117,599 research outputs found
"Una procedura per il calcolo degli oneri relativi agli assegni familiari", con L. Crescentini,
No full textLa meditazione mindfulness per i disturbi del neurosviluppo
No full textIn questo capitolo, il tema della meditazione mindfulness nell’ambito dei
disturbi del neurosviluppo è organizzato in tre sezioni. La prima introduce il
tema della meditazione mindfulness (Fabbro, 2019a): partendo dal contesto
storico-filosofico da cui essa proviene, viene delineato il panorama degli odierni
interventi che la utilizzano. La seconda sezione descrive i principali effetti psicologici
e neuropsicologici degli interventi basati sulla meditazione mindfulness in
riferimento a popolazioni adulte. L’ultima sezione si concentra sugli interventi
basati sulla meditazione mindfulness in età evolutiva (Crescentini e Menghini,
2019), descrivendo i risultati ottenuti nell’ambito dei disturbi del neurosviluppo
Achievement Emotions Adjective List: Some data related to gender with Swiss secondary school students
No full textOur main aim was to test some psychometric properties of the Achievement Emotions Adjective List (AEAL, Raccanello & Brondino, 2017) with students at-tending the first year of Lyceum in the Swiss context and to investigate gender issues
Parameters of the Earth’s Free Core Nutation from Diurnal Strain Tides
No full textEarth deformation at the diurnal tidal frequencies includes the resonant tidal-forcing response caused by the Free Core Nutation (FCN), a retrograde mode related to the slight misalignment of the rotation axes of the outer core and mantle. We analyse data from four underground high-sensitivity laser extensometers, whose signal-to-noise ratio in the diurnal tidal band is particularly high, and provide an alternative independent estimate of the FCN complex frequency with respect to more usual techniques (nutation and gravity). Firstly, we differentiate displacements due to diurnal solid tides to obtain extension along any azimuthal direction in terms of three complex parameters (A, S, C) which depend on latitude and frequency. Then, we demonstrate that we can invert the FCN complex frequency and the sensitivity of Im(A) and Re(S) to the resonance from our data. Lastly we obtain the probability distributions of those four parameters. Our results are in full agreement with those from nutation and gravity, as well as with reference IERS (International Earth Rotation and Reference Systems Service) values. Sensitivities of Im(A) and Re(S) to the resonance are estimated here for the first time and are in agreement with values computed using reference Love and Shida numbers from IERS
Nonisothermal Emplacement of Sills at Calderas: An Approximate Approach to Stopping by Magma Freezing
No full textThe emplacement and inflation of a kilometer-sized kilometer-deep magmatic sill is often invoked to explain caldera unrest, like Fernandina and Sierra Negra (Galapagos), Kilauea south caldera (Hawaii), and Campi Flegrei (Italy). Although the mechanism controlling sill formation is under investigation since decades, still unanswered questions include the following: How do sills spread? Why can magma propagate for kilometers without solidifying? We show that the free-surface effects may often be neglected and kilometer-sized kilometer-deep magmatic sills spread like hydraulic fractures in an infinite medium. Magma propagation details depend on overburden pressure, magma viscosity, injection rate, and difference between magma and rock temperatures. A small lag, filled with vapors from the fluid and/or the rock, exists between the propagating magma and fracture fronts. If the sill spreads along an interface or in a weak rock, the lag slightly affects isothermal sill spreading but takes a key role in the case of nonisothermal propagation: A sill would stop after few tens of meters without it, unless magma intrudes rocks that are as hot as the solidification temperature or has unrealistic overpressures, because spreading velocity decreases soon to the critical value at which the tip becomes blocked with solidified magma. The lag defers magma solidification as heat exchange between the magma and the rock is effective only behind the thermal-insulating lag, where magma has some finite thickness and sill opening grows with distance from the tip faster than thickness of solidified magma. Thus, the critical velocity decreases, allowing greater maximum sill sizes
Free Core Resonance and Ocean Loading from Diurnal Strain Tides Recorded by the Canfranc (Spain) Underground Geodetic Interferometers
No full textThe Canfranc underground laboratory, located under the Central Pyrenees (Spain) more than 120 km from the Bay of Biscay and 290 km from the Mediterranean Sea, hosts two 70-m-long high-resolution laser strainmeters, referred to as GAL16 and LAB780. The instruments are operating since end 2011, but, unfortunately, strain data acquisition suffered several interruptions, because of power outages during local severe storms, failures of the vacuum pumps, and, mainly, laser tube replacements. We present and discuss the tidal analysis of about 4.6 years of LAB780 data (ranging January 2012 to November 2018) in the diurnal band. The strain spectrum shows clear tidal peaks also for the weak Psi1 and Phi1 harmonics, which are very close to the Free Core Resonance (FCR) frequency. The observed S1 amplitude is comparable to the theoretical one, provided that both the solid Earth and the ocean loading tides are combined; however, its phase indicates a thermal effect due to the day/night temperature variation, whose annual modulation slightly affects both P1 and K1. Carefull removal of thermal effects and the good Psi1 and Phi1 signal-to-noise ratios allow a robust determination of the FCR frequency, fully consistent with determinations from VLBI and gravity data. Moreover, while ocean loading tides, computed using FES2014 and TPXO9-atlas models, are in full agreement with strain data as for the major diurnal harmonics, we show that the computed amplitude of the small J1 tide (included in FES2014 only) is larger than strain observations, which in turn are in agreement with tidal gauge data
Clues of Ongoing Deep Magma Inflation at Campi Flegrei Caldera (Italy) from Empirical Orthogonal Function Analysis of SAR Data
No full textUnderstanding the characteristics of a volcanic system is always important and becomes crucial when the volcano is in pluri-decadal unrest and located in a densely populated area, such as Campi Flegrei caldera, Italy. Ground deformation is a powerful source of information for studying the activity of magmatic sources and hydrothermal systems, even when difficult to detect otherwise. Here, we use ground displacement from ERS-ENVISAT and Sentinel-1A SAR images to investigate the 1993–2000 subsidence and part (2015–2022) of the present unrest. For each of the two time periods, we combine the line-of-sight displacements to obtain vertical and eastward displacements, and apply the empirical orthogonal function analysis to these latter time series—treated as a single data set—to decompose space-time fields into separated modes, consisting of uncorrelated spatial patterns and associated temporal evolutions. We only retain the first mode, since it captures the main deformation during both investigated periods, is the sole mode related to long-lasting (years) processes, and is less affected by noise than original data. Our analyses: (i) Confirm that most of the deformation is related to the activity of a 3–4 km deep sill-like source, which is inflated by magma and/or magmatic fluids during periods of unrest and deflates during periods of subsidence; (ii) Evidence ongoing deformation linked to local fluid migration in the Solfatara area; (iii) Identify persistent deformation features where peculiar fluid migration processes occurred during the 1982–1984 unrest; (iv) Most importantly, provide direct evidence of deep magma inflation at least since 2015, thus giving a strong warning of increasing risk at Campi Flegrei. Results demonstrate the capability of our approach to disclose hardly detectable processes and suggest a tool to monitor the activity of the deep magmatic source. Our approach can be useful also in other volcanic systems
DInSAR Data Reveal an Intriguing Contemporaneous Onset of Deep Deflation below Vesuvio and the Ongoing Campi Flegrei Uplift
No full textCampi Flegrei and Vesuvio volcanoes are only about 25 km apart, located on opposite sides of the densely inhabited area of Naples (Italy). Since neighbouring volcanoes may influence each other’s activity, it is of great interest to identify signs of any mutual interaction between Campi Flegrei and Vesuvio, or at least note coincidences in their recent deformation dynamics. After a large uplift, Campi Flegrei was generally subsiding from 1985 to 2001, while it has been uplifting—probably driven by deep magma inflation—at an accelerating rate since then. Here, we analysed the ground displacement in the whole Vesuvian area and its surroundings around the early 2000s using 1993–2010 ERS/ENVISAT ascending- and descending-orbit line-of-sight displacements obtained through the Small BAseline Subset Differential Synthetic Aperture Radar Interferometry technique. Although ground deformation is slow—a few millimetres per year—Empirical Orthogonal Function analysis shows a sudden trend change around 2001. Pre-2001 velocity maps confirm previously published results: subsidence mainly occurred inside the caldera rim—probably because of the sliding and compaction of young incoherent materials—and in a few spots around 10 km from the summital crater; eastward displacement occurred in a lobe east of Vesuvio, and westward displacement occurred in a lobe west of Vesuvio, as in the case of the spreading of the volcanic edifice and/or extensional tectonics. We attribute the subsidence spots to the previous high local number of new buildings per year. Post-2002 velocity maps provide evidence of a very different scenario: general subsidence in the whole Vesuvian area, westward displacement in a lobe east of Vesuvio, and eastward displacement in a lobe west of Vesuvio. This last arrangement of the ground displacement field is made even clearer by subtracting the post-2002 velocity from the pre-2001 value. The results of our analyses are consistent with the deflation of a deep pressurised source. Additionally, Vesuvio’s deep seismicity decreased at the beginning of 2002. The coincidence between the transition from deflation to inflation at Campi Flegrei and the onset of deflation below Vesuvio may suggest the possible transfer of magma and/or magmatic fluids between the two plumbing systems
Inversion of synthetic geodetic data for the 1997 Colfiorito events: clues on the effects of layering, assessment of model parameter PDFs, and model selection criteria
No full textThe 1997 September-October Umbria-Marche sequence has been extensively studied in the past by analyzing
coseismic displacement data (GPS, leveling, SAR). Here we focus on synthetic data representative of the main
event of the 1997 Umbria-Marche sequence and investigate the effects of a crustal layering proper to the Colfiorito
area on surface displacements and inferred source features when inverting coseismic geodetic data without
taking into account layering. We compare bootstrapping and NA-Bayes as tools for parameter uncertainty assessment
and show how the Akaike Information Criterion can be used to select the model which is most likely
to be correct. Since SAR images offer the most complete coverage of the study area, we use synthetic line-ofsight
displacement data.JCR Journalope
An Approximate Approach to Nonisothermal Emplacement of Kilometer-Sized Kilometer-Deep Sills at Calderas
No full textCaldera unrest is often caused by kilometer-sized kilometer-deep sills. Still unanswered questions include the following: How do sills spread? Why can magma propagate for kilometers without solidifying? Why do ground deformation data rarely, if ever, detect sill propagation? We show that kilometer-sized kilometer-deep magmatic sills spread like hydraulic fractures in an infinite medium. How magma propagates depends on overburden pressure, magma viscosity, injection rate, and difference between magma and rock temperatures. A small lag, filled with vapors from the fluid and/or the rock, exists between the propagating magma and fracture fronts. If the sill spreads along an interface, the lag slightly affects isothermal sill spreading but takes a key role in the case of nonisothermal propagation: A sill would stop after few tens of meters without it, unless magma intrudes rocks that are as hot as the solidification temperature or has unrealistic overpressures, because spreading velocity decreases soon to the critical value at which the tip becomes blocked with solidified magma. The lag defers magma solidification as heat exchange between the magma and the rock is effective only behind the thermal-insulating lag, where magma has some finite thickness and sill opening grows with distance from the tip faster than thickness of solidified magma. Thus, the critical velocity decreases, allowing greater maximum sill sizes. We also show that the ground deformation pattern does not change appreciably over time if the final sill radius is smaller than 2 to 3 km, explaining why deformation is usually attributed to the inflation of a stationary source
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