Turbidity Currents Physical Simulation in a Small-Scale Model of Large Dimensions (Canyon Almirante Câmara – Campos Basin, Brazil): Methodology and Preliminary Results

Rafael Manica, Rodrigo Sartor, Rogério Dornelles Maestri, and Ana Luiza De Oliveira Borges
Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil

International knowledge concerning three-dimensional physical modeling of turbidity currents and its depositional patterns is not well developed. For this reason, a small-scale model of large dimensions (167m²) was built at NECOD, representing the area of the submarine Canyon Almirante Câmara. The Canyon was scaled down in a 1:3000H and 1:1500V bases, being the relationships prototype/model based on Densimetric Froude Number. Several successive simulations were performed, allowing the occurrence of erosion/deposition processes and thus forming stratified sedimentary layers, similar to the ones find in nature. The three-dimensional dynamical behavior of the currents and its depositional patterns were also evaluated. The generated deposits have shown a trend of fining-grain towards the basin, with normally graded and massive beds predominance. The lack of more flows however, prevented the deposited material from reaching the distal region. Depositional bedforms were composed of current ripples at the proximal region, which spread out towards the basin. Results indicate that successive simulations influenced the current kinematics, decreasing its velocity. A wide scattering of the current was also noticed, creating a main front of advance followed by two secondary fronts. Complementary experiments, already being performed, will contribute to enhance the knowledge in turbidity currents physical simulation.