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

重力驱动的沉积物流和海底流塑造了洋底，并在很大程度上控制了大陆边缘海底斜坡上沉积物的运输和沉积。拟议的研究计划依赖于应用最先进的海洋学数据采集方法和高分辨率沉积学和地球物理数据集，研究气候变化背景下浊流和海底滑坡的形成，以及受海底流影响的深水沉积序列的发展。该项目植根于一个庞大的国家和国际合作网络，重点关注三个关键研究领域：巴芬岛峡湾、西北大西洋边缘和坦桑尼亚近海的西印度洋。研究领域的选择是基于它们在解决该计划未来五年的具体问题和实现长期科学目标方面的独特性。在巴芬岛东部的峡湾，我们将研究不同触发机制下浊度流的形成，如冰川融化和海底沉积物失效。此外，我们将探索沿海和近海沉积记录，为评估巴芬岛人口稠密地区的海啸风险提供关键信息。其目标是验证一个重要的假设，即由于气候变化，危险的海啸引发的海底滑坡的频率可能会增加，并解决与海啸有关的北部沿海社区的脆弱性。在西北大西洋边缘，我们将研究自冰川消融以来海底滑坡的分布、时间和规模，并讨论潜在的触发机制。一个预期的结果是评估类似1929年大浅滩事件（加拿大唯一有记录的致命海啸）的海啸性滑坡的再次发生，以及未来发生此类危险事件的可能性。在西印度洋，初步调查强调了深水沉积物的存在，这些沉积物是在浊流/等高线流同步相互作用时形成的，即混浊岩-等高线岩混合体系。我们将定义坦桑尼亚近海斜坡沉积体系的建筑元素、层次结构和相关的岩性特征，以开发混合浊积-轮廓岩沉积形成的基于过程的模型。对这种越来越被认可但却知之甚少的含油气斜坡矿床的详细描述，将为全球和加拿大的石油工业提供支持，加拿大最近发现了类似的系统。该项目将培养在国际和北极研究、过程沉积学、地震地层学和科学传播方面知识渊博的高素质人才（3名博士和1名硕士）。

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.