Effectiveness of geophysical surveys for water wells relocation in overexploited aquifers (the example of Maggiore and Traversola Valleys,Northwestern Italy)     

Domenico Antonio De Luca  Cesare Comina  Manuela Lasagna  Enrico Destefanis  Luciano Masciocco  Alberto Godio  Stefano Stocco 《Environmental Earth Sciences》2018,77(1):19

Aquifer overexploitation is a common problem in drinking water management. This will become more and more important given the general reduction of water resources. To overcome overexploitation, one of the most adopted solutions is the relocation of extraction wells. To establish the positions of new wells, a precise knowledge of the hydrogeological setting is required. Specific surveys are therefore necessary to obtain information over wide investigation zones. Geophysical methods, particularly electromagnetic and electrical, can be useful with this aim. In the present paper a case history on the combined use of Electric Resistivity Tomography and Time Domain Electromagnetic soundings is reported. Surveys have been performed within the Maggiore and Traversola Valleys, to investigate the uppermost part of the Quaternary deposits, hosting the near surface aquifer. The electromagnetic data have been inverted with a spatially constrained approach by assuming a quasi 1D model of the subsurface. Geophysical surveys allowed for depicting the depth and lateral continuity of the supposed aquifer level in the surveyed area up to a depth of about 200 m and proposing potential positions for well relocation.  相似文献   

Foreland-dipping normal faults in the inner edges of syn-orogenic basins: a case from the Central Apennines, Italy     

V. Scisciani  F. Calamita  E. Tavarnelli  G. Rusciadelli  G. G. Ori  W. Paltrinieri 《Tectonophysics》2001,330(3-4):211-224

Extensional deformations are common within foredeep basins and generally consist of hinterland-dipping normal faults located at the foredeep–foreland transition zones. Foreland-dipping normal faults at the belt–foredeep boundaries, by contrast, are far less documented and their occurrence is not predicted by simple orogenic load models. New surface data integrated with seismic reflection profiles across the Central Apennines of Italy reveal the occurrence of foreland-dipping normal faults located in the inner edges of foredeep depressions. Extensional deformations are systematically found within sequentially younger Tortonian, Messinian and Early Pliocene foredeep basins, thus suggesting that normal fault development was an intrinsic feature of the evolving belt–foredeep–foreland system and could have influenced the stratal architectures of the host syn-orogenic deposits. Foreland extension is consistent with existing geodynamic models for the Apennines and could represent the effects of lithospheric bending: its recognition and documentation elsewhere could provide significant insights to improve our understanding of syn-orogenic basin dynamics.  相似文献   

Dark matter electron anisotropy: A universal upper limit     

Enrico Borriello  Luca Maccione  Alessandro Cuoco 《Astroparticle Physics》2012,35(8):537-546

We study the dipole anisotropy in the arrival directions of high energy CR electrons and positrons (CRE) of dark matter (DM) origin. We show that this quantity is very weakly model dependent and offers a viable criterion to discriminate among CRE from DM or from local discrete sources, like e.g. pulsars. In particular, we find that the maximum anisotropy which DM can provide is to a very good approximation a universal quantity and, as a consequence, if a larger anisotropy is detected, this would constitute a strong evidence for the presence of astrophysical local discrete CRE sources, whose anisotropy, instead, can be naturally larger than the DM upper limit. We further find that the main source of anisotropy from DM is given by the fluctuation in the number density of DM sub-structures in the vicinity of the observer and we thus devote special attention to the study of the variance in the sub-structures realization implementing a dedicated Montecarlo simulation. Such scenarios will be probed in the next years by Fermi-LAT, providing new hints, or constraints, about the nature of DM.  相似文献   

Risk analysis for remediation of contaminated sites: the geostatistical approach   总被引：1，自引：0，他引：1  

Enrico Guastaldi  Andrea Alessandro Del Frate 《Environmental Earth Sciences》2012,65(3):897-916

The assessment of the risks associated with contamination by elevated levels of pollutants is a major issue in most parts of the world. The risk arises from the presence of a pollutant and from the uncertainty associated with estimating its concentration, extent and trajectory. The uncertainty in the assessment comes from the difficulty of measuring the pollutant concentration values accurately at any given location and the impossibility of measuring it at all locations within a study zone. Estimations tend to give smoothed versions of reality, with the smoothing effect being inversely proportional to the amount of data. If risk is a measure of the probability of pollutant concentrations exceeding specified thresholds, then the variability is the key feature in risk assessment and risk analysis. For this reason, geostatistical simulations provide an appropriate way of quantifying risk by simulating possible “realities” and determining how many of these realities exceed the contamination thresholds, and, finally, provides a means of visualizing risk and the geological causes of risk. This study concerns multivariate simulations of organic and inorganic pollutants measured in terrain samples to assess the uncertainty for the risk analysis of a contaminated site, an industrial site in northern Italy that has to be remediated. The main geostatistical tools are used to model the local uncertainty of pollutant concentrations, which prevail at any unsampled site, in particular by means of stochastic simulation. These models of uncertainty have been used in the decision-making processes to identify the areas targeted for remediation.  相似文献   

Horizontal rotation signals detected by “G-Pisa” ring laser for the M w = 9.0, March 2011, Japan earthquake     

Jacopo Belfi  Nicolò Beverini  Giorgio Carelli  Angela Di Virgilio  Enrico Maccioni  Gilberto Saccorotti  Fabio Stefani  Alexander Velikoseltsev 《Journal of Seismology》2012,16(4):767-776

We report the observation of the ground rotation induced by the M _w = 9.0, 11th of March 2011, Japan earthquake. The rotation measurements have been conducted with a ring laser gyroscope operating in a vertical plane, thus detecting rotations around the horizontal axis. Comparison of ground rotations with vertical accelerations from a co-located force balance accelerometer shows excellent ring laser coupling at periods longer than 100?s. Under the plane wave assumption, we derive a theoretical relationship between horizontal rotation and vertical acceleration for Rayleigh waves. Due to the oblique mounting of the gyroscope with respect to the wave direction of arrival, apparent velocities derived from the acceleration/rotation rate ratio are expected to be always larger than or equal to the true wave propagation velocity. This hypothesis is confirmed through comparison with fundamental mode, Rayleigh-wave phase velocities predicted for a standard Earth model.  相似文献   

Asymptotic giant branch stars in the Phoenix dwarf galaxy     

John Menzies  Michael Feast  Patricia Whitelock  Enrico Olivier  Noriyuki Matsunaga  Gary Da Costa 《Monthly notices of the Royal Astronomical Society》2008,385(2):1045-1052

JHK _s near-infrared photometry of stars in the Phoenix dwarf galaxy is presented and discussed. Combining these data with the optical photometry of Massey et al. allows a rather clean separation of field stars from Phoenix members. The discovery of a Mira variable ( P = 425 d), which is almost certainly a carbon star, leads to an estimate of the distance modulus of 23.10 ± 0.18 that is consistent with other estimates and indicates the existence of a significant population of age ∼2 Gyr. The two carbon stars of Da Costa have   M _bol=−3.8  and are consistent with belonging to a population of similar age; some other possible members of such a population are identified. A Da Costa non-carbon star is  Δ K _s∼ 0.3  mag brighter than these two carbon stars. It may be an asymptotic giant branch star of the dominant old population. The nature of other stars lying close to it in the   K _s, ( J − K _s)  diagram needs studying.  相似文献   

Aliphatic hydrocarbons in metasomatized gabbroic xenoliths from Hyblean diatremes (Sicily): Genesis in a serpentinite hydrothermal system     

Enrico Ciliberto  Carmelo Crisafulli  Fabio Carmelo Manuella  Filippo Samperi  Salvatore Scirè  Vittorio Scribano  Marco Viccaro  Ezio Viscuso 《Chemical Geology》2009,258(3-4):258-268

Many tholeiite gabbro xenoliths from the Hyblean tuff-breccia deposits (Sicily, southern Italy) present mineralogical and geochemical evidence for hydrothermal alteration at different temperatures and water/rock ratios. In some cases, the primary mineral assemblage has been entirely replaced by Na-rich alkali feldspar, chlorite/smectite interlayers, zeolites, aegirine–augite, titanite, zircon etc. Hence the chemical composition of such metasomatic rocks displays larger amounts of volatiles, alkalis, Zr, Hf, U, Th and lower Ca, Mg, Fe with respect to the original gabbro. Five hydrothermally altered gabbroic xenoliths were selected for thermal decrepitation and bulk gas analyses by quadrupole mass spectrometry. All the samples analyzed display the same Electron Impact-Direct Pyrolysis Mass spectra (EI-DPMS). These show a series of peaks differing by 14 mass units due to loss of methylene groups (–CH₂), by a fragmentation process typical of saturated aliphatic and aliphatic–aromatic hydrocarbons. In addition, Fourier Transform Infrared (FT-IR) spectra of the samples present several bands typical of vibration frequencies of aliphatic hydrocarbons. The high-molecular-weight hydrocarbons observed probably originated from Fischer–Tropsch-type (FT-t) synthesis in the high temperature section of a serpentinite-hosted hydrothermal system. This suggestion may lend support to the recent hypothesis regarding the original oceanic nature of the Hyblean lithospheric basement.  相似文献   

Influence of FPS bearing properties on the seismic performance of base‐isolated structures          下载免费PDF全文

Paolo Castaldo  Enrico Tubaldi 《地震工程与结构动力学》2015,44(15):2817-2836

The paper analyzes the influence of friction pendulum system (FPS) isolator properties on the seismic performance of base‐isolated building frames. The behavior of these systems is analyzed by employing a two‐degree‐of‐freedom model accounting for the superstructure flexibility, whereas the FPS isolator behavior is described by adopting a widespread model that considers the variation of the friction coefficient with the velocity. The uncertainty in the seismic input is taken into account by considering a set of natural records with different characteristics scaled to increasing intensity levels. The variation of the statistics of the response parameters relevant to the seismic performance is investigated through the nondimensionalization of the motion equation and an extensive parametric study carried out for different isolator and system properties. The proposed approach allows to explore a wide range of situations while limiting the required nonlinear response history analyses. Two case studies consisting of base‐isolated building frames described as shear‐type systems are finally investigated in order to demonstrate the capabilities of the proposed simplified model in unveiling the essential characteristics of the performance of buildings isolated with FPS bearings. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Guidelines for the good practice of surface wave analysis: a product of the InterPACIFIC project     

Sebastiano Foti  Fabrice Hollender  Flora Garofalo  Dario Albarello  Michael Asten  Pierre-Yves Bard  Cesare Comina  Cécile Cornou  Brady Cox  Giuseppe Di Giulio  Thomas Forbriger  Koichi Hayashi  Enrico Lunedei  Antony Martin  Diego Mercerat  Matthias Ohrnberger  Valerio Poggi  Florence Renalier  Deborah Sicilia  Valentina Socco 《Bulletin of Earthquake Engineering》2018,16(6):2367-2420

Surface wave methods gained in the past decades a primary role in many seismic projects. Specifically, they are often used to retrieve a 1D shear wave velocity model or to estimate the V_S,30 at a site. The complexity of the interpretation process and the variety of possible approaches to surface wave analysis make it very hard to set a fixed standard to assure quality and reliability of the results. The present guidelines provide practical information on the acquisition and analysis of surface wave data by giving some basic principles and specific suggestions related to the most common situations. They are primarily targeted to non-expert users approaching surface wave testing, but can be useful to specialists in the field as a general reference. The guidelines are based on the experience gained within the InterPACIFIC project and on the expertise of the participants in acquisition and analysis of surface wave data.  相似文献   

BeppoSAX observations of GRS 1915+105.     

Giorgio Matt  Enrico Costa  Marco Feroci  Tomaso Belloni  Marco Tavani 《New Astronomy Reviews》1998,42(9-10)

Results from a BeppoSAX observational campaign on GRS 1915+105, performed in October/November 1996, are presented. The source was observed 10 times (nine 10 ksec snapshots, one 100 ksec long observation). The broad band spectral analysis reveals a complex spectrum, including Compton reflection and an iron emission line, probably originating from a relativistic disc.  相似文献