Search results for "Vulcan"

Active geodynamic in the central Mediterranean: Transfer of mantle fluids across the eastern Sicily

2018

Outgassing of mantle fluids across an tectonically active crustal segment in between two volcanic systems (Etna and Aeolian arc): the Nebrodi-Pelorit…

2018

Mantle-degassing occurs primarily through active volcanic systems and young oceanic lithosphere. Mantle-volatiles are also released by tectonically active continental regions, but the magnitude of this phenomenon is far less characterised. Helium (He) is a powerful tracer to track deep volatile degassing, because the mantle contains more 3He than the crust/atmosphere systems, which are dominated by radiogenic 4He produced in the crust. Here, we studied the volatiles in thermal manifestations discharged along the Nebrodi- Peloritani chain in north-eastern Sicily, with the aim of investigating the origin of thermalism and the related fluids. Thisseismically active region connects the African-…

Preliminary results of systematic sampling of gas manifestations in geodynamically active areas of Greece

2016

Greece is located on a convergent plate boundary comprising the subduction of the African Plate beneath the Eurasian, while the Arabian plate approaches the Eurasian in a northwestward motion. It is considered to be one of the most tectonically active regions of Earth with a complex geodynamic setting, deriving from a long and complicated geological history. Due to this specific geological background, conditions for the formation of many thermal springs are favoured. In the past years, almost all the already known sites of degassing (fumaroles, soil gases, mofettes, gas bubbling in cold and thermal waters) located in the Hellenic area were sampled at least one time. Collected samples were a…

Distribution and air-sea exchange of mercury (Hg) in polluted marine environments

2012

Mercury (Hg) is emitted in the atmosphere by anthropogenic and natural sources, these last accounting for one third of the total emissions. Since the pre-industrial age, the atmospheric deposition of mercury have increased notably, while ocean emissions have doubled owing to the re-emission of anthropogenic mercury. Exchange between the atmosphere and ocean plays an important role in cycling and transport of mercury. We present the preliminary results from a study on the distribution and evasion flux of mercury at the atmosphere/sea interface in the Augusta basin (SE Sicily, southern Italy), a semi-enclosed marine area affected by a high degree of contamination (heavy metals and PHA) due to…

The precious treasure of Mariano Valenza: The history of Ludovico Sicardi and the birth of geochemical volcano monitoring

2020

I was lucky enough to meet Mariano Valenza in September 1995. I was hitchhiking on the highway that leads from Cefalu to Palermo to go back home. I had spent my summer holidays in the beautiful and wild Madonie mountains. An off-road vehicle (a Land Rover Defender) stopped and a refined gentleman with a curious and charismatic gaze offered me a ride. During our journey, we chatted pleasantly and he told he was originally from that area. When I told him, I was a Geology student, he smiled at me and said Then we will meet again soon, I am going to be your Teacher of Geochemistry!. After a few weeks the lessons began and I met again Professor Valenza in Via Archirafi 36, at the University of P…

Occurrence of palladium and platinum in human scalp hair of adolescents living in urban and industrial sites

2023

Platinum group elements (PGEs) can be naturally found at very low concentrations in the Earth's crust. However, the increasing uses of PGEs in vehicle exhaust catalysts, in addition to some other applications (industry, jewelry, anticancer drugs) cause their anthropogenic emission and dispersion in the environment. The use of human hair samples analysis is considered a suitable biological indicator to assess human occupational and environmental exposure. It is an easily accessible material for individuals or population groups of non-invasive sampling. The aim of this study is a comparative analysis to investigate human hair content of Pd and Pt in adolescents, of both genders, residing near…

Effects of soil gas permeability and recirculation flux on soil CO2 flux measurements performed using a closed dynamic accumulation chamber

2009

Abstract Dynamic accumulation chamber methods have been extensively used to estimate the total output of CO2 released from active volcanic area. In order to asses the performance and reliability of a closed dynamic system several tests were carried out with different soil permeabilities and soil CO2 fluxes. A special device was used to create a constant one-dimensional CO2 flux through a soil column with a known permeability. Three permeabilities were investigated, ranging between 3.6 × 10− 2 and 3.5 × 10 μm2, as were several CO2 fluxes (ranging between 1.1 × 10− 6 and 6.3 × 10− 5 kg m− 2 s− 1). The results highlight that the accuracy of soil CO2 flux measurements strictly depends on the so…

Hydrogeochemistry and Water Balance in the Coastal Wetland Area of “Biviere di Gela,” Sicily, Italy

2006

In the study area physical and chemical factors control the composition of surface and groundwaters, which in turn determine the water quality of the "Biviere di Gela" lake. These factors combine to create diverse water types which change their compositional character spatially as rainfall infiltrates the soil zone, moves down a topographically defined flow path, and interacts with bedrock minerals. Low-salinity waters, which represent the initial stage of underground circulation, start dissolving calcium carbonate from the local rocks. The progressive increase in salinity, characterized by substantially higher Ca, SO4, Na and Cl concentrations, suggests that dissolution of CaSO4 and NaCl i…

Evaluation of the environmental impact of volcanic emissions from the chemistry of rainwater: Mount Etna area (Sicily)

2001

Abstract The S, halogen and NO 3 contents of rainwater samples from the Etnean area were studied in order to define the environmental impact of plume emissions on the local environment. Samples, collected on a network of 11 bulk rain gauges, show significant variability in anion content, which can be ascribed to different meteorological and environmental conditions at each sampling site and to a variable distance from the different source areas. Data analysis suggests that S, F, Cl and Br are mainly magma-derived, whereas NO 3 mainly originates from anthropogenic sources. Samples collected from sites close to craters display considerable temporal variability, with increased anion concentrat…

Total (fumarolic + diffuse soil) CO2 output from Furnas volcano

2015

Furnas volcano, in São Miguel island (Azores), being the surface expression of rising hydrothermal steam, is the site of intense carbon dioxide (CO2) release by diffuse degassing and fumaroles. While the diffusive CO2 output has long (since the early 1990s) been characterized by soil CO2 surveys, no information is presently available on the fumarolic CO2 output. Here, we performed (in August 2014) a study in which soil CO2 degassing survey was combined for the first time with the measurement of the fumarolic CO2 flux. The results were achieved by using a GasFinder 2.0 tunable diode laser. Our measurements were performed in two degassing sites at Furnas volcano (Furnas Lake and Furnas Villag…