1,721,062 research outputs found
Geophysical Investigations for exploring marine sand deposits (Cilento Peninsula – Southern Italy).
No full textAbstract in vol. II : Beach & Shoreline Management
Geophysical investigation on the continental shelf of Cilento Peninsula (Southern Italy) to preliminary asses beach renourishment resources.
No full text675 km of high resolution seismic profiles and more than 50 sediment samples (grabs and gravity-cores) were collected at water depth ranging from 20 m to 100 m, offshore Cilento peninsula (southern Italy), in order to assess sand resources potential in this area belonging to the eastern Tyrrhenian margin. The Cilento peninsula is located in Campania region that is one of the most popular vacation spots for tourists in Italy. Its scenic coastline is dominated mainly by cliffs, but also important beach systems and small bays are present, where evidences of constant coastal retreat have occurred in the latest years, threatening commercial developments. The high economic value of these beach systems justifies high investments from local authority to choose soft protection measures searching marine sand for beach nourishment. The oceanographic survey has been carried out thanks to a research agreement between the local authority "Autorità di Bacino Sinistra Sele" and CoNISMa (National Interuniversity Consortium for Marine Sciences); the cruise took place during April 2004 and the large amount of data collected allowed us to study in detail the development of late Pleistocene/Holocene sedimentary deposits formed during the latest cycles of high-frequency sea-level variations. In fact it is well know that in microtidal coast the main targets for sand research are relict deposits formed on the shelf when sea level was lower than present. In the investigated area we found two main locations where the chirp data showed sand bodies on the continental shelf. Unfortunately, the volume of such deposits is not large enough to ensure the nourishment of the whole costal area affected by erosion. In any case the methodology employed showed to be successfully suitable to assess the presence of beach nourishment resources, in particular to recognise in fine detail sand bodies (in terms of their 3D geometry and of the thickness of overlying mud) and to reenact specific geomorphologic/sedimentary conditions occurred on the continental shelf
Late Pleistocene planktonic assemblages in three box-cores from the Mediterranean Ridge area (west-southwest of Crete): paleoecological and paleoceanographic reconstruction of Sapropel S1 interval
No full textA case study of the correlation between steep and narrow margin with the development of fluvial structures: the Ionian Calbrian area
No full text
The Vlora project
No full textThis volume collects the main results of 2 years of multidisciplinary researches (2007–08) on the Vlora Gulf ecosystem,
carried out by a joint Italian (National Interuniversity Consortium for Marine Sciences [CoNISMA], National Research
Council [CNR, Consiglio Nazionale delle Ricerche] and Agenzia Regionale per la Prevenzione e la Protezione Ambientale
[ARPA] Puglia) and Albanian (University of Tirana, the Science Academy, and the Ministry of the Environment)
research team.
The studies and analyses were aimed at identifying the environmental factors and components that strongly interact
with, and affect, the marine ecosystem of the region. In particular, the main research tasks were related to geological and
hydrogeological aspects of the river basins, the bottom morphology of the whole marine area, the problems of coastal
erosion phenomena, the stratigraphy of the marine sediment, the physical and chemical parameters of the water column,
an examination of primary production, the biodiversity of benthic and pelagic ecosystems, and the existence of problems
connected to the ecotoxicology of the biota.
The results pointed out the weakness to the Vlora Gulf ecosystem from several sources, including the (1) heavy human
impacts on the natural coastal evolution, resulting in coastal erosion and/or accretion; (2) considerable influence of the
input of suspended mud from the Vjosa River, causing conspicuous degeneration phenomena on the benthic biocoenoses
(e.g., on the Posidonia oceanica meadow; and (3) conspicuous urban and industrial water discharge, producing diffuse
pollution related to the presence of heavy metals (mercury, among others) in the sediments of the gulf area.
Finally, a further aim of the project was the planning of an International Center for Marine Research, located in
Albania, to support an international focal point for researchers involved in environmental studies of the Eastern
Mediterranean
Maerl facies distribution offshore Cilento Peninsula (Tyrrhenian Sea, Italy).
No full textQuantifying the areal distribution of maërl and coralline carbonate production and accumulation is instrumental to define their role on present shelves sedimentation and in the carbonate budget of the Mediterranean Sea. The Cilento coastal area (eastern Tyrrhenian Sea) has been mapped and characterized by acoustic survey techniques combined with sediment sample analysis. Maërl-beds are reported for the first time off the Cilento coasts, where calcareous red algae are the most important carbonate producer between 40 and 60 meter of water depth (w.d.). Within the study area maërl-beds dominate on submerged terraces located at variable w.d. between 42 and 52 m. The preferred distribution of maërl-beds on submerged terraces is associated to the role that terraces exert in the local circulation dynamic, deviating bottom currents and thus preventing the detrimental sediment accumulation on maërl. We calculated the coralline carbonate accumulation from the percentage cover of coralline algae (by thin section mapping) x 1-cm thick layer of sediment x measured coralline density. The total coralline cover (live plus dead) in the Cilento area is 13.96 km2, with a total 316800 t of algal carbonate in the surface 1cm-thick layer, that is to say 20430 g m-2. Living maërl is recorded at a depth of 47 m, with a live coralline cover of about 40% over a minimum area of about 1.19 km2. This live maërl has a thickness of about 1 cm and is mostly composed of unattached branches of Lithothamnion corallioides Crouan & Crouan, 1867. The molluskan association of the maërl bed is dominated by characteristic species of the Coastal Detritic Biocoenosis. Living coralline production rate has been calculated as weight of live corallines in 1-cm thick layer x 100 y-1 x total area-1 and corresponds to 90.8 g m-2 y-1
Viruses, Prokaryotes and DNA in the sediments of a deep-hypersaline anoxic Basin (DHAB) of the Mediterranean Sea
No full textIndications of low macrobenthic activity in the deep sediments of the eastern Mediterranean Sea
Full text linkThe fluxes and budget of organic matter from the oligotrophic surface waters of the eastern Mediterranean to the deep waters are poorly known, and little information is available on past and present macrobenthic activity on the sea floor. Evidence of macrobenthic activity can be direct, through recovery of living organisms or their autochthonous skeletal remains, or indirect, through bioturbation and trace fossils. The evidence of biological activity in deep eastern Mediterranean sediments has been evaluated and compared through 210Pb profiles from box-cores and study of dredge samples from sites on Medina Rise (1374 m water depth), the Messina Abyssal Plain (4135 m) and several sites along the Mediterranean Ridge, SW and S of Crete (1783 to 3655 m). All these sites are remote from the continental shelves, so the biological benthic activity is expected to depend primarily on primary production from surface waters. The results show that present-day macrobenthos and trace fossils are generally scarce, especially at depths > 2500 m. This observation is supported by surface sediment 210Pb excess distributions that show a surface mixed layer (SML) 2500 m. The historical layer of some box-cores and the Pleistocene hardgrounds collected in the Cleft area (Mediterranean Ridge) do, however, record a macrobenthic activity that is apparently more intense than at present, which may be related to higher primary production of the Pleistocene glacial intervals. In contrast with most areas of the present-day deep eastern Mediterranean which depend on surface primary production based on photosynthesis, a relatively dense and diversified macrobenthic community based on chemosynthesis has been recognised at depths > 1100 m on the Napoli Dome mud volcano in the Olimpi area, and on the Kazan and other mud volcanoes in the Anaximander Mountains.En el Mediterráneo oriental los flujos de materia orgánica desde las aguas superficiales oligotróficas hasta las aguas profundas son poco conocidos y en general hay poca información sobre la actividad del macrobentos en el fondo del mar. La evidencia de la actividad macrobentónica puede ser directa, a través de los organismos vivos o de los restos de esqueletos autóctonos, o inidrecta, a través d ela bioturbación y fósiles. La evidencia de la actividad biológica en los sedimentos profundos del mediterráneo Oriental se ha evaluado y comparado por medio de los perfiles del 210Pb provenientes de muestreos con box-corer y dragas tomados en varios puntos del dorsal mediterráneo, al SO y S de Creta (entre 1783 y 3655 m). Se espera que la actividad biológica de estos fondos alejados de la plataforma continental dependa principalmente de la producción primaria de las aguas superficiales. Los resultados muestran que el macrobentos actual y los fósiles son generalmente escasos, especialmente en fondos superiores a los 2500 m. Estas observaciones se basan en la distribución del exceso de 210Pb que se ha encontrado en la capa superficial de mezcla del sedimento, inferior a 6 cm de grosor, en los cores de aguas inferiores a 2500 m; y de solo 2-3 cm a mayor profundida. Estos valores son mucho más bajos que la media de la capa supqerfical de mezcla de unos 10 cm en los sedimentos marinos de otras zonas. Es probable que la producción primaria actual en el Mediterráneo oriental no pueda soportar ninguna actividad macrobentónica estructurada a más de 2500 m. la capa histórica en algunos box-corer de los fondos duros del Pleistoceno muestreados en el áreade Cleft registran, sin embargo, una catividad macrobentónica aparentemente más inyensa que la actual, y que podría relacionarse con una producción primaria alta durante los intervalos interglaciales del Pleistoceno. Contrariamente a lo encontrado en la mayoría de las áreas actuales en el mediterráneo oriental profundo, el cual depende de la producción primaria superficial basada en la fotosíntesis, en le volcán fangoso de Napoli Dome en el área de Olimpi, en el Kazan y otros volcanes fangosos de las montañas Anaximader, se ha encontrado una comunidad macrobentónica relativamente densa y diversificada basada en procesos quimiosintéticos
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