http://hdl.handle.net/2122/186 Ricerca nel canale cerca http://www.earth-prints.org/simple-search http://hdl.handle.net/2122/6067 Titolo: CO2 degassing at La Solfatara volcano (Phlegrean Fields): Processes affecting d13C and d18O of soil CO2<br/><br/>Autori: Federico, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Corso, P. P.; Dipartimento di Scienze Fisiche e Astronomiche, Universita` di Palermo.Italy; Fiordilino, E.; Dipartimento di Scienze Fisiche e Astronomiche, Universita` di Palermo,Italy; Cardellini, C.; Dipartimento di Scienze della Terra, Universita` di Perugia,Italy; Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Parello, E.; Dipartimento CFTA, Universita` degli Studi di Palermo, Italy; Pisciotta, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia<br/><br/>Abstract: The soil CO2 degassing is affected by processes of isotope exchange and fractionation during transport across the soil,which can deeply modify the pristine isotope composition. This has been observed in the Solfatara volcano, upon a field surveyof 110 points, where the CO2 flux was measured, together with temperature, CO2 concentration and oxygen and carbonisotopes within the soil. Furthermore, in some selected sites, the measurements were made at different depths, in order to analyzevertical gradients. Oxygen isotope composition appears controlled by exchange with soil water (either meteoric or fumaroliccondensate), due to the fast kinetic of the isotopic equilibrium between CO2 and water. Carbon isotope composition isreliably controlled by transport-driven fractionation, due to the differences in diffusion coefficients between 13C16O2 and12C16O2. We model the processes affecting CO2 transport across the soil in La Solfatara volcano by means of the DustyGas Model applied to a multicomponent system, to evaluate the reciprocal effect on diffusion of involved gases, i.e.12C16O2, 13C16O2, N2 and O2 in our case. Both numerical and simplified analytical solutions of the equations based on theDusty Gas Model are given. The modeling results fit well with the experimental data and put in evidence an isotope fractionationof carbon up to about þ4:4& with respect to the source value in the soil gas. This fractionation is independent from theentity of the CO2 flux, and occurs as long as a concentration gradient exists within the soil. On these grounds, the Dusty GasModel can be applied to whichever diffusing gas mixture to evaluate the extent of chemical and/or isotopic fractionation thatcan affect ascending gases upon diffusion in any geothermal, volcanic or tectonic area. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/2122/5595 Titolo: Re-orientation in clock-shifted homing pigeons subjected to a magnetic disturbance: a study with GPS data loggers<br/><br/>Autori: Gagliardo, A.; Dipartimento di Biologia, University of Pisa, Via Volta 6, 56126 Pisa, Italy; Savini, M.; Dipartimento di Biologia, University of Pisa, Via Volta 6, 56126 Pisa, Italy; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Dell’Omo, G.; Ornis Italica, Piazza Crati 15, 00199 Rome, Italy; Ioalè, P.; Dipartimento di Biologia, University of Pisa, Via Volta 6, 56126 Pisa, Italy<br/><br/>Abstract: Some authors have proposed that homingpigeons are able to correct the error in orientation following a phase-shift treatment by using the magnetic compassreference. They reported that clock-shifted pigeons bearing magnets display a greater deflection compared to magneticallyunmanipulated clock-shifted birds. However, this hypothesis tested by recording pigeons’ vanishing bearings has led to contradictory results. The present study reports pigeons’ tracks recorded with a GPS and shows that clockshifted pigeons bearing magnets displayed a greater deviation through the whole route compared to the magnetically unmanipulated shifted pigeons. Moreover,the analysis of the tracks shows that the birds belonging to both experimental groups stop in coincidence with their subjective night. When re-starting their journey, the birds corrected the clock-shift induced error in orientation, but the magnetically manipulated pigeons were less efficient in doing so. Our results are consistent with the hypothesis that homing pigeons released from unfamiliar location re-orient after clock shift by using the magnetic compass. Tue, 01 Dec 2009 00:00:00 GMT http://hdl.handle.net/2122/4912 Titolo: Comparison between different methodologies for detecting Radon in soil along an active fault: the case of the Pernicana fault system, Mt. Etna (Italy)<br/><br/>Autori: Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Immè, G.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Mangano, G.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Morelli, D.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia<br/><br/>Abstract: Three different methodologies were used to measure Radon (222Rn) in soil, based on both passive and active detection system. The first technique consisted of Solid State Nuclear Track Detectors (SSNTD), CR-39 type, and allowed integrated measurements. The second one consisted of a portable device for short time measurements. The last consisted of a continuous measurement device for extended monitoring, placed in selected sites. Soil 222Rn activity was measured together with soil Thoron (220Rn) and soil carbon dioxide (CO2) efflux, and it was compared with the content of radionuclides in the rocks. Two different soil gas horizontal transects were investigated across the Pernicana fault system (NE flank of Mount Etna), from November 2006 to April 2007. The results obtained with the three methodologies are in a general agreement with each other and reflect the tectonic settings of the investigated study area. The lowest 222Rn values were recorded just on the fault plane, and relatively higher values were recorded a few tens of meters from the fault axis on both of its sides. This pattern could be explained as a dilution effect resulting from high rates of soil CO2 efflux. Time variations of 222Rn activity were mostly linked to atmospheric influences, whereas no significant correlation with the volcanic activity was observed. In order to further investigate regional radon distributions, spot measurements were made to identify sites having high Rn emissions that could subsequently be monitored for temporal radon variations.. SSNTD measurements allow for extended-duration monitoring of a relatively large number of sites, although with some loss of temporal resolution due to their long integration time. Continuous monitoring probes are optimal for detailed time monitoring, but because of their expense, they can best be used to complement the information acquired with SSNTD in a network of monitored sites.. Thu, 01 Jan 2009 00:00:00 GMT http://hdl.handle.net/2122/4608 Titolo: Campionatore di profondità per gas disciolti<br/><br/>Autori: Cosenza, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Riccobono, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Caracausi, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Nicolosi, M.; Dipartimento CFTA, Universita` di Palermo, Palermo, Italy.<br/><br/>Abstract: I sistemi di campionamento d’acque per lo studio dei gas disciolti, devono rispondere all’esigenza di mantenere integra la quantità di gas disciolto, in relazione al volume di acqua campionata, e di preservarne la composizione fino all’analisi in laboratorio. Le procedure di campionamento descritte in letteratura si riferiscono quasi esclusivamente a due tipologie di campionatori:a) bottiglie di campionamento tipo Niskin, progettate per il campionamento di acque profonde, ma che non consentono una facile operatività in laboratorio ed un’adeguata conservazione dei gas disciolti dopo ilcampionamento, soprattutto quando la loro pressione è superiore a quella atmosferica;b) bottiglie di vetro con tappi di gomma e ghiere di alluminio, estraendo i gas disciolti mediante l’immissione di un gas di estrazione, secondo la metodologia descritta in Capasso & Inguaggiato [1998] eInguaggiato & Rizzo [2004].In letteratura sono anche riportate metodologie di campionamento, per il prelievo delle acque in profondità, che utilizzano pompe peristaltiche; queste metodologie tuttavia provocano fenomeni diessoluzione e separazione dei gas disciolti, rendendo impossibile un’accurata stima delle quantità di gas disciolti per volume di acqua.Il campionamento di acque profonde, sia marine che lacustri, implica spesso la presenza di volatili disciolti aventi pressioni anche notevolmente superiori a quella atmosferica, con la facile conseguenza di indesiderati effetti di essoluzione precoce e perdita parziale dei gas stessi, poiché tali campioni si trovano apressione più elevata rispetto a quella della superficie. Essendo, infatti, la concentrazione dei gas disciolti inacqua (Xi) legata alla pressione parziale del gas stesso (Pi), oltre che alla costante di Henry (Khi) (Xi=Pi/Khi), risulta evidente come una diminuzione della pressione rischi di fare raggiungere la sovrassaturazione delle specie gassose, la loro essoluzione e la loro parziale perdita. Quindi risulta di fondamentale importanza prelevare il campione d’acqua, coi gas disciolti, con campionatori in grado d’isolare il campione d’acqua prelevato dalle condizioni di pressione esterne, prevenendo la separazione del gas per depressurizzazione. Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/2122/4139 Titolo: Comparison between different methodologies for detecting Radon in soil along an active fault: the case of the Pernicana fault system, Mt. Etna (Italy)<br/><br/>Autori: Giammanco, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Immè, G.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Mangano, G.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Morelli, D.; Dipartimento diFisicaeAstronomia,Universita` degli StudidiCatania,viaS.Sofia,64,95123Catania,Italy; Neri, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia<br/><br/>Abstract: Three different methodologies were used to measure Radon (222Rn) in soil, based on both passive and active detection system. The first technique consisted of Solid State Nuclear Track Detectors (SSNTD), CR-39 type, and allowed integrated measurements. The second one consisted of a portable device for short time measurements. The last consisted of a continuous measurement device for extended monitoring, placed in selected sites. Soil 222Rn activity was measured together with soil Thoron (220Rn) and soil carbon dioxide (CO2) efflux, and it was compared with the content of radionuclides in the rocks. Two different soil gas horizontal transects were investigated across the Pernicana fault system (NE flank of Mount Etna), from November 2006 to April 2007. The results obtained with the three methodologies are in a general agreement with each other and reflect the tectonic settings of the investigated study area. The lowest 222Rn values were recorded just on the fault plane, and relatively higher values were recorded a few tens of meters from the fault axis on both of its sides. This pattern could be explained as a dilution effect resulting from high rates of soil CO2 efflux. Time variations of 222Rn activity were mostly linked to atmospheric influences, whereas no significant correlation with the volcanic activity was observed. In order to further investigate regional radon distributions, spot measurements were made to identify sites having high Rn emissions that could subsequently be monitored for temporal radon variations.. SSNTD measurements allow for extended-duration monitoring of a relatively large number of sites, although with some loss of temporal resolution due to their long integration time. Continuous monitoring probes are optimal for detailed time monitoring, but because of their expense, they can best be used to complement the information acquired with SSNTD in a network of monitored sites. Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/2122/2963 Titolo: Towards a permanent deep sea observatory,: the GEOSTAR European Experiment.<br/><br/>Autori: Favali, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Smriglio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Braun, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Calcara, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; D'Anna, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; De Santis, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Di Mauro, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Etiope, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Frugoni, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Iafolla, V.; Ist. di Fisica dello Spazio Interplanetario, Roma; Monna, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Montuori, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Nozzoli, S.; Ist. di Fisica dello Spazio Interplanetario, Roma; Palangio, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Romeo, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia<br/><br/>Curatori: Beranzoli, L.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Favali, P.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia; Smriglio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia<br/><br/>Abstract: GEOSTAR is the prototype of the first European long-term, multidisciplinary deep sea observatory for continuous monitoring of geophysical, geochemical and oceanographic parameters. Geostar is the example of a strong synergy between science and tecnology addressed to the development of new technological solutions for the observatory realisation and management. The GEOSTAR system is described outlining the enhancements introduced during five years of project activity. An example of data retrieved from the observatory being the deep sea mission running is also given. Tue, 01 Jan 2002 00:00:00 GMT http://hdl.handle.net/2122/2218 Titolo: Eddy covariance measurements of geothermal heat flux at Solfatara Volcano, Naples, Italy<br/><br/>Autori: Werner, C.; Institute of Geological and Nuclear Sciences, Private Bag 2000, Taupo, New Zealand; Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Granieri, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Caliro, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Avino, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Russo, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia<br/><br/>Abstract: The first measurements of volcanic/hydrothermal water vapor and heat flux using eddy covariance (EC) were made at Solfataracrater, Italy, June 8–25, 2001. Deployment at six different locations within the crater allowed areas of focused gas venting to bevariably included in the measured flux. Turbulent (EC) fluxes of water vapor varied between 680 and 11200g H2O m−2 d−1. Heatfluxes varied diurnally with the solar input, and the volcanic component of sensible heat ranged from ∼25 to 238W m−2. Thehighest measurements of both sensible and latent heat flux were made downwind of hot soil regions and degassing pools andduring mid-day. The ratio of average volcanic heat (both latent and sensible) to CO2 flux resulted in an equivalent H2O/CO2 fluxratio of 2.2 by weight, which reflects the deep source H2O/CO2 gas ratio. The amount latent heat flux/evaporation was determinedto be consistent both with what would be expected from the magnitude of CO2 fluxes and the fumarolic H2O/CO2 ratio, as well aswith observed surface temperatures and wind speeds given a moist soil. This suggests that the water vapor that condenses in theshallow subsurface is remobilized at the soil–atmosphere interface through variable evaporation dependent on the deep heat fluxand surface temperature. The results suggest that EC provides a quick and easy method to monitor average H2O/CO2 ratioscontinuously in volcanic regions, providing another important tool for volcanic hazards monitoring. Sun, 01 Jan 2006 00:00:00 GMT http://hdl.handle.net/2122/531 Titolo: A simple method to determine the δ13C content of total dissolved inorganic carbon<br/><br/>Autori: Favara, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Grassa, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Inguaggiato, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Pecoraino, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia; Capasso, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia<br/><br/>Abstract: A simple method for determining the d13C of TDIC (Total Dissolved Inorganic Carbon) in natural waters was developed and tested. The proposed method is based on chemical and physical stripping of CO2 from water samples. The sampling apparatus consists of a glass bottle (ca 100 ml) totally filled with water sample in the field and sealed by gas-tight rubber/teflon plug. In thelaboratory, we introduce 10 ml of pure Ar as host gas into the bottles and draw out an equal volume of water. About 0.5 ml of 37% extra-pure HCl is then injected into the bottle. Water pH decreases to values close to 1 and, therefore, the only carbon species present is CO2 both as dissolved and gaseous phase. Then the bottle is connected to a vacuum line to extract CO2 gas and to purifyit by means of standard techniques for CO2 purification. In order to test this method, several sea water samples were prepared andanalysed, as well as a series of standard solutions of Na2CO3 at known isotopic composition of carbon. The accuracy of these measurements was ± 0.2 %° vs V-PDB and their reproducibility was better than 0.2 %° vs V-PDB. Tue, 01 Jan 2002 00:00:00 GMT