Search results for "volcan"
showing 9 items of 899 documents
Le lave. Gli usi ornamentali nell'architettura storica in Sicilia
2012
L’attività vulcanica in Sicilia e nelle isole limitrofe ha nel corso dei millenni contribuito a modellare l’aspetto fisico di un vasto comprensorio, generando sconfinati giacimenti naturali di materiale lapideo impiegato fin dall’età antica nell’attività edificatoria. Relativamente all’utilizzo in architettura, va sottolineata l’ambivalenza di questo materiale chiamato nei secoli a svolgere tanto la funzione di pietra da costruzione, quanto quella di pietra ornamentale. Catania e l’intera area etnea, ma anche l’isola di Lipari, conservano le testimonianze più consistenti e significative di un ricorso ab antiquo alla pietra lavica e ai suoi derivati in architettura. Da una ricognizione compl…
Selenium around Etna Volcano, Italy
2010
Humans are attracted by the fertile properties of volcanic soils and currently around 10% of the world population lives within active volcanic areas. Volcanoes emit significantly amounts of potentially toxic elements such as selenium (Se), even in the absence of obvious volcanic activity. Although Se is an essential element for humans, ingestion of an excess amount of Se can produce adverse effects. Mt. Etna, the biggest volcano in Europe, is persistently active for the last 200,000 years and one of the most intensely monitored volcanoes. We have studied selenium in rainwater and soils from Mt Etna volcano. Bulk depositions were collected from April 2006 to December 2007, using a network of…
Intercomparison of volcanic gas monitoring methodologies performed on Vulcano Island, Italy,
2004
Evolution of Seismicity During a Stalled Episode of Reawakening at Cayambe Volcano, Ecuador
2021
Cayambe Volcano is an ice-capped, 5,790 m high, andesitic-dacitic volcanic complex, located on the equator in the Eastern Cordillera of the Ecuadorian Andes. An eruption at Cayambe would pose considerable hazards to surrounding communities and a nationally significant agricultural industry. Although the only historically documented eruption was in 1785, it remains persistently restless and long-period (LP) seismicity has been consistently observed at the volcano for over 10 years. However, the sparse monitoring network, and complex interactions between the magmatic, hydrothermal, glacial, and tectonic systems, make unrest at Cayambe challenging to interpret. In June 2016 a seismic “crisis” …
Rapid sensing of volcanic SO₂ fluxes using a dual ultraviolet camera system: new techniques and measurements at Southern Italian volcanoes
2012
Volatiles carry crucial information on pre- to sin-eruptive processes at active volcanoes. Measurements of gas emission rates (crater plumes, fumaroles, diffuse soil degassing) therefore improve our understanding of degassing processes and subsurface magmatic and hydrothermal conditions, and contribute to eruption forecasting. Recent technological developments in spectroscopy have allowed, over the last 30 years, the remote sensing of magmatic volatile emissions from quiescent and erupting degassing volcanoes. These data-sets have contributed to discovering cyclic gas flux components due to periodic magma supply and replenishment in magma storage zones, and/or timescales of magma migration …
Are the Salinelle mud volcanoes threatening human health or are anthropogenic activities threatening the Salinelle mud volcanoes?
2012
Passive samplers were used to measure the atmospheric concentrations of SO2 naturally emitted at three volcanoes in Italy (Etna, Vulcano and Stromboli) and of H2S naturally emitted at three volcanic/geothermal areas in Greece (Milos, Santorini and Nisyros). The measured concentrations and dispersion patterns varied with the strength of the source (open conduits or fumaroles), the meteorological conditions and the area topography. At Etna, Vulcano and Stromboli, SO2 concentrations reach values that are dangerous to people affected by bronchial asthma or lung diseases (>1000 μg m−3). H2S values measured at Nisyros also exceed the limit considered safe for the same group of people (>3000 μg m−…
High-Frame Rate Thermal Imagery of Strombolian Explosions: Implications for Explosive and Infrasonic Source Dynamics
2012
Chemical weathering of volcanic rocks, Pantelleria Island: information from soil profile and soil solution investigations
2007
Concentrations of major, minor and trace elements were determined in soil profiles and soil solutions from the island of Pantelleria, Sicily Channel, to evaluate the weathering extent of soils evolved on trachytic and pantelleritic rocks and the aqueous transport of elements by their soil solutions. The chemical index of alteration (CIA) indicates a low-to-moderate degree of weathering; consistently, the mineralogical and geochemical imprints of the parent rocks are generally preserved. The chemical weathering appears to be incongruent, owing to primary minerals and glass dissolving to a variable degree while secondary minerals have formed. Based on the calculated saturation state of primar…