the pH of the water. The increasing water–rock ratio within the hydrothermal system lowers the Ca availability, so the aqueous solution becomes less acidic. Seawater flowing towards the boiling hydrothermal brine dissolves a large quantity of pyrite along its path. In the boiling hydrothermal system, dissolved sulphur precipitates as pyrite and anhydrite, and becomes partitioned in vapour phase as H₂S and SO₂. These results are in agreement with the paragenesis of hydrothermal alteration minerals recovered in drilled wells at Vulcano and are also in agreement with the isotopic composition of sulphur emitted by the crater fumaroles.  相似文献   

Geothermal energy release at the Solfatara of Pozzuoli (Phlegraean Fields): Phreatic and phreatomagmatic explosion risk implications     

F. Italiano  P. M. Nuccio  M. Valenza 《Bulletin of Volcanology》1984,47(2):275-285

The H₂O, CO₂ and H₂S outputs at the Solfatara of Pozzuoli have been measured and a map of the exhaling areas has also been made. The energy released at the surface by the fluids has been estimated to be 10¹⁹ ergs/day.The presence of aquifers at Phlegraean Fields increases the phreatic and phreatomagmatic explosion risk.Our results suggest that even if an uprising magma may interact with water at depth, an explosion could occur only at the shallow levels of a few hundred meters. Since the transfer of energy toward the surface is favoured by the presence of fractures, a detailed analysis of the deep fracture network would help to evaluate the risk levels of the various areas of Phlegraean Fields.  相似文献   

Fundamental physics and absolute positioning metrology with the MAGIA lunar orbiter     

Simone Dell��Agnello  Caterina Lops  Giovanni O. Delle Monache  Douglas G. Currie  Manuele Martini  Roberto Vittori  Angioletta Coradini  Cesare Dionisio  Marco Garattini  Alessandro Boni  Claudio Cantone  Riccardo March  Giovanni Bellettini  Roberto Tauraso  Mauro Maiello  Luca Porcelli  Simone Berardi  Nicola Intaglietta 《Experimental Astronomy》2011,32(1):19-35

MAGIA is a mission approved by the Italian Space Agency (ASI) for Phase A study. Using a single large-diameter laser retroreflector, a large laser retroreflector array and an atomic clock onboard MAGIA we propose to perform several fundamental physics and absolute positioning metrology experiments: VESPUCCI, an improved test of the gravitational redshift in the Earth?CMoon system predicted by General Relativity; MoonLIGHT-P, a precursor test of a second generation Lunar Laser Ranging (LLR) payload for precision gravity and lunar science measurements under development for NASA, ASI and robotic missions of the proposed International Lunar Network (ILN); Selenocenter (the center of mass of the Moon), the determination of the position of the Moon center of mass with respect to the International Terrestrial Reference Frame/System (ITRF/ITRS); this will be compared to the one from Apollo and Lunokhod retroreflectors on the surface; MapRef, the absolute referencing of MAGIA??s lunar altimetry, gravity and geochemical maps with respect to the ITRF/ITRS. The absolute positioning of MAGIA will be achieved thanks to: (1) the laboratory characterization of the retroreflector performance at INFN-LNF; (2) the precision tracking by the International Laser Ranging Service (ILRS), which gives two fundamental contributions to the ITRF/ITRS, i.e. the metrological definition of the geocenter (the Earth center of mass) and of the scale of length; (3) the radio science and accelerometer payloads; (4) support by the ASI Space Geodesy Center in Matera, Italy. Future ILN geodetic nodes equipped with MoonLIGHT and the Apollo/Lunokhod retroreflectors will become the first realization of the International Moon Reference Frame (IMRF), the lunar analog of the ITRF.  相似文献   

Flood-prone areas assessment using linear binary classifiers based on flood maps obtained from 1D and 2D hydraulic models   总被引：3，自引：0，他引：3  

Salvatore Manfreda  Caterina Samela  Andrea Gioia  Giuseppe Gerardo Consoli  Vito Iacobellis  Luciana Giuzio  Andrea Cantisani  Aurelia Sole 《Natural Hazards》2015,79(2):735-754

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Adjustability of exposed elements by updating their capacity for resistance after a damaging event: application to an earthquake–tsunami cascade scenario     

Negulescu  Caterina  Benaïchouche  Abed  Lemoine  Anne  Le Roy  Sylvestre  Pedreros  Rodrigo 《Natural Hazards》2020,104(1):753-793

Natural Hazards - The 2011 Great East Japan earthquake and tsunami remind us once again that these types of cascade event can occur and cause considerable damage. The scientific community realizes...  相似文献   

Petrographic and geochemical characterization of Archaic‐Hellenistic tableware production at Solunto,Sicily     

Giuseppe Montana  Ioannis Iliopoulos  Valeria Tardo  Caterina Greco 《Geoarchaeology》2009,24(1):86-110

A selected assortment of Archaic‐Hellenistic tableware samples from Solunto, a Phoenician‐Punic site located 20 km east of Palermo (Sicily), has been subjected to thin‐section petrography and chemical analysis (XRF). In this settlement several ceramic kilns remained operative over a long time period (7th to 3rd century B.C.). The main goal of this analytical study is to distinguish the ceramics manufactured locally from regional and off‐island imports. Analytical results were matched to similar data concerning local natural clay sources and to coeval tableware productions from other sites in the same area. The ceramic pastes used by the ancient craftsmen of Solunto in the case of this class of pottery could be differentiated clearly by their petrochemical characteristics. We conclude that ceramics were locally produced far beyond satisfying just internal consumption needs, indicating interaction of Solunto with neighboring Greek colonies, indigenous people, and Phoenician‐Punic colonies of Sicily. © 2009 Wiley Periodicals, Inc.  相似文献   

Characterization of an Area Polluted by Copper and Zinc:the Relation between Soil Texture,Mineralogy and Pollutant Concentration     

Caterina RINAUDO  Daniela GASTALDI  Orfeo ZERBINATI  Elisa FORNERO  Graziella BERTA 《《地质学报》英文版》2009,83(6):1224-1231

Abstract: Twenty-four soil samples were collected at three depths from an approximately 2.5 acre contaminated site in southern Piedmont (Italy) and then analyzed. The main soil parameters determined were: pH, Cation Exchange Capacity (CEC), particle size distribution, total organic carbon (TOC) content and retained metal concentration. The mineral phases were identified by X-Ray Powder Diffraction (XRPD). All of the samples contained Zn and Cu resulting from industrial contamination during the last century, and those obtained at depths of 20-40 cm consistently showed the highest levels. To determine which size fraction was most active in the retention process, the samples were separated into four fractions (≤2 mm, ≤63 μm, ≤30 μm and ≤2 μm) and the amount of pollutant measured in each. It was found that metal retention was the highest in the clayey fraction, whose clay minerals were identified by XRPD after K+ and Mg2+ saturation, glycerol treatment and heating to 550°C. The clayey fraction was also the richest in TOC, and a direct correlation between TOC amount and metal retention was observed.  相似文献   

Geotechnical characterization of a landslide in a Blue Clay slope   总被引：1，自引：1，他引：0  

Caterina Di Maio  Roberto Vassallo 《Landslides》2011,8(1):17-32

This paper describes the results of an experimental, as well as theoretical, analysis of a landslide in a clay slope at the margin of a small town of Southern Italy, whose reactivation of 1998 caused severe damages to some structures. To protect the upslope urban area, an anchored diaphragm wall and a drainage system were constructed in 2001. In the meantime, in order to understand the processes which caused the reactivation, a Department of the Basilicata Administrative Region provided financial support to a geotechnical investigation. Laboratory tests on undisturbed and reconstituted specimens, in situ pore pressure and deep displacement measurements were carried out. Both experimental and theoretical in situ water content (and porosity) profiles were determined. Theoretical analyses of pore pressure distribution and stability analyses were carried out. The influence of the drainage system on the slope safety factor was evaluated. Experimental and theoretical data suggest that a first time process occurred in the lower part of the landslide system. The upper part moved on pre-existing surfaces on which an average shear strength close to the residual strength was available. Noticeable water content increase was found around some of these surfaces. Erosion at the toe of the landslide was the probable cause of reactivation. The analysis of the drain system effectiveness suggests that drainage has not significantly influenced pore pressures on the considered slip surfaces yet, mainly because of the very low permeability of the clay.  相似文献   

Risk-targeted seismic design maps for mainland France   总被引：3，自引：2，他引：1  

John Douglas  Thomas Ulrich  Caterina Negulescu 《Natural Hazards》2013,65(3):1999-2013

In this article, the recently proposed approach known as ‘risk targeting’ for the development of national seismic design maps is investigated for mainland France. Risk targeting leads to ground-motion maps that, if used for design purposes, would lead to a uniform level of risk nationally. The Eurocode 8 design loads currently in force for France are used as the basis of this study. Because risk targeting requires various choices on, for example, the level of acceptable risk to be made a priori and these choices are not solely engineering decisions but involve input from decision makers we undertake sensitivity tests to study their influence. It is found that, in contrast to applications of this methodology for US cities, risk targeting does not lead to large modifications with respect to the national seismic hazard map nor to changes in the relative ranking of cities with respect to their design ground motions. This is because the hazard curves for French cities are almost parallel. In addition, we find that using a target annual collapse probability of about 10^?5 for seismically designed buildings and a probability of collapse when subjected to the design PGA of 10^?5 leads to reasonable results. This is again in contrast to US studies that have adopted much higher values for both these probabilities.  相似文献   

Assessment of toxicological status of a SW Mediterranean segment population of striped dolphin (Stenella coeruleoalba) using skin biopsy     

M. Cristina Fossi  Letizia Marsili  Giancarlo Lauriano  Caterina Fortuna  Simone Canese  Stefania Ancora  Claudio Leonzio  Teresa Romeo  Ruben Merino  Esteban Abad  Begoa Jimnez 《Marine environmental research》2004,58(2-5):269

Various studies have revealed high concentrations of contaminants such as organochlorines (OCs) and heavy metals in Mediterranean cetaceans. A geographical trend of contamination (PCBs and DDTs) has been found for striped dolphin (Stenella coeruleoalba). In this study we used a non-lethal approach (skin biopsy) to investigate bioaccumulation of OCs, including polychlorobiphenyls (PCBs), DDTs, polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), trace elements (Hg, Cd, Pb) and CYP1A activity (BPMO) in nine striped dolphins sampled in the Aeolian area (Sicily – Italy) in summer 2002. The arithmetic mean value of BPMO activity in this group was 43.46 AUF/g tissue/h. This value is approximately 3 times and 5 times lower, respectively, than the value found in the Ionian and in the Ligurian groups. Skin biopsies of striped dolphins emerged as a suitable material for assessing the toxicological status of the various Mediterranean groups.  相似文献