Earth walls as repositories of background levels of soil metal contaminants

Data about the background concentration of potentially toxic elements in soils are indispensable for establishing legislative limits, risk thresholds and, in general, assess the intensity of the pollution. Crude earth buildings are diffuse in the Mediterranean area and may be used as archives for original concentration of various metals. The building technique uses local soil which is mixed with water, let dry in formworks and covered with plaster. This has protected the soil material from external additions. The aim of this work was to evaluate the crude earth walls as repositories of the original concentration of some metals. Six crude earth walls were investigated in a location in northwestern Italy. Their concentration in Cd, Cu, Cr, Ni, Pb and Zn were measured and compared with those of surrounding soil profiles. Also, the results were compared with those of the Province. Organic carbon and pH seem to confirm the different evolution of the soils in the field with respect to that in the wall while iron oxides were not useful in discriminating the samples. Cadmium and Pb appeared to be the most reliable for the evaluation of the accumulated contamination evaluated while Cr and Ni are influenced by the lithogenic substratum.     

Research and development of advanced technologies for landslide hazard analysis in Italy

The Research Centre on Prediction, Prevention and Control of Georisks, "Sapienza Università di Roma" (CERI) was selected as one of the World Centres of Excellence on Landslide Risk Reduction (WCoE) under the title of “Research and development of advanced technologies for landslide hazard analysis in Italy” in the period 2008–2011. The present paper provides background information on the activities carried out by the CERI, in the frame of the WCoE network. Pre-defined purposes have been achieved by the implementation of integrated monitoring systems and early warning systems for landslides movements. The application of GBInSAR technique for monitoring landslides interacting with infrastructures is discussed, and two case histories are presented. It is shown that this technique is particularly suitable for the displacements monitoring of landslides interacting with infrastructures, thanks to its peculiar features (i.e. areal mapping, operability under every weather and lighting conditions and continuous and completely remote monitoring). Hence, it can be considered a very important tool for the reduction of risks connected to the realisation and activity of large infrastructures.     

Coastal deformation between the Versilia and the Garigliano plains (Italy) since the last interglacial stage

The opening of the north‐central Tyrrhenian Sea is the result of the Cretaceous–Paleogene alpine collision, which triggered a series of regional uplift, subsidence and transcurrent tectonic mechanisms along the coastal Tyrrhenian sectors of peninsular Italy. These tectonic processes, in conjunction with the effects of glacio‐ and hydro‐isostasy during the Quaternary, produced substantial crustal responses that, in some cases, reached metres in extent. In the study of coastal neotectonics, geomorphological markers of the last interglacial maximum, corresponding to marine isotope stage 5.5, are generally used to quantify the magnitude of the vertical crustal displacements that have occurred since 125 kyr. Through altimetrical, palaeoenvironmental and chronological reinterpretation of the most significant works published since 1913, combined with an additional set of data reported here, a detailed reconstruction of the shoreline displacements evident along 500 km of coast between northern Tuscany and southern Latium is presented. The reconstruction was carried out by quantifying the vertical movement since the last interglacial period and by identifying the tectonic behaviour of different coastal sectors. This has been done by carefully choosing the eustatic marker, among those available at each study site, in order to minimize the margin of error associated with the measurements. Copyright © 2003 John Wiley & Sons, Ltd.     

3D-electrical resistivity tomography monitoring of salt transport in homogeneous and layered soil samples

Monitoring transport of dissolved substances in soil deposits is particularly relevant where safety is concerned, as in the case of geo-environmental barriers. Geophysical methods are very appealing, since they cover a wide domain, localising possible preferential flow paths and providing reliable links between geophysical quantities and hydrological variables. This paper describes a 3D laboratory application of electrical resistivity tomography (ERT) used to monitor solute transport processes. Dissolution and transport tests on both homogeneous and heterogeneous samples were conducted in an instrumented oedometer cell. ERT was used to create maps of electrical conductivity of the monitored domain at different time intervals and to estimate concentration variations within the interstitial fluid. Comparisons with finite element simulations of the transport processes were performed to check the consistency of the results. Tests confirmed that the technique can monitor salt transport, infer the hydro-chemical behaviour of heterogeneous geomaterials and evaluate the performances of clay barriers.     

Spatial and temporal patterns of the mean annual precipitation at decadal time scale in southern Italy (Calabria region)

Mean annual precipitation variability at decadal time scale over a southern Italy area (Calabria) was investigated to quantify the spatial and temporal patterns. A multivariate approach has been applied to analyse spatial?Ctemporal (1921?C2000) data of annual precipitation. A nested isotropic linear model of coregionalization was fitted to the experimental variograms including three basic structures: a nugget effect, an exponential model and a spherical model. The correlation structure between the decades was analysed by applying principal component analysis at each spatial scale, and specific factors at each characteristic scale were cokriged and mapped. Two components were identified: the first is mainly linked to local factors, which could be identified by the orographic characteristics of the region, while the long range component could be related to large-scale factors, like for example the processes of the global atmospheric circulation. In addition, in order to obtain a better insight into the pattern of relatively dry or wet zones, a standardized relative difference was calculated. The results showed that the annual precipitation decreased during the period 1921?C2000 and the spatial distribution changed with an increase of dry areas.     

The 2012 Northern Italy Earthquakes: modelling human behaviour

The aim of this study was to investigate human behaviour during the 2012 Northern Italy Earthquakes. Furthermore, the current study used Kuligowski and Mileti’s (Fire Saf J 44:487–496, 2009) extended model and the Social Attachment Model as a framework to explain the behavioural responses. The study included 1839 participants who were affected by the earthquake occurred in the Emilia-Romagna region (Italy) on 20 May 2012. The most frequent behavioural responses during the earthquake were moving to another room of the house, escaping from home, and waiting in bed. According to Kuligowski and Mileti’s (Fire Saf J 44:487–496, 2009) extended model, perceived risk was associated with evacuation, and emergency preparedness was related to more efficient and effective responses during the earthquake. In line with the Social Attachment Model, affiliation behaviours were more frequent than flight behaviours, while, contrary to predictions, the social context did not influence emotional responses, evacuation behaviour, and search for protection.     

U–Pb zircon dating and nature of metavolcanics and metarkoses from the Monte Grighini Unit: new insights on Late Ordovician magmatism in the Variscan belt in Sardinia, Italy

In the external units of the Sardinian Variscides Nappe Zone, volcanic and volcanoclastic successions of Middle Ordovician age follow Lower Paleozoic calc-alkaline magmatism developed at the northern Gondwana margin. We present geochemical and zircon U–Pb isotopic data for the Truzzulla Formation, a low-to-medium-grade metamorphic volcanic–volcanoclastic succession belonging to the Monte Grighini Unit, the deepest unit in the Nappe Zone. Geochemical and radiometric data allow us to define a Late Ordovician (Katian) magmatic (volcanic) event of calc-alkaline affinity. These new data, in conjunction with previously published data, indicate that in the Sardinian Variscides, the age of Lower Paleozoic Andean-type calc-alkaline magmatism spans from Middle to Late Ordovician. Moreover, the age distribution of calc-alkaline volcanics and volcanoclastic rocks in the Nappe Zone is consistent with a diachronous development of Middle–Late Ordovician Andean-type magmatic arc through the portion of the northern Gondwanian margin now represented by the Sardinian Variscides. This reconstruction of the Sardinian Variscides reflects the complex magmatic and tectonic evolution of the northern margin of Gondwana in the Lower Paleozoic.     

An analysis of debris-flow events in the Sardinia Island (Thyrrenian Sea, Italy)

On 6 December 2004, the Villagrande Strisaili area (middle-east Sardinia), was struck by debris flows; 330 mm of rainfall took place within 3 h with an hourly intensity of 120 mm, which is far more above than normal for the study area. In the urban center stony and driftwood deposits accounted for a total volume estimated as 10,000 m³. The event claimed huge amount of infrastructural loss and two human lives. According to the chronicle reports, the area experienced two debris-flow events in the last century. The present paper is the outcome of an intensive study of such debris-flow events including their physical processes and geomorphological effects through both field survey and laboratory analysis.     

Shadows as a tool to evaluate black hole parameters and a dimension of spacetime

Shadow formation around supermassive black holes were simulated. Due to enormous progress in observational facilities and techniques of data analysis researchers approach to opportunity to measure shapes and sizes of the shadows at least for the closest supermassive black hole at the Galactic Center. Measurements of the shadow sizes around the black holes can help to evaluate parameters of black hole metric. Theories with extra dimensions (Randall–Sundrum II braneworld approach, for instance) admit astrophysical objects (supermassive black holes, in particular) which are rather different from standard ones. Different tests were proposed to discover signatures of extra dimensions in supermassive black holes since the gravitational field may be different from the standard one in the general relativity (GR) approach. In particular, gravitational lensing features are different for alternative gravity theories with extra dimensions and general relativity. Therefore, there is an opportunity to find signatures of extra dimensions in supermassive black holes. We show how measurements of the shadow sizes can put constraints on parameters of black hole in spacetime with extra dimensions.     

On the rheological characterisation of liquefied sands through the dam-breaking test

This paper concerns the rheological characterisation of liquefied sands as non-Newtonian Bingham fluids. For this purpose, dam-breaking laboratory tests are often executed and interpreted, offering a viable option to identify the properties of fluidised water-soil mixtures. However, limited attention has been devoted so far to clarify what variables and measurements would allow unambiguous calibration of Bingham parameters, namely, the viscosity η and the yield stress τ_y. The numerical results of parametric studies based on the particle finite element method (PFEM) are critically inspected to gain deeper insight into the problem. First, it is confirmed that multiple η − τ_y pairs may reproduce the same experimental evidence when formed by only one measurement—usually, the post–dam-breaking displacement of the bottom toe (tip) of the liquefied mass. Then, two alternative procedures are proposed for unambiguous identification of both η and τ_y: one is based on monitoring the evolving aspect ratio of the fluid mass during free, gravity-driven flow; the other relies on a slightly different dam-breaking test, also including impact against a rigid obstacle. In particular, the latter approach reduces the relevant duration of the test, reducing the possible influence of reconsolidation effects on the calibration of rheological parameters.