Search results for " Vulcano"
showing 10 items of 457 documents
Temporal evolution of the Fogo Volcano magma storage system (Cape Verde Archipelago): a fluid inclusions perspective
2023
The architecture of the magma storage system underneath Fogo Volcano (Cape Verde Archipelago) is characterised using novel fluid inclusion results from fifteen basanites, spanning the last 120 thousand years of volcanic activity, and encompassing a major flank collapse event at -73 ka. Fluid inclusions, hosted in olivine and clinopyroxene, are made of pure CO2, and based on their textural characteristics, are distinguished in early (Type I) and late (Type II) stage. Inclusions homogenize to a liquid phase in the 2.8 to 30.8 degrees C temperature range. Densities values, recalculated assuming an original 10% H2O content at the time of trapping, range from 543 to 952 kg center dot m(-3), and …
So close, so different: geothermal flux shapes divergent soil microbial communities at neighbouring sites
2016
This study is focused on the (micro)biogeochemical features of two close geothermal sites (FAV1 and FAV2), both selected at the main exhalative area of Pantelleria Island, Italy. A previous biogeochemical survey revealed high CH4 consumption and the presence of a diverse community of methanotrophs at FAV2 site, whereas the close site FAV1 was apparently devoid of methanotrophs and recorded no CH4 consumption. Next-Generation Sequencing (NGS) techniques were applied to describe the bacterial and archaeal communities which have been linked to the physicochemical conditions and the geothermal sources of energy available at the two sites. Both sites are dominated by Bacteria and host a negligib…
Gaseous emissions from geothermal and volcanic areas: focus on methane and methanotrophs
2014
Ogni anno, 22 Tg di CH4 vengono rilasciati in atmosfera da numerose sorgenti sia naturali che antropiche. Il metano riveste un ruolo molto importante nella chimica dell’atmosfera terrestre e nel bilancio dell’energia radiante assorbita, essendo il secondo gas serra più potente dopo la CO2. Le aree vulcaniche e geotermali contribuiscono al flusso di metano in atmosfera, essendo vaste aree di degassamento. Studi preliminari hanno stimato che le emissioni globali di metano dai sistemi geotermali e vulcanici europei sono nel range di 4-16 kt a-1. Questa stima è stata ottenuta indirettamente dai dati delle emissioni di CO2 o H2O e dal rapporto del flusso CO2/CH4 oppure H2O/CH4 misurati nelle pri…
The Domuyo volcanic system: An enormous geothermal resource in Argentine Patagonia
2014
Fil: Chiodini, Giovanni. Istituto Nazionale Di Geofisica E Vulcanologia. Italia. Fil: Liccioli, Caterina. Universidad Nacional de Rio Negro. Instituto de Investigaciones en Paleobiologia y Geologia; Argentina. Río Negro, Argentina Fil: Vaselli, Orlando. Universita Degli Studi Di Firenze; Italia Fil: Calabrese, Sergio. Università di Palermo; Italia Fil: Tassi, Franco. Universita Degli Studi Di Firenze; Italia Fil: Caliro, Stefano. Istituto Nazionale Di Geofisica E Vulcanologia; Italia Fil: Caselli, Alberto Tomás Universidad Nacional de Rio Negro. Instituto de Investigaciones en Paleobiologia y Geologia; Argentina. Río Negro, Argentina Fil: Agusto, Mariano R. Universidad de Buenos Aires. Facu…
A tool for evaluating geothermal power exploitability and its application to Ischia, Southern Italy
2015
Abstract The paper proposes a method to evaluate the potential for electric power production at any site of possible geothermal interest. Accounting for geological data of the reservoirs, the method allows the computation of the available electrical power of the investigated site. Electrical energy production from geothermal sources is realized through different techniques, such as single flash and double flash, dry steam, and binary ORC plants. The technique chosen to be the most productive is determined by analyzing a specific range of geofluid properties, mainly temperature and pressure. Moreover, each plant typology has a global efficiency that may be correlated to geofluid enthalpy by …
Magmatic gas flux emissions from Gorelyi volcano, Kamchatka, and implications for volatile recycling in the NW Pacific
2012
The Kamchatka peninsula, in the north-western part of the Pacific ’Ring of Fire’, is one of the most active volcanic realms on Earth, with 29 historically erupting volcanoes along its 700 km-long Eastern Volcanic Belt (EVB). This notwithstanding, volatile input and output fluxes along this arc sector have remained poorly characterised until very recently. We here report on the very first assessment of volatile flux emissions from Gorelyi, a large (25 km3, 1830 m high) and most active shield-like Holocene volcano located on the southern segment of the Kamchatka EVB. By combing results from a variety of in situ and remote sensing techniques (MultiGAS, filter packs, and UV camera), we determine the…
Preliminary study on geogenic degassing through the big karstic aquifers of Greece
2019
Non-volcanic degassing contributes to the C-cycle by providing on a global scale a significant amount of CO2 emitted through diffuse earth degassing processes (Kerrick et al 1995). Due to the elevated solubility of the CO2 in water, in the areas where high CO2 fluxes directly affect regional aquifers, most of it can be dissolved, transported and released by groundwaters. Therefore, quantification of this contribution to the atmosphere has a substantial implication for modeling the global carbon cycle. According to Chiodini et al. (2000), total dissolved inorganic carbon (TDIC) concentrations and δ13CTDIC values of groundwaters are useful tools to both quantify the geogenic degassing and dis…
Origin of He and CO2 in the gas manifestations of Greece.
2018
In the period from 2004 to 2017, more than 350 samples of free and dissolved gases were collected along the whole Hellenic area. Some literature data have also been taken into consideration (Rizzo et al., 2016). Samples have been analysed for their chemical and isotope composition. The concentrations range from 0.10 to 3370 μmol/mol for He, 600 to 995,000 μmol/mol for N2, 0.60 to 915,000 μmol/mol for CH4 and 17 to 1,002,000 μmol/mol for CO2, whereas the isotope values range from 0.01 to 7.10 for R/RA and -29.91 to +6.00 for δ13C-CO2. Considering the R/RA and 4He/20Ne ratios the atmospheric, mantle and crustal contributions for He have been calculated (Sano and Wakita, 1985). The highest man…
Geothermal mercury output at Nisyros Volcano (Greece)
2019
Nisyros (Greece) is an active volcano in the eastern part of the South Aegean Active Volcanic Arc (SAAVA), hosting a high-enthalpy geothermal system. On June 2013, an extensive survey on Hg concentrations in different types of matrices (fumarolic fluids, atmosphere, soils and plants) was carried out at Lakki plain, an area affected by widespread soil degassing and fumarolic manifestations. To investigate the spatial distribution of mercury emission and its possible relationships with diffuse degassing of hydrothermal fluids, Hg concentrations in soils were related to their physicochemical parameters (e.g. temperature, soil-pH, hydrothermal gases and elemental C, N and S concentrations). Fur…
A geochemical traverse along the “Sperchios Basin e Evoikos Gulf” graben (Central Greece): Origin and evolution of the emitted fluids
2014
The studied area is a 130 km long fast spreading graben in Central Greece. Its complex geodynamical setting includes both the presence of a subduction slab at depth responsible for the recent (Quaternary) volcanic activity in the area and the western termination of a tectonic lineament of regional importance (the North-Anatolian fault). A high geothermal gradient is made evident by the presence of many thermal springs with temperatures from 19 to 82 C, that discharge along the normal faults bordering the graben. In the period 2004e2012, 58 gas and 69 water samples were collected and their chemical and isotopic analysis revealed a wide range of compositions. Two main groups of thermal waters…