CAREER: Probing the connections between mantle convection and oceanic gateways in the North Atlantic using deep-sea drilling

炽热的地幔物质从地球内部深处上升到冰岛地下，形成了一个巨大的羽流，以数百万年的时间尺度脉动。羽流的脉动导致了连接格陵兰岛、冰岛和苏格兰的海洋门户高度的变化。这些门户控制着过去数百万年来从挪威海流向大西洋的冷水和深水的数量。该项目将利用从海底深处收集的岩芯数据，研究北大西洋区域羽流活动和海洋环流的历史。该项目的结果将对我们对过去海洋环流和气候的了解产生直接影响，这是应对当今社会面临的环境挑战的关键。更广泛的影响包括参加为当地教师举办的讲习班、举办K-12活动、开设地球系统第一年班，以及支持一名博士后学者和研究生。冰岛南部的雷克雅内斯海脊两侧位于地球上最大的羽脊系统之一上方，被迅速积累的等高线漂流沉积物覆盖，这些沉积物对邻近深水航道影响的海洋条件很敏感。这种配置提供了一个理想的自然实验室来测试关于地幔动力学、古海洋学和气候之间相互作用的假说。该项目将调查冰岛地幔羽流在多大程度上控制了北大西洋新生代期间的大洋门户和深水环流。在国际海洋发现方案第395次考察期间，在比约恩和加达尔等值线漂流现场收集的样品和数据提供了一个机会，大大增进了我们对整个北大西洋区域沉积模式和海洋环流历史的了解。海洋盆地演化的运动学和古生物测量学模型将与最近钻探的岩心的沉积物累积速度和海流速度估计相结合，作为破译过去海洋环流模式的工具。综合考虑，建议的模型和观测将提供对地球内部、海洋和表面领域耦合性质的洞察。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Hot mantle material rises up beneath Iceland from deep within Earth’s interior forming a giant plume that pulses on timescales of millions of years. Plume pulsing contributes to changes in the height of oceanic gateways that link Greenland, Iceland, and Scotland. These gateways control the amount of cold, deep water that has flowed from the Norwegian Sea to the Atlantic ocean over the past few million years. This project will examine the history of plume activity and ocean circulation in the North Atlantic region using data from rock cores collected deep beneath the seabed. The outcomes of this project will have immediate impact upon our knowledge of past ocean circulation and climate, which is key to addressing the environmental challenges that society is confronting today. Broader impacts include participation in workshops for local teachers, delivery of K-12 activities, development of a first year Earth systems class, and support for a post-doctoral scholar and graduate students.The flanks of Reykjanes Ridge south of Iceland lie above one of Earth’s largest plume-ridge systems, and are covered by rapidly accumulating contourite drift sediments that are sensitive to the oceanographic conditions influenced by adjacent deep-water gateways. This configuration provides an ideal natural laboratory to test hypotheses about the interactions between mantle dynamics, paleoceanography, and climate. This project will investigate the extent to which the Iceland mantle plume has controlled oceanic gateways and deep-water circulation in the North Atlantic Ocean during Cenozoic times. Samples and data collected at sites on Björn and Gardar contourite drifts during International Ocean Discovery Program Expedition 395 provide an opportunity to significantly advance our understanding of the history of sedimentation patterns and ocean circulation across the North Atlantic region. Kinematic and paleobathymetric models for ocean basin evolution will be integrated with sediment accumulation rate and current speed estimates from recently drilled cores, as tools to decipher past ocean circulation patterns. Considered together, the proposed models and observations will provide insights into the coupled nature of Earth’s interior, ocean, and surface domains.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.