Turbidity currents in submarine canyons

Wednesday 6 June 2018 - 14:00
NOC Liverpool - Nicholson Lecture Theatre (University of Liverpool).
Dr Marta Payo Payo (NOC)

Turbidity currents in submarine canyons are the main contribution for sediment transfer across the continental margins. Geological studies of submarine canyons and associated turbiditic systems for more than 30 years led to an extraordinary breakthrough in the understanding of how turbidite systems evolve. However, these studies remain limited to a posteriori interpretations, based on the distribution of deposits and morphological evidences. In this work I apply a 2DH process-based model to simulate large-scale turbidity currents on two different submarine canyons in the western Mediterranean coast.

The work in La Fonera canyon, in the Catalan margin, focuses on the sediment transport and accumulation resulting from trawling activities. The study represents a starting point for the assessment of the sedimentary impact of bottom trawling in deep continental margins. The present work can help in the identification of trawling areas with lesser impacts. The Var Sedimentary System, located near Nice (France), is connected to the Var River during both low and high-stands and it can be considered as a natural laboratory for the study of the climatic control on the turbiditic activity. The influence of Coriolis forces on the spatial evolution of the hyperpycnal flows and hence in the construction of the Var Sedimentary Ridge is evidenced and supported for the first time.

The major drawback is the limited amount of information for the necessary initial and boundary conditions; hence, modelling results might not be of predictive quality. However, modelling results provide a full-scale vision of the system allowing the identification of sediment pathways and deposition areas based on physical processes and enlarge the present knowledge of the canyons studied. The results obtained may help in the identification of strategic mooring and coring sites to further advance the state of our knowledge.



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