56,305 research outputs found
Stratigrafia dei depositi recenti della Sacca di Goro. In: La Sacca di Goro (U. Simeoni Ed.).
No full textMagnetic susceptibility of surficial sediments from the Strait of Magellan
No full textMagnetic susceptibility (MS) was measured on the bulk samples (MSmv) and on the following three size fractions: gravel (MSg), sand (MSs) and mud (MSf). There is a direct correlation between MSmv on the one side, and MSg and MSs on the other; the MS of the sand and gravel fractions probably determine the bulk average. Furthermore, MS decreases with increase in mud content of the sediment. The MSmv, MSg and MSs values are independent of the depth of sampling; this is due to the change in texture of the sediments, which is controlled by the complex fluid-dynamics of the currents in the Strait. -from Author
Assessment of coastal erosion susceptibility at the national scale: The Italian case
No full textTo improve the present national and local sustainable planning capability for the coastal zone a GI application for the Italian Coastal Susceptibility Assessment was planned within an institutional agreement between ENEA and the Land Defence Service of the Italian Ministry of Environment. Taking into account previous European actions a suitable methodology to assess, in a quantitative way, the susceptibilty of beaches to be eroded has been set up. The methodology balances the coastline trend as evaluated for a defined time period with the present coastal areas morphology and land use, this in order to derive a value that expresses the evolutionary process in terms of probability of the loss of goods within the 'Homogeneous Coastal Tracts'. The trend in the movement of the sea-land line has been used as geo-indicator of a complex dynamic balance that refers both to marine and inland systems, and a vector GI application was built and locally applied in southern Italian coastal areas. The present shoreline position and some other information describing the intrinsic beach morphologies, and having significance for the coastal erosion hazard assessment, have been derived from the national 1:10.000 ortho-images of the National Cartographic Reference System provided by the Italian Ministry of Environment. The illustrated GI application - CoSTAT - keeps the nominal scale of all data collected or produced. In this analysis the coastal dune presence is analysed as factor limiting coastal erosion susceptibility. Applying a matrix calculation a quantitative evaluation of erosion susceptibility degree was achieved and plans were made to develop new information for a suitable use of Italian coastal areas. The work describes the methodology, the conceptual framework and the results of a local application
Recent sediments and sedimentological processes in the Strait of Magellan
No full textThe Strait of Magellan is made up of 5 main morphological-sedimentological units: 3 are located in the Atlantic arm and two in the Pacific. The first unit consists of the first two basins that open onto the Atlantic Ocean and that are separated by a narrow (Primera Angostura) and by the northernmost tip of Punta Arenas Basin. The second morphological-sedimentological unit basically consists of the Punta Arenas Basin, which follows the first two basins through as additional narrow (Segunda Angostura). This is the largest basin and has a depth of 400-500 m. The energy levels, which tend to decrease gradually from the north to the south, affect the distribution of sands become finer. Starting from the Punta Arenas Basin, a network of bays and channels branch off forming the third physiographical unit which is characterized by both ancient tillite deposits and fluvio-glacial mud. The Pacific arm is characterized by two narrow, prolonged basins (fourth and fifth unit). These basins are the ..
Domains of spit evolution in the Goro area, Po delta, Italy
No full textGoro lagoon was formed during the 19th century in the southern part of the Po Delta. Its origin is related to the growth of a spit system, which progressively occluded the southernmost interdistributary bay from the sea. The development of the spits is due to the morphological prominence of the Po Delta which causes a divergent littoral drift, enhanced by wave refraction over the delta front. During the last century the spit was abandoned, destroyed, and re-constructed several times because of the development of newer spits seawards. Using historical maps and aerial photographs, three different periods are recognised, featuring distinctive spit growth styles: parallel, fan-shaped and branched. The different domains of spit evolution are related to several factors, mainly to the mutual influence of sediment discharge, sand mining along the Po river, wave action over the delta front, human-induced subsidence and direct human interventions along the spits and for flood-control
A review of the Coastal Geomorphology of Karavasta Lagoon (Albania): Short Term Coastal Change and Implications for Coastal Conservation
No full textStudio sulla geomorfologia delle lagune albanes
Coastal studies in northern Victoria Land (Antarctica): Holocene beaches of Inexpressible Island, Thetys Bay and Edmonson Point
No full textThe study of a number of coastal areas in the Terra Nova Bay, carried out during austral summer 1987-88, allowed identification of some of the geomorphological and lithological features of the Quaternary raised beaches of Northern Victoria Land (Antarctica). A modern pitted-like beach was studied, the morphogenesis of which is ascribed to floating ice beached by a storm
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