Search results for "Vulcan"

Contaminated sediments from dredging activities as modern turbidites: geochemical signatures in box-core sediments from the Augusta area, Ionian Sea,…

2009

The Augusta area (SE Sicily) is one of the most industrialized and contaminated coastal environments in the Mediterranean region, having a relatively high influx of unregulated industrial effluents. Valuable sets of geochemical data (major elements and trace metals), obtained from box-core sediments collected along a transect from the Sicilian coastal zone seawards of Augusta and dated via 210Pb and 137Cs, indicated increased metal contamination (notably Hg) since ca 1940-1950, related to the industrial development of the area. Metal enrichment is considerable in the coastal sediments, being significantly in excess (for Hg and Pb) of background values estimated for the Strait of Sicily. Mor…

Geochemical and eco-toxicological evaluations in box-core sediments from the Sicilian coast, central Mediterranean

2007

Flussi di evasione marina del mercurio elementare gassoso (Hg0) nell’atmosfera della Rada di Augusta

2015

Il mercurio (Ilg) è uno dei principali inquinanti emessi in atmosfera. La sua complessità geochimica, unitamente alla tossicità c agli effetti persistenti della sua presenza nell’ecosistema terrestre, lo hanno inserito nella lista delle priorità di un numero sempre crescente di accordi internazionali rivolti alla tutela ambientale e della stiline umana (The Arctic- Monitoring and Assessment Program, AMAR, United Nations - Economie Commission for Europe: Ileavy Metals Protocol, UN- ECE, The Helsinki Commission, IIELCOM, la convenzione OSPAR). I progressi raggiunti neH’ullimo decennio sullo studio del Hg come ‘global poi Intani '(Pirrone et al.. 2001; Hedgecock et al, 2000: Paeyna et al, 2006…

First combined flux chamber survey of mercury and CO2 emissions from soil diffuse degassing at Solfatara of Pozzuoli crater, Campi Flegrei (Italy): M…

2014

Abstract There have been limited studies to date targeting gaseous elemental mercury (GEM) flux from soil emission in enriched volcanic substrates and its relation with CO 2 release and tectonic structures. In order to evaluate and understand the processes of soil–air exchanges involved at Solfatara of Pozzuoli volcano, the most active zone of Campi Flegrei caldera (Italy), an intensive field measurement survey has been achieved in September 2013 by using high-time resolution techniques. Soil–air exchange fluxes of GEM and CO 2 have been measured simultaneously at 116 points, widely distributed within the crater. Quantification of gas flux has been assessed by using field accumulation chamb…

Measurements of gaseous elemental mercury (GEM) in diffuse soil emission using the static closed-chamber method

2015

Measurements aimed to evaluate the contribution of natural and anthropogenic gaseous elemental mercury (GEM) to the atmosphere are critical for monitoring and mitigating the impact of this highly toxic air contaminant. Notwithstanding, the amounts of GEM originating from different sources are difficult to be estimated, since specific protocols dictating the most appropriate sampling and analytical techniques are lacking. This study was aimed to test a methodological approach enables to measure GEM released through diffuse degassing from the soil, a mechanism that in volcanic and geothermal areas significantly contributes to the discharge of geogenic fluids to the atmosphere. A static closed…

New evidences on mercury emissions from Earth volcanism

2010

Estimates of mercury emission rates in active volcanic systems

2007

Mercury from volcanoes: fluxes and speciation

2008

Mercury is a toxic bio-accumulating metal that, due to its volatility has an extended atmospheric lifetime. Understanding Hg sources and sinks is therefore has importance on the global scale. We present new measurements of volcanic Hg from Mount Etna and Vulcano in Italy and Masaya volcano in Nicaragua to improve our estimates of the volcanic Hg flux. In contrast to other metals emitted from volcanoes, volcanic Hg can exist in 3 forms, namely gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and in the particle phase. These measurements also represent the first fully speciated measurements of volcanic Hg, as well as the first high time resolution measurements of gaseous Hg. Vo…

Soils as natural filters for GHG: an imbalance between the expected CH4 fluxes and the direct measurements

2018

The final composition of the atmosphere results from several processes and exchanges between all the Earth’s spheres. Some of these are widely known and others, such as the methane degassing from hydrothermal areas, are still understudied. Methane plays a key role in climate change being an efficient greenhouse gas. Although it would be crucial, the total CH4 output from geogenic sources is still not well defined; limitations in CH4 output estimations are due to many factors concerning a scarce dataset availability, difficulty in direct measurements, and interaction with methane-consuming microbiota in the soil. Often, the CH4 flux estimation was obtained indirectly, e.g. cross-correlating …

Profiling microbial communities in hyperalkaline waters of the Kizildag ophiolite complex (Turkey).

2016

It has recently been hypothesized that life on Earth could have been originated in hyperalkaline waters related to serpentinization of ophiolitic rocks, despite their extreme conditions (high pH and very low levels of nutrients). Five hyperalkaline springs of the Kizildag ophiolite complex (Turkey) were characterized. The dominant gases are either H2, CH4 or N2 . Bacterial diversity, analysed by RISA (Ribosomal Intergenic Spacer Analysis) revealed different profles for each spring. Sequencing of excised DNA bands allowed to identify the presence of Bacillus, Ralstonia, Pseudoalteromonas., Ureibacillus, Alicycliphilus, Anaerococcus. 16S ribosomal DNA sequencing by Illumina is in progress. Th…