Search results for "canyon"

Future coastal hazard scenarios. A case study in NE Sicily (Italy)

2012

The coastal dynamics is the result of several causes that contribute to change the balance of beach deposits over time. The beach system is not always able to maintain coastal balance: the factors contributing to this phenomenon are to be found in both natural and anthropogenic spheres. In this context we present the analysis of marine geology and coastal geomorphological data of a sector between Rocca di Caprileone and Tindari (north-eastern Sicily) with the aim to: i) determine their onland-offshore area relationships, ii) analyze which natural features may contribute to coastal retreat, iii) present coastal hazard scenarios. Until fifty years ago the natural balance of this coastal area …

Ultraviolet radiation protection by a beach umbrella.

2010

A beach umbrella intercepts all direct UV irradiance, but only part of the diffuse component. Using a simple sky view factor model, we have determined the fraction of the hemispheric diffuse irradiance that is not intercepted by the umbrella. Assuming a sensor at the surface and close to the center of the umbrella, isotropic diffuse irradiance and for an umbrella of 80 cm radius and 100 cm high, our results show that approximately 34% of the incident horizontal irradiance is not intercepted by the umbrella. These results agree with irradiance measurements conducted with and without the umbrella. The model is next extended to examine receipt of UV radiation by a human figure in a vertical po…

Submarine canyons of north-western Sicily(Southern Tyrrhenian Sea): Variability in morphology, sedimentary processes and evolution on a tectonically …

2014

Phytoplankton distribution along trophic gradients within and among reservoirs in Catalonia (Spain)

2008

SUMMARY 1. Longitudinal gradients in the epilimnetic waters of stratified reservoirs provide a useful database to study changing environmental conditions. The spatial distribution, assemblage structure and specific adaptations of phytoplankton assemblages can be analysed along these gradients over short time scales. 2. Four reservoirs with a similar typology, located along an altitudinal gradient in the same eco-region, were sampled along their longitudinal axes. In total, 19 sampling stations provided a trophic spectrum, ranging from oligo-mesotrophy to hypertrophy, which was quantified by calculating the trophic state index of each sampling station in the four reservoirs. 3. Several patte…

Geomorphology and speleogenesis of the Vallone Ponte-Grotte d'Acqua karst system (Sant'Angelo Muxaro - Southern Sicily

2010

Bathy-morphological analysis of submarine canyons across the north-western Sicily continental slope

2016

We present here the results of the morpho-bathymetric analyses of the main submarine canyons along the upper slope off the north-western Sicily. This region developed during the Neogene as the transition area between the Sicilian fold and thrust belt and the Tyrrhenian basin realm. Along the upper slope, a dense network of submarine canyon develops from 80 m water depth up to more than 2000 m, showing a large variability of sizes and morphology. In this area submarine canyons play a crucial role related to the along-slope sedimentary transport and are among the most distinctive features of the submarine seascape. This study is based on a quantitative analysis of a high resolution multibeam …

Submarine Mass Movements Along a Sediment Starved Margin: The Menorca Channel (Balearic Islands - Western Mediterranean)

2014

6th International Symposium on Submarine Mass Movements and Their Consequences (ISSMMTC), 23-25 September 2013, Kiel, Germany.-- 10 pages, 5 figures

Potential Cyclic Steps in a Gully System of the Gulf of Palermo (Southern Tyrrhenian Sea)

2016

Multibeam bathymetric data revealed the occurrence of atrain of bedforms along a gully system in the Gulf of Palermo, Southern Tyrrhenian Sea. The observed gullies, located in the westernmost sector of the Gulf of Palermo, incise the outer shelf at a depth of 120 m and converge at the Zafferano Canyon, connecting to the Palermo Basin at a the depth of 1300 m. Bedforms develop along these gullies and along the thalweg of the canyon, displaying an average wavelength of 200 m, with maximum values of 340 m. Their gully floor location combined with their wave length, upslope asymmetry and crescent shape point to a possible cyclic steporigin of these bedforms. Preliminary numerical modeling sugge…

Controlli stratigrafici e tettonici sull'evoluzione morfo-sedimentaria dell'offshore della Sicilia nord-occidentale durante il Quaternario

2013

High Resolution Dispersion Modeling near Tunnel Exits

1996

This contribution is concerned with a critical problem which usually occurs at motortraffic tunnels within towns. All exhaust gases accumulating along the entire tunnel distance readily leave the tunnel exits in a very concentrated form. Since modern urban traffic management affords more and more tunnel constructions within highly built-up areas, a reliable calculation of the resulting immission distribution in the neighbourhood of tunnel exits is of great importance.