Legal protection is not enough: Posidoniaoceanica meadows in marine protected areas are not healthier than those in unprotected areas of the northwest Mediterranean Sea

Using the Conservation Index, which measures the proportional amount of dead matte relative to live Posidonia oceanica, we assessed the health of 15 P. oceanica meadows at a regional scale along the coast of Liguria (NW Mediterranean). These areas were characterized by different degrees of anthropization, from highly urbanized sites to marine protected areas. Two different scenarios were identified according to depth: in shallow zones, the health of P. oceanica meadows was related to the degree of anthropization along the coastline. In contrast, in deep zones, most meadows exhibited poor health, independent of both the degree of disturbance and the legal measures protecting the area. Working synergistically with the regional impact of increased water turbidity, local impacts from the coast were recognized as the main causes of the severe regression of most Ligurian P. oceanica meadows. We conclude that marine protected areas alone are not sufficient to guarantee the protection of P. oceanica meadows. We emphasize the need for a management network involving the Sites of Community Interest (SCIs) containing P. oceanica meadows.     

Dissipative devices for earthquake resistant composite steel structures: bolted versus welded solution

This paper investigates and compares the seismic performance of two types of innovative repairable fuse devices for earthquake resistant composite steel frames through experimental tests and numerical analyses. The fuses are energy dissipating devices consisting of steel plates that can be welded or bolted to the beam web and bottom flange. The numerical analyses performed in this study are based on the results of experimental tests carried out on beam-to-column sub-assemblages equipped with both the types of fuse devices. The main differences in terms of hysteretic behavior and failure modes of the fuses are identified through the experimental campaign. Detailed three-dimensional finite element models of the beam-to-column sub-assemblages are then created to provide a deeper insight into both the response and the effectiveness of the two investigated devices. On the basis of the results of both the experimental tests and numerical analyses, simplified models of different types of fuses are developed in order to study the effects of bolted and welded devices on the seismic response of composite steel frames. The results are then extended to the case of three-dimensional building structures with different number of storeys. The experimental and numerical investigations prove the effectiveness of the fuses and highlight the main differences between the two possible solutions.     

Numerical study on basin-edge effects in the seismic response of the Gubbio valley,Central Italy

The Gubbio basin in Central Italy is a intermountain basin of extensional tectonic origin, typical of Central and Southern Apennines, characterized by moderate seismicity. The strongest recorded event within the area is a magnitude 5.7 earthquake which occurred on 29 April 1984 along the Gubbio fault, bordering the eastern side of the basin. The main objective of this study is to analyze the features of earthquake ground motion as related to basin-edge effects, by performing physics-based numerical simulations of the 1984 earthquake through a high-performance spectral element code. The simulated ground motions are found in reasonable agreement with the recorded motions when using the kinematic source model developed by Ameri et al. (Bull Seismol Soc Am 99:647–663, 2009), with a rise-time equal to 1 s and a nucleation point located in the middle of the fault. Pronounced differences were noted between records from the basin and adjacent sites at outcropping bedrock, owing to both the strong impedance contrast between soft alluvial sites and bedrock formations (lithostratigraphic amplification), as well as lateral discontinuities related to the 2D/3D geometry of the basin (generation of surface waves). Since the fault was located beneath the basin, 1D amplification effects were found to be more relevant than those associated with the generation of surface waves from the basin edge. Finally, an envelope delay spectrum was computed for the simulated ground motions, showing that surface waves are excited in the frequency band of 0.2–0.8 Hz with a significant increase of ground motion duration within the basin.     

Earthquake early warning and operational earthquake forecasting as real-time hazard information to mitigate seismic risk at nuclear facilities

Based on our experience in the project REAKT, we present a methodological framework to evaluate the potential benefits and costs of using earthquake early warning (EEW) and operational earthquake forecasting (OEF) for real-time mitigation of seismic risk at nuclear facilities. We focus on evaluating the reliability, significance and usefulness of the aforementioned real-time risk-mitigation tools and on the communication of real-time earthquake information to end-users. We find that EEW and OEF have significant potential for the reduction of seismic risk at nuclear plants, although much scientific research and testing is still necessary to optimise their operation for these sensitive and highly-regulated facilities. While our test bed was Switzerland, the methodology presented here is of general interest to the community of EEW researchers and end-users and its scope is significantly beyond its specific application within REAKT.     

Geodetic aspects of seismological phenomena

Seismology is related to many problems of geodesy. The energy production of our planet is rather close to energy consumption of the Earth so that the energy balance can be disturbed significantly by minor processes acting on global scale. From this point of view the effect of tidal triggering of earthquakes is discussed by the study of tidal stress tensor components expressed in spherical system of coordinates. Tidal friction influences through the despinning of the axial rotation the geometrical flattening. This flattening variation causes stresses along the longitude and this phenomenon is closely related to the seismic energy release. Until now there is no unambiguous success to relate changes of the Earth orientation parameters with seismicity. Present-day accuracy of the length of day variations is not sufficient yet to detect spin variation generated by the greatest earthquakes. The polar motion is probably more sensitive to earthquakes and then there is a chance to detect the polar displacements generated by seismic events. In the last section of the present contribution, the strain rates derived from the static seismic moments and from space geodetic observations are compared. Future geodetic strain rate data will be useful in earthquake prediction.     

Tangible User Interfaces (TUIs): A Novel Paradigm for GIS

In recent years, an increasing amount of effort has gone into the design of GIS user interfaces. On the one hand, Graphical User Interfaces (GUIs) with a high degree of sophistication have replaced line‐driven commands of first‐generation GIS. On the other hand, a number of alternative approaches have been suggested, most notably those based on Virtual Environments (VEs). In this paper we discuss a novel interface for GIS, which springs from recent work carried out in the field of Tangible User Interfaces (TUIs). The philosophy behind TUIs is to allow people to interact with computers via familiar tangible objects, therefore taking advantage of the richness of the tactile world combined with the power of numerical simulations. Two experimental systems, named Illuminating Clay and SandScape, are described here and their applications to GIS are examined. Conclusions suggest that these interfaces might streamline the landscape design process and result in a more effective use of GIS, especially when distributed decision‐making and discussion with non‐experts are involved.     

Trasformazioni con mezzi ottico-meccanici fra le proiezioni cartografiche della sfera

Riassunto I. Premesso che l'analizzatore differenziale diBush è adattabile alla costruzione di funzioni di due variabili, si studiano alcuni strumenti che, applicati all'analizzatore, permettono di eseguire varie transformazioni fra le proiezioni cartografiche della sfera, espresse in forma esplicita. In particolare si esaminano le transformazioni fra le proiezioni cilindriche e coniche. — II. Rilevati gliinconvenienti che comporta l'impiego di soli mezzi meccanici, si introducono dispositivi ottico-meccanici che restringono il campo delle transformazioni, ma le rendono, praticamente effettuabili. Detti dispositivi vengono applicati, oltre alle transformazioni citate, anche per ottenere la equivalente sinusoidale a paralleli rettilinei e circolari.

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Summary I. The Differential Analyser ofBush, being fit for the construction of two variables functions, some instruments are studied which, applied to the Analyser, allow several transformations between cartographic projections of the sphere, expressed in explicit form, to be executed. Particularly, transformations between cylindrical and conical projections are examined. — II. After having revealed the failures produced by the use of mechanical means only, optic-mechanical devices are introduced, which restrain the range of transformations but make them practically effectible. Such devices are applied, besides the previous transformations, also to obtain the sinusoidal equivalent in rectilinear and circular parallels.

     

Groundwater Modeling of Fractured Aquifers in Mines: The Case Study of Gavorrano (Tuscany,Italy)

In this paper, we describe the hydrogeological problems related to the closure of the mine at Gavorrano (Tuscany, Italy). The geological and geo-structural settings of the Gavorrano area affect the groundwater flow systems and their chemical composition; hence, the settings also affect the chance and modalities to rehabilitate and re-utilize these water resources. This paper reports the results of studies, analyses of existing data and the consequent implementation of preliminary numerical models with particular reference to the effects of controlled water recovery and the complex measures required for stopping dewatering. The study incorporates recent data and the available historical records in an analysis of the hydrodynamic impact of water recovery and an assessment of the consequences of water recovery for water resources restoration. The applied numerical simulations have been demonstrated to be a promising and effective tool for planning and managing the future applications of groundwater recovery in the Gavorrano mining area. Using these applications, it will be possible to implement mitigation measures and types of re-use that consider thermal, chemical and discharge features.