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dc.contributor.authorKoller, Débora Karinept_BR
dc.contributor.authorManica, Rafaelpt_BR
dc.contributor.authorBorges, Ana Luiza de Oliveirapt_BR
dc.contributor.authorFedele, Juanpt_BR
dc.date.accessioned2019-07-19T02:38:55Zpt_BR
dc.date.issued2019pt_BR
dc.identifier.issn2317-4889pt_BR
dc.identifier.urihttp://hdl.handle.net/10183/197170pt_BR
dc.description.abstractBedforms are sedimentary features that can be generated on the seafloor by the interaction between density currents and mobile beds. Developing knowledge about the hydraulic and sedimentary processes involved during these events is in the interest of research groups and oil companies. Because of the magnitude of the density currents in its natural environment and the challenge in collecting data, studies in laboratory are of great value. We present results of 29 experiments focusing in the bedform development generated by saline currents, testing two different sediment typesT and three grain sizes: melamine (245 µm-plastic) and sands (206 and 485 µm). We analyzed the current velocity and fractional density profiles as well as pictures taken during and after each run. Results have showed classical velocity and concentration profiles, for 8 subcritical and 21 supercritical currents, with densimetric Froude numbers (Frd) between 0.5 and 2.2. Some correlations were identified, such as the decrease of the velocity peak height and increase in the mean velocity (with consequent reduction of the current thickness), due to an increase of the concentration and/or flume slope. The occurrence of bedforms was more likely for high discharge and concentration rates of current density, which directly influence the Frd. Bedforms were classified according to the shear stresses values applied by the current to the bed, resulting in the generation of lower plane bed, ripples and dunes. Dunes and ripples were observed in supercritical flow conditions, which is a hydraulic scenario of bedforms generation not predicted by fluvial models. Thus, this study demonstrated the existence of differences in generation and, consequently, the classification approach for density current bedforms, compared to those generated by river flows. To this fact is attributed the hydrodynamic (velocity and concentration profiles) and sediment transport differences between fluvial flows and density currents. Further studies may be carried out in order to constructing new concepts of bedforms generation by density currents.en
dc.format.mimetypeapplication/pdfpt_BR
dc.language.isoengpt_BR
dc.relation.ispartofBrazilian Journal of Geology. Sao Paulo, SP: Sociedade Brasileira de Geologia. Vol. 49, n. 2 (May 2018), 10 p.pt_BR
dc.rightsOpen Accessen
dc.subjectBedformsen
dc.subjectCorrentes de densidadept_BR
dc.subjectPhysical modellingen
dc.subjectModelagem físicapt_BR
dc.subjectTransporte de sedimentospt_BR
dc.subjectDensity currentsen
dc.subjectLeitos moveispt_BR
dc.subjectMobile beden
dc.titleExperimental bedforms by saline density currentspt_BR
dc.typeArtigo de periódicopt_BR
dc.identifier.nrb001097166pt_BR
dc.type.originNacionalpt_BR


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