The VLTI – A Status Report     

A. Glindemann  J. Algomedo  R. Amestica  P. Ballester  B. Bauvir  E. Bugueño  S. Correia  F. Delgado  F. Delplancke  F. Derie  Ph. Duhoux  E. di Folco  A. Gennai  B. Gilli  P. Giordano  Ph. Gitton  S. Guisard  N. Housen  A. Huxley  P. Kervella  M. Kiekebusch  B. Koehler  S. Lévêque  A. Longinotti  S. Ménardi  S. Morel  F. Paresce  T. Phan Duc  A. Richichi  M. Schöller  M. Tarenghi  A. Wallander  M. Wittkowski  R. Wilhelm 《Astrophysics and Space Science》2003,286(1-2):35-44

The Very Large Telescope (VLT) Observatory on Cerro Paranal (2635 m) in Northern Chile is approaching completion. After the four 8-m Unit Telescopes (UT) individually saw first light in the last years, two of them were combined for the first time on October 30, 2001 to form a stellar interferometer, the VLT Interferometer. The combination in pairs of all four UTs was completed in September 2002. In this article, we will describe the subsystems of the VLTI and the planning for the following years. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Mantle and crustal processes in the magmatism of the Campania region: inferences from mineralogy, geochemistry, and Sr–Nd–O isotopes of young hybrid volcanics of the Ischia island (South Italy)     

Massimo D’Antonio  Sonia Tonarini  Ilenia Arienzo  Lucia Civetta  Luigi Dallai  Roberto Moretti  Giovanni Orsi  Mariachiara Andria  Alberto Trecalli 《Contributions to Mineralogy and Petrology》2013,165(6):1173-1194

Ischia, one active volcano of the Phlegraean Volcanic District, prone to very high risk, is dominated by a caldera formed 55 ka BP, followed by resurgence of the collapsed area. Over the past 3 ka, the activity extruded evolved potassic magmas; only a few low-energy explosive events were fed by less evolved magmas. A geochemical and Sr–Nd–O isotope investigation has been performed on minerals and glass from products of three of such eruptions, Molara, Vateliero, and Cava Nocelle (<2.6 ka BP). Data document strong mineralogical, geochemical, and isotopic heterogeneities likely resulting from mingling/mixing processes among mafic and felsic magmas that already fed the Ischia volcanism in the past. Detailed study on the most mafic magma has permitted to investigate its origin. The mantle sector below Ischia underwent subduction processes that modified its pristine chemical, isotopic, and redox conditions by addition of ≤1 % of sediment fluids/melts. Similar processes occurred from Southeast to Northwest along the Apennine compressive margin, with addition of up to 2.5 % of sediment-derived material. This is shown by volcanics with poorly variable, typical δ¹⁸O mantle values, and ⁸⁷Sr/⁸⁶Sr progressively increasing toward typical continental crust values. Multiple partial melting of this modified mantle generated distinct primary magmas that occasionally assimilated continental crust, acquiring more ¹⁸O than ⁸⁷Sr. At Ischia, 7 % of Hercynian granodiorite assimilation produced isotopically distinct, K-basaltic to latitic magmas. A SW–NE regional tectonic structure gave these magmas coming from large depth the opportunity to mingle/mix with felsic magmas stagnating in shallower reservoirs, eventually triggering explosive eruptions.  相似文献   

Subsurface thermal conductivity assessment in Calabria (southern Italy): a regional case study     

Eloisa Di Sipio  Antonio Galgaro  Elisa Destro  Giordano Teza  Sergio Chiesa  Aurelio Giaretta  Adele Manzella 《Environmental Earth Sciences》2014,72(5):1383-1401

Determining the suitability of a local area at a regional or local scale for the geothermal application of low enthalpy systems requires the knowledge of rock thermal conductivity values to evaluate the possibility of low-enthalpy heat exchange. A digital cartographic tool is also needed to synthesize the thermal properties of the underground. This tool should be easily accessible and upgradeable and thus suitable for territorial planning and environmental control. In order to address these key issues, a methodological approach was developed within the framework of the national VIGOR Project, dedicated to evaluating the geothermal potential in southern Italy. In this paper the region of Calabria was selected as a case study. Around 70 samples that were representative of the main geological formations were collected from all over the area. Thermal property tests were carried out both in dry and wet conditions, using a thermal device in accordance with the modified transient plane source method. The thermal conductivity values were then compared with data from the international literature. In order to consider the influence of the entire stratigraphic sequence on the thermal conductivity parameters, a geostatistical analysis of the available lithostratigraphic data was performed using the MATLAB toolbox Modalstrata, specially developed for this purpose. A comprehensive geothermal subsurface characterization of Calabria was thus obtained.  相似文献   

A Bayesian vulnerability assessment tool for drinking water mains under extreme events   总被引：2，自引：1，他引：1  

Alessandro Pagano  Raffaele Giordano  Ivan Portoghese  Umberto Fratino  Michele Vurro 《Natural Hazards》2014,74(3):2193-2227

Drinking water security is a life safety issue as an adequate supply of safe water is essential for economic, social and sanitary reasons. Damage to any element of a water system, as well as corruption of resource quality, may have significant effects on the population it serves and on all other dependent resources and activities. As well as an analysis of the reliability of water distribution systems in ordinary conditions, it is also crucial to assess system vulnerability in the event of natural disasters and of malicious or accidental anthropogenic acts. The present work summarizes the initial results of research activities that are underway with the intention of developing a vulnerability assessment methodology for drinking water infrastructures subject to hazardous events. The main aim of the work was therefore to provide decision makers with an effective operational tool which could support them mainly to increase risk awareness and preparedness and, possibly, to ease emergency management. The proposed tool is based on Bayesian Belief Networks (BBN), a probabilistic methodology which has demonstrated outstanding potential to integrate a range of sources of knowledge, a great flexibility and the ability to handle in a mathematically sound way uncertainty due to data scarcity and/or limited knowledge of the system to be managed. The tool was implemented to analyze the vulnerability of two of the most important water supply systems in the Apulia region (southern Italy) which have been damaged in the past by natural hazards. As well as being useful for testing and improving the predictive capabilities of the methodology and for possibly modifying its structure and features, the case studies have also helped to underline its strengths and weaknesses. Particularly, the experiences carried out demonstrated how the use of BBN was consistent with the lack of data reliability, quality and accessibility which are typical of complex infrastructures, such as the water distribution networks. The potential applications and future developments of the proposed tool have been also discussed accordingly.  相似文献   

The stabilization value of groundwater: evidence from Indian tank irrigation systems   总被引：1，自引：0，他引：1  

K. Palanisami  Mark Giordano  Krishna Reddy Kakumanu  C. R. Ranganathan 《Hydrogeology Journal》2012,20(5):933-941

Groundwater is now a major source of agricultural water supply in many parts of the world. The value of groundwater as a new source of supply is well known. However, its additional buffering or stabilization value is less appreciated and even less analysed. Knowledge on groundwater’s stabilization value is advanced by developing and estimating an empirical model using the case of tank irrigation systems in Tamil Nadu, India. Unlike previous work, the model uses cross-sectional rather than time-series data. The results show that for the case-study region, the stabilization function added approximately 15% to supply value. Scenarios with surface water and electricity price were incorporated in the model. Increased surface-water supply and electricity price caused reduction in groundwater use but the percent of stabilization value of groundwater increased. The findings are used both to suggest improvements in tank irrigation systems and to further contextualize knowledge of groundwater’s stabilization value.  相似文献   

Political economy of the energy-groundwater nexus in India: exploring issues and assessing policy options     

Tushaar Shah  Mark Giordano  Aditi Mukherji 《Hydrogeology Journal》2012,20(5):995-1006

Indian agriculture is trapped in a complex nexus of groundwater depletion and energy subsidies. This nexus is the product of past public policy choices that initially offered opportunities to India’s small-holder-based irrigation economy but has now generated in its wake myriad economic, social, and environmental distortions. Conventional ‘getting-the-price-right’ solutions to reduce these distortions have consistently been undermined by the invidious political economy that the nexus has created. The historical evolution of the nexus is outlined, the nature and scale of the distortions it has created are explored, and alternative approaches which Indian policy makers can use to limit, if not eliminate, the damaging impacts of the distortions, are analysed.  相似文献   

A new hydrostratigraphic model of Venice area (Italy)   总被引：3，自引：3，他引：0  

Matteo Cultrera  Renzo Antonelli  Giordano Teza  Silvia Castellaro 《Environmental Earth Sciences》2012,66(4):1021-1030

Two environmental problems affect the Venice area: subsidence, which has been increasing due to the intensive water abstraction after the Second World War, and contamination of the soil and shallow aquifers. In order to address these problems, which are decisive factors in the entire Venetian ecosystem, the aquifer structure must be known in detail. The lithologic data are abundant and of good quality up to a depth of 50 m, whereas boreholes beyond this depth are much rarer and more dispersed, making their associated lithological data unreliable. This work, which uses the available data together with fast and low cost passive seismic measurements, provides an improved understanding of the deeper hydrogeologic domain. For this purpose, a MATLAB package (Modalstrata) has been developed to improve the correlation of the stratigraphic succession for each selected homogeneous sub-area and applied to obtain a new, upgraded hydrostratigraphic model. The horizontal to vertical spectral ratio passive seismic surveys have confirmed the lateral correlations among the sample areas at least for the two main aquifer horizons. Analysis and comparisons of several previous studies performed on the data related to the only drilling continuous coring 951 m deep in the Tronchetto Island (Venice), have allowed a satisfactory validation of the proposed hydrogeological model.  相似文献   

Integration of local and scientific knowledge to support drought impact monitoring: some hints from an Italian case study     

Raffaele Giordano  Elisabetta Preziosi  Emanuele Romano 《Natural Hazards》2013,69(1):523-544

According to the Hyogo Framework for Action, increasing resilience to drought requires the development of a people-centered monitoring and early warning system, or in other words, a system capable of providing useful and understandable information to the community at risk. To achieve this objective, it is crucial to negotiate a credible and legitimate knowledge system, which should include both expert and local knowledge. Although several benefits can be obtained, the integration of local and scientific knowledge to support drought monitoring is still far from being the standard in drought monitoring and early warning. This is due to many reasons, that is, the reciprocal skepticism of local communities and decision makers, and the limits in the capacity to understand and assess the complex web of drought impacts. This work describes a methodology based on the sequential implementation of Cognitive Mapping and Bayesian Belief Networks to collect, structure and analyze stakeholders’ perceptions of drought impacts. The methodology was applied to analyze drought impacts at Lake Trasimeno (central Italy). A set of drought indicators was developed based on stakeholders’ perceptions. A validation phase was carried out comparing the perceived indicators of drought and the physical indicators (i.e., Standard Precipitation Index and the level of the lake). Some preliminary conclusions were drawn concerning the reliability of local knowledge to support drought monitoring and early warning.  相似文献   

Slope instability induced by volcano-tectonics as an additional source of hazard in active volcanic areas: the case of Ischia island (Italy)   总被引：1，自引：0，他引：1  

Marta Della Seta  Enrica Marotta  Giovanni Orsi  Sandro de Vita  Fabio Sansivero  Paola Fredi 《Bulletin of Volcanology》2012,74(1):79-106

Ischia is an active volcanic island in the Gulf of Naples whose history has been dominated by a caldera-forming eruption (ca. 55 ka) and resurgence phenomena that have affected the caldera floor and generated a net uplift of about 900 m since 33 ka. The results of new geomorphological, stratigraphical and textural investigations of the products of gravitational movements triggered by volcano-tectonic events have been combined with the information arising from a reinterpretation of historical chronicles on natural phenomena such as earthquakes, ground deformation, gravitational movements and volcanic eruptions. The combined interpretation of all these data shows that gravitational movements, coeval to volcanic activity and uplift events related to the long-lasting resurgence, have affected the highly fractured marginal portions of the most uplifted Mt. Epomeo blocks. Such movements, mostly occurring since 3 ka, include debris avalanches; large debris flows (lahars); smaller mass movements (rock falls, slumps, debris and rock slides, and small debris flows); and deep-seated gravitational slope deformation. The occurrence of submarine deposits linked with subaerial deposits of the most voluminous mass movements clearly shows that the debris avalanches impacted on the sea. The obtained results corroborate the hypothesis that the behaviour of the Ischia volcano is based on an intimate interplay among magmatism, resurgence dynamics, fault generation, seismicity, slope oversteepening and instability, and eruptions. They also highlight that volcano-tectonically triggered mass movements are a potentially hazardous phenomena that have to be taken into account in any attempt to assess volcanic and related hazards at Ischia. Furthermore, the largest mass movements could also flow into the sea, generating tsunami waves that could impact on the island’s coast as well as on the neighbouring and densely inhabited coast of the Neapolitan area.  相似文献   

Explosion craters associated with shallow submarine gas venting off Panarea island, Italy     

Thomas Monecke  Sven Petersen  Mark D. Hannington  Marco Anzidei  Alessandra Esposito  Guido Giordano  Dieter Garbe-Sch?nberg  Nico Augustin  Bernd Melchert  Mike Hocking 《Bulletin of Volcanology》2012,74(9):1937-1944

Explosions of hot water, steam, and gas are common periodic events of subaerial geothermal systems. These highly destructive events may cause loss of life and substantial damage to infrastructure, especially in densely populated areas and where geothermal systems are actively exploited for energy. We report on the occurrence of a large number of explosion craters associated with the offshore venting of gas and thermal waters at the volcanic island of Panarea, Italy, demonstrating that violent explosions similar to those observed on land also are common in the shallow submarine environment. With diameters ranging from 5 to over 100?m, the observed circular seafloor depressions record a history of major gas explosions caused by frequent perturbation of the submarine geothermal system over the past 10,000?years. Estimates of the total gas flux indicate that the Panarea geothermal system released over 70?Mt of CO₂ over this period of time, suggesting that CO₂ venting at submerged arc volcanoes contributes significantly to the global atmospheric budget of this greenhouse gas. The findings at Panarea highlight that shallow submarine gas explosions represent a previously unrecognized volcanic hazard around populated volcanic islands that needs to be taken into account in the development of risk management strategies.  相似文献