The MED-SUV virtual research environment for enabling the GEO Geohazard supersites in Italy     

Paolo Mazzetti  Giuseppe Puglisi  Luca D’Auria  Roberto Roncella  Danilo Reitano  Riccardo Merenda  Stefano Nativi 《Earth Science Informatics》2017,10(4):443-455

This paper presents the Virtual Research Environment (VRE) enabling two European GEO Geohazard Supersites in Italy. According to GEO (Group on Earth Observation) vision, Geohazard Supersites provide access to spaceborne and in-situ geophysical data and models for selected sites prone to natural hazards –noticeably, earthquakes and volcano eruptions. The VRE was implemented in the framework of the Mediterranean Supersite Volcanoes (MED-SUV) project, funded by the European Commission. MED-SUV realized one of the European supersite demonstrators covering the two Permanent Supersites selected in Italy: Mt. Etna and Campi Flegrei/Vesuvius. The MED-SUV VRE provides advanced services for heterogeneous data and information management and sharing. MED-SUV started identifying the main supersite requirements including: the interoperability with existing data/information supply systems, the support of policy-based access control, the access to processing capabilities provided by external platforms, the management resources for publishing and sharing new products, the integration with significant global systems such as GEOSS and EPOS. MED-SUV adopted a System of Systems (SoS) approach to address interoperability with the identified heterogeneous systems supplying data and information. The SoS approach is based on a brokering architecture, where a specialized component (i.e the MED-SUV Broker: MSB) connects the existing and next-coming data sources leaving them autonomous. MSB carries out all the necessary mediation and harmonization tasks exposing standard interfaces enabling the interconnection with external systems like GEOSS and EPOS. In addition, MSB is accessible via a JavaScript library implementing Web APIs to facilitate the development of Web and mobile applications.  相似文献   

Preliminary geochemical characterization of groundwater drained by the Roman emissary of Lake Albano (Italy)     

Paolo Madonia  Marianna Cangemi  Carla Galeazzi  Carlo Germani  Mario Parise  Rocco Favara 《Environmental Earth Sciences》2017,76(7):289

Many lakes have been the object of hydraulic works in historical times, and the drainage tunnel carved by Romans for regulating the level of Lake Albano (Central Italy) can be considered as one of the most important historical hydraulic tunnels in the world. We sampled and analysed lake water, as well as groundwater samples from the Lake Albano emissary and another hydraulic work in the area (Ninfeo), which were analysed for their geochemical and isotopic composition in order to extract useful information for a possible reuse of the tunnel for anthropogenic purposes. The collected water samples exhibit common chemical features, typical of water–rock interaction processes in volcanic areas. Analyses of minor and trace elements confirmed the abovementioned results, indicating the presence of an atmospheric pollution source for heavy metals, although their concentrations are mostly below the Maximum Admitted Concentrations for drinking water issued by the World Health Organization. The chemical composition of dissolved gases indicated that both lake and groundwater are mainly enriched in CO₂. Isotopic analyses suggested a clear volcanic origin for CO₂ dissolved in lake water, while carbon dioxide in groundwater from the Roman emissary is produced by soil respiration. As further confirmed by Oxygen and Deuterium isotopic composition, the Roman emissary drains local suspended aquifers neither in contact with the lake water body nor influenced by volcanic activity, suggesting the opportunity to use the tunnel as a “zero-condition” monitoring site for individuating a possible future renewal of volcanic activity.  相似文献   

Formation of Asteroid Families by Catastrophic Disruption: Simulations with Fragmentation and Gravitational Reaccumulation: Volume 160, Number 1 (2002), pages 10-23 (: PII: S0019-1035(02)96948-4)     

Patrick MichelWilly Benz  Paolo TangaDerek C. Richardson 《Icarus》2002,160(2):448

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Imaging polarimetry of comet Hale-Bopp (C/1995 O1) around perihelion     

Paolo Tanga  Alberto Cellino  Mario Di Martino 《Earth, Moon, and Planets》1997,78(1-3):359-364

The polarization distribution of the inner coma of comet Hale-Bopp was measured by CCD imaging around perihelion. The dust shell positions correlate well with relative maxima of polarization. The images taken in the I-band identify different shell systems, each showing individual polarization properties. This could be related to differences in the dust properties of the associated jets. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

A new model to simulate impact breakup     

Alessandro Cordelli  Paolo Farinella 《Planetary and Space Science》1997,45(12):1639-1647

We have developed a preliminary version of a new type of code to simulate the outcomes of impacts between solid bodies, which we plan to further refine for application to both asteroid science and space debris studies. In the current code, colliding objects are modeled as two-dimensional arrays of finite elements, which can interact with each other in both an elastic and a shock-wave regime. The finite elements are hard spheres with a given value for mass and radius. When two of them come into contact the laws of inelastic scattering are applied, thus giving rise to the propagation of shock waves. Moreover each spherical element interacts elastically with its nearest neighbours. The interaction force corresponds to that of a spring having an equilibrium length equal to the lattice spacing, and results into the propagation of elastic waves in the lattice. Dissipation effects are modeled by means of a dissipative force term proportional to the relative velocity, with a given characteristic time of decay. The possible occurrence of fractures in the material is modeled by assuming that when the distance of two neighbouring elements exceeds a threshold value, the binding force between them disappears for ever. This model requires finding a plausible correspondence between the input parameters appearing in the equations of motion, and the physical properties of real solid materials. Some of the required links are quite obvious (e.g., the relationship between mass of the elements and elastic constant on one side, and material density and sound velocity on the other side), some others a priori are unclear, and additional hypotheses on them must be made (e.g., on the restitution coefficient of inelastic scattering). Despite the preliminary character of the model, we have obtained some interesting results, which appear to mimic in a realistic way the outcomes of actual impacts. For instance, we have observed the formation of craters and fractures, and (for high impact energies) the occurrence of catastrophic breakup. The masses and velocities of the fragments resemble those found in laboratory impact experiments.  相似文献   

Propagation of vortices within a rotating,fluid shell     

Paolo Lanzano 《Earth, Moon, and Planets》1992,58(1):39-55

We consider a spherical, solid planet surrounded by a thin layer of an incompressible, inviscid fluid. The planet rotates with constant angular velocityWe study the vortex motion within this rotating ocean. For this purpose, we obtain a linearized version of the Navier-Stokes equation and adopt it as our ocean model; next, we prove analytically that a certain function of vorticity is an invariant of motion.Using this ocean model and this invariant property of vorticity, we are able to establish a general equation governing the motion of vortices within a fluid shell: it is a nonlinear partial differential equation of the third order for the stream function of motion.We finally examine some particular solutions of this vorticity equation that represent solitary waves of permanent form and decay within a finite distance. These solutions have been represented in terms of quadratic, exponential, and hyperbolic functions.The question whether these vortices that propagate as solitary waves could be solitons depends on their behavior when they collide with each other; this has not yet been resolved.Retired, U.S. Naval Research Laboratory, Washington, D.C., U.S.A.  相似文献   

Pollen Viability for Air Pollution Bio-Monitoring     

Elena Gottardini  Fabiana Cristofolini  Elena Paoletti  Paolo Lazzeri  Giancarlo Pepponi 《Journal of Atmospheric Chemistry》2004,49(1-3):149-159

Biological characterization of Corylus avellana L. and Pinus nigra L. pollen samples was carried out to determine the actual value of pollen as a bio-indicator of the effects of atmospheric pollution, using samples from plants naturally developed in sites controlled for air pollution. In Trentino (North Italy), we selected six stations at three different levels of air pollution, which are constantly monitored with automatic gauges by the Environmental Protection Agency of Trento.First results showed that pollen viability of both species, germinability and pollen tube length of P. nigra, were higher in areas with no road traffic compared to heavy traffic ones. Pollen viability of P. nigra was positively correlated to ozone (O₃) concentrations and altitude but negatively to sulphur dioxide (SO₂), particulate matter with a diameter less than 10 m (PM₁₀), nitrogen oxides (NO_x) and nitrogen dioxide (NO₂) concentrations.  相似文献   

Defining a model of 3D seismogenic sources for Seismic Hazard Assessment applications: The case of central Apennines (Italy)   总被引：6，自引：0，他引：6  

Paolo Boncio  Giusy Lavecchia  Bruno Pace 《Journal of Seismology》2004,8(3):407-425

Geology-based methods for Probabilistic Seismic Hazard Assessment (PSHA) have been developing in Italy. These methods require information on the geometric, kinematic and energetic parameters of the major seismogenic faults. In this paper, we define a model of 3D seismogenic sources in the central Apennines of Italy. Our approach is mainly structural-seismotectonic: we integrate surface geology data (trace of active faults, i.e. 2D features) with seismicity and subsurface geological–geophysical data (3D approach). A fundamental step is to fix constraints on the thickness of the seismogenic layer and deep geometry of faults: we use constraints from the depth distribution of aftershock zones and background seismicity; we also use information on the structural style of the extensional deformation at crustal scale (mainly from seismic reflection data), as well as on the strength and behaviour (brittle versus plastic) of the crust by rheological profiling. Geological observations allow us to define a segmentation model consisting of major fault structures separated by first-order (kilometric scale) structural-geometric complexities considered as likely barriers to the propagation of major earthquake ruptures. Once defined the 3D fault features and the segmentation model, the step onward is the computation of the maximum magnitude of the expected earthquake (M _max). We compare three different estimates of M _max: (1) from association of past earthquakes to faults; (2) from 3D fault geometry and (3) from geometrical estimate corrected by earthquake scaling laws. By integrating all the data, we define a model of seismogenic sources (seismogenic boxes), which can be directly used for regional-scale PSHA. Preliminary applications of PSHA indicate that the 3D approach may allow to hazard scenarios more realistic than those previously proposed.  相似文献   

Solitary waves of vortices     

Paolo Lanzano 《Earth, Moon, and Planets》1995,69(3):271-283

We study the propagation of solitary waves of vortices within a spherical shell which constitutes the uppermost layer of a solid planet. This solid-liquid configuration rotates with constant angular velocity about an axis which is fixed with respect to the solid surface. The fluid within the shell is inviscid, incompressible, and of constant density. The motion imparted by the planetary rotation upon this fluid mass is governed by the Laplace tidal equation from which the potential of the extraplanetary forces has been deleted. Consistent with this ocean model, we establish that the stream function of a solitary wave of vortices must satisfy a third-order partial differential equation. We obtain solutions to this wave equation by imposing the condition that the vertical component of vorticity be functionally related to the stream function. We find that this dependence must necessarily be of the exponential type and that the solution to the wave equation then reduces to a quadrature depending on some arbitrary parameters. We prove that we can always choose the values of these parameters in order to approximate the integral in question by means of an analytic function: we reach a representation of the stream function of a solitary wave of vortices in terms of hyperbolic functions of time and position.This paper is dedicated to the memory of Professor Zdenek Kopal.  相似文献   

The dangerous border of the 5:2 mean motion resonance     

Zoran Kne?evi?  Andrea Milani  Paolo Farinella 《Planetary and Space Science》1997,45(12):1581-1585

After discovering that asteroid (2953) Vysheslavia, a Koronis family member, has a typical dynamical lifetime of the order of 10 Myr only against “falling” into the 5:2 Kirkwood gap and ending up in a hyperbolic orbit (Milani and Farinella, 1995. Icarus 114, 209–212), we decided to repeat the same study for two other asteroids, 1991 UA₂ and 1993 FR₅₈, lying also very close to the outer edge of the same resonance. The orbital elements of these bodies were not yet accurate enough and we appealed to observers, both professional and amateur, to obtain more astrometric data. Eight groups in three different countries carried out observations, and as a result the Minor Planet Center could derive updated, accurate orbits for both objects. Here we report on the preliminary results of our study. Whereas the long-term behavior of 1991 UA₂ looks fairly regular and stable, 1993 FR₅₈ exhibits a typical “stable chaos” behavior; nevertheless, it does not end up in the resonance within a time span of 50 Myr. On the other hand, its fictitious clones, placed just 3–4 × 10⁻³ AU closer to the resonance, undergo large irregular semimajor axis changes, fall into the resonance and escape on a timescale <1 Myr.  相似文献