Sediment transport and deposition on submarine slopes: drivers, feedbacks, and implications

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Gravity-driven sediment flows and ocean bottom currents shape the ocean sea floor and largely control the transport and deposition of sediment along submarine slopes of continental margins. The proposed research program relies on applying state-of-the-art oceanographic data acquisition methods with high-resolution sedimentological and geophysical datasets to investigate the formation of turbidity currents and submarine landslides in the context of a changing climate, and the development of deep-water depositional sequences influenced by ocean bottom currents. The program is rooted in a large network of national and international collaborations and focuses on three key study areas: the fjords of Baffin Island, the northwestern Atlantic margin, and the western Indian Ocean offshore Tanzania. The study areas are selected based on their uniqueness in addressing the specific problems of this program during the next five years, and for achieving longer-term science goals. In the fjords of eastern Baffin Island, we will investigate the formation of turbidity currents in relation to different trigger mechanisms, such as glacial melting and submarine sediment failures. In addition, we will explore coastal and offshore sedimentary records to provide critical information for assessing the tsunami risk along populated areas of Baffin Island. The goal is to test the overarching hypothesis that the frequency of hazardous tsunamigenic submarine landslides is likely to increase owing to climate change, and to address the vulnerability of northern coastal communities as related to tsunamis. In the northwestern Atlantic margin, we will investigate the distribution, timing, and size of submarine landslides since the deglaciation, and discuss potential trigger mechanisms. An expected outcome is to evaluate the recurrence of tsunamigenic landslides similar to the 1929 Grand Banks event, the only fatal tsunami recorded in Canada, and the likelihood of such hazardous events to occur in the future. In the western Indian Ocean, preliminary investigations have highlighted the existence of deep-water deposits which form when a synchronous turbidity/contour currents interaction occurs, namely mixed turbidite-contourite systems. We will define architectural elements, hierarchy and associated lithological properties of slope depositional systems offshore the margin of Tanzania to develop process-based models for the formation of mixed turbidite-contourite deposits. The detailed characterization of this increasingly recognised and yet poorly understood hydrocarbon-bearing slope deposit will support the petroleum industry, worldwide and in Canada where similar systems have been recently identified. The projects deriving from the proposed research program will train highly qualified personnel (three PhD and one MSc) who will become knowledgeable in international and Arctic research, process sedimentology, seismic stratigraphy, and science communication.