Atmospheric anomalies over Mt.Etna using GPS signal delays and tomography of radio wave velocities

Due to the prominent topography of Mt. Etna, the use of satellite geodetic techniques may significantly suffer from atmospheric heterogeneities. This problem mainly affects the DInSAR technique. To overcome these drawbacks the present study attempts to make headway in measuring and interpreting atmospheric anomalies. We used the GAMIT software to obtain the ZTD (Zenith Total Delay) values for the GPS sessions performed on 1996-97, during ERS-2 passes at Mt. Etna. GAMIT software also allows to characterize the statistical behaviour of the tropospheric effects, by using residuals for each station-satellite pair, and to locate the atmospheric anomalies, present mostly at low altitudes. The attempt at using these results to produce a tomography of radio waves velocity of the troposphere suggests that the number of GPS stations used to investigate atmosphere is a critical point in such a study. The three stations are too few to invert anomalies eventually existing in the lower atmosphere. This result is a good starting point for better direct future study to verify the applicability of this tomographic technique to a geodetic network with a higher number of stations, with the aim of characterizing the lower atmosphere of Mt. Etna for a more accurate monitoring of ground deformations

Radon Concentration by SSNTD in South-East Sicily Buildings

Abstract Radon levels in buildings vary widely from area to area also depending on local geology. Thus, it is important to assess the radon prone area of a geographic region on the basis of geological data and to search for any possible correlation between the local geology and the indoor radon concentrations. We report about indoor radon measurements in Ragusa, a municipality of the SE Sicily, placed in the Hyblean Plateau (northern region of the African Plate), carried out in collaboration with schools. The survey was performed using Solid State Nuclear Track Detectors (SSNTD), CR-39 type, and a well-established methodology for chemical etching and reading, developed at the Radioactivity Laboratory of the Department of Physics - University of Catania

Gas radon emission related to geodynamic activity on Mt. Etna

We report preliminary observations on possible correlations between anomalies of subsoil radon concentration and geodynamical events on Mt. Etna. In recent years several studies have been carried out on radon as a precursor of geophysical events, most of them performed either on tectonic or volcanic areas. The peculiarity of our investigation lies on the choice of the etnean region, in which tectonic and volcanic features are both present. In order to characterize Mt. Etna features by investigating radon gas in soil, two stations were located along the NE-SW direction on Mt. Etna. Each of the two stations is fitted with a radon detector, a 3D seismic station and a meteorological station. Differences in the radon concentration trend in the data from north and south flanks could be linked to different faulting mechanisms and then to different mechanisms of radon uprising. The increase in soil radon concentration could be related to both seismic and volcanic events

The MEV project: design and testing of a new high-resolution telescope for Muography of Etna Volcano

The MEV project aims at developing a muon telescope expressly designed for the muography of Etna Volcano. In particular, one of the active craters in the summit area of the volcano would be a suitable target for this experiment. A muon tracking telescope with high imaging resolution was built and tested during 2017. The telescope is a tracker based on extruded scintillating bars with WLS fibres and featuring an innovative read-out architecture. It is composed of three XY planes with a sensitive area of \SI{1}{m^2}; the angular resolution does not exceeds \SI{0.4}{\milli\steradian} and the total angular aperture is about $\pm$\SI{45}{\degree}. A special effort concerned the design of mechanics and electronics in order to meet the requirements of a detector capable to work in a hostile environment such as the top of a tall volcano, at a far distance from any facility. The test phase started in January 2017 and ended successfully at the end of July 2017. An extinct volcanic crater (the Monti Rossi, in the village of Nicolosi, about 15km from Catania) is the target of the measurement. The detector acquired data for about 120 days and the preliminary results are reported in this work

Indoor and soil radon measurements in the Hyblean Foreland (South-East Sicily)

Indoor radon behavior in two sites of SE Sicily was studied as a function of the soil radon concentration. The chosen locations were Ragusa and Modica towns, placed in the Hyblean Plateau (northern margin of the African Plate). Soil samples were analysed by gamma spectrometry to determine the amount of radionuclides. Indoor air and soil gas radon measurements were simultaneously performed in both sites using active detectors. Radon in soil was measured one meter deep. A positive correlation was obtained between indoor radon concentration and the soil gas concentration

Natural radioactivity content in groundwater of Mt. Etna’s eastern flank and gamma background of surrounding rocks

Waters of Mt. Etna are the main source of drinking water for the local population and are also distributed in municipal supply systems to neighbouring areas. Radioactivity in underground waters and surrounding rocks from the eastern flank of Mt. Etna was investigated on the basis of 9 water and 8 rock samples from 12 localities altogether. Three samples were from water drainage galleries and six from water wells. All water intakes are used for consumption. Activity concentration of uranium isotopes 234,238U, radium isotopes 226,228Ra and radon 222Rn were determined with the use different nuclear spectrometry techniques. The determination of uranium isotopes was carried out with the use of alpha spectrometry. The measurements of radium and radon activity concentration in water were performed with the use of a liquid scintillation technique. Additionally, rocks surrounding the intakes were examined with gamma spectrometry. All water samples showed uranium concentration above Minimum Detectable Activity (MDA), with the highest total uranium (234U + 238U) activity concentration equal to 149.2±6 mBq/L. Conversely, all samples showed radium isotopes activity concentrations below MDA. Radon activity concentration was within the range from 2.91±0.36 to 21.21±1.10 Bq/L, hence these waters can be classified as low-radon waters. Gamma natural background of the rocks surrounding the water sampling sites was found on the same levels as other volcanic rocks of Italy

Atmospheric anomalies over Mt.Etna using GPS signal delays and tomography of radio wave velocities

Due to the prominent topography of Mt. Etna, the use of satellite geodetic techniques may significantly suffer from atmospheric heterogeneities. This problem mainly affects the DInSAR technique. To overcome these drawbacks the present study attempts to make headway in measuring and interpreting atmospheric anomalies. We used the GAMIT software to obtain the ZTD (Zenith Total Delay) values for the GPS sessions performed on 1996-97, during ERS-2 passes at Mt. Etna. GAMIT software also allows to characterize the statistical behaviour of the tropospheric effects, by using residuals for each station-satellite pair, and to locate the atmospheric anomalies, present mostly at low altitudes. The attempt at using these results to produce a tomography of radio waves velocity of the troposphere suggests that the number of GPS stations used to investigate atmosphere is a critical point in such a study. The three stations are too few to invert anomalies eventually existing in the lower atmosphere. This result is a good starting point for better direct future study to verify the applicability of this tomographic technique to a geodetic network with a higher number of stations, with the aim of characterizing the lower atmosphere of Mt. Etna for a more accurate monitoring of ground deformations

Indoor and soil radon measurements in the Hyblean Foreland (South-East Sicily)

Indoor radon behavior in two sites of SE Sicily was studied as a function of the soil radon concentration. The chosen locations were Ragusa and Modica towns, placed in the Hyblean Plateau (northern margin of the African Plate). Soil samples were analysed by gamma spectrometry to determine the amount of radionuclides. Indoor air and soil gas radon measurements were simultaneously performed in both sites using active detectors. Radon in soil was measured one meter deep. A positive correlation was obtained between indoor radon concentration and the soil gas concentration

Discriminant Analysis and Secondary-Beam Charge Recognition

The discriminant-analysis method has been applied to optimize the exotic-beam charge recognition in a projectile fragmentation experiment. The experiment was carried out at the GSI using the fragment separator (FRS) to produce and select the relativistic secondary beams, and the ALADIN setup to measure their fragmentation products following collisions with Sn target nuclei. The beams of neutron poor isotopes around 124La and 107Sn were selected to study the isospin dependence of the limiting temperature of heavy nuclei by comparing with results for stable 124Sn projectiles. A dedicated detector to measure the projectile charge upstream of the reaction target was not used, and alternative methods had to be developed. The presented method, based on the multivariate discriminant analysis, allowed to increase the efficacy of charge recognition up to about 90%, which was about 20% more than achieved with the simple scalar methods.Comment: 6 pages, 7 eps figures, elsart, submitted to Nucl. Instr. and Meth.

RadioLab tra presente e futuro

Il progetto nazionale dell’INFN sul monitoraggio ambientale del radon ha coinvolto per oltre un decennio scuole su tutto il territorio nazionale. Recentemente, alcune attività hanno coinvolto molte sedi rafforzandone l’efficacia e l’impatto su studenti e insegnanti. Tra queste ricordiamo il sondaggio sulla conoscenza del radon, la scuola estiva nazionale e le attività di calibrazione con protocolli comuni. La pandemia ha interrotto bruscamente le attività in presenza e l’organizzazione scolastica post-lockdown richiede di ripensare alcune azioni per ampliare la diffusione della consapevolezza di questa problematica tra i cittadini, ora che il recepimento della normativa europea sul radon `e giunto a compimento