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Objectives Melody TPV is the first percutaneous valvular bio–prosthesis approved for trans–catheter pulmonary valve implantation (TPVI). We describe our ten–years experience about Melody TPV implantation in patients with congenital heart disease (CHD). Methods This is an observational retrospective single–center study. All patients undergone Melody TPV implantation were included. The early outcomes analyzed were: procedural failure, death of patient, life–threating adverse events. The long–term outcomes analyzed during follow–up were: infective endocarditis, trans–catheter redo–procedure, and surgical redo–procedure. Results From 2012 to 2022, 39 patients were evaluated in our catheterization laboratory for TPVI with Melody TPV. Mean age and weight were 21,31±11,58 (range 8–66) years and 57,5±16,24 (range 23–96) kilograms. The patients were affected by the following CHD: tetralogy of Fallot (22 pts, 56,4%), pulmonary atresia with ventricular septal defect (VSD) (4 pts, 10,3%), aortic stenosis s/p Ross surgery (4 pts, 10,3%), transposition of the great arteries with VSD and PS (3 pts, 7,7%), pulmonary stenosis (PS) (2 pts, 5,1%), truncus arteriosus (2 pts, 5,1%), double outlet right ventricle (1 pt, 2,5%), Ebstein’s anomaly (1 pt, 2,5%) In 4 cases (10,3%), the procedure failed because of coronary compression during balloon RVOT interrogation. One patient (2,5%) died due to post–procedural septic shock. In the other 34 patients (87,2%), the Melody TPV was implanted effectively. No life–threating adverse events were recorded. In 3 cases, the Melody TPV was implanted off–label: in tricuspid position (one case) and in “small conduits” ( Conclusion Trans–catheter Melody TPV implantation is effective to deal RVOT dysfunction. At a mid–term follow–up, the most of the implanted Melody TPV worked properly and only a few patients required surgical valve replacement.

Background Transcatheter patent foramen ovale (PFO) closure is a validated strategy to prevent recurrent cerebral events in adult patients; limited data are available for children. Methods This is a retrospective analysis including pediatric population underwent to percutaneous treatment of PFO in our center. Results From 2006 to 2021, 21 transcatheter PFO closures have been performed in children (mean age: 14 +3 years; female: 58%, weight: 59 + 20 kg). Indications for the closure of PFO consisted in the occurrence of cryptogenic ischemic events for 18 patients (86%), in disabling migraine symptoms for 2 patients (9,5%) and in prophylactic measure to prevent paradoxical embolism in high risk abdominal surgery for 1 patient (4,5%). Transcatheter PFO closure was performed under general anesthesia with transesophageal ultrasound guidance. Complex anatomies of PFO included atrial septal aneurysm in 4 cases (with accessory fenestration of atrial membrane in 2 of these cases) and long and stiff PFO tunnel in one case. Single device was used in 20 procedures. ASD closure device was required for 5 cases because of anatomic characteristics of PFO. In one case of large multifenestrated atrial septal aneurysm, percutaneous treatment was performed using both PFO closure device and ASD closure device. No peri and/or post procedural complications have been reported . All patients were treated with Acetylsalicylic acid and Clopidogrel for the first six months after the procedure. Conclusions Transcatheter PFO closure is a safe procedure in pediatric patients in high volume center that should be used for preventing recurrent cerebral events also in children.

Background Multifenestrate aneurysms of interatrial septum (ISA) are a challenge in paediatric age, not only for the complex anathomy, but also for small body surface and small dimensions of cardiac chambers of the patients, that may limit the use of large and multiple devices. Aim of the study: to evaluate the efficacy of percutaneous closure of multifenestrate aneurysms during mid–term and long–term follow–up; to evaluate if the morphological characteristics of interatrial septum may influence the success of the procedure. Materials and Methods We retrospectively analyzed 63 patients (mean–age 9,12±3,12 years) undergone to cardiac catheterism from 2000 to 2021, for percutaneous closure of interatrial aneurysm in our division of Cardiology, subdivided into 3 groups on the basis of side and morphological characteristics of the interatrial aneurysm: Group I (2 o more defects DIA>5 mm); Group II (one defect >5 mm and more than one further fenestrations); Group III (multiple fenestrations). Results Percutaneous closure was efficacy in 60 patients (95%), while in 3 patients (5%) surgery closure was necessary. In half of the treated patients (30) we used 2 devices. Complications occurred in 4 patients (6%). Only in 2 patients occurred major complications (Atrio–Ventricular Block that needed PMK implantation and partial displacement of device, treated by removal and percutaneous replanting). Residual shunts, not emodynamically significant appear in the immediate post–operative period in 26% and during the follow–up in 18%. The group I was associated with greater risk of failure of the procedure (P Conclusions Percutaneous closure of multifenestrate aneurysm of interatrial septum in paediatric age are effective and shows low incidence of failure and complications. If is present residual shunt is not significant. The anathomy of interatrial septum influences procedural outcome.

Pyroclastic currents are described as gravity currents, and the classic conceptual model gives a first-order importance to the density of such currents. This directs quantitative models to assume specific flow structures (shallow water or equilibrium turbulent boundary layer), which may apply to restricted volcanic areas independently of source dynamics or may correspond to source dynamics separate from topographic interaction. The recent introduction of two end-members of pyroclastic currents, inertial and forced, is further developed here, leading to a global conceptual model in which source dynamics and topographic interaction are both taken into account. The concept of energy facies is defined here as the ensemble of the first-order indicators of pyroclastic currents (topological aspect ratio, competence ratio and emplacement temperature) that are proxies of the energy of such currents. Nine energy facies are introduced with general applicability and with the goal to globally characterize pyroclastic currents from vent to deposit.

Abstract The name peperino derives from the Italian word pepe (from the Latin word piper, pepper) and has been used in the common language for lithified volcanic deposits characterized by light grey through dark grey tones and granular textures, resembling that of ground pepper. Among these, the best-known examples are represented by some phreatomagmatic deposits of the Colli Albani Volcanic District, near Rome (Italy), and ignimbrite deposits of the Cimini Mountains near Viterbo (Northern Latium, Italy), which have been widely employed in artefacts of historical and archaeological interest. In particular, these resistant volcanic rocks have been widely employed by the Etruscans and Romans since the seventh century BCE to produce sarcophagi and dimension stones, as well as architectural and ornamental elements. These rocks are still in use for building ornaments, street furniture and artworks in central Italy today. In this review, we provide an overview of the use of this term, and an exhaustive review of the different rocks of central Italy defined as peperino, describing their distinctive textural features, as well as their eruptive sources and outcrop areas. Indeed, despite the common macroscopic aspect, peperino rocks can be associated with several different eruptive styles and emplacement mechanisms. Our review is also addressed to archaeologists concerned with restoration initiatives and provenance studies, as well as to volcanologists studying the genetic processes of pyroclastic rocks and related naming conventions.

International audience; The Fucino Basin, central Italy, with its long and continuous history of Quaternary sediment accumulation, is one of the richest Mediterranean Middle Pleistocene tephra records. Here, we present a new detailed investigation of tephra layers (tephras) of the 250-170 thousand years before present (ka) interval, corresponding to the entire Marine Isotope Stage (MIS) 7 and parts of the MIS 8 and MIS 6. The investigated tephras have been characterised in terms of major, minor and trace elements, Sr-Nd isotopic compositions and 40Ar/39Ar ages. For correlation purposes, glass compositions and several new 40Ar/39Ar ages of selected proximal pyroclastic units spanning the same temporal interval from Vulsini (Latera Volcanic Complex), Sabatini, and Vico volcanic systems, central Italy, were measured. The late MIS 8-early MIS 6 Fucino tephras were backtracked to their corresponding volcanic sources, which include the Vulsini, Vico, Sabatini, Roccamonfina, Ischia and Campi Flegrei volcanic systems. While some of these tephras have been correlated to specific eruption units, other layers are currently not documented or described in near-vent sections, thus highlighting previously unrecognised events generated by these volcanic systems. Furthermore, the new high precision 40Ar/39Ar ages provide improved temporal constraints for Fucino making it one of the most detailed and chronologically best constrained tephra records for central Mediterranean MIS 7 tephrochronology. The Fucino record thus provides new integrative information for reconstructing the explosive history of Italian volcanoes during the investigated time interval. Furthermore, the geochronological constraints provide the basis for future paleoclimatic investigations at local and regional scale.

Pyroclastic currents (PCs) represent the most hazardous manifestations of explosive volcanic activity. The evaluation of their mobility, as related to the eruptive source parameters and the interactions with the surroundings along their path, is crucial for hazard assessment at active volcanoes in order to define the areas exposed to their impacts. Here we report on two case studies from the Latera Volcanic Complex (Vulsini Volcanic District, central Italy) that may approach the two end-members of the classical spectrum of PC dynamics in terms of particle concentration and dominant flow regime (i.e., dilute, turbulent vs. concentrated, laminar PCs). For the two examples, we document specific (and contrasting) variation trends of deposit thickness and maximum lithic and pumice clast sizes with distance from vent, which provide a further characterization in terms of forced vs. inertial flow behavior. In the first case, thickness and maximum lithic and pumice sizes show a mild, linear decrease with distance, implying a sort of balance between forced and inertial regimes. Flow pressure and mass progressively drop via deposition, along with flow competence. For given source conditions (i.e., mass eruption rate, fountaining height, erupting mixture, etc.) and slope angle of topography, the PC runout depends primarily on the waning density contrast between the flow and the surrounding atmosphere (density current), ending with the loft of the current. The second case, representative of moderate- to large-volume, dense PCs derived by continuous feeding with high mass discharge rate (i.e., from collapsing Plinian columns or caldera-forming events), shows an increase of deposit thickness with distance, which is accompanied by opposite lithic and pumice clast size-distance trends (i.e., decreasing lithic sizes and increasing pumice sizes downcurrent), compatible with high particle concentration and forced, non-turbulent, granular flow regime. By analogy with the mobility of dry debris flows, we suggest that the sliding component of transport, which prevails in proximal to intermediate settings, may account for the prevailing tendency of the PC to transport than to deposit, which leaves behind relatively thin sheets with coarse lithics, while the dominant spreading component downcurrent would result in increasing accumulation and the stacking of coarse pumice-rich flow lobes in more distal settings. The spreading component of transport would become more and more important with increasing material supply at PC source, resulting in additional runout. These findings cast new light on the first-order controlling factors of flow mobility for the two PC end-members, laying the groundwork for determining the most relevant PC hazard parameters, i.e. the maximum runout and the flow properties upon impact (dynamic pressure, burial potential, temperature).

Transient volcanic plumes are time-dependent features generated by unsteady eruptive sources, having similar eruption duration and plume development timescales. Their morphological evolution reflects both the discharge history at the vent and air entrainment, crucial parameters controlling volcanic ash dispersal and impact on the environment and human activities. However, despite its importance, transient plume morphology has been scarcely quantified, due to both observational and analytical hindrances. In this study, we introduce new tools to quantify the initial morphological evolution of transient volcanic plumes by applying fractal analysis and plume's perimeter measurements to thermal high-speed and visible-light high-resolution videos of eruptions. Eruptive plumes from Sakurajima (Japan), Stromboli (Italy), and Fuego (Guatemala) volcanoes were recorded during several field campaigns in 2012–2016. The eruption dataset has been complemented by the fractal analysis of three 2D numerical gas-jet simulations at different Reynolds number (2 × 103, 5 × 103 and 10 × 103) in order to provide reference configurations to compare with the natural cases. The two shape analysis methods used show different sensitivities. The ratio between plume and bounding box perimeters appears to be more perceptive of punctual dynamical variations, while fractal analysis reflects the overall plume evolution. Both methods highlight that plume shape complexity increases over time and is related to the formation and development of smaller scale vortexes. The variability of the rate of fractal dimension increase over time (αD) effectively captures plume evolution. It also appears that αD correlates with the ash eruption rate (AER) evolution and the instability of the source. This study shows that discharge history and intensity at the vent are the first order control on plume's shape evolution and, by inference, on its air entrainment ability.

This narrative review describes implementation, current status and perspectives of a pharmacogenomic (PGx) program at the Brazilian National Cancer Institute (INCA), targeting the cancer chemotherapeutic drugs – fluoropyrimidines, irinotecan and thiopurines. This initiative, designed as a research project, was supported by a grant from the Brazilian Ministry of Health. A dedicated task force developed standard operational procedures from recruitment of patients to creating PGx reports with dosing recommendations, which were successfully applied to test 100 gastrointestinal cancer INCA outpatients and 162 acute lymphoblastic leukemia pediatric patients from INCA and seven other hospitals. The program has been subsequently expanded to include gastrointestinal cancer patients from three additional cancer treatment centers. We anticipate implementation of routine pre-emptive PGx testing at INCA but acknowledge challenges associated with this transition, such as continuous financing support, availability of trained personnel, adoption of the PGx-informed prescription by the clinical staff and, ultimately, evidence of cost–effectiveness.

The Quaternary Volsci Volcanic Field (VVF) represents one of the products of the west-directed subduction of the Adriatic slab that drove the development of the Apennine mountain belt in central Italy. Here, we present new results on the eruptive history and the diatreme processes of exemplar tectonically controlled carbonate-seated maar-diatreme volcanoes. The VVF is defined by phreatomagmatic surge deposits, rich in accidental carbonate lithics, and subordinate Strombolian scoria fall deposits and lava flows, locally sourced from some tens of monogenetic eruptive centers, mostly consisting of small volume (0.01-0.1 km3) tuff rings and scoria cones. In light of new 40Ar/39Ar geochronological data and compositional characterization of juvenile eruptive products, we refine the history of VVF activity and envisage the implications on the pre-eruptive magma system and the continental subduction processes involved. Leucite-bearing, high-K (HKS) magmas mostly fed the early phase of activity (∼761–539 ka); primitive, plagioclase-bearing (KS) magmas appeared during the climactic phase (∼424–349 ka), partially overlapping with HKS ones, and then prevailed during the late phase of activity (∼300–231 ka). As the volcanic centers cluster along high-angle faults, we investigate the relationships between faulting and explosive magma-water interaction, as well as the distribution pattern of the eruptive centers. New field data allowed to retrieve the fold-and-thrust belt structure associated with the eruptive centers. Analysis of componentry, grain-size, degrees of whiteness and roundness of carbonate lithic inclusions, along with their micropaleontological features, has allowed to establish volcano tectonic correlations. In our interpretation, the clustering of eruptive centers is controlled by tectonic features. Specifically, a first order control is tentatively related to crustal laceration and deep magma injection along a ENE-trending Quaternary lateral tear in the slab and to Mesozoic rift-related normal faults. A second-order control is provided by orogenic structures (mainly thrust and extensional faults). In particular, magma-water explosive interaction occurred at multiple levels (< 2.3 km depth), depending on the structural setting of the Albian-Cenomanian aquifer-bearing carbonates, which are intersected by high-angle faults. The progressive comminution, rounding and whitening of entrained carbonate lithics allow us to trace multistage diatreme processes. Finally, our findings bear implications on volcanic hazard assessment in the densely populated (> 0.4 million people) areas of the Volsci Range and adjoining Pontina Plain and Middle Latin Valley.

Explosive volcanic eruptions eject a mixture of gas and pyroclasts into the atmosphere at a range of velocities. Directly above the vent, in the gas-thrust region, a supersonic jet may be generated that strongly controls the eruptive dynamics. To improve our quantitative understanding of volcanic supersonic jets, the effect on particles within them, and their acoustic emission, we have performed small-scale explosive eruptions in the laboratory using a shock-tube. The shock-tube is composed of 3 parts, a bottom (5.6 m long, elevated pressure) and a top (48mm long, ambient pressure) plexiglass cylinder (5 mm inner diameter), separated by an electrovalve.We have run experiments using ambient air as gas and sand, with diameter between 0.1 and 0.3 mm, as particles. The gas volume was fixed while the pressure ratio (the shock-tube reservoir to ambient pressure ratio) was varied from about 4 to 8.4 to obtain supersonic flows. During the experiments, the jet was recorded with a high-speed camera operating at 34660 fps, and the resulting noise acoustic emission with microphones (6 Hz-140 kHz; 1000 kfps) positioned at 90° from the jet axis.Among the acoustic signals produced by a supersonic jet (jet noise) we have particularly focussed on the broad-band shock noise (BBSN) that is emitted by the interaction between shock cells and the turbulence in the jet. We estimated the jet velocity using an acoustic model based on the identification of the peak frequency of the BBSN. We also identified the BBSN frequency and its variation over time by applying the complex Morlet wavelet transformation. As expected, the BBSN frequency is inversely proportional to the gas velocity. Concerning the video recording, we analysed the shock cells behaviour and their temporal oscillation due to the presence of particles. Finally, the particle ejection rate was calculated in every video frame.We found that the acoustic signal and shock cells are influenced by the presence of particles. In fact, fluctuations in particle concentration are well visible and decelerate the flowing gas. As a consequence, there is a temporary decrease of the stand-off-distance between the vent and the first shock-cell and concurrent rise of the BBSN frequency. We noticed, in some cases, that the shock-cells disappear during a short time interval. The BBSN frequency and the stand-off-distance behaviour over time follow the oscillation of the particle ejection rate confirming their sensitivity to particle load variation.The future prospectives of this embryonal study could lead to new instruments for determining either the amount of pyroclasts inside the volcanic jets and their exit velocity on the basis of the recorded acoustic signals.

Here, we report on the Quaternary Volsci Volcanic Field (VVF, central Italy). In light of new 40Ar/39Ar geochronological data and compositional characterization of juvenile eruptive products, we refine the history of VVF activity, and outline the implications on the pre-eruptive magma system and the continental subduction processes involved. Different from the nearby volcanic districts of the Roman and Campanian Provinces, the VVF was characterized by small-volume (0.01–0.1 km3) eruptions from a network of monogenetic centers (mostly tuff rings and scoria cones, with subordinate lava occurrences), clustered along high-angle faults of lithospheric depth. Leucite-bearing, high-K (HKS) magmas (for which we report for the first time the phlogopite phenocryst compositions) mostly fed the early phase of activity (∼761–539 ka), then primitive, plagioclase-bearing (KS) magmas appeared during the climactic phase (∼424–349 ka), partially overlapping with HKS ones, and then prevailed during the late phase of activity (∼300–231 ka). The fast ascent of primitive magma batches is typical of a tectonically controlled volcanic field, where the very low magma flux is a passive byproduct of regional tectonic strain. We suggest that the dominant compressive stress field acting at depth was accompanied by an extensional regime in the upper crust, associated with the gravity spreading of the Apennine chain, allowing the fast ascent of magma from the mantle source with limited stationing in shallow reservoirs.

In our original paper (Buono et al., 2020), we investigated the dynamics of degassing (e.g., bubble nucleation and growth, degassing styles and regimes) of H2O-, CO2- and H2O-CO2-rich evolved alkaline melts over a wide range of variables (final pressures, decompression rates, volatile compositions and contents, temperatures) through a comprehensive review of previous and new HP (high pressure)-HT (high temperature) decompression experiments. The criticism of Allabar and Nowak regards a restricted part of our results, i.e., those concerning homogeneous bubble nucleation from our new experiments on H2O-rich melts. Their aim is refusing the classical nucleation theory (CNT), widely accepted in literature to explain homogeneous bubble nucleation in magmas, for evolved alkaline melts in favour of the spinodal decomposition. We found that the Authors of the Comment do not provide any new evidence in support of their thesis, but they keep only arbitrary and erroneous conjectures of our new experimental data. As we stated in our original paper, the evaluation of the specific bubble nucleation mechanism (CNT vs. spinodal decomposition) is beyond the scope of our research, as appropriate studies on both experimental and natural products would be necessary to shed light on this complex issue.

This paper details the experimental validation of a multi-scale simulation strategy that we developed for predicting the stresses and distortions induced by Powder Bed Fusion processes. The strategy comprises a meso-scale model, a macro-scale model, and a scaling method named Pointwise Strain Superposition. The first model evaluates the temperature, stress, and strain fields produced by a single scan line. The scaling method transfers the meso-scale results to the macro-scale model, which is then able to simulate the entire manufacturing process with a reasonable computational cost. The simulation strategy was validated by comparing its results with the stresses and distortions measured on several specimens made of selective laser melted Inconel 718. Stresses were measured through the blind hole drilling method on a cylindrical specimen printed with two different scanning strategies, while distortions were measured on a hollow cylinder and on a cantilever-shaped specimen after removing its supports. In both cases the simulation showed first- or higher-order accuracy despite the significant uncertainties regarding the input parameters and material properties. This robustness, coupled with its computational efficiency, leads us to believe that our simulation strategy could enhance the process optimization and provide a better understanding of the underlying physical phenomena along with their effects on the manufactured parts.

International audience; Glacial-interglacial variations in ice volume and sea level are essential components of the Pleistocene global climate evolution. Deciphering the timing of change of these key climate parameters with respect to the insolation forcing is central to understanding the processes controlling glacial terminations. Here we exploit the sensitivity of the Paleo Tiber River (central Italy) to sea-level forced changes in the base level and the frequent occurrence of datable tephra layers in its sedimentary successions to reconstruct the timing of the relative sea-level (RSL) change between 450 and 403 ka, i.e., across the glacial termination (T-V) that marks the transition between Marine Isotope Stage (MIS) 12 and MIS 11. The analysis hinges on new stratigraphic data, tephra geochemical fingerprinting, and 40Ar/39Ar dating from a fluvial section that represents the inland counterpart of the near mouth, coastal aggradational successions of the San Paolo Formation (SPF). Tephra correlation indicates that the morpho-stratigraphic record of the inland section is as sensitive to the sea-level change as its coastal counterparts, which makes it ideal to complement previous RSL reconstructions from the Tiber River catchment basin, thereby providing a more detailed picture of the sea-level history across T-V. Combined sedimentological and morphological proxies of the composed inland-coastal SPF record document the occurrence of two phases of relatively rapid sea-level rise, here interpreted as meltwater pulse (MWP) events. The earlier MWP occurred between ∼450 and ∼445 ka and matches a relatively minor episode of the sea-level rise documented in an existing RSL record, while the younger MWP at ∼430 ka corresponds to the high amplitude sea-level rise that marks T-V. We find that both MWPs coincide with episodes of ice-rafted debris deposition in the North Atlantic (Heinrich-like events) and with attendant Southern Hemisphere warming, plausibly associated with the bipolar seesaw.

Through a systematic integrated approach, which combined lithostratigraphic, geochronological and geochemical analyses of tephra from near-source sections of the peri-Tyrrhenian volcanoes and mid to distal settings, here we provide an improved tephrochronological framework for the Marine Isotope Stage 11c interglacial (MIS 11c, ∼425–395 ka) in the Central Mediterranean area. Specifically, we present the complete geochemical dataset and new high-precision 40Ar/39Ar ages of the previously poorly characterized earliest pyroclastic products of the Vico volcano (420–400 ka), including the Plinian eruptions of Vico α and Vico β and the immediately post-dating lower magnitude explosive events. Furthermore, we also provide new geochronological and geochemical data for the distal tephra layers preserved in the aggradational succession of the Tiber delta (San Paolo Formation), Roman area, which records sea level rise relating to the MIS 12 (glacial) to MIS 11 (interglacial) transition. Five pyroclastic units were recognized in Vico volcanic area, four out of which, Vico α, Vico β, Vico βtop (a minor eruption immediately following Vico β and temporally very close to it) and Vico δ were directly dated at 414.8 ± 2.2 ka, 406.5 ± 2.4 ka, 406.4 ± 2.0 ka and 399.7 ± 3.2 ka respectively (2σ analytical uncertainties). These new data allow a critical reappraisal of the previously claimed identifications of Vico tephra from mid-distal to ultra-distal successions (i.e., Vico-Sabatini volcanic districts, Roman San Paolo Formation and Castel di Guido archaeological site, Sulmona Basin, Valdarno and Lake Ohrid), which were unavoidably biased by the poor and incomplete geochemical and geochronological reference datasets previously available. Such an improvement of the tephrochronological framework brings great benefits to any future investigations (e.g., paleoclimatology, archaeology, active tectonic, volcanology) in the dispersal areas of the studied eruptions at the key point in time that is MIS 11.

This multi-disciplinary work provides an updated assessment of possible future eruptive scenarios for the city of Rome. Seven new 40Ar/39Ar ages from selected products of the Monti Sabatini and Vulsini volcanic districts, along with a compilation of all the literature ages on the Colli Albani and Vico products, are used to reconstruct and compare the eruptive histories of the Monti Sabatini and Colli Albani over the last 900 ka, in order to define their present state of activity. Petrographic analyses of the dated units characterize the crystal cargo, and Advanced-InSAR analysis highlights active deformation in the MS. We also review the historical and instrumental seismicity affecting this region. Based on the chronology of the most recent phases and the time elapsed between the last eruptions, we conclude that the waning/extinguishment of eruptive activity shifted progressively from NW to SE, from northern Latium toward the Neapolitan area, crossing the city of Rome. Although Monti Sabatini is unaffected by the unrest indicators presently occurring at the Colli Albani, it should be regarded as a dormant volcanic district, as the time of 70 kyr elapsed since the last eruption is of the same order of the longest dormancies occurred in the past.

The Fucino Basin is the largest and probably the only Central Apennine basin hosting a thick, continuous lacustrine sediment succession documenting the environmental history from the Early Pleistocene to recent historical times. The basin is located downwind of the Italian volcanic districts (< 150 km), which makes it the best candidate available in the central Mediterranean to construct a long and continuous tephrostratigraphic and tephrochronological record. Tephrostratigraphic investigations conducted on a first core (F1-F3) revealed 21 tephra layers of different Italian volcaoes. Among them several widespread and well-dated key Mediterranean marker tephra layers (e.g., Neapolitan Yellow Tuff, Y-1, Campanian Ignimbrite, Y-7, X-5, X-6, and Taurano Ignimbrite) were recognized and allowed to date, together with 40Ar/39Ar ages directly obtained from the Fucino tephra layers, the record back to 190 ka.Based on these promising results, a new drilling site with a lower sedimentation rate was targeted, bringing forth the ~98 m long F4-F5 record. In addition to the already recognised tephra layers occurring in the section that overlaps with core F1-F3, ~110 additional tephra and cryptotephra horizons were identified in the composite sediment succession of the F4-F5 record, providing new insights into the Italian volcanic history for the poorly explored interval beyond 200 ka.Here we present the first tephrostratigraphic and tephrochronological results for this interval, which is dominated by eruptions from the Sabatini, Vulsini, Vico, and Colli Albani volcanoes. Several important known eruptions were identified and dated for the first time in distal settings: e.g., Canino (256.8 ± 1.1 ka), Tufo Giallo di Sacrofano (288.0 ± 2.0 ka), Magliano Romano Plinian Fall (315.0 ± 2.0 ka), Orvieto-Bagnoregio Ignimbrite (335.8 ± 1.4 ka), Villa Senni (367.5 ± 1.6 ka), Pozzolane Nere and its precursor (408.5 ± 1.3 ka, and 407.1 ± 4.2 ka, respectively). Finally, a tephra located at the base of the succession was directly dated by 40Ar/39Ar at 424.3 ± 3.2 ka, thus extending the record back to the MIS 12/11 transition (~430 ka).Ongoing geochemical analysis, including trace elements, Sr and Nd isotopes, and 40Ar/39Ar dating of both Fucino tephra layers and potential proximal counterparts will help to reveal their volcanic sources and enable further tephrostratigraphic correlations supported by independent age determinations. These results will contribute towards an improved MIS 11-MIS 7 Mediterranean tephrostratigraphy, which is still poorly characterized and exploited.The recognition and dating of the numerous tephra layers from the F4-F5 record can be directly combined to construct a comprehensive age-depth series of biogeochemical proxies and geomagnetic excursions derived from the lacustrine sediments, forming the backbone for an independent, radioisotopically anchored chronology for the F4-F5 multi-proxy record. Through paleoclimatic alignments and geomagnetic excursion synchronizations, the independent Fucino chronology can be propagated to the North Atlantic records, and possibly on a global scale, setting the framework for a better understanding of the spatio-temporal variability, magnitude, and different expressions of Quaternary orbital and millennial-scale paleoclimatic changes.

We report the first experimental study on CO 2 bubble nucleation and growth in silicate magmas in response to pressure release. The starting materials were nominally anhydrous trachyte and trachybasalt glasses that were CO 2 saturated at 1200 °C and 300 MPa for at least 48 h under oxidizing conditions. These starting glasses were doped with diverse crystals relevant to the studied melt compositions: olivine, Cr-spinel, clinopyroxene, K-feldspar and leucite. Decompression experiments were performed after an initial equilibration at 1128–1156 °C and 300 MPa for time durations ranging between 15 and 45 h. Pressure was subsequently decreased to a final value of 30 MPa with a decompression rate of 4 MPa/min. Backscattered electron microphotographs of the quenched products were collected using a scanning electron microscope. In all experiments, we observed an event of homogeneous and heterogeneous bubble nucleation, testified by the formation of vesicles with diameters up to 30 μm on the crystal rims as well as in the residual melts. In the samples containing K-feldspar and leucite, another generation of bubbles with diameter up to 130 μm is present in proximity of those crystals, suggesting the occurrence of an earlier heterogeneous nucleation event. CO 2 bubble nucleation and growth was investigated by the determination of the wetting angles (ϑ) between the vesicles and the crystal surfaces, which can be used as proxy for the efficiency of the crystals as nucleation sites. It was calculated that the activation energy for bubble nucleation in the studied magmas it is lowered by a factor φ up to approx. 0.64 in presence of crystals. The experimental results show several peculiarities of heterogeneous CO 2 bubble nucleation: i) CO 2 vesicles form indiscriminately on diverse crystals, in accordance to the small ϑ distribution range between 40° and 70°; ii) CO 2 bubbles do not nucleate preferentially on capsule walls; iii) the crystal shapes seem to not to influence bubble nucleation. Our findings are compared with data on heterogeneous H 2 O bubble nucleation from previous studies to highlight distinctive features. Our new experimental data on crystal wettability in CO 2 dominated magmas allow a first assessment of the surface tension through the classical nucleation theory approach. The new findings about CO 2 bubble nucleation will be useful to better understand the onset and the intensity of the eruptions in the K-rich magmatic systems.

Quaternary carbonate-seated maar-diatremes in the Volsci Range are one of the most intriguing products of the west-directed subduction of the Adriatic slab that drove the development of the Apennine mountain belt in Central Italy. The Volsci Volcanic Field is characterized by phreatomagmatic surge deposits, rich in accidental carbonate lithics, and subordinate Strombolian scoria fall deposits and lava flows, locally sourced from some tens of monogenetic eruptive centers (at least fifty tuff rings and scoria cones). We investigate the subsurface maar-diatreme processes in terms of relationships between faulting and explosive magma-water interaction, as well as the distribution pattern of the eruptive centers. With this aim, we present the following new data: i) description of the fold-and-thrust belt structure and associated eruptive centers, ii) componentry of volcanic rock-types, iii) determination of grain-size, degrees of whiteness and roundness of carbonate lithic inclusions, iv) micropaleontological analysis of carbonate lithics. We show that the clustering of eruptive centers is controlled by tectonic features. A first order control is tentatively related to crustal laceration and deep magma injection along a ENE-trending Quaternary lateral tear in the slab and to Mesozoic rift-related normal faults. A second-order control is provided by orogenic structures (mainly thrust and extensional faults). In particular, magma-water explosive interaction occurred at multiple levels (

We present a multidisciplinary study of a fossiliferous site located in the Vulsini Volcanic District, on the western side of the Tiber River Valley north of Rome, highlighting the peculiar geologic factors that contributed to the origin and preservation of an outstanding archaeological record testifying of the early human frequentation in this region. Mighty explosive eruptions since at least 500 ka affected the investigated area eventually culminating in the formation of the huge Bolsena caldera. Tectonic deformation accompanying volcanic activity caused large fault displacements, shaping the ground surface and contributing to route the path, and possibly to trigger, the catastrophic emplacement of volcaniclastic flows. A sedimentary trap originated by fault scarp cutting through a streambed was likely the cause for the large accumulation of bones and stone artifacts ripped up and carried by a volcaniclastic flow at 322 ka. The analysis of the fossil assemblage reveals both gnawing traces by carnivores and cut-marks from the percussion tools employed by humans to butch the carcasses. However, the occurrence of retouched and unretouched blanks within the lithic assemblage also testifies for provenance from a wider area of human activity, which included hunting and scavenging, probably at a nearby butchering site.

Product defects are a major challenge for the understanding and application to new products of mass additive manufacturing. This work starts from an overview of typical defect categories, especially focusing on direct metal laser sintering (DMLS), their causes and the capability/reliability of in process sensors. Individual sensor applications are available in the literature. The proposed sensor system preliminary explores the qualitative and quantitative correlation and integration of an accelerometer mounted on the powder spreading recoater, with photodiodes, a visible and an IR camera. An online control strategy is also proposed for early detection and prevention of product defects.

Here we present the first tephrostratigraphic, palaeomagnetic, and multiproxy data from a new ∼98 m-deep sediment core retrieved from the Fucino Basin, central Italy, spanning the last ∼430 kyr. Palaeoenvironmental proxy data (Ca-XRF, gamma ray and magnetic susceptibility) show a cyclical variability related to interglacial-glacial cycles since the Marine Isotope Stage (MIS) 12-MIS 11 transition. More than 130 tephra layers are visible to the naked eye, 11 of which were analysed (glass-WDS) and successfully correlated to known eruptions and/or other equivalent tephra. In addition to tephra already recognised in the previously investigated cores spanning the last 190 kyr, we identified for the first time tephra from the eruptions of: Tufo Giallo di Sacrofano, Sabatini (288.0 ± 2.0 ka); Villa Senni, Colli Albani (367.5 ± 1.6 ka); Pozzolane Nere and its precursor, Colli Albani (405.0 ± 2.0 ka, and 407.1 ± 4.2 ka, respectively) and Castel Broco, Vulsini (419–490 ka). The latter occurs at the bottom of the core and has been 40Ar/39Ar dated at 424.3 ± 3.2 ka, thus providing a robust chronological constrain for both the eruption itself and the base of the investigated succession. Direct 40Ar/39Ar dating and tephra geochemical fingerprinting provide a preliminary radioisotopic-based chronological framework for the MIS 11-MIS 7 interval, which represent a foundation for the forthcoming multiproxy studies and for investigating the remaining ∼110 tephra layers that are recorded within this interval. Such future developments will contribute towards an improved MIS 11-MIS 7 Mediterranean tephrostratigraphy, which is still poorly explored and exploited.

We present a geomorphological, stratigraphical and geochronological study reconstructing a suite of paleo-surfaces in a 200 km-long coastal sector of the central Tyrrhenian Sea between Argentario and Circeo promontories. Identification of the near-shore deposits associated with these paleo-surfaces allow us to define corresponding marine terraces and paleo sea-levels. 40Ar/39Ar and ESR/U-Th geochronologic constraints on key deposits provide correlation with the terraces previously recognized in the coast of central Latium, refining their correlation with the Marine Isotopic Stages. Results of this study enable us to: Propose a re-assessment of the ages for the sea-level markers of MIS 5.5, 5.3, 5.1 in the central Tyrrhenian Sea; Suggest that a continuous tectonic uplift with an average rate of 0.224 mm/yr affects the Latium coast since 200 ka; Provide new evidence for a MIS 5.5 paleo-sea level marker occurring at ~35 m a.s.l. on the coastal sector extending from Montalto di Castro to Latina, while it possibly drops down and connects to a paleo sea-level ranging 10 - 5 m between Monte Circeo and Gaeta, previously attributed to this interglacial; Discussing possible evidence of similar elevation of the sea level during MIS 5.5, 5.3 and 5.1 interglacials in the Tyrrhenian Sea; Compare this datum with those from the western Pacific and several coral reefs, where the differences with respect to tectonically stable regions were attributed either to tectonics or to the Glacial Isostatic Adjustment, showing that the presented record of sea-level markers may have a strong impact on modeling the post-glacial effects in the Mediterranean Sea and on the paleoclimatic and paleoceanographic studies in this region.

International audience; the accumulation of magma within the Monti Sabatini Volcanic District (MSVD), italy, coupled with the extensional tectonics of the region, pose both volcanic and tectonic hazards to the city of Rome, located 20 km to the southeast. We combine 40 Ar/ 39 Ar geochronology of volcanic deposits and a geomorphologic/stratigraphic/paleomagnetic study of fluvial terraces to determine the recurrence interval and the time elapsed since the last eruption of the MSVD. Moreover, we provide a date for the youngest known eruption of the MSVD and assess the timing of the most recent volcanic phase. Results of this study show: (i) The most recent eruptive phase occurred between 100 ka and 70 ka; (ii) the anomalously high elevation of the MIS 5 terrace indicates that it was concurrent with 50 m of uplift in the volcanic area; (iii) the time since the last eruption (70 ka) exceeds the average recurrence interval (39 ky) in the last 300 ky, as well as the longest previous dormancy (50 ky) in that time span. (iv) the current duration of dormancy is similar to the timespan separating the major explosive phase that occurred 590-450 ka. The magnitude and patterns of deformation of a volcanic field provide constraints on the magmatic processes operating beneath a volcano. A recent geomorphological study 1 reconstructed a series of paleo-surfaces along a 40-km-long stretch of the Tiber River Valley north of Rome, between Magliano Sabina and Monterotondo, located at the eastern margin of the Monti Sabatini Volcanic District (MSVD) (Fig. 1a). These paleo-surfaces are interpreted as fluvial terraces formed through the interplay between regional uplift and glacio-eustasy (e.g. 2) during a regressive phase that formed the hydrographic network of the Paleo-Tiber River since the end of the Santernian (1.78-1.5 Ma; lower Calabrian) 3. The reconstructed rates of uplift during the last 1.8 Ma recognized two major pulses: 0.86 through 0.5 Ma, and 0.25 Ma through the present time 1. The coincidence of the uplift pulses with the ages of the main volcanic phases 1 are interpreted as mainly driven by uprising magma bodies from a metasomatized mantle source of the Roman Magmatic Province (e.g. 4-6). This "magmatic" uplift overlaps a smaller isostatic component on the Tyrrhenian Sea Margin of central Italy. In the present study, we further refine the chronostratigraphy of the paleo-surfaces in the area previously investigated, providing five new 40 Ar/ 39 Ar age determinations on volcanic products intercalated within the

Volcanic processes occur in a wide range of temporal and spatial scales. However, a key step of magma ascent is recognizable in the dynamics of gas and magma in the shallow plumbing system, where volatiles play a fundamental role in controlling the eruptive style. With the aim of investigating shallow degassing processes, an experimental setup was deployed at Mt. Yasur, an active volcano located in Tanna Island (Vanuatu arc), from 9th to 12th July 2011. The setup comprised high-speed and thermal cameras, as well as a microphone, capable of recording both in the infrasonic and audible range. The analysis of acoustic signals, validated by observing images from the high-speed and thermal cameras, has enabled characterizing the explosive activity during the investigated period. Two types of explosions, distinct for spectral features and waveforms, were observed: (i) minor events, corresponding to small overpressurized bursts, occurring almost continuously; (ii) major events, characterizing the Strombolian activity at Mt. Yasur. By investigating variation in the occurrence rate of the minor events, we found that, on a short timescale, the dynamics responsible for the two types of explosions are decoupled. These results, together with previous literature data, bring additional evidence of the existence of distinct sources of degassing. Finally, major events can be distinguished as emergent events, i.e. long-lasting signals, corresponding to ash-rich explosions, and impulsive events, featuring shorter duration and larger amplitude.

We present new 40Ar/39Ar data which allow us to refine the recurrence time for the most recent eruptive activity occurred at Colli Albani Volcanic District (CAVD) and constrain its geographic area. Time elapsed since the last eruption (36 kyr) overruns the recurrence time (31 kyr) in the last 100 kyr. New interferometric synthetic aperture radar data, covering the years 1993–2010, reveal ongoing inflation with maximum uplift rates (>2 mm/yr) in the area hosting the most recent (

The Sabatini Volcanic District (SVD), active between 0.8 and 0.07 Ma, is a volcanic field in the Roman province (Central Italy) located along the Tyrrhenian margin of the Italian peninsula. In this volcanic region, high-K magmas originated from a metasomatised phlogopite-bearing peridotite mantle recording subduction-related fluids and/or melting processes. Here, we investigate magma evolution during the six main eruptive phases of the SVD by means of chemical and isotopic (Sr and Nd) analyses. Specifically, we analyzed clinopyroxene crystals from juvenile pumice and scoria clasts and lavas, from 40 major SVD eruptive units chronologically well constrained by 40Ar/39Ar dating. 87Sr/86Sr and 144Nd/143Nd ratios in SVD clinopyroxene range 0.7095–0.7115 and 0.51210-0.51214, respectively. The mean Sr and Nd isotope compositions of each eruptive phases show a gradual, long-term decrease over the entire SVD eruptive history. However, when considering the distinct temporal windows of the individual eruptive phases, a significant variability of the Sr-Nd isotope ratios emerges, thus highlighting a more complex, time-dependent geochemical trend for the erupted magmas, with respect to a previously described trend at the nearby Colli Albani Volcanic District (0.6–0.04 Ma). Geochemical features of clinopyroxene in lavas and juvenile pyroclasts suggest that magma differentiation occurred in an open system due to assimilation of siliciclastic sedimentary rocks. Moreover, a critical review of the available geochemical data, in light of 40Ar/39Ar ages, allows the recognition of the SVD as the source of widespread tephra markers recorded in the central Mediterranean area by previous works.

In the present paper, we analyze the regional interplay between glacio-eustasy and volcano-tectonic uplift on the Tyrrhenian Sea margin of central Italy. We reconstruct a succession of fluvial terraces in the Tiber River Valley east of the Vulsini Volcanic District and we provide geochronologic constraints allowing for correlation with the sea-level highstands of the Marine Isotope Stage timescale. Results of this study show that glacio-eustatic forcing affected the hydrographic network of the Tiber River, as far as 70 km inland with respect to the present Tyrrhenian coast, consistent with a regional uplift on the order of several tens of meters that affected this region over the last 250 ky. Using six new 40Ar/39Ar dates, we demonstrate the synchronicity between sea-level rise during glacial termination IV and the deposition of a fining-upward sedimentary succession of the Paleo-Tiber River in this area. A detailed reconstruction of the chronostratigraphic setting enabled us to assess local uplift and fault displacement due to volcano-tectonic processes associated with the activities of Bolsena-Orvieto and Latera volcanoes since 350 ka, and develop an uplift curve for the different sectors of the investigated area. Moreover, we estimate sedimentation rate during post-glacial sea-level rise. Strong differential uplift, with rates on the order of 0.6–1.2 mm/yr corresponded with the onset of major eruptive phases, whereas a homogeneous regional uplift of 0.24 mm/yr during the last 125 ky followed this climactic phase. These uplift rates are significantly smaller than sedimentation rate during the glacial termination, consistent with the observed independence of the glacio-eustatic signal.

Conceptual models explaining the characteristics of ignimbrites and their basal deposits have mainly focused on variations in particle concentration and speed of the parent pyroclastic currents. Here, we focus on the effects of relative proportions of clasts that are well coupled to the carrier gas phase and those that are poorly coupled, i.e., the proportions of fine and/or low-density clasts compared to coarse and/or dense clasts. We document facies and macroscopic clast populations of two ignimbrite-producing eruptive sequences of similar volume and composition, both erupted from Latera caldera (central Italy). The Sovana ignimbrite has 1–15 vol% dense lithic clasts and locally up to 70 vol% in lithic-rich domains. It preserves evidence of emplacement of multiple overlapping flow units with local internal channeling. The ignimbrite is underlain by two basal deposits: (1) a radially distributed, 20–80-cm-thick vitric tuff referred to as BUS (basal unit Sovana) that thins gradually with distance and shows evidence of emplacement by lateral currents; and (2) a fines-depleted, lenticular, massive lapilli tuff, up to 20 cm thick, with abundant lithic clasts. The Sorano ignimbrite, in contrast, has

Lake Ohrid, located in the Central Mediterranean region downwind of the Italian volcanoes, has great potential for developing a detailed record of the explosive activity of these volcanoes. Electron microprobe and Laser Ablation Inductively Coupled Plasma Mass Spectrometry geochemical analyses of juvenile glass fragments of previously not analysed tephra layers of the DEEP site sediment record of Lake Ohrid expand the existing tephrostratigraphy for the interval Marine Isotope Stages 1–16. The geochemical signatures of all tephra layers suggest an origin exclusively from the Italian volcanism. Eight of these tephra layers have potential equivalents in marine and terrestrial archives of the Central Mediterranean region (OH-DP-1966/SC5/A7; OH-DP-1955/CES1/A2; OH-DP-1055/S1; OH-DP-1006/S2; OH-DP-0997/S3, OH-DP-0710/S8/C-51; OH-DP-0766/ODP5/P-13; OH-DP-0505/ODP4). Nine tephra layers, which have not been described so far, help to reconstruct the late volcanic activity of Mount Vulture (OH-DP-2439) and the Paleovulsini (OH-DP-1998), the pre- and post Rio Rava activity of the Roccamonfina volcano (OH-DP-1911/-1812/-1733/-1640/-1527), the early activity of the Aeolian Arc (OH-DP-1513/-1520), and the Bracciano activity of the Monti Sabatini volcanic district (OH-DP-1175). The multi-proxy dataset and chronology of the DEEP site sediments allowed definition of the climatostratigraphic position for all tephra layers and constrain the ages of so far unknown and/or undated tephra layers. The presented data provide a crucial increase of knowledge of the Middle Pleistocene tephrostratigraphy in the Central Mediterranean back to 630 ka and allows new insights of the volcanic activity of Roccamonfina, the Roman Province, the Campanian Volcanic Zone (CVZ), the Aeolian Arc, Pantelleria, and Mount Vulture.

The crater terrace of Stromboli Volcano (Italy) hosts several active vents which have evolved and migrated through time within three main vent areas: south-west (SW), central (C), and north-east (NE). Frequent, jet-like explosions typically take place, episodically interrupted by larger-scale paroxysms, which can substantially modify the morphology of the crater terrace and vent geometries. However, the link between the time-space evolution of vent activity and the shallow conduit system are still a matter of debate. In this work, we analyze the vent position and explosion parameters (jet duration and geometry) of 4296 events at Stromboli in five 72-h-long time-windows between 2005 and 2009, as recorded by an infrared surveillance camera. Vent locations illustrate the resilience of the shallow conduit system, which controls explosive activity at different time scales and depths. At the shallowest depth, where slugs burst, conduit branching and merging determines the evolution of simultaneous or alternating twin vents, while vent shape and slug size control local explosion parameters. These processes show variability on an hourly to daily time scale. Below the depth of the slug burst, the conduit system feeding each vent area controls which specific vent will host the explosions and also, possibly, the size of the slugs. Several observations suggest that the C and SW vent areas may be connected at this depth. The deeper conduit system, common to all vent areas, sets the overall explosion rate of the volcano and maintains a balance of this rate between the NE and the combined SW and C vent areas.

High-speed imaging of Strombolian explosions brings into view the motion of pyroclasts upon leaving the volcanic vent. The erupted gas-pyroclast mixtures form jets with well-defined leading vortex rings that rise at almost constant velocity proportional to the time-averaged velocity of pyroclasts. The ejection velocity of pyroclasts decreases over time and defines a conical profile centered on the jet central streamline. Pyroclast deceleration patterns are related to their velocity and compatible with drag force but are also strongly controlled by jet dynamics. These patterns include constant, decreasing, or abruptly increasing decelerations up to 104 m s−2. Nonuniform deceleration focuses at the jet sides and, mostly, in a narrow zone across the vortex ring. This deceleration zone is trailed by a reduced drag zone, where deceleration is drastically reduced. In these highly transient eruptions, both zones move upward and attenuate over time. Our results provide the first quantitative mapping of reduced drag zones.

High-pressure treatments (400 and 600 MPa) combined with the addition of sodium lactate (1 and 3%) were tested to reduce Escherichia coli O157:H7 (STEC O157) and spoilage microbiota contamination in a manufactured cured beef carpaccio in fresh or frozen conditions. Counts of spoilage microorganisms and STEC O157 were also examined during the curing step to prepare the carpaccio. STEC O157 counts remained almost unchanged through the curing process performed at 1 ± 1 C for 12 days, with a small decrease in samples with 3% of sodium lactate. High-pressure treatments at 600 MPa for 5 min achieved an immediate reduction of up to 2 logarithmic units of STEC O157 in frozen carpaccio, and up to 1.19 log in fresh condition. Counts of spoilage bacteria diminished below detection limits in fresh or frozen carpaccio added with sodium lactate by the application of 400 and 600 MPa. Maximum injury on STEC O157 cells was observed at 600 MPa in carpaccio in fresh condition without added sodium lactate. Lethality of high-pressure treatments on STEC O157 was enhanced in frozen carpaccio, while the addition of sodium lactate at 3% reduced the lethality on STEC O157 in frozen samples, and the degree of injury in fresh carpaccio. Fil: Masana, Marcelo Oscar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Fil: Barrio, Yanina Ximena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Argentina de la Empresa. Facultad de Ingeniería y Ciencias Exactas; Argentina. Fil: Palladino, Pablo Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Fil: Sancho, Ana Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina. Fil: Vaudagna, Sergio Ramon. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimentos; Argentina.Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Universidad Argentina de la Empresa. Facultad de Ingeniería y Ciencias Exactas ; Argentina.

Magma dynamics at Mt. Etna volcano are frequently recognized as the result of complex crystallization regimes that, at shallow crustal levels, unexpectedly change from H2O-undersaturated to H2O-saturated conditions, due to the impulsive and irregular arrival of volatile-rich magmas from mantle depths. On this basis, we have performed hydrous crystallization experiments for a quantitative understanding of the role of H2O in the differentiation of deep-seated trachybasaltic magmas at the key pressure of the Moho transition zone. For H2O = 2.1&ndash, 3.2 wt %, the original trachybasaltic composition shifts towards phonotephritic magmas never erupted during the entire volcanic activity of Mt. Etna. Conversely, for H2O = 3.8&ndash, 8.2 wt %, the obtained trachybasalts and basaltic trachyandesites reproduce most of the pre-historic and historic eruptions. The comparison with previous low pressure experimental data and natural compositions from Mt. Etna provides explanation for (1) the abundant release of H2O throughout the plumbing system of the volcano during impulsive ascent of deep-seated magmas, (2) the upward acceleration of magmas feeding gas-dominated, sustained explosive eruptions, (3) the physicochemical changes of gas-fluxed magmas ponding at shallow crustal levels, and (4) the huge gas emissions measured at the summit craters and flank vents which result in a persistent volcanic gas plume.

The Campi Flegrei volcanic field (Italy) poses very high risk to the highly urbanized Neapolitan area. Eruptive history was dominated by explosive activity producing pyroclastic currents (PDCs; (Proclastic Density Currents) ranging in scale from localized base surges to regional flows. Here we apply probabilistic numerical simulation approaches to produce PDC hazard maps, based on a comprehensive spectrum of flow properties and vent locations. These maps and provide all probable Volcanic Explosivity Index (VEI) scenarios from different source vents in the caldera, relevant for risk management planning. For each VEI scenario, we report the conditional probability for PDCs (i.e., the probability for a given area to be affected by the passage of PDCs) and related dynamic pressure. Model results indicate that PDCs from VEI, 43 pages, 9 figures

Gravity-driven, ground-hugging gas-pyroclast mixtures produced during explosive volcanic eruptions define a full spectrum of particle concentration, flow regime and particle support mechanisms. To describe these phenomena, the term “pyroclastic density current” (PDC) has become increasingly popular in the last few tens of years. Here, I question the general application of the term PDC to the whole flow spectrum and, instead, I propose the simpler term “pyroclastic current”.