Geomorfologia del Margine Continentale della Sardegna meridionale
The study submitted in this thesis is related to the continental margin of southern Sardinia, including the continental platform and the upper portion of the continental slope to a depth of about 2000 meters, is included within the Gulf of Cagliari, limited to the west by Capo Teulada and on the east by Capo Carbonara. The continental margin of southern Sardinia has been investigated for the first time through high resolution morphobatimetric (multibeam) data not interpolated. Have been defined Geo Risks associated with characteristics of escarpment‟s gravitational processes and the dynamics of channeled flows that affect the evolution of systems of canyons. The multibeam data have been acquired during two cruises: MaGIC Canale di Sardegna 2009 and MaGIC Sardegna 2010, whit the research ship “Universitatis”; Subbottom Profile data have been acquired to support the geological interpretation. The classification of the morphobatimetric elements identified the continental shelf, the slope, areas of diffused erosion, canyons and channels and areas affected by big submarine landslides. The detailed morphometric analysis carried out for each system of canyons and channel offered further information on the evolution dynamics and on the state of activity of the margin. Were detected evidence related to uplift movements for the Sarroch Canyon, which present meander features and at least three orders of terraces. In the Pula Canyon area was observed the absence of intra-channel storage, index of tectonic activity related to the recent evolution of the western margin of the Gulf of Cagliari. Have been studied in detail five great submarine landslides in the Gulf of Cagliari, including the margin between the continental shelf and the upper continental slope. Models have been proposed of the evolutionary dynamics and triggering of landslides, related the slowly tectonic influence, the presence of hydrates, within the sedimentary package, and finally the seismic triggering as the main factor of initiation of underwater landslides
Geologia marina, canyon, frane sottomarine, geohazard, georischi, marine geology, submarine landslide, tsunami, Settore GEO/04 - Geografia Fisica e Geomorfologia
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