Search results for "Thermal"

Hydrothermal alteration can result in pore pressurization and volcano instability

2021

AbstractThe collapse of a volcanic flank can be destructive and deadly. Hydrothermal alteration is common to volcanoes worldwide and is thought to promote volcano instability by decreasing rock strength. However, some laboratory studies have shown that not all alteration reduces rock strength. Our new laboratory data for altered rhyodacites from Chaos Crags (Lassen volcanic center, California, USA) show that pore- and crack-filling mineral precipitation can reduce porosity and permeability and increase strength, Young's modulus, and cohesion. A significant reduction in permeability, by as much as four orders of magnitude, will inhibit fluid circulation and create zones of high pore fluid pr…

Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

2014

Abstract. Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10–40 Tg of CH4 a−1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a−1. Laboratory incubation experiments with three top-soil samples from Favara Gra…

A Review of “Volcano and geothermal tourism: sustainable georesources for leisure and recreation”

2013

A Sustainable Energy Mix for the Aeolian Islands

2018

The paper examines the current status of the electrical energy production in the Aeolian Islands, an Italian archipelago, composed by small island North of Sicily. Instead the availability of renewable energy sources, like wind, solar, geothermal and sea wave, these islands produce electrical energy using almost entirely fossil fuels. Starting from this initial condition, the paper proposes an energetic mix based on the available resources and focusing the attention on sea wave. An innovative device is presented in order to exploit this energy source.

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

1984

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 F…

A Methodology for Comparing the Surface Urban Heat Island in Selected Urban Agglomerations Around the World from Sentinel-3 SLSTR Data

2020

[EN] Retrieval of land surface temperature (LST) from satellite data allows to estimate the surface urban heat island (SUHI) as the difference between the LST obtained in the urban area and the LST of its surroundings. However, this definition depends on the selection of the urban and surroundings references, which translates into greater difficulty in comparing SUHI values in different urban agglomerations across the world. In order to avoid this problem, a methodology is proposed that allows reliable quantification of the SUHI. The urban reference is obtained from the European Space Agency Climate Change Initiative Land Cover and three surroundings references are considered; that is, the …

Assessing areal geothermal potential: a new approach and its application to Southern Italy VIGOR-Project regions

2013

Microbial methane oxidation leading to extreme isotopic fractionation in thermal springs of central Greece

2017

The Greek territory belongs to the geodynamically active Alpine-Himalayan orogenic belt. As such, it shows intense seismic activity, active volcanic systems and areas of enhanced geothermal fluxes. One of these areas is the Sperchios basin and the northern part of Evia island in central Greece, which present widespread thermal manifestations (D’Alessandro et al., 2014). Five of them with temperatures from 33 to 80°C present bubbling gases whose dominating species are either CO2 or N2. All gases contain from 27 to 4000 ppm of CH4. The isotopic composition of CH4 in these gases covers a wide range with δ13C values ranging from -21.7 to +16.9 ‰ and δ2H values ranging from -124 to +301 ‰. The h…

RENEWABLE ENERGY AND INNOVATION FOR SUSTAINABLE GREENHOUSE DISTRICTS

2009

Funkcjonowanie elektrowni geotermalnych oraz ich wpływ na środowisko przyrodnicze na przykładzie elektrowni działających na Islandii

2017

Niniejszy artykuł prezentuje możliwości wytwarzania energii elektrycznej z zasobów geotermalnych. Przedstawia klasyfikację złóż geotermalnych ze względu na temperaturę płynu geotermalnego oraz technologie produkcji energii elektrycznej w elektrowniach geotermalnych pracujących w systemach klasycznej turbiny parowej oraz binarnych (ORC i Kalina). Przedstawiono problemy związane z eksploatacją złóż geotermalnych oraz funkcjonowaniem elektrowni geotermalnych na przykładzie Elektrowni Krafla na Islandii. Dokonano charakterystyki potencjalnych zagrożeń dla środowiska przyrodniczego i środowiska pracy związanych z procesem technologicznym w elektrowniach geotermalnych.