Late quaternary tephra layers along the Cilento coastline (southern Italy)

The results of stratigraphic and tephrostratigraphic analyses of several pyroclastic levels, collected along the coastal sector of the Cilento region (southern Italy), are presented. Some of these levels are here described for the fist time, others, already known in literature, were reconsidered in order to better understand their stratigraphic position and to point out the possible volcanic sources.     

Using the present to estimate the future: A simplified approach for the quantification of climate change effects on urban flooding by scenario analysis

Understanding and modelling pluvial flood patterns is pivotal for the estimation of flood impacts in urban areas, especially in a climate change perspective. However, urban flood modelling under climate change conditions poses several challenges. On one hand, the identification and collection of climate change data suitable for flood-related evaluations requires consistent computational and scientific effort. On the other hand, large difficulties can arise in the reproduction of the rainfall-runoff transformation process in cases when only little information about the subsurface processes is known. In this perspective, a simplified approach is proposed to address the challenges regarding the quantitative estimation of climate change effects on urban flooding for real case applications. The approach is defined as “bottom-up” because climate change information is not included in flood modelling, but it is only invoked for the interpretation of results. In other words, the challenge faced in this work is the development of a modelling strategy that is expeditious, because it does not require flood simulations for future rainfall scenarios, but only under current climate conditions, thus reducing the overall computational effort; and it is flexible, because results can be easily updated once new climate change data, scenarios or methods become available, without the need of additional flood simulations. To simulate real case applications, the approach is tested for a scenario analysis, where different return periods and hyetograph shapes are used as input for urban inundation modelling in Naples, Italy. The approach can support public and private stakeholders, such as land administrators and water systems managers; moreover, it represents a valuable and effective basis for climate change risk communication strategies.     

Digital simulation of multivariate earthquake ground motions

In this paper a new generation procedure of multivariate earthquake ground motion is presented. The technique takes full advantage of the decomposition of the power spectral density matrix by means of its eigenvectors. The application of the method to multivariate ground accelerations shows some very interesting physical properties which allows one to obtain significant reduction of the computational effort in the generation of sample functions relative to multivariate earthquake ground motion processes. Copyright © 2000 John Wiley & Sons, Ltd.     

The use of predictive modeling techniques for optimal exploitation of spatial databases: a case study in landslide hazard mapping with expert system-like methods

. A case study is presented in which different probabilistic prediction models (Bayesian probability, fuzzy logic "and", "or", "sum", "product", "gamma" operations, and certainty factors) are used to produce landslide hazard maps for a hilly and mountainous region in the northern Apennines, Italy. Seven data layers are exploited to detect most vulnerable areas: lithology, distance from the geological lineaments, annual rainfall amount, land cover type, topographic slope and aspect, and the distance from hydrographic network segments. The results of the different predictions are compared using the prediction rate index and critically discussed, to evaluate the possibility of using readily available databases for land planning.     

ESO's new CCD Testbench

During the forthcoming years, ESO will implement a large number of CCDs in optical instruments for the Paranal and La Silla observatories. An important step in this process is the CCD characterization and optimization that is done after the device is received from the manufacturer. In order to accommodate the new large CCDs and to interface to the new FIERA controller, ESO is building a new CCD testing facility in Garching. Among the measurements that will be made with this new facility are: quantum efficiency, conversion factor, charge transfer efficiency, dark current, read out noise and cosmetic quality.     

An analysis of global model projections over Italy, with particular attention to the Italian Greater Alpine Region (GAR)

This study surveys the most recent projections of future climate change provided by 20 Atmospheric-Ocean General Circulation Models (AOGCMs) participating in the Coupled Model Intercomparison Project 3 (CMIP3) with focus on the Italian region and in particular on the Italian Greater Alpine Region (GAR). We analyze historical and future simulations of monthly-mean surface air temperature (T) and total precipitation (P). We first compare simulated T and P from the AOGCMs with observations over Italy for the period 1951–2000, using bias indices as a metric for estimating the performance of each model. Using these bias indices and different ensemble averaging methods, we construct ensemble mean projections of future climate change over these regions under three different IPCC emission scenarios (A2, A1B, and B1). We find that the emissions pathway chosen has a greater impact on future simulated climate than the criteria used to obtain the ensemble means. Across all averaging methods and emission scenarios, the models project annual mean increase in T of 2–4°C over the period 1990–2100, with more pronounced increases in summer and warming of similar magnitude at high and low elevations areas (according to a threshold of 400 m). The models project decreases in annual-mean P over this same time period both over the Italian and GAR regions. This decrease is more pronounced over Italy, since a small increase in precipitation over the GAR is projected in the winter season.     

Speleothems in a north Cuban cave register sea‐level changes and Pleistocene uplift rates

A flight of marine terraces along the Cuban coast records Quaternary sea‐level highstands and a general slowly uplifting trend during the Pleistocene. U/Th dating of these limestone terraces is difficult because fossil reef corals have been affected by open system conditions. Terrace ages are thus often based on geological and geomorphological observations. In contrast, the minimum age of the terraces can be constrained by dating speleothems from coastal mixing (flank margin) caves formed during past sea‐level highstands and carving the marine limestones. Speleothems in Santa Catalina Cave have ages >360 ka and show various cycles of subaerial–subaqueous corrosion and speleothem growth. This suggests that the cave was carved during the MIS 11 sea‐level highstand or earlier. Some stalagmites grew during MIS 11 through MIS 8 and were submerged twice, once at the end of MIS 11 and then during MIS 9. Phreatic overgrowths (POS) covering the speleothems suggest anchialine conditions in the cave during MIS 5e. Their altitude at 16 m above present sea level indicates a late Pleistocene uplift rate of <0.1 mm/ka, but modelling also shows uplift to have been insignificant over a long timespan during the middle Pleistocene since the cave was carved. Our study shows that some flank margin caves in the region of Matanzas are older than commonly believed (i.e. MIS 11 rather than MIS 5). These caves not only can be preserved but are good markers of interglacial sea‐level highstands, more reliable than marine abrasion surfaces. Copyright © 2018 John Wiley & Sons, Ltd.     

Biogeochemical effects of disturbance in shallow water sediment by macroalgae harvesting boats

In the shallow water of Orbetello lagoon, macroalgae harvesting boats produce sediment disturbance. To evaluate the effect of this, during 2001-2002, a trial study was carried out in the lagoon in order to: verify seasonal and diurnal trends in nutrients and estimate the quantity of resuspended organic sediment. An unbalanced and balanced ANOVA (one and two way) analysis was applied. The disturbance did not produce strong and lasting eutrophication effects. In the seasonal survey, dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) showed significant decreases in disturbed areas at the end of the trial, while the control area showed a constant, significant increase. Dissolved organic nitrogen (DON) and phosphorus (DOP) significantly increased everywhere. In disturbed areas, sediment redox (Eh((NHE))) increased and porosity values decreased, contrary to the control area. Total organic carbon (TOC) remained unchanged in disturbed areas, but increased in the control area, where the C:P ration increased. The fall-out of sedimentary material resuspended by boat action for as far as 50 m from the boat route, was 189 g(dw)m(-2) made up mainly of organic matter. This disturbance could be the cause of change in vegetation in the lagoon.     

Lanslide hydrogeological susceptibility of Maierato (Vibo Valentia, Southern Italy)

A large landslide occurred at Maierato (Vibo Valencia District), Southern Italy, on 15 February 2010, when rapid failure was produced after several days of preliminary movements. The landslide can be classified as a rotational slide with flowing of the mass. It occurred within a larger deep-seated gravitational movement area and was preconditioned for failure by the intrinsic geological weakness of the area. Actually, the in situ survey showed the presence of several ancient movement surfaces all around the urban area. The landslide-triggering factor was the increase in the groundwater flow, consequent to a period of heavy and prolonged rainfall. The aim of the paper is to explain the mechanism of occurrence of the February 2010 composite landslide, in order to assess the landslide hydrogeological susceptibility in the whole urban area of Maierato. For this reason, the present paper deals with: (1) identification of the landslide mechanism and triggering factors (2) slope stability back-analysis using a finite-difference-based shear strength reduction method, and (3) 3D groundwater flow modelling extended to the whole urban area both in pre- and post-failure conditions. The results show that the February 2010 composite landslide was triggered by a water table increase of about 15 m uphill the landslide scarp. This hydrogeological condition could be reached after the period of heavy and prolonged rainfall preceding the landslide event. Finally, based on the groundwater modelling in post-failure condition, a landslide hydrogeological susceptibility map was drawn for the all urban area of Maierato, showing the presence of extended areas exposed to hazard.