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

重力驱动的沉积物流动和海底洋流塑造了海底，并在很大程度上控制了沿大陆边缘海底斜坡的沉积物的运输和沉积。拟议的研究方案依赖于应用最先进的海洋数据采集方法和高分辨率的沉积学和地球物理数据集，以调查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区域：巴芬岛峡湾、西北大西洋边缘和坦桑尼亚西印度洋近海。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更长期的科学目标方面的独特性。在巴芬岛东部的峡湾，我们将研究与不同触发机制有关的浑浊流的形成，如冰川融化和海底沉积物破裂。此外，我们将探索海岸和近海沉积记录，为评估巴芬岛人口稠密地区的海啸风险提供关键信息。其目标是检验最重要的假设，即引发海啸的危险海底山体滑坡的频率可能会因气候变化而增加，并解决北部沿海社区与海啸有关的脆弱性问题。在西北大西洋边缘，我们将调查自冰川消融以来海底滑坡的分布、时间和大小，并讨论潜在的触发机制。一个预期的结果是评估类似1929年大浅滩事件的海啸引发的山体滑坡的复发，这是加拿大有记录以来唯一致命的海啸，以及未来发生此类危险事件的可能性。在西印度洋，初步调查突出了深水沉积的存在，这些沉积是在发生同步浑浊/等深流相互作用时形成的，即混合浊积-等深岩体系。我们将定义坦桑尼亚边缘近海斜坡沉积系统的建筑元素、等级和相关的岩性，以开发基于过程的浊积-等深岩混合矿床形成模型。对这一日益被认识但又鲜为人知的含油气斜坡矿床的详细描述将支持世界各地和加拿大的石油行业，最近加拿大也发现了类似的系统。从拟议的研究计划产生的项目将培养高素质的人员(三名博士和一名硕士)，他们将成为国际和北极研究、过程沉积学、地震地层学和科学交流方面的知识。

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.