Submarine gravity flows entrained by ocean circulation: Processes and related sedimentary products – SWEPT

• Applicant: Professorin Dr. Elda Miramontes García
• Subject Area: Geology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 509877600

Turbidity currents are underwater sediment density flows that transport vast amounts of sediments to the deep sea. These processes are very powerful and can pose a hazard for seafloor infrastructure, but are crucial for ecosystems because they transport nutrients to deep waters. It is conventionally assumed that turbidity currents cannot strongly be affected by ocean currents since their velocity is usually about one order of magnitude higher. It has however been shown that despite this difference in energy, ocean circulation can deflect turbidity currents alongslope and profoundly affect the morphology and internal architecture of submarine channels, particularly by developing asymmetric channel-levee systems. Nevertheless, the processes that control the interaction between downslope turbidity currents and alongslope ocean currents and their related sedimentary products are still not well constrained mainly due to the lack of direct measurements in natural environments and of process-based studies. The SWEPT project will implement a multidisciplinary approach that combines the analysis of geophysical observations of asymmetric submarine channels, using multibeam bathymetry and seismic data, with in situ flow measurements from moorings (sites in the NW Mediterranean Sea and in the northern Mozambican continental margin), as well as with numerical modelling (using the model Nixes-TC), in order to be able to link particular geometries of channels with specific flow types. This approach will permit to identify the typical morphosedimentary and architectural characteristics of submarine channels formed by the interaction of turbidity currents and ocean currents, and to be able to differentiate them from other processes that could form similar asymmetric channels, such as the Coriolis force acting on turbidity currents. The results of this project will improve palaeoceanographic reconstructions based on the sedimentary record and will permit to predict particle transport and accumulation in submarine canyons, channels and adjacent areas, which would have important implications for deep-marine ecosystems, distribution and fate of pollutants and carbon burial.

• DFG Programme: Research Grants
• International Connection: France, United Kingdom
• Co-Investigators: Professor Dr. Gerhard Bohrmann; Professor Dr. Achim Kopf; Dr. Tilmann Schwenk; Professor Dr. Volkhard Spieß
• Cooperation Partners: Dr. Michael A. Clare; Professor Dr. F. Javier Hernández-Molina; Dr. Ricardo Silva Jacinto